FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: sumfoo1 on March 19, 2014, 10:40:32 AM
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What head gasket should i use and what boost pressure should i consider 0 ringing the engine?
Right now she's sitting @ 9.7/1 CR with a .030 head gasket on it and a relatively large cam (especially for 9.7/1 cr) (262 intake and exhaust @.050) She's a 500 CID pond side oiler. With Crower crank and rods both designed for way more power than i'd ever turn it to. Should i drop her compression down further with a bigger head gasket? I know if i go too far with HG i'll start running into quench issues.
.050 = 9.17/1
.080 =8.73/1
.100=8.5/1
.120= 8.22/1
The plan is two gt4202 turbos (because no matter what the boost pressure, turbine pressure on the 1.15 a/r turbine should stay roughly equal through out the 6 psi- 25psi band i would consider running them at.
"setting it on kill" would be @ 25 psi and would be on race gas or e-85
to be honest i'll probably never see 25 psi even with the forged-completely machined finish rods and crank so if is should stop at 18 or 20 that's fine too.
Long story short... i know turbos and EFI.... i don't know FE engines very well. My background is in subarus and mod motors and neither would i consider 25 psi to be o-ring worthy but they also have much larger heads with pent roof designs less likely to have hot spots...
Any intel would be nice.
Thank you,
-bill
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Quench is Not as much an issue with a boosted combo ,that said I am NOT a fan of O-rings , now that we have MLS gaskets , I would use Cometic , leave the Quench at the Min , as it makes the engine more efficient and less detonation prone , Limit the Boost ,I realize spouting numbers online these days seems to be the Norm , I still believe in Time Slips , NOT Dyno or Build sheets as Bragging Right , ( if that's your Bag ) , seen too many KILLER COMBOS on Both Dyno Sheets and Build that performed Poorly , make the combo Work ( Tuning ) IMHO
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Sorry not trying to brag if that's how it came off just trying to give a run down of what we're dealing with and how i'm stumped... I know when sizing turbos head flows and cams are of the utmost importance i didn't know if that would have an effect on the threshold for lifting the heads as the DCR is actually really low due to cam duration and shorter than ideal for a turbo LSA (which may change too)
Trying to make sure i can use the bottom end i'm running to its fullest without having a really expensive pile of metal.
I don't like O-rings either but i also don't want to be lifting the heads off the motor.
I guess better to know when the heads lift then not to and keep pushing it.
so... i'll go with MLS gasket truth is... the car will be street driven from time to time and probably be set at 6psi for the majority of its life. But it will see some track events from time to time and probably some grudge racing at the local 8th mile.
I agree about the tuning. I plan on watching her every move and listening to every hiccup and ping. That's how i learned EFI i kept getting tunes for my subaru and someone would go to number hungry and leave me with a tune that ate the engine and someone else would stay so far from the edge the big turbo combo made less hp than the stock turbo setup i had with a canned Cobb tune. So i learned how to tweak and tune until i had a wicked legacy that flat rolled out any day of the week... but i also drove to work with the laptop sitting on the passengers seat every day. (survived 78k miles before it ate the tranny)
But truth be told this is my first attempt at a full on build so i'm really nervous trying to do everything right because this galaxie is my baby.
The numbers and names are just to get the most accurate info and to prevent getting flamed by people saying "bet you don't even have the bottom end to hold 25 psi on that engine" I may not... but dangit i'm trying my best to get it there.
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If you get anywhere near 20 lbs. of boost or even have a bad tune-up (read:detonation) not o-ringing is just plain silly as you will pay for it...big time.....if you lift the gaskets once!
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I ran 17 pounds of boost with my supercharged FE, using Cometic MLS gaskets, and never had an issue, even when running very lean on the initial tune-up (15.5:1). Those gaskets make a big difference. I have two T-80 turbos for an SOHC project that should go to 30 psi, and I plan to use the same approach. The only time I've considered O-ringing the block is when I'm running copper head gaskets.
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I ran 17 pounds of boost with my supercharged FE, using Cometic MLS gaskets, and never had an issue, even when running very lean on the initial tune-up (15.5:1). Those gaskets make a big difference. I have two T-80 turbos for an SOHC project that should go to 30 psi, and I plan to use the same approach. The only time I've considered O-ringing the block is when I'm running copper head gaskets.
And THAT is the voice of experience ;)
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Some years ago when I was messing with first a 2 litre and then the 2300 Ford engines and turbos, I used wire O-rings and copper gaskets. My current turbo project---TT on a four litre 'AJ' Jag engine for ECTA---I've opted for Cometic gaskets. They are quite universally thought to be 'The Cat's PJs'. I'd not go back to O-rings! (I ran as much as 25 pounds of boost using all aftermarket-massaged internals.)
KS
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what is it about the MLS gaskets that makes it so much better than the conformity of the soft copper to the block and head surfaces and around the O-ring? I do know that in order to use the MLS gaskets, you have to have a smoother Ra number for the surfaces. Is that Ra number the entirety of the improvement?
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Viton + stainless spring steel. Cometic's site does a fair job of explaining same and also notes the RA required.
http://www.cometic.com/technical.aspx
Yikes, I seemed to 'see' copper head gaskets (in my previous post reply) when now it's apparent they weren't even mentioned! They do of course require o-ringing. I've also used the MLS gaskets with good luck but in non-supercharged engines. Funny too that most nostalgia supercharged nitro runners I'm aware locally can't use MLS gaskets as almost all their stuff already has O-rings! Old habits = die hard!
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Yeah I remember that conversation. I think the issue was the pressure would go down not up, pretty shure it did. Bottom end failure, can't recall what though? Think Jay has tried everything but sending an FE to the moon LOL.
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First - daydreaming about a 500" FE at 25 PSI makes me kinda dizzy and I find myself slobbering on the keyboard. Sounds like a whole lot of fun....
Now - I guess the other end of the question is whether in "ends of the earth" build scenarios the FE engine design (around head bolt configuration) is susceptible to lifting the head.
I know that "back in the day" in the turbo-mustangs world one of the admitted advantages of the SBC engines relative to the SBF in high boost scenarios was that with the five bolt per cylinder head bolt pattern they were somewhat less susceptible to lifting the head. I know that upsized head studs made of high zoot metal combined with cometic MLS gaskets did the trick for many folks. If memory serves World Products also made an aftermarket "Ford Windsor" block with a modified head bolt configuration including "extra" bolts (no clue how you do this and consider the thing a SBF) that had some popularity in the high boost crowd...
So - maybe another way to ask the question is "if we exclude detonation conditions, at what level / under what conditions have we seen FE platform engines lift a head / push a head gasket?"
Maybe some of the old knowledge can speak to this?
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That's one of the things i was thinking too..
They can't be too awful prone to it as some of the original blower fuel cars were FE powered.
I know when one reads things like this they're often hypothetical and to be honest it will probably be longer than expected after seeing what she did N/A on pump gas i'll have plenty to keep my hands full for the time being. (she hit 700 @ 7200 [evil grin])
But in the long run i subscribe to John Hennessey's Motto
"too much horse power is never enough"
That and it's going to be in a car that i plan on grudge racing with at the local track and if i get an infusion of capital i'd like to go for one of these some day.
(http://twinjugsracing.com/images/PICT0284.jpg)
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Without the infusion of major capital, you can still go LSR racing on the 'cheap'. Not sure if Texas Mile does it, but World of Speed at Bonneville has both a 130mph and a 150mph amateur classes. 130 class is 1 mile prior to traps, 150 guys get it 'easy' with a 2 mile run-up. ;D Pending no R-*-I-N this year and cancellation of all land-speed canoeing classes, I'll be doing the 130 class with my wagon. :)
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it's my understanding that those two classes are limited to the 130/150 speeds respectively right?
I'm hoping when all is said and done i'll exceed those in the 1/4 mile.
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They can't be too awful prone to it as some of the original blower fuel cars were FE powered.
You should be o.k. at that power level but......read what the original "engine master" Ed Pink had to say about all the nitro, supercharged SOHC's his shop built in the day for almost all the top fuel and funny car runners. Catch the part about broken blocks. This with approx. 1,800-2,000 hp, 90% nitro loads, 40% overdriven 6-71's and a single mag/single fuel pump. Tough but breakable.
http://www.enginelabs.com/features/interviews/the-old-master-ed-pink-reflects-on-sohc-irl-and-midget-engines/
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it's my understanding that those two classes are limited to the 130/150 speeds respectively right?
I'm hoping when all is said and done i'll exceed those in the 1/4 mile.
Correct, each class is limited to the upper bound of that, 139.999 and 159.999 respectively. I looked at the Texas Mile classifications and it doesn't look like they do a similar setup. So long as you could get your power to the ground effectively, you would probably easily be able to hit both speeds assuming this engine isn't in an articulated bus. It's a cheap way to explore the sport without having to dump a mortgage into a dedicated LSR vehicle.
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articulated bus, no... but close...
61 galaxie 4 door.
(which i think a 200 club membership would make it the fastest 4 door in the mile)
cage is designed to spec... weight has been cut everywhere it can be without going to fiberglass panels because i like the factory steel. There are plans for an underbelly pan to keep air flow under the car nice and neat. Splitter on the front directing air to and intercooler and a pro-mod/pro stock style rear spoiler. I might go to glass bumpers but that unless someone can show me where to pick up an aluminum re-production (and keep the originals for when i'm not trying to hit 200)
But again... these goals are a few years out (so i can re-coup my car funds) so i doubt anything will go too far too quickly as i blew my initial (car designated) nest egg on the engine, rust removal paint, tranny, rear end, fabrication tools, etc. thus far. LOL... basically i have everthing i need to make what i want... i just refuse to put 6 grand in turbos on a credit card to finish it earlier than necessary. I've never had 600+hp before (well 400whp in a subaru could be close with drivetrain loss but its awd so i don't think that counts) so the engine as-is should be a riot. Right now it's just a half painted body/chassis at a shop, with a complete engine in my shop with trans/clutch setup bolted to it ready to go in. 4 link rear in design/fabrication right now on a 9" i've built and parts every where.... So my pipe dream is really so close... yet so far away.
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Hey, you could pattern your car after Dr. N's build-up of a '61 LSR Galaxie!
http://www.curbsideclassic.com/blog/bonneville-wonders-1961-ford-galaxie-starliner/
It's a repo of the original Holman-Moody prepared LSR Starliner (the one that was a convertible with the lift-off top that NASCAR nixed after 1/2 a season) that did set records with a 481-483 stroked FE long ago. The current car isn't apparently FE equipped (Roush 358 NASCAR) but heck, it still did 206 MPH.
Besides, one has to smile at the moniker the current owner has painted on the flanks of his '61: Camel Toe Racing ;)
http://www.cameltoe.net/index.php?page=gallery&id=MQ==&gall_id=MzI=
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yeah I've seen that car before... i love it... i wish mine was a starliner to be honest but i really dig the 4 door too. I picked it up for 3500 with nearly no rust in the car and 53k miles (it was being used as an Andy Griffith car in a Mayberry parade in Flint MI lol.
I laughed the first time i saw it because when we were in college my buddy and i had jeeps with winches and access to a vinyl printer.... Needless to say trouble ensued
We made stickers for the side of the jeeps during a snow storm that said "Camel Towing"
We had joe camel's head hanging out of a jeep with a tow truck crane on the back.
Anyway... we made about 2k pulling people out of ditches for $50 bucks a pop.
The ice was so bad most of the local tow trucks couldn't go anywhere.
(raleigh nc... we aren't really equipped for icy weather)
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Hey, you could pattern your car after Dr. N's build-up of a '61 LSR Galaxie!
http://www.curbsideclassic.com/blog/bonneville-wonders-1961-ford-galaxie-starliner/
I've seen that car in person at Bonneville several times now, it's absolutely awesome. I'm not sure what HP that motor is rated at, but on the starting line from 10 feet away it sounds like it wants to kick it's own grandmother in the face.
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Hey, you could pattern your car after Dr. N's build-up of a '61 LSR Galaxie!
http://www.curbsideclassic.com/blog/bonneville-wonders-1961-ford-galaxie-starliner/
It's a repo of the original Holman-Moody prepared LSR Starliner (the one that was a convertible with the lift-off top that NASCAR nixed after 1/2 a season) that did set records with a 481-483 stroked FE long ago. The current car isn't apparently FE equipped (Roush 358 NASCAR) but heck, it still did 206 MPH.
Besides, one has to smile at the moniker the current owner has painted on the flanks of his '61: Camel Toe Racing ;)
http://www.cameltoe.net/index.php?page=gallery&id=MQ==&gall_id=MzI=
That car is now owned by George Poteet, and is an actual 61 Starliner not a 62 Starlifter clone. He also has another 61 Starliner show car with a Cammer in it.
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They can't be too awful prone to it as some of the original blower fuel cars were FE powered.
You should be o.k. at that power level but......read what the original "engine master" Ed Pink had to say about all the nitro, supercharged SOHC's his shop built in the day for almost all the top fuel and funny car runners. Catch the part about broken blocks. This with approx. 1,800-2,000 hp, 90% nitro loads, 40% overdriven 6-71's and a single mag/single fuel pump. Tough but breakable.
http://www.enginelabs.com/features/interviews/the-old-master-ed-pink-reflects-on-sohc-irl-and-midget-engines/
I was thinking about this post some... and compared to a over driven 6-71 running nitro 2000 hp through inter-cooled turbos on efi is next to no stress on the engine as long as she doesn't knock... i mean a 6-71 making 1800hp is making more heat than it is hp. The evaportative cooling effects of the nitro meth are the only reason the engine was thinking about running in the first place... so on e-85 or meth my engine should be relatively "relaxed" in comparison.... that and its built on a block with twice as much meat as a factory FE.
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Agree that a turbo'ed gasoline engine doesn't quite share the same hardships as a blown nitro engine. It's also true a sane level of boost and zero detonation will keep it out of trouble. The iron blocked FE's of the SOHC nitro racer era seemed to mostly split the area at the main webs with the trace crack running up vertically through the (unused) lifter valley area. Ed Pink related this in in other articles and claimed that he had rows (no kidding!) of Cammers in the back of the shop, almost all with the aforementioned broken mains. Always wondered whatever happened to all the leftover good parts!
Today, it seems all the aftermarket blocks are well beefed-up in this critical area, no doubt giving a much larger safety margin than any OEM iron block.
http://www.dragracingonline.com/special/bachgould_1.html