356" Y-Block - This isn't a FE, but it's a Ford cousin and another "dinosaur"

[JC-427Stroker]

 
(IF the Mods want to move this to "non-FE discussion" I understand )

Back in early February I got to spend the afternoon at Westech with a couple friends and their 356" Y-Block.  Engine has Mummert Alumi heads and a Mummert Y-block tunnel ram and rockers system.  (Maybe I can get some  FE rockers out of them ... ? ? )

Geoff Mummert has my 427MR stroker parts at his shop,  and before the year is over we hope to get things bolted together and have some dyno time with a couple of manifolds.  He's ported the Survival MR heads I got from Barry some years back.  We'll be working on the cam selection here before too long.

This 356" Y-block made 1.42 lbs ft per cubic and 1.7 hp per cube.   Intakes flow 275 cfm with a 1.97" valve, so 2.18 hp per cfm.
The engine is 14:1  and was running on Q-16.   Pk power 608    Trq  508.

She's a good running little engine.








Spec's Geoff posted on Speed-Talk:
https://www.speed-talk.com/forum/viewtopic.php?f=84&t=64715

- 3.860" bore 3.800 stroke
-14.25:1 compression
-268* @.050 263*@.050 .630" lift
-1.97" 1.51" valves
- CFM 275 int 195 exh
-1.7 roller rockers

[JC-427Stroker]

Dyno video ...   Check out the AF readings.

https://vimeo.com/673498812


Tuned with 8 -02's
Steve at Westech said this engine just might have the most consistent A/F across the board of any carbureted engine he's had on the dyno. I think my 565 is pretty close though.

The video is of a "lash loop" run.  We loosened up the Int (pulled duration out) and it picked up over the baseline.

[BattlestarGalactic]

Pretty cool stuff.

[frnkeore]

This is a good example of not needing thick cylinder walls to make big power.

[JC-427Stroker]

This is a good example of not needing thick cylinder walls to make big power.

 I believe this block is 3/4 filled.

[4twennyAint]

Awesome.  What vehicle will this be going in?

[blykins]

This is a good example of not needing thick cylinder walls to make big power.

 I believe this block is 3/4 filled.

Isn't a 3.860" bore just a .060" over 312 anyway?

[frnkeore]

Brent, yes, it is but, the 312 is built on the same block as the 292 with just larger mains. So at 3.860, it is a .110 over and Geoff used a 292 block. Geoff used a, in his words "filled a little over 1/2 way".

Ford's spec on cylinder walls for both the 292 and FE's for at least the first 3 years is .170 with a max over bore of .060. The spec for the 312 is .145 with a max over bore of .040. Ford may have payed special attention to the castings, after 56 when the 312 came out, because a .040 over 312 wouls be a .080 over 292. Geoff's cylinder walls should have a nominal thickness of .115.

I have conflicting specs on the .170 wall, one just list it as .170 (nominal assumed) and one says min .170. My Edsel block, with it's sonic map, would fit into the min .170, with it's 4.050 bore, now 4.110.

[JC-427Stroker]

Awesome.  What vehicle will this be going in?

Here's the ride:

[blykins]

Brent, yes, it is but, the 312 is built on the same block as the 292 with just larger mains. So at 3.860, it is a .110 over and Geoff used a 292 block. Geoff used a, in his words "filled a little over 1/2 way".

Ford's spec on cylinder walls for both the 292 and FE's for at least the first 3 years is .170 with a max over bore of .060. The spec for the 312 is .145 with a max over bore of .040. Ford may have payed special attention to the castings, after 56 when the 312 came out, because a .040 over 312 wouls be a .080 over 292. Geoff's cylinder walls should have a nominal thickness of .115.

I have conflicting specs on the .170 wall, one just list it as .170 (nominal assumed) and one says min .170. My Edsel block, with it's sonic map, would fit into the min .170, with it's 4.050 bore, now 4.110.

I'm sure that's why Geoff poured the block.  Block fill goes a long way to stabilize the bores and help the rings to seal.   It's a good trick for Cleveland blocks too, where the cylinder wall thicknesses are thin to start with. 

[frnkeore]

I started a thread, three weeks ago, on Speed Talk, regarding wall thickness and what might be to thin as well as, at what point it will cause hp lose:

https://www.speed-talk.com/forum/viewtopic.php?f=1&t=64800

I know that TODAY, it's commonly accepted, that you shouldn't bore a block more than .030 and the main reason seems to be that, it's because you will loose hp, if you do. I started the thread on ST because there is a wide variety of engine builders of all common American V8's. I also, checked what wet sleeve tractors use.

In my day, we didn't have  sonic testing and everyone bored, at least .060 and many 1/8" but, I don't recall anyone splitting a cylinder wall because of it. So, in those days, if you bored a 352, FE 1/8", you had a basic .107 cylinder wall. My best friend had a 303 Olds, he bore 1/8" to 324 but, 56 Olds heads, then put in a 280 duration, Herbert roller cam and mounted a 4-71 blower, w/2 AFB's and drove it for 8 years and 2 years before that, w/o the 4-71 but, 4 x 2's instead.

My own opinion is that you should have a min wall thickness of .120 but I found some wet sleeves at .115. Those are even, all the way around and not thicker in some/most areas. But, my main interest was at what thickness do you start loosing hp. There was no answer to that! I was hoping to find a few builders that said "I freshen this engine, X number of times and dyno it, each time. When it got to .X over, it lost power and I had to replace the block".

The diameter and length of the unsupported cyl wall make a difference, too but, there wasn't any input on anything that showed lose of hp.

Sorry, JC-427Stroker for taking this a little OT but, with that much power per ci, it does seem some what relevant to Geoff's engine.

I know the 351C had a problem splitting blocks but, don't remember them says they lost hp until they found a split.

[JC-427Stroker]

No worries It's all relevant to the discussion.   

[blykins]

There is an absolute that I truly believe in, that a thicker cylinder wall (or a better supported cylinder wall) will always be better than a thinner one.   

I understand that sometimes there is a desire to open up the bores to unshroud the valves, but that's where experience comes in, to see which trade-off is more detrimental.   Obviously, Geoff knows the Y-block stuff better than most of us here, so to offset opening up the bores to help with shrouding, he went back and filled the block to get back ring seal and cylinder stability.  In this case, a thin wall really didn't make big power, as he essentially increased the cylinder wall thickness and stabilized the bores with block fill.

On an FE, which I have a ton of experience with, I know that my 4.080" bore 445 strokers are not hindered by bore size when it comes to making horsepower and will make the same hp/ci as the 428 strokers, given the same parts combinations (of course changing cam specs per displacement).   Experience has also shown me that you can ruin a 390 block very quickly by boring them to a 428 bore (or close to it), even when a sonic test says it's ok, just because of manufacturing voids, pits, etc., on the backside of the cylinder.   It's not feasible to map out every 1/8" of landscape of a cylinder wall. 

On a Cleveland, which I also have a ton of experience with, they were thin when they were first cast.   I have sonic tested many standard bore Cleveland blocks and have seen .060"-.080" cylinder wall thicknesses.  You are not going to see a loss in power on subsequent builds because you (tongue in cheek) started out with junk to begin with.  One of the best things to do to help a Cleveland block live is to fill it. 

The biggest example of horsepower per cylinder wall stability can be found in aluminum engine blocks.   An aluminum block will be down in horsepower right off the gate in comparison to an equal iron-blocked combination.  The reason for that isn't really the sleeve thickness, but it's the material supporting the sleeve.  I have built all-aluminum FE's, dyno'd, then tore them down, to see shadows in the cylinder walls where the bores were distorting.

I just went through and read the SpeedTalk thread.  Seems like you got a lot of well thought-out responses from a lot of guys who build and they all reflect the "thicker is better" way of thinking as well.

[My427stang]

So your earlier parrot comment was a bit whiny and maybe rude Frank, which am never to you, but it’s simple….many of us say the same thing because we have walked this path and have seen the indicators of cylinders deforming.

If a cylinder distorts, rings seal gets worse, power goes down……..that’s it, like it or not. Vacuum and power stroke are affected.

Not using torque plates, thin walls, bore dimensions, internal support, thick rings, lots of reasons. You won’t find a number because cylinder pressure, temp, and even thrust loading isn’t even a constant in one engine, never mind different engines

We didn’t realize it either in the old days, not me or my father in our shop, and we built some hot stuff for the period.  However we also didn’t have the technology, tools or information we have today.

[Joe-JDC]

First, the C1, C2 292 Y block cylinder blocks are the best for most performance applications.  If you can find a standard bore block, then do a sonic map, and offset boring can be accomplished to +.130-135" in many instances.  My own 292Y is +.132" in the 375Y stroker.  Also, John Mummert has his own aluminum heads cast by Edelbrock that have improved combustion chamber shape and allows for porting to flow near 280 cfm on the intake side with 1.970" intake valve.  Valve position is such that they don't hit the cylinder walls like stock heads do above .535" valve lift, so a camshaft with much more lift can be used.  Also, on the race heads, he angle mills them .125" to get the intake valve even better position in the bore.  The heads are CNC'd and use 1.7 rocker arms on their special stands.  He sold several sets to racers, including myself a few years ago.  John M also has intake manifolds, front timing covers, valley covers, valve covers, thermostat housings, etc., cast for the Y for sale on his site.  The Y block is a side oiler, pre FE.  The blocks are very sturdy when minimal bore is accomplished, and can support upwards of 750hp with turbos or blowers.  The 289 SBF has same bore spacing, and the Y crankshaft can be machined for use in the 289 block for a stroke increase.  I have ported dozens of the aluminum Y block heads and intakes over the last 13 years for folks.  A simple head change can increase the power 70 hp on a 292/312 Y with the matching intake.  Joe-JDC 

[frnkeore]

I wish there had been someone like the Mummert's, in the 50's and 60's, because in the SoCal race scene, the Y-block was almost completely shunned. It was a shame! I was 13, threw most of '58 and we had a '54 Ranch Wagon, that my dad put a '55 272 engine in (first 18mm spark plug). But, in those days even the 265 Chev, would out run it. The Y was a very short lived car engine and I didn't care much for it. It was heavy and didn't have the advertised hp of the 352 so, I went the FE route. It didn't help, that in the 8 years I was a mechanic, that the only Ford I saw with a cracked block, was a 312. Cracked from the main, to the cam. It might have been a different story if they had opened the bore, to at least 3.94, with a aluminum timing cover and manifold and the 312 heads. But, it was just a quick transition engine, for Ford's hp cars. I would have loved rooting for the Y-block, in those early years.

[frnkeore]

As I said, I did that thread on ST, specifically because, there are many more high end engine builder over there. Yes, some of them said that thick walls would make more hp BUT, not a one of them offered proof!

Again, I am not advocating running under .120 walls but, I am saying that if your sonic test shows a area down to that, I wouldn't worry about it.

I think the 351C and the Ford FH are two good examples. The FH was bored from .020 over to as much as .250 over with certain blocks but, .188 over was the norm for them. My first car, a '48 Merc was 3/16 over. No sonic testers in those days so, there is no way of know how thick the walls are and no one, including the machine shops said not to do it.
Edit:
If in that range of bores, there would have been a sweet spot of at which hp fell off with ci increase, it would have been found by trial and error.

The 351C, if it was loosing so much hp, how come it was winning a LOT of races? I'm sure the Chev and Mopars had thicker blocks. Cracked blocks, yes but, not short on hp. Don't even make since. If your loosing hp on the dyno, w/o a vacuum pump, why isn't there a huge amount of blow by? Even 10 hp, would be a lot of blow by. That hp is cylinder pressure, where is it going? I don't see a market for crank case headers, for the fools that bore there engines over .030.

As for aluminum engines. Heat is also hp and is what creates pressure, alum engines loose more heat but, I think the major reason is the block growth, that lowers the C/R. Aluminum grows at 3 times the rate as cast iron and steel. It's one of the first things I learned, as a machinist. Close tolerance, aluminum parts, have to be measured, after they have returned to 20C temp, to be accurate measurements, comparable to other metals.

I started that thread on ST for factual answers and it appears that there is only speculation available. I was surprised at that! I really was.

It might be a very interesting project, for someone with much more money than I have to sonic map a few different engines, then bore each of them in .010 increments, until they either split or lost power and then examine the failure. That would give the real answer to this question.

[Joe-JDC]

Y blocks were in production from 1954-1967.  Stayed in production in South America into the '80s.  Joe-JDC

[frnkeore]

Yes, Joe, I do know that but, they were only the top car engine for just 4 years and they weren't used much in cars, after the 289 came out.

As I said, it might have been a different story, if the Ted Eaton and the Mummert's around in the 50's and 60's.

Personally, I wish the Linc Y-block would have lasted, a lot longer. It could have been opened to more than 430 in '58 but, Ford was into big bore, short stroke in '58.

[blykins]

As for aluminum engines. Heat is also hp and is what creates pressure, alum engines loose more heat but, I think the major reason is the block growth, that lowers the C/R. Aluminum grows at 3 times the rate as cast iron and steel. It's one of the first things I learned, as a machinist. Close tolerance, aluminum parts, have to be measured, after they have returned to 20C temp, to be accurate measurements, comparable to other metals.

When I build an all-aluminum engine, I know that it's going to grow through the decks roughly about .008-.009" because lash grows by .014".   When I order pistons and set up the rotating assembly, I allow for that growth in the compression ratio and plan accordingly.  Still, the engines are down in horsepower, and the reason you gave (aluminum grows.....) is why.  An aluminum block has steel sleeves supported by a backing material that grows very quickly with heat, which distorts the bores. 

Frank, you can bore your blocks until the walls are .005" thick.  It really doesn't bother me.  But you won't find a single professional engine builder that will tell you that they wouldn't rather have a thicker cylinder wall.

As for the 351C, it was winning a lot of races because it was a good engine!   An all-aluminum FE will still make a LOT of horsepower and you don't really know how much you're losing until you compare it to something else.   Your comment about Clevelands was not really a logical/reasonable comment.   If you have a cylinder that doesn't stay round or straight, then you're going to lose ring seal.  It's not difficult to understand that.  A bore that's flexing enough to crack is going to flexing enough to lose ring seal. 

I've laid the spurs to this dead horse about as much as I'm going to. 

[frnkeore]

Ok Brent, thanks for your input.

Even though people say things, unless there is proof, it's just speculation and opinion. I haven't even had one person that can document blow by looses. If those rings are loosing enough pressure, to loose hp, that pressure HAS to be going somewhere. Where is it going and who has measured it.

If you read to the end of the ST thread, you'll see that the high end OEMs and F1 type engines, use ~ .120 cylinder walls on aluminum engines.

 

[blykins]

Well, I guess since you haven't found proof of it, then it doesn't exist, right?  ;-)   Here, let me help.

A quote from Darin Morgan on Speed Talk....(head porter, worked for Reher Morrison, etc, etc.)

"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."

There's your blow-by losses due to loss of ring seal.  They've been documented.  If it can happen with an aluminum block, it can certainly happen to a flimsy, thin-bored, cast iron block.  Blair Patrick told me once that an aftermarket cast iron block was good for an X amount of horsepower over an exact duplicate combination with a factory block.  Block rigidity counts for a whole lot. 

[JC-427Stroker]

The 351C, if it was loosing so much hp, how come it was winning a LOT of races? I'm sure the Chev and Mopars had thicker blocks. Cracked blocks, yes but, not short on hp. Don't even make since. If your loosing hp on the dyno, w/o a vacuum pump, why isn't there a huge amount of blow by? Even 10 hp, would be a lot of blow by. That hp is cylinder pressure, where is it going? I don't see a market for crank case headers, for the fools that bore there engines over .030.

Are you just speculating ?    10 hp over 8 cyls is 1.25 hp per cyl.   That's not much in a 400-600 hp engine. Not much at all.

 Many moons ago (17-18 years ago)  I ran the 565 on the dyno before a rebuild. It had been together for many years with lots of nitrous bottles thru it and a couple of "quick and dirty" rebuilds" (including back yard hone jobs with a dingle ball). It was down 10 hp from when it was last dyno'd
it was making 927 hp at 6,800 (worn out).  When I pulled it down it had so much piston rock in a few cyl's  that it had witness marks on the heads where the pistons were saying "Hello" to the heads.  I don't recall the exact piston to wall,  but it was  something like .002 more than it should have been. The engine was passing oil through the exhaust in a couple cyl.. 

Long story short ...  Fresh hone, new pistons, new rings ....    The dyno printed 935 hp.

I can't quantify how much the top ZERO GAP rings were helping the engine still make power while worn out, but they were probably helping at least a little.

Oh.. The 351C won, in part,  because they had great Cyl heads.

[JC-427Stroker]

Ok Brent, thanks for your input.

Even though people say things, unless there is proof, it's just speculation and opinion. I haven't even had one person that can document blow by looses. If those rings are loosing enough pressure, to loose hp, that pressure HAS to be going somewhere. Where is it going and who has measured it.

If you read to the end of the ST thread, you'll see that the high end OEMs and F1 type engines, use ~ .120 cylinder walls on aluminum engines.

Just curious .. What's your experience on the dyno with performance engines ? 

[My427stang]

Frank, I am not sure what proof you need, but I have a fresh 433 that came in and I needed to swap a block.  Unfortunately I also fixed a bunch of other mistakes done by the prior builder and I didn't dyno it before, I will after though

It was a 390 bored to 4.160, it was way down on power, leaked everywhere and has ring tracks showing how the rings (gapless top Total Seal) couldn't follow the bore.  It had some walls as low as .057 thick, which I checked myself.  However, I didn't need to see the sonic to know the issue as soon as I saw no marks on the back and the behavior.  It's a shame what the last guy did to the block

It's now a real 428 block and a lot of goodies, you'll see it here soon

That old block is still on a stand, no ridge and relatively clean, it's likely up for grabs for a song, and likely not even a good song   This engine looked clean inside and the bores measured within specs, pistons were clean, even in the ring lands.

If I understand you, do you not think the bores move as they get thinner? 

If you don't think they move, do you think torque plates are needed?

If you think they move, are you saying it doesn't matter to the ring seal?

Or are you just saying .120 is enough?   Not being a wise guy, just trying to understand your perspective

I'll see if I can some pictures that show the tracks, I did a lot of cleaning to get an accurate look at what was happening, but I should be able to show you

[frnkeore]

Ross,
In answer to your question, if you re-read my responses, you'll find this:

My own opinion is that you should have a min wall thickness of .120 but I found some wet sleeves at .115. Those are even, all the way around and not thicker in some/most areas. But, my main interest was at what thickness do you start loosing hp. There was no answer to that! I was hoping to find a few builders that said "I freshen this engine, X number of times and dyno it, each time. When it got to .X over, it lost power and I had to replace the block".


Again, I am not advocating running under .120 walls but, I am saying that if your sonic test shows a area down to that, I wouldn't worry about it.

Don't worry about not seeing it at first, most of the guy's on ST, that couldn't answer my question with facts, did the same thing, I said it 3 or 4 times there and Brent thinks I want to run .005 thick walls. I really don't know what to think about that type reaction?

Yes, I know Blair advocates thick cylinder walls but, he bored his EMC engine .047, I think.

Brent bored JJ, .040 and the 360's aren't know for think cylinder walls. I don't know if he did a sonic map but, he says he has no faith in mapping.

At least one, maybe two, have bored their 427's .060. The 427 has a clover leaf shaped cyl core but, between cyl, at 4.234, the cyl wall is only .123 and at .030 over is .108 and at .060 over, it's .093. That is with out any core shift.

Brent brought up aluminum blocks but, my question is about production, American, cast iron blocks. I don't know the specs on the alum blocks he speaks of but, I do know about heat and expansion. I'd be interested in studying the specs on those blocks if, he can provide them to me.

One of the ST responses did offer this insight into modern high hp and extreme hp, aluminum engines:

ST response by hoffman900

Some numbers digging around:

Honda NSX. 3.5L Turbo V6. 500hp from 6500-7500rpm, 405lb-ft from 2000-6000rpm. They mention a conventional iron bore sleeve would need 2.5mm (0.098in) between it and the water jacket. A 0.2mm (0.008in) Fe spray was applied, thus closing it up some. They now have 11mm (0.43in) in the bore bridge, including water jacket. 3.6in (91.4mm) bore size.

The Ford RY45 (large displacement, aluminum block developed by Roush Yates from the NASCAR FR9 for Late Model and off road trucks) has 4.500 (114.3mm) bore spacing and a max bore of 4.250" (107.95mm). My math shows it has a bore bridge of 0.250" (6.35mm) and no cooling jackets in them. So that would be a liner thickness of 0.125in (3.175mm). This engine in development, made 901hp @ 7500rpm and 692 ft-lbs at 6200rpm. 436ci and 14.5:1 compression. They found a peak of 135 bar was too high for the short block components they designed, so they tuned for an average pressure of 105 bar (bar = 14.7 lb), noting it could be higher with more robust short block components. There was a package shared this summer of this platform that made 958hp @ 8500rpm and 657 lb-ft at 6600rpm. 438ci and 15:1 compression, so I can imagine peak cylinder pressures aren't too much higher than the test engine, just rpm has moved up.

The Audi R4 TFSI DTM engine makes > 570bhp from 6500-9000rpm, and 590bhp at peak. Boost limited to 3.5 bar and fuel flow limited to 90kg/hr. It is allowed a 100kg/hr fuel flow rate push to pass that boosts power to 644hp. The bore bridge has a distance of 9mm (0.35in) and a bore spacing of 97mm (3.89in) on a 88mm bore (3.46in). I don't believe there is a water jacket in the bridges, so this would result in a liner thickness of 4.5mm (0.177in). Because they run these engines at AFR of 16:1 to 20:1, they are built to be knock resistant. It seems they rule detonation as anything in excess of 300 bar, but looking it seems 250 bar peak, maybe higher, seems to be a more realistic design number (just my guess). These engines are designed to go 4000 miles between rebuilds, have a 40.5-42% Brake Thermal Efficiency, and can "cope with more than 5000 severe (300 bar + ?) knock events before damage becomes a limiting factor" - Race Engine Technology, January 2022 issue.

Here is the Honda F1 V6. I don't know what cylinder pressures are, but 1.6L V6 hybrid, fuel flow limited to 100kg/hr, making in excess of 1000hp peak. Likely similar afr to the Audi engine (but likely even leaner due to turbulent jet ignition / HCCI combustion concepts) and need to be just as knock resistant. Brake Thermal Efficiency approaching 50% and have to go 1500 miles plus. They are also a structural component of the chassis in these cars.

All these engine blocks are aluminum with liners + coatings. Need to be sealed really well and last for thousands of miles.

So, it appears that if a aluminum engine, is designed right, they could have .098 - .125 liners and live as well as seal.

After throwing those last two numbers out (.098 - .125), let me say, for a third time that I am not advocating running cylinder walls, under .120.

I'm adding Ford's drawing of the 427 cylinder wall so, you can all see the thin side walls. Just subtract 1/2 the bore you want to use, from 2.24 and that gives you the wall thickness. This is the nominal dimension and does not consider any core shift.

[blykins]

JJ was a 352, not a 360.  It started life as a 4.000" bore. 

It seems like you misunderstand a lot of my posts, so let's go over a couple of things.

1.  I said .005" very tongue in cheek, as in "I really don't care what you do to your own engines and if you wanted to try a cylinder wall at .005" thickness, then more power to you."  I'm scratching my head as to why you would even think about taking that literally?

2.  I didn't say I had no faith in sonic tests.  I do them on almost every block.  I trust what they give me, but I also recognize that you can't map every single point in a cylinder wall and I've been bit MULTIPLE times by this. 

Once or twice a week I get emails from guys who want to bore their 390 blocks out to 4.100-4.110-4.130 without even thinking about stopping at 4.060, 4.070, or 4.080.  My response is that the extra-large bore really does nothing for you, but the extra cylinder wall thickness does.  I'll continue to firmly stand by that comment.

I know you're a sharp guy, Frank, you have to be in order to be a machinist and own your own business.  However, your experience level is just not up-to-date and is based on decades-old information.   Time and time again, you refuse to believe that anyone here has any authority to speak on modern engine building techniques, so you always roll back to SpeedTalk, where they reiterate the very things that you hear here.   Let me say that *every* post on that ST thread validates a thicker cylinder wall over a thinner one.  In addition, you also need to re-read the comment on ST that says there's absolutely no way to put a number to this because every engine is different.  It has to be based off of experience.   That is why Geoff poured this block and it's also why you can't compare an Acura NSX block that was designed in a specific way to a Ford 390....or a Ford 289.....or a Ford 351C. 

[My427stang]

Well, I guess I can pontificate a bit

A new-style  block, with consistent casting from modern methods, or fully supported liners/spray, no jacket pitting and no detonation, would likely live at .120, and does using your modern examples, assuming are accurate and liners or liner support aren't siamesed, bell shaped OD, etc.

I would be hard pressed to trust that on anything from Dearborn on this forum. Cylinder depth and bore, inconsistent castings, materials, pitting, non-uniform casting, and no way to check 3 dimensionally for thickness.

Everything gets worse (head bolt, heat, flex, etc) with thinner, and gets better with thicker.  It's wild, I even see CX scratch blocks with #2 and #4 mains cracking, who would expect those to break one journal in and supported on both sides on a low rpm industrial engine? 

I am also sure there is a breaking point that is too thin and inversely, there is a thickness that is "wasted metal" that is too thick.  I don't know those numbersr, but I would say they are pretty far apart, meaning there is some range, probably based on materials, design, bore diameter and depth, that the min to max thickness strength can be evaluated by math. 

Again, without knowing the numbers on every inch of a 50 year old block absolutely, unless someone has some sort of 3D sonic check, I prefer to stay closer to .180+, unless I have a very good reason.  I know you are looking for facts and proof, but the truth is, any proof on an FE is thrown out the window when you grab a second block that is dimensionally different and unverifiable like our FEs

To keep things bowling ball simple, 1/8 inch isn't a lot, so a little more makes me feel better when it gets in the hands of someone and an environment trying to break it LOL

The combination of engine dynamics and materials/design contributing to strength is interesting though, and needless to say, a modern FE block could be made more efficiently, which likely would mean "lighter but stronger" but I can't see how anyone with normal evaluation capability, like a sonic testing machine could get enough info to evaluate and old block without lots of assumptions.

Those assumptions then start poking at the math and push us into rules of thumb after testing what we can. I do like my sonic tester, and use it all the time, but it doesn't tell me the entire picture, no matter how many sample measurements I take. 

Last comment, let's assume a 1.5 HP per cid.  462 versus 465 inches, that extra 3 inches of displacement would yield 4.5 HP, and that HP/CID number is above many of the FE power levels around here.  I know your effort is academic to a point, but that 4.5HP assumes you are within that range of "good enough" wall thickness.  I don't like playing on the edge without reason and very specific measurements, so again, I'd rather trade for a safety buffer

You may be interested in some diesel study, it doesn't directly apply, but fascinating how they have to manage the coolant formulation  to ensure that the shock of combustion doesn't push coolant away from the liner and superheat/unsupport the liner, this will cause damage to the liner.  We aren't talking 1000 hp racers, we are talking 400 HP / 850 ft lb to 500 hp/1000 ft lb street driven pickups bought at the dealer, wild stuff.

[blykins]

A Dart SHP 351W block is listed as maximum bore size of 4.185".  That's mainly due to bore spacing and what head gasket you can fit in between the cylinders. 

HOWEVER....

They have purposefully cast that block to have .230" MINIMUM thick cylinder walls at 4.185" bore.  They did that for a reason, especially when everyone is screaming for lighter blocks.

[MeanGene]

I think quikbbmustang might be back lol 

[cjshaker]

I think quikbbmustang might be back lol 

LOL

When my engine is done, I'm beginning to think it might not be worth posting results.
Here's a novel suggestion; instead of killing someones cool engine dyno post, why not pose a question in the main forum? Frank?

[JC-427Stroker]

JJ was a 352, not a 360.  It started life as a 4.000" bore. 

It seems like you misunderstand a lot of my posts, so let's go over a couple of things.

1.  I said .005" very tongue in cheek, as in "I really don't care what you do to your own engines and if you wanted to try a cylinder wall at .005" thickness, then more power to you."  I'm scratching my head as to why you would even think about taking that literally?

Stunning, isn't it ?

[JC-427Stroker]

Ross,
In answer to your question, if you re-read my responses, you'll find this:

My own opinion is that you should have a min wall thickness of .120 but I found some wet sleeves at .115. Those are even, all the way around and not thicker in some/most areas. But, my main interest was at what thickness do you start loosing hp. There was no answer to that! I was hoping to find a few builders that said "I freshen this engine, X number of times and dyno it, each time. When it got to .X over, it lost power and I had to replace the block".


Again, I am not advocating running under .120 walls but, I am saying that if your sonic test shows a area down to that, I wouldn't worry about it.

Don't worry about not seeing it at first, most of the guy's on ST, that couldn't answer my question with facts, did the same thing, I said it 3 or 4 times there and Brent thinks I want to run .005 thick walls. I really don't know what to think about that type reaction?

You also stated:
 " This is a good example of not needing thick cylinder walls to make big power."

Those thin cyl walls were SUPPORTED with block fill so that very much negates the point you were trying to make.

[JC-427Stroker]

LOL

When my engine is done, I'm beginning to think it might not be worth posting results.
Here's a novel suggestion; instead of killing someones cool engine dyno post, why not pose a question in the main forum? Frank?

Some people ......   

[frnkeore]

No worries It's all relevant to the discussion.

I hate to bring this up, JC but, this is what you said about this subject in this/your thread.

Other wise I would have started a new thread since this seems to be of interest.

[JC-427Stroker]

No worries It's all relevant to the discussion.

I hate to bring this up, JC but, this is what you said about this subject in this/your thread.

Other wise I would have started a new thread since this seems to be of interest.

And you’ve gone on and on and on and on and on and on to the point where it’s no longer relevant as you argue  a point that people who know far more about it than you do. But you demand proof.

Once you found out the block was filled it kind of takes away your argument regarding "thin walls" . The block was filled to give it rigidity.

Hope that clears it up for you. 

[jayb]

Please gentlemen, no more pointless arguments.  It takes away from the usefulness of the forum.  Thanks, Jay

[JC-427Stroker]

Ok Captain...   

Thanks.