FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 338Raptor on June 04, 2019, 12:30:41 AM
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I’m within about 6 months from starting an Aluminum SOHC engine build for my 67 fastback. I have been researching the specs of each component I will need. My goal is 800hp and high 600’s torque (700tq would be ideal). I’m confident with all the parts and pieces I have selected my goal is achieveable. My concern is with the Aluminum FE blocks. I’ve read several threads about HP loss in aluminum blocks when compared to Iron blocks. I understand I will likely give up 30+ horsepower with an aluminum block vs an Iron block. I’m OK with that since the weight advantage of aluminum will reduce my cars front end weight by 100 lbs. My concern with the aluminum blocks is cylinder distortion and ring seal. I plan to use a Napier lower compression ring and Total Seal gapless upper ring. This may help but not solve the real issue.
My question for this group is:
1. Will the BBM or Pond aluminum blocks handle my build?
2. Or should I pony up the extra money for a Shelby aluminum block?
3. Or should I forget about aluminum and buy an Iron block?
More details on my build:
93 octane
Hilborn EFI
510 cid
4.375” 4340 crankshaft (probably custom Scat)
4.310” pistons (if the liners/block can handle this large bore)
11:1 compression
Pond SOHC heads
T&D steel rockers
Holly HP EFI
Cam specs are still undecided but they will need to be big
90% street, 10% drag use. And maybe even a little autocross.
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1. Yes.
2. I don't see the need. The aluminum blocks are pricy enough.
3. Yes.
Everyone knows I stay clear of aluminum blocks when I can, so call me biased. But I'm just not a fan. They have their place, but IMO that's a very small niche. Paying an extra $2200-3700 for a block that will noticeably be down in horsepower in comparison to a cast iron piece, in a 90% street car just doesn't seem prudent to me. There's also extra block prep and machine work involved which adds to the cost.
Most of us that have built a few of each notice anywhere from 30-40 hp difference on similar builds. The general "rule of thumb" is that 20-25 hp will change your ET by .1 second. There's also a general "rule of thumb" that dropping 100 lbs will decrease your ET by .1 second. In a street/straight-line situation, the savings of weight of the aluminum block won't really give you any performance advantage. If this were a roundy-round application, or another race class that focuses on weight reduction, then there would be a benefit.
Your ring seal loss comment is the key here. On an all-aluminum engine build, valve lash/preload changes by about .014". Compare that to an iron block/aluminum head combo, which changes about .006". Unfortunately, aluminum has a much higher heat expansion coefficient and the blocks move in every direction.
The pros of an aluminum block is that you can change sleeves if the cylinders are worn. They are also easier to repair if you decide to window one.
Whatever you do, make sure and have it pressure tested and/or sealed internally. Casting aluminum is hit or miss and I've had to reject multiple aluminum FE blocks because of porous areas behind the lifter bores that leak air on a pressure test.
BTW, with reference to your camshaft note, you'd be surprised at how low duration/lift you need with well-flowing heads, even on a 500+ inch engine.
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If you want an aluminum cammer, then get an aluminum cammer. Screw the data. If all we do is crunch numbers when making decisions, then there's no passion in living. How many opportunities are you going to get for a '67 Mustang with an aluminum cammer? Go for the gusto, my friend and screw the data.
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I think "all-aluminum" has become one of those hot-rod buzz words.....something that people crave to own but they don't really understand why. Same deal with 6-speed transmissions. Maybe because of the rarity? Price?
I've got a good buddy who's a "car guy" but just doesn't understand a lot about them if that makes any sense. He was in my shop the other day while I was assembling a 347. "What's that?" "A 347." "Ooohhh, I'd love to own one of those." I feel like he'd pass up a 351, 393, 408, etc., just because the 347 is more of a buzz word. He's also a Chevy guy and wondered why I suggested for him to build a 400 instead of a "383".
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I’m still horny for an aluminum block to knock a couple hundred pounds off the nose of my mustang.
Totally get the straight line argument but how sweet to have an all aluminum big block ‘stang.
Of coarse as long as it’s taking me to get an iron block in it I might be doing aluminum from my grave.
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Pond block for aluminum. BBM is OK for iron but so is the Pond iron block.
Brent's points about the iron block being more powerful are all valid . The only advantage ( besides the wow factor) to the aluminum block is that "nose weight" which is oh so critical when cornering is a must. Your Horsepower goal can be reached with either block material.
Randy
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Pond block for aluminum. BBM is OK for iron but so is the Pond iron block.
Brent's points about the iron block being more powerful are all valid . The only advantage ( besides the wow factor) to the aluminum block is that "nose weight" which is oh so critical when cornering is a must. Your Horsepower goal can be reached with either block material.
Randy
I think for $2500, I could find other places to save/relocate weight.....LOL
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I have a couple questions from blykins post.
Is the valve lash differences between aluminum vs Iron blocks really an issue on a cammer? I can see that being an issue on a push rod engine but the cams/rockers are all in the head of the cammer.
Also, I didn’t mention this earlier. My fastback is setup with road race suspension so I would like to optimize my cars handling with light weight parts. That’s my primary reason for looking at Aluminum.
I hope you don’t take my questioning your comments the wrong way. I did ask your opinion and I do appreciate the points you bring up. It’s all going to help me make the right choices for my build.
I should mention. As for the additional cost of an aluminum block for a cammer. I think common sense $/horsepower reasoning is probably out the window on any cammer build. But like many I want the car/engine combo to be kinda period correct even if a Mustang never had a cammer factory installed. I still want to save money wherever is possible (ie. Shelby block) but truth be told we all know I could build a stroker 460/557 at 1000 horsepower for half the cost. In fact I have one in my mud truck.
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If you do go aluminium, I'd go with the pond block as well. The BBM piece looks awesome in pictures but how many of them really exists and out of those how many really get used beyond a show car cobra or something that gets driven back and forth from the trailer to the spot at the car show. Pond has been doing aluminum blocks for quite a while and there are many that really get used and regularly beat on at the strip. Pond is also great to work and deal with and freely will give you honest and any information you may want or need. I to have always wanted a Shelby block but unless I'm turbo'ing or pro charging I cant see spending the extra $2500.oo for a Shelby over a pond. I also think pond is your best bet at actually getting one unless things have finally changed for the better. Also, nothing against BBM, I'd surely use one if that's what I had or all I could get. They look like nice pieces, I'm assuming BBM finally has them available? I along with the chatter of a few other builders talked myself out of another aluminum block (for now) because of all the points Brent mentioned and also because my machine shop friend passed and I wouldn't trust any of these shops around here to handle an aluminum block correctly.
Good luck to you and keep us posted.
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Pond block for aluminum. BBM is OK for iron but so is the Pond iron block.
Brent's points about the iron block being more powerful are all valid . The only advantage ( besides the wow factor) to the aluminum block is that "nose weight" which is oh so critical when cornering is a must. Your Horsepower goal can be reached with either block material.
Randy
I think for $2500, I could find other places to save/relocate weight.....LOL
i put my battery in the trunk,put on alu heads,intake,radiator,and water pump and it took 150+ pounds of the front of my car.it even brought my headers another inch off the ground.really noticeable diff in the cornering too.i wouldnt want to give up 30 hp for alu block,my goal is to squeeze every hp out of what i have.i actually ordered a alu block,they werent in stock at the time.when i read about the hp loss i canceled my order.jmo
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What is the actual weight difference between a all aluminum complete cammer (ready to install) verses a cammer with aluminum heads and iron block ready to install ? I'm afraid to ask what a all iron cammer weighs , lol
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seems the only main weight diff would be the top end
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I have a couple questions from blykins post.
Is the valve lash differences between aluminum vs Iron blocks really an issue on a cammer? I can see that being an issue on a push rod engine but the cams/rockers are all in the head of the cammer.
Also, I didn’t mention this earlier. My fastback is setup with road race suspension so I would like to optimize my cars handling with light weight parts. That’s my primary reason for looking at Aluminum.
I hope you don’t take my questioning your comments the wrong way. I did ask your opinion and I do appreciate the points you bring up. It’s all going to help me make the right choices for my build.
I should mention. As for the additional cost of an aluminum block for a cammer. I think common sense $/horsepower reasoning is probably out the window on any cammer build. But like many I want the car/engine combo to be kinda period correct even if a Mustang never had a cammer factory installed. I still want to save money wherever is possible (ie. Shelby block) but truth be told we all know I could build a stroker 460/557 at 1000 horsepower for half the cost. In fact I have one in my mud truck.
The issue with lash is because of the aluminum parts growing faster than the steel parts (pushrods, etc.) on a wedge engine. I've never built an all-aluminum SOHC engine, so I'd have to defer that question to Jay or Barry.
Two things that would remain consistent between a SOHC and a wedge all-aluminum FE are the compression ratio changes and main bearing clearance changes when hot. All of this has to be allowed for in the design and setup stages of the engine. The blocks expand with heat, so the block actually expands up past the piston (so when hot the piston would be further down in the hole at TDC) and the main bearing bores grow. On all-aluminum FE's, I would set the main bearing clearances up at .0018-.002" cold, as opposed to .0028-.003" with an iron block. All of that growing and contracting can be a little harder on the gaskets.....especially the oil pan gasket.
Everyone wants what they wants, but I always like for guys to have all the facts in front of them before making a decision.
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I'm surprised that no one has come up with a CNC program to lighten up a BBM or Pond cast iron block. There has to be some potential to shave weight off of one of those blocks without taking too much away from the integrity.
I was hot for an aluminum block when I started my Mustang project a few years ago. I talked to an engine guy and he advised me that unless the weight was critical the power gain more than offsets the weight savings. He also advised that a Ford block would be just about as light an a modern aluminum block. He also added that Shelby blocks are the heaviest of the aluminum blocks. I believe this all to be true.
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Does anyone have first hand knowledge or experience with the BBM aluminum block? Can anyone say with confidence it is as strong as the Pond block?
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
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Several manufacturers do CGI. However, it's hard enough for small-quantity manufacturers to get anything done with any amount of QC and at a reasonable price.
Dart does some CGI SBF blocks but they also move a lot more blocks than Pond or BBM.
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
Magnesium banned in F1 for any use for decades as one car went up and melted a hole in the track. Forget if it was a Honda.
Yeah, just found the link and it was the Honda.
https://www.carthrottle.com/post/wy355r8/
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Pond block for aluminum. BBM is OK for iron but so is the Pond iron block.
Brent's points about the iron block being more powerful are all valid . The only advantage ( besides the wow factor) to the aluminum block is that "nose weight" which is oh so critical when cornering is a must. Your Horsepower goal can be reached with either block material.
Randy
I think for $2500, I could find other places to save/relocate weight.....LOL
This is on the money. You can get aluminum radiators, aluminum intakes, aluminum water pumps, forged (not cast) aluminum wheels, aluminum heads. You could get fiberglass body parts. You can take the power steering and power brakes off.....You can save a lot of weight and still get the advantages of an iron block.
JMO,
paulie
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If it were my money and I was going to build something of this caliber....I'd pay up for the Shelby aluminum block. They will sell you a block with all SOHC oil modifications already made. They sell it in a "big bore" model that'll handle 4.375" bore I believe, so you can make it a square 4.375"x4.375". They also avoid drilling the lifter bores (not needed for SOHC) so the valley is all solid. If you want to justify it, it's probably a 5-8% upgrade cost when considering the price of the whole engine. That's how my girlfriend does math when she's shopping or planning a vacation anyhow.
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
Magnesium banned in F1 for any use for decades as one car went up and melted a hole in the track. Forget if it was a Honda.
Yeah, just found the link and it was the Honda.
https://www.carthrottle.com/post/wy355r8/
Not a magnesium ENGINE. The Honda had a magnesium body and 58 laps worth of fuel onboard when it burned
With liners for cylinders and whatever, why not a carbon fiber block? Other than cost, why not titanium (reason why I mentioned F1)?
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I have five aluminum FE blocks, four Shelby and one Pond. The Shelby blocks are far superior in my opinion. I would not trust a Pond aluminum block past about 700 HP. I had an 840 HP SOHC with my Pond aluminum block and the block couldn't take the power/RPM; main bearing bores distorted, spun the #2 main, lost oil to two rods and blew the motor going down the track. My Shelby blocks on the other hand have been trouble free, and are much, much beefier around the main web than the Pond block. My naturally aspirated Shelby block SOHC makes just over 1000 HP, and I've made just over 1200 HP with supercharged FE on another Shelby block. No concerns with that one.
The problem with the Pond block is that it uses the same casting patterns as the cast iron block. The area around the main bearing bores is strong enough in iron, but not in aluminum. The Pond aluminum block is fine up to 700 HP, and I've used mine there with no issues, but one thing that I did notice is that even at those power levels, every time the block was torn down to be freshened there was evidence of cap walk. And its not that cap, because the Pond caps are very beefy. Its the block itself.
Here are a couple pictures illustrating this issue, Pond block first. By the way, this block is now junk after tossing two rods after the main spun, so it was sitting outside for a while, hence the rust:
(http://fepower.net/Photos/Posts/Pond Main Saddle.jpg)
(http://fepower.net/Photos/Posts/Shelby Main Saddle.jpg)
Any doubt as to which is stronger?
Also, I strongly disagree with the other comments in this thread regarding aluminum blocks. In my opinion, aluminum blocks are far superior to iron blocks for several reasons. From a weight perspective, a bare Shelby block weighs about 130 pounds, whereas a BBM cast iron block weighs about 270 pounds. That is a big difference that will affect acceleration, braking, traction, and cornering. Further, I have never seen definite proof that a cast iron block makes more power than an aluminum block. Everybody says this, and maybe it's true, but I have never seen a definitive back to back test. Someday I'm going to do one myself. Being able to replace a sleeve in an aluminum block, in case of damage, is a big advantage, and aluminum blocks are much easier to repair than a cast iron block. I had the pin end of a rod give up on my big SOHC with the Shelby block back in 2013, and the rod came through the block, but despite extensive damage the block was able to be repaired and went back to making 1000+ HP the next year. But the big advantage is weight savings.
Also, any comments regarding checking an aluminum block when you get it also applies to any aftermarket cast iron blocks. BBM cast iron blocks have had porosity and leak issues, so have Sideoiler garage blocks from what I've been told. Any aftermarket block needs to be checked, and all should be subject to the same basic machining operations. My Shelby blocks did not require any more machining than an aftermarket iron block; just a power hone to fit the pistons and an align hone of the mains.
If you have a horsepower target, you can reach it with either a cast iron block or an aluminum block. Why not take advantage of the aluminum block's light weight? Seems like a no brainer to me, except for the cost factor, and as mentioned if you are going to build an SOHC, what's the difference? Its going to cost a lot no matter what.
I don't know anything about the BBM aluminum block, but I would wonder if it is a dedicated aluminum design (like the Shelby block), or an aluminum block that is cast with the cast iron patterns (like the Pond block). If it is not a dedicated aluminum design, I would steer clear of it.
One other thing about Shelby blocks, is that I have heard for a while they went to an aluminum main cap, rather than steel. That was a bad idea, and would make me steer clear of them also. Now they are supposed to be back to the steel caps, but if you call Shelby for a block make sure to ask about that.
My advice - get a Shelby block.
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I’ve had this discussion with several other builders including Barry, Blair, and Lance at Craft Racing. The consensus seems to be a 40 hp difference between exact combos, with just the block material being different.
A 140 lb difference could be absorbed by a 40 hp difference, but the handling in a curve car would be the only variable, and that’s if you can’t make up the difference somewhere else.
As for machining differences, the block has to be heated and the sleeves have to be set with torque plates. Not really “machining” but it is a step that your machinist will have to do.
FWIW, the aluminum block differences just doesn’t apply to FEs, but this discussion on Speedtalk gained the same 30-40 hp results on BBC, SBC, and SBF engines. Darin Morgan made the most interesting comment, saying that it usually took several rebuilds to “season” the block in order to stabilize the shifting. One other dirt track engine builder said that on his aluminum block dry sump engines he could hardly pull crankcase vacuum but his iron blocks required a regulator to keep from pulling too much. It’s a ring seal issue.
I think my vote if the OP is trying to keep it period correct looking would be to snag a factory block and heads. Nothing more precious than original parts.
$8100 for a new Shelby big bore block. Not sure if that includes their head studs. $3800 for a new BBM iron block. Big difference. Is there enough value to justify the $4300 delta?
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I have never heated the block or set the sleeves with torque plates on any of my aluminum blocks. Its never been necessary; I assume if the block has been improperly machined, that could be a problem. And sorry Brent, but I'm just not buying the 40 HP difference. I think with all the engines I've built, I would have noticed something like that...
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I don’t think it’s a matter of improper machining because the blocks are all stepped. I think it’s a matter of the block expanding and settling when hot and the sleeves dropping. I have done it on every Pond and Dart aluminum block that I’ve used and you can see the difference when they come out of the oven. I had a sleeve drop on the dyno once on a block that supposedly had the sleeves installed by the manufacturer. Not fun.
As for the hp difference, I wish I could be as bold to discount the testimonies of 6-7 other builders....lol
I suppose the Shelby block could be made of some magical alloy that is completely different from every other aluminum block out there, but for the extra $4300 I think I’ll stick with my old heavy cast iron.
Still love you, Jay.
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;D ;D
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Jay, your engines make so much power that 40 hp is a much smaller percentage. Going from 1000 to 960 is kind of hard to feel, or even measure at the track. :)
Maybe it is not 40 hp. Maybe it is 30? or ??? But I do think there is a difference. That would make for a great dyno test which could be included in the next book. :)
JMO,
paulie
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Without getting too deep into any sort of contest....the iron block will definitely make more power than the aluminum one. I would need to spend time I do not have to pull together hard data, but every iron combination seems to outpour similar aluminum ones by a good bit. Don't know if its a certain amount of power, but its definitely a few percentage points. Have a local shop here that does a ton of really similar rules limited oval track deals and he thinks its about 20HP on his 450ish HP stuff. So maybe 3-5% is a usable figure. I would expect that compression and quench loss through growth would be a piece of this since the aluminum stuff grows by .008-.010 more at temperature.
Not sure where things are now, but in the past it was really common to have high end naturally aspirated Pro Stock and Cup teams use an iron (or compacted graphite) block, following up with a ton of external CNC machine work to reduce weight, even when an aluminum block was allowed. Stuff running boost do not really care as much - they can just turn up the wick...weight and reparability are worthwhile when you can make a few thousand horsepower....
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Don't know if its a certain amount of power, but its definitely a few percentage points. Have a local shop here that does a ton of really similar rules limited oval track deals and he thinks its about 20HP on his 450ish HP stuff. So maybe 3-5% is a usable figure. I would expect that compression and quench loss through growth would be a piece of this since the aluminum stuff grows by .008-.010 more at temperature.
That is an interesting thought. Can the last minute tolerances for compression and quench be compensated for in an aluminum block build? Tighter quench and higher calculated compression? To gain some of that 3-5% back? Maybe the block would have to be pre-heated before startup? Or Just allowed to fully heat up before doing anything above idle? Different piston to wall numbers? This might be old stuff for you engine builders, but I had not really thought about it. I have never had an aluminum block, though. :)
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So now I believe at my target power level (800hp) the Shelby aluminum or someone else’s iron block are my two best options. I’m willing to concede 20-40 horsepower for 100+ pounds of weight advantage so the Shelby block is my preference. Now that I have decided the Shelby block is best for me my next question has to do with stroke. Since crank to cam lobe interference isn’t an issue in a cammer.
Would I be able to utilize a 4.5” crankshaft (with some slight clearancing in the block) and some stroker rods with the rounded/clearances shoulders?
And if I can get the 4.5” crank to fit would the need for 6.8” or longer rods require oil ring support rails and wrist pin buttons to support the oil rings with such a short compression height?
Jay, Did you have to do all this stuff on your Shelby strokers?
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My iron display mill is way to heavy to move when its blocking something
Ima cut out the insides of the iron heads cept for 2 head bolts, crank will be just the ends
Ricky.
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Don't know if its a certain amount of power, but its definitely a few percentage points. Have a local shop here that does a ton of really similar rules limited oval track deals and he thinks its about 20HP on his 450ish HP stuff. So maybe 3-5% is a usable figure. I would expect that compression and quench loss through growth would be a piece of this since the aluminum stuff grows by .008-.010 more at temperature.
That is an interesting thought. Can the last minute tolerances for compression and quench be compensated for in an aluminum block build? Tighter quench and higher calculated compression? To gain some of that 3-5% back? Maybe the block would have to be pre-heated before startup? Or Just allowed to fully heat up before doing anything above idle? Different piston to wall numbers? This might be old stuff for you engine builders, but I had not really thought about it. I have never had an aluminum block, though. :)
What I have done in the past is let the pistons hang out of the block so that when the block gets to operating temp you are at zero deck or a hair under. It’s the same deal as running aluminum rods, you have to allow for it in the design stage.
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So now I believe at my target power level (800hp) the Shelby aluminum or someone else’s iron block are my two best options. I’m willing to concede 20-40 horsepower for 100+ pounds of weight advantage so the Shelby block is my preference. Now that I have decided the Shelby block is best for me my next question has to do with stroke. Since crank to cam lobe interference isn’t an issue in a cammer.
Would I be able to utilize a 4.5” crankshaft (with some slight clearancing in the block) and some stroker rods with the rounded/clearances shoulders?
And if I can get the 4.5” crank to fit would the need for 6.8” or longer rods require oil ring support rails and wrist pin buttons to support the oil rings with such a short compression height?
Jay, Did you have to do all this stuff on your Shelby strokers?
If you are building a Cammer with any sort of stroke in it you might as well concede to the use of oil groove spacers. The SOHC dome configuration mandates a really low ring groove position because the intake pocket drops so low along the side of the piston. At that point you may as well choose your stroke based on your own desires in terms of engine characteristics.
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Brent, Would the use of Aluminum rods eliminate the problem of decreasing quench height as the block heats up?
With a 4.375” or 4.5” stroke in a Shelby block would it be possible to run aluminum rods, or would the dimensionally larger big end of an aluminum rod vs a steel rod create too much of a clearance problem? I know it’s not common to run Aluminum rods on the street, but I’m not afraid to do so.
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Brent, Would the use of Aluminum rods eliminate the problem of decreasing quench height as the block heats up?
With a 4.375” or 4.5” stroke in a Shelby block would it be possible to run aluminum rods, or would the dimensionally larger big end of an aluminum rod vs a steel rod create too much of a clearance problem? I know it’s not common to run Aluminum rods on the street, but I’m not afraid to do so.
Even if they would dimensionally fit inside of a block with that long of a stroke, adding aluminum rods to the mix would throw a million other variables into the situation. They are not something you would want for a street engine.
As I mentioned above, you can counter-act the quench height in the design phase of the engine build. It still will not eliminate the horsepower loss from lack of ring seal. The Shelby blocks may be more rigid than the other manufacturers' blocks, but you're still putting a ductile iron cylinder sleeve into an aluminum casing, which grows and moves around as heat is introduced. If you're looking for other options, maybe consider a lightened, large bore cast iron block? Even relocating the battery would put you 25-30 lbs ahead in the game and give you a head start if your primary goal is weight loss. It wouldn't take much to shed 125 lbs. I'll have to go through the calculations but I think you lose a couple pounds just by going to a 4.310" bore from a 4.250".
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Isn't he going to be shedding a 100 pounds just by cutting out the shock towers etc. to fit the SOHC into the Mustang? Then more pounds by going to a modern suspension? Then there's all the metal he's going to cut out of the center of the hood to clear the injector stacks...
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My big SOHC has a 4.600" stroke crank now, and I'm currently waiting for a 4.750" stroke version to up the cubes a little more. The 4.600" crank uses Crower billet BBC rods, 6.700". The oil ring rail is required. For the bigger stroke I've had to go to 6.550" rods. These components fit in the block but the bottom of the cylinder bores have to be notched to clear the rod shoulders. Barry is correct about the ring package, with the deep intrusion into the piston dome of the intake valve, you aren't going to get away from the oil ring rail.
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Is it possible to mitigate the ring sealing losses with different ring and/or piston clearances? How about honing hot?
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
Magnesium banned in F1 for any use for decades as one car went up and melted a hole in the track. Forget if it was a Honda.
Yeah, just found the link and it was the Honda.
https://www.carthrottle.com/post/wy355r8/
Not a magnesium ENGINE. The Honda had a magnesium body and 58 laps worth of fuel onboard when it burned
With liners for cylinders and whatever, why not a carbon fiber block? Other than cost, why not titanium (reason why I mentioned F1)?
I should have answered differently. Yes, the Honda was mag bodied but after the fire, F.I.A. banned any use of magnesium, block included. Today, decades later, some rules changes did allow limited use of magnesium sheet but no engine nor transaxle
nor suspension parts. Funny though, at that time carbon fiber came into being and due to stiffness, I'm told,it's a far better choice.. which is why all F1 cars use it instead. Btw, my rules book is old or else I'd post some fascinating passages here.
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Is it possible to mitigate the ring sealing losses with different ring and/or piston clearances? How about honing hot?
Hot honing was more of a fad IMHO. The Nascar guys began doing it almost 20 years ago and it was a sketchy process. They ended up using heated cooking oil and reverse flowing it to get consistent results. Most stopped doing it.
Pistons ( especially custom pistons) can and should be made different ( dimensionally) for aluminum blocks. Cold piston to wall should be tighter as well. "Modern" ring technology is helping a bunch in the way of ring seal . Many current production engines have aluminum blocks and no ring seal issues.
Randy
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Jack of Dart fame and Jason of Brodix both say iron=aluminum these days and why that is true. Note too what Dart says about a back-to-back test. Perhaps that's why Jay hasn't seen any difference: all his FE blocks are modern creations and not 30-40 year old versions of essentially old FE cast iron blocks.
"Aluminum Blocks
Jack McInnis: "The perception that aluminum blocks lose power through decreased ring seal, as compared to iron blocks, is largely based on early aluminum blocks, which lacked the integrity we can achieve today. Aluminum blocks might have sacrificed power many years ago, but that's not the case anymore. A properly engineered modern aluminum block will make the same power as an iron block. We were recently involved in a direct comparison test with a big-block dragster engine making in excess of 1,100 hp. The engine was assembled and dyno tested with an iron Dart block, then disassembled and rebuilt using an aluminum Dart block. At the end of the day, the power figures were nominally identical for the iron and aluminum blocks."
Jason Neugent: "In the early days of manufacturing aftermarket aluminum blocks, the material that was used did indeed move around a lot under heavy abuse. This caused the cylinder sleeves to move, sink, or go out of round. The consequence was that this deflection would cause water leaks and poor ring seal, which are prime ingredients for poor reliability and power loss. Today we have solved these problems with the use of our virgin A-356 aluminum recipe, tighter tolerances, and more rugged sleeve materials. In independent testing, Brodix has witnessed our own aluminum blocks seal as well as a quality cast iron block.""
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Jack of Dart fame and Jason of Brodix both say iron=aluminum these days and why that is true. Note too what Dart says about a back-to-back test. Perhaps that's why Jay hasn't seen any difference: all his FE blocks are modern creations and not 30-40 year old versions of essentially old FE cast iron blocks.
"Aluminum Blocks
Jack McInnis: "The perception that aluminum blocks lose power through decreased ring seal, as compared to iron blocks, is largely based on early aluminum blocks, which lacked the integrity we can achieve today. Aluminum blocks might have sacrificed power many years ago, but that's not the case anymore. A properly engineered modern aluminum block will make the same power as an iron block. We were recently involved in a direct comparison test with a big-block dragster engine making in excess of 1,100 hp. The engine was assembled and dyno tested with an iron Dart block, then disassembled and rebuilt using an aluminum Dart block. At the end of the day, the power figures were nominally identical for the iron and aluminum blocks."
Jason Neugent: "In the early days of manufacturing aftermarket aluminum blocks, the material that was used did indeed move around a lot under heavy abuse. This caused the cylinder sleeves to move, sink, or go out of round. The consequence was that this deflection would cause water leaks and poor ring seal, which are prime ingredients for poor reliability and power loss. Today we have solved these problems with the use of our virgin A-356 aluminum recipe, tighter tolerances, and more rugged sleeve materials. In independent testing, Brodix has witnessed our own aluminum blocks seal as well as a quality cast iron block.""
That's all fine and good except for the fact that we are seeing horsepower differences *now*, not years ago. I also wouldn't say that new aluminum blocks are copies of 40 year old factory pieces. The 40 year old factory pieces don't have lifter valley ribbing, etc, etc. I know that Pond also uses a 356 alloy.
So what's "nominal" at 1100????? 25 hp? 50?
Since we're offering up quotes, here's one from Darin Morgan from a few years ago on Speedtalk:
"We see the EXACT same thing. The Billet blocks are the only aluminum block I have seen that makes the same power as a cast iron block. Aluminum blocks take longer "season" and stop moving around as well. The second or third rebuild always nets anouther twenty HP. Also, as the aluminum block engines get hotter on the dyno the crank case pressure rises dramatically and the power goes south in a hurry! They just expand and move around so much its impossible to maintain any semblance of stability." Im assuming reher Morrison has some experience with aftermarket block offerings.
A lot of guys always point to the OEM on how well aluminum blocks work, but I will say that the OEM spends millions upon millions of dollars on R&D for one particular engine. They will also give up a few ponies in order to recoup some much needed fuel economy.
The thing that bites my booty is that guys are always eager to spend so much money on aluminum pieces. A few years back on Club Cobra, I asked the general population why they were willing to pay so much for them. The majority vote was for "bling" purposes. All I can say is that there's a lot of guys out there with money to blow, if they're willing to spend an extra $4000 to just say "I have an aluminum block" or to justify that they need 100 lbs taken off the front of the car.
I had 3 issues in a row with some aluminum FE blocks. Two of them cost me lost time and one cost me a nice little chunk of money. I decided after that, that the other builders could take all the all-aluminum FE orders.
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Pricing on aluminum blocks didn't used to be so ridiculous. For a long time Pond's aluminum block was about $1000 more than his cast iron block, the difference being the price of the Darton sleeves that are used in the aluminum block. Now the price differential has gotten out of hand, that's for sure.
When I start to manufacture my FE Power aluminum block, it will be reasonably priced. Couple years away on that, though...
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When I start to manufacture my FE Power aluminum block, it will be reasonably priced. Couple years away on that, though...
When will there be a thread on what to name it? Just asking because I want to make sure I'm on vacation that week. ;D
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When I start to manufacture my FE Power aluminum block, it will be reasonably priced. Couple years away on that, though...
When will there be a thread on what to name it? Just asking because I want to make sure I'm on vacation that week. ;D
;D
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Jay's Light and Strong Block ? sounds good lol
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When I start to manufacture my FE Power aluminum block, it will be reasonably priced. Couple years away on that, though...
When will there be a thread on what to name it? Just asking because I want to make sure I'm on vacation that week. ;D
Now THAT'S funny!
Hey, somebody asked where FElony is? I know.....
He's at the library figuring out a 100 names for Jay's new block!
LOL
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Jack of Dart fame and Jason of Brodix both say iron=aluminum these days and why that is true. Note too what Dart says about a back-to-back test. Perhaps that's why Jay hasn't seen any difference: all his FE blocks are modern creations and not 30-40 year old versions of essentially old FE cast iron blocks.
"Aluminum Blocks
Jack McInnis: "The perception that aluminum blocks lose power through decreased ring seal, as compared to iron blocks, is largely based on early aluminum blocks, which lacked the integrity we can achieve today. Aluminum blocks might have sacrificed power many years ago, but that's not the case anymore. A properly engineered modern aluminum block will make the same power as an iron block. We were recently involved in a direct comparison test with a big-block dragster engine making in excess of 1,100 hp. The engine was assembled and dyno tested with an iron Dart block, then disassembled and rebuilt using an aluminum Dart block. At the end of the day, the power figures were nominally identical for the iron and aluminum blocks."
Jason Neugent: "In the early days of manufacturing aftermarket aluminum blocks, the material that was used did indeed move around a lot under heavy abuse. This caused the cylinder sleeves to move, sink, or go out of round. The consequence was that this deflection would cause water leaks and poor ring seal, which are prime ingredients for poor reliability and power loss. Today we have solved these problems with the use of our virgin A-356 aluminum recipe, tighter tolerances, and more rugged sleeve materials. In independent testing, Brodix has witnessed our own aluminum blocks seal as well as a quality cast iron block.""
That's all fine and good except for the fact that we are seeing horsepower differences *now*, not years ago. I also wouldn't say that new aluminum blocks are copies of 40 year old factory pieces. The 40 year old factory pieces don't have lifter valley ribbing, etc, etc. I know that Pond also uses a 356 alloy.
So what's "nominal" at 1100????? 25 hp? 50?
Since we're offering up quotes, here's one from Darin Morgan from a few years ago on Speedtalk:
"We see the EXACT same thing. The Billet blocks are the only aluminum block I have seen that makes the same power as a cast iron block. Aluminum blocks take longer "season" and stop moving around as well. The second or third rebuild always nets anouther twenty HP. Also, as the aluminum block engines get hotter on the dyno the crank case pressure rises dramatically and the power goes south in a hurry! They just expand and move around so much its impossible to maintain any semblance of stability." Im assuming reher Morrison has some experience with aftermarket block offerings.
A lot of guys always point to the OEM on how well aluminum blocks work, but I will say that the OEM spends millions upon millions of dollars on R&D for one particular engine. They will also give up a few ponies in order to recoup some much needed fuel economy.
The thing that bites my booty is that guys are always eager to spend so much money on aluminum pieces. A few years back on Club Cobra, I asked the general population why they were willing to pay so much for them. The majority vote was for "bling" purposes. All I can say is that there's a lot of guys out there with money to blow, if they're willing to spend an extra $4000 to just say "I have an aluminum block" or to justify that they need 100 lbs taken off the front of the car.
I had 3 issues in a row with some aluminum FE blocks. Two of them cost me lost time and one cost me a nice little chunk of money. I decided after that, that the other builders could take all the all-aluminum FE orders.
Good one Brent! I had also seen that quote by Morgan but could not find it earlier today.
So...........this means Jay has to try it on his dyno, right? ;) ;) ;)
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I think the "issue" is not "all" aluminum blocks are equal. Dart and Brodix can claim all they want. A Dart or Brodix BBC is not a Pond , Shelby , or BBM FE. The two blocks are vastly different and from 5 different manufacturers. When we have "hands on" experience from well respected builders regarding the FE block specifically , we should take notice of that fact and not compare it to other aluminum blocks.
In my day job , I deal with many builders that use aluminum blocks and MANY complain about ring seal on them. Chevy , Ford , small block , big block , Brodix , Dart , Ford , C and C , no difference. When I made my suggestion on the Pond aluminum block it was because of use of the Pond aluminum head , not because it would make the same power as an iron block.
Randy
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I can say with absolute certainty that an iron BBM block is the strongest FE block that has been produced to date. Not knocking anyone else's effort, that is just a fact. I have had over 100 BBM blocks pass through here. Two blocks have had MINOR issues that were easily corrected. One block had a major issue, and BBM replaced the block, no hassle. Really good percentage of success in my opinion, and the man rectified the situation on the one with a major issue.
I can say with absolute certainty that the Shelby designed aluminum block was engineered and intended to be produced only as an aluminum block. It is the best aluminum block, hands down, but you are going to pay for it.
I can say with absolute certainty that with the same exact engine at the 900-ish hp level, there is 30 hp difference between an iron BBM block and a Shelby aluminum block with neither having a vacuum pump. The iron block being superior. I think a Shelby with a vacuum pump is just about even with an iron BBM with only pan-evacs. A vacuum pump makes any of them better. It makes more difference on an aluminum block.
I have repaired several Pond aluminum blocks with high horsepower and compression that have experienced main bearing issues. They need a step above the threads at the parting line, and they need a deeper rooted main stud. It cannot be made as strong as the Shelby as it is currently being cast. I will say however, that the cylinders and head fastener design in the Pond blocks are at least as good as the Shelby. I have seen the Pond cylinders come back after thousands of miles and hard running, and the cylinders are pretty good, and they hone very well.....may stay at home a little better than a Shelby, but the main web situation is notable. The mains have to survive for the engine to survive......
The BBM aluminum block has better main web structure than the Pond. The ones I have seen could benefit from using longer studs. I think that is probably going to happen at some point.
I believe that an early centeroiler might be a touch better on ring seal than an aluminum Shelby, but I think the Shelby mains are stronger than OE iron.
I think an OE side oiler is tit for tat with a Shelby aluminum in terms of ring seal, but as with the centeroiler, the bottom end will not stand the power that a Shelby will.
All of the above is based on what I have seen and what I have used. Just my observations and opinions......
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
Magnesium banned in F1 for any use for decades as one car went up and melted a hole in the track. Forget if it was a Honda.
Yeah, just found the link and it was the Honda.
https://www.carthrottle.com/post/wy355r8/
Not a magnesium ENGINE. The Honda had a magnesium body and 58 laps worth of fuel onboard when it burned
With liners for cylinders and whatever, why not a carbon fiber block? Other than cost, why not titanium (reason why I mentioned F1)?
I should have answered differently. Yes, the Honda was mag bodied but after the fire, F.I.A. banned any use of magnesium, block included. Today, decades later, some rules changes did allow limited use of magnesium sheet but no engine nor transaxle
nor suspension parts. Funny though, at that time carbon fiber came into being and due to stiffness, I'm told,it's a far better choice.. which is why all F1 cars use it instead. Btw, my rules book is old or else I'd post some fascinating passages here.
Ford GT40 used a transaxle with a magnesium case to reduce weight.
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Has anyone ever experimented with more exotic materials for blocks? For F1 maybe? Magnesium? Titanium? Carbon fiber?
Magnesium banned in F1 for any use for decades as one car went up and melted a hole in the track. Forget if it was a Honda.
Yeah, just found the link and it was the Honda.
https://www.carthrottle.com/post/wy355r8/
Not a magnesium ENGINE. The Honda had a magnesium body and 58 laps worth of fuel onboard when it burned
With liners for cylinders and whatever, why not a carbon fiber block? Other than cost, why not titanium (reason why I mentioned F1)?
I should have answered differently. Yes, the Honda was mag bodied but after the fire, F.I.A. banned any use of magnesium, block included. Today, decades later, some rules changes did allow limited use of magnesium sheet but no engine nor transaxle
nor suspension parts. Funny though, at that time carbon fiber came into being and due to stiffness, I'm told,it's a far better choice.. which is why all F1 cars use it instead. Btw, my rules book is old or else I'd post some fascinating passages here.
Ford GT40 used a transaxle with a magnesium case to reduce weight.
True, but a GT-40 ain't quite an F1 car as I noted.
F.I.A. controlled (at the time at least) both distance racing (Sebring, LeMans, et al) but banned magnesium at the request of the F1 officials. Not sure it's still banned these days.
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If you want to see something funny make i fire and throw a
VW trans on the fire ;D
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Ford cast a handful of magnesium "494" ( 429-460 style) mag blocks . P&S foundry in Ohio did some BBC's and Mickey Thompson did some SBC's those ware the only American V8's "I" know of done in mag. Dyno Don ( rip) had one of the P&S mag BBC's and at 557ci it made around 900 hp when a 500ci legal Pro Stock engine was making 1200. But it was LIGHT LOL Ring seal was non existent as the motor warmed up.
Mag is a terrible alloy for a high horsepower block.
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Catches on fire too. :o
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Ford GT40 used a transaxle with a magnesium case to reduce weight.
[/quote]
I'm not sure which iteration of the Ford GT you're referencing, but the one usually, properly labeled as a "GT40" was the original from back in the '60s. The transaxles for the FE-powered cars were produced at T&C Livonia, and when the program was done there was a storage shelf of them in a 'crib' just across the aisle from the Quality Control Lab. I knew the Executive engineer for the plant and had several discussions with him regarding the stored items. They called on whoever was handy as they were making the interior parts and I was detailed to follow some forged gear blanks through the hobbing operation as they were being created. The blanks came, I believe, from Canton Forge.
The cases were an amalgamation of an ordinary four-speed and a 9" centersection with an enbloc bell-housing on the front end. They were assuredly aluminum.
KS
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Dr. Craft (the NASCAR race car restorer) posted his thoughts only a few days ago on the old FE Forum with two pics of what does look an awful lot like a magnesium cased GT-40 transaxle. Can't seem to copy over here the pics however, just his text (below). Don't know if these ever made it into the actual race cars however just like maybe the one-off mag Boss 429 blocks (Can-Am) or other extremely rare parts.
Anyway, here's the link showing (a few pages in) the disassembled magnesium-looking case in the background and two round aluminum bearing retainers, clearly shiny aluminum versus that unique magnesium look to the case in the background.
https://www.fordfe.com/viewtopic.php?p=1084069#p1084069
8:28 AM - 2 days ago#48
The early transmission problems were resolved by taking the bullet proof internals components of a Ford T&C four speed and repackaging them in a Magnesium transaxle housing.
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The MKIV transaxles I saw at H&M Charlotte were indeed mag. Ten stacked like cord wood. There were two automatic tranaxles as well but they were aluminum for sure. That was 1977.
Randy