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" TURBO BUILDS " Post your Turbo build-Up or any that you have in process

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Old 05-17-10, 09:35AM   #16
turbo69BIRD
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THis whole post was dispelled by liefert machine torrington CT So I removed it so no one would get confused!
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Old 05-17-10, 09:50AM   #17
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OK foot in mouth!!!!

I just spoke with THE MAN Larry Liefert. Those of you who know of him will know he built most of PAUL NEWMAN's race engines.

He has been doing my machine work for many years. He says Absolutely no relationship between the cranking compression and the mechanical compression ratio.

BECAUSE. at cranking speed the cam can bleed off tremendous amounts of compression, but at higher RPM the compression will come back.

There is a gauge that will tell you the mechanical compression through the spark plug hole. ITS $4000.00 and SOME of the nascar engine builders have them for thier cars at the track.

BILLY MATHIS otherwise known as "billy the kid" in torrington CT has one. Who else has one in Have no Idea. BUt maybe you can call some machine shops local to you and ask around.
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Old 05-17-10, 10:38AM   #18
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alright. i thought the cam had a lot to do with it, so best way to get an idea of compression will be to pull the heads and see what pistons are in there right.?

trying to figure out what heads to use.. all the ones I have seem to be around the 100cc mark, the 96 head on it now are supposes to be 96cc, the 6x-8 are 98ish, and the 4x-7h are around 98 too.. this is of course according to just searching online. so just trying to figure out what set to use.

i am going to go with the MSD 6a system, and matching distributor, just trying to find one now, Still searching for a good turbo cam,

want to get all parts in line at least to get the car back running then start plumbing the turbo.
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Old 05-17-10, 04:29PM   #19
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Just as a note...and I'm laying my limited experience out for you as a relative newbie to turbos...its not impossible to use the heads you have on there, or for example the 6x-8 heads.

Its scary on a personal level.....I am experiencing that scenario when I use my car because I bought the car from Mark, and Mark I think mistakenly built it with a set of 6x-8 heads. He believes chamber size to be around 97cc. He was new to turbos and I dont think it was intentional.

Technically that places my compression over 9:1....maybe even closer to 9 and a quarter to 1. Still, it has been run at up to 15 psi with no apparent detonation on 91 octane. I say no apparent, because who really knows? To be safe I have added methanol injection (uses windshield washer fluid) to the setup and plumbed it to come on with a 760cc/min nozzle at 4 lbs boost. If I've calculated correctly this is probably eqivalent to using around 104-106 octane fuel at that point and hopefully enough with the intercooler to prevent detonation.

Still, its a crapshoot and I'm using bandaids to fix an inherent problem. We'll see as time goes by how effective it is.

On that other note Jeff I had been told and read it wasnt possible to determine static compression from cylinder psi during rotation, but I certainly dont know it all. Would be really cool to know more about that gauge that can do the job! Lets see....if 40 of us coughed up $10 a piece we could buy one! Then we could rent it out at $20 a shot to the performance oriented world and get back our investment in say........30 light years?

LOL
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Old 05-17-10, 09:47PM   #20
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I will take responsibility for that one.LOL

I mistakenly put in one of my posts that I used 124 CC 6X-8 heads. Of course the -8 was the Mess up. I always forget the stamped numbers and what CC they are because my stuff stays together for a while and I look it up when I need it on wallaces site. I cant keep everything in memory too many numbers in the turbo thing.

So anyway I think mark went by the 6x-8 and didnt really look at the CC I had or felt it was a misprint.

So thats how it ended up so high.

Or at least I think thats how.

Mark ???
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Old 05-17-10, 09:49PM   #21
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Quote:
Originally Posted by aronhk_md View Post
Just as a note...and I'm laying my limited experience out for you as a relative newbie to turbos...its not impossible to use the heads you have on there, or for example the 6x-8 heads.

Its scary on a personal level.....I am experiencing that scenario when I use my car because I bought the car from Mark, and Mark I think mistakenly built it with a set of 6x-8 heads. He believes chamber size to be around 97cc. He was new to turbos and I dont think it was intentional.

Technically that places my compression over 9:1....maybe even closer to 9 and a quarter to 1. Still, it has been run at up to 15 psi with no apparent detonation on 91 octane. I say no apparent, because who really knows? To be safe I have added methanol injection (uses windshield washer fluid) to the setup and plumbed it to come on with a 760cc/min nozzle at 4 lbs boost. If I've calculated correctly this is probably eqivalent to using around 104-106 octane fuel at that point and hopefully enough with the intercooler to prevent detonation.

Still, its a crapshoot and I'm using bandaids to fix an inherent problem. We'll see as time goes by how effective it is.

On that other note Jeff I had been told and read it wasnt possible to determine static compression from cylinder psi during rotation, but I certainly dont know it all. Would be really cool to know more about that gauge that can do the job! Lets see....if 40 of us coughed up $10 a piece we could buy one! Then we could rent it out at $20 a shot to the performance oriented world and get back our investment in say........30 light years?

LOL
We already tried the EVERYBODY KICK IN TEN BUCKS thing.LOL

Thats didnt work out to well.
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Old 05-17-10, 09:52PM   #22
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Heres billy mathes' info
BILL MATHES PERFORMANCE ENGINES
79 HAYES STREET BY BILLY THE KID
TORRINGTON, CT 06790 (860)-489-0363

hes the guy with the tester if you want to call him and find out more about it.

I think allot of rouny round shops may have it if they are big into it because they are checked at the track for compression all the time.
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Old 05-18-10, 03:55AM   #23
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I appreciate it Jeff, but I hate to bug the guy just for my curiosity...and he might not appreciate that either.

Funny thing is I wonder why we couldn't do it......20 guys coughing up $20 each and the tool stays in the hands of someone highly trusted. We could probably come up with 10 without even trying.

You Jeff? Paul Spotts? Tom Vaught? Mark Leischer? When I was in special forces we trusted our lives to each other. There are still a couple of guys I stay in touch with that I'd trust my life to. I think I could come up with a name somehow of someone I'd entrust $20 to.

When someone needs it that didnt invest the original $20, it gets loaned out for the cost of shipping and $20, with the idea that it is returned in one week. Yes its a trust thing. The $20 gained from its use goes to a charity. Those who originally bought it can use it just for cost of shipping?

I dont know, maybe I'm just dreaming. I still believe in honor.
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Old 05-18-10, 09:33AM   #24
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Id be up for it and I could even keep it here, and do the shipping for those who need it. I wouldn't mind The problem is getting everyone on board

If anyone is interested in this group purchase post up here.

Maybe I could buy billys cheaper and he could buy a brand new one?
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Old 05-18-10, 09:42AM   #25
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Dont know when I would use it, but I'm in.
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1979 Trans-Am Turbo Charged 535 IA2,
CV 1 heads with convertible exhaust option. 305cc, flowing 405cfm with mild intake port clean up


1979 Silver Anniversary 4 speed, numbers matching.
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Old 05-18-10, 09:48AM   #26
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Its nice to know your ACTUAL compression not just go by math.
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Old 05-18-10, 10:40AM   #27
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Good point.
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1979 Trans-Am Turbo Charged 535 IA2,
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1979 Silver Anniversary 4 speed, numbers matching.
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Old 05-18-10, 11:43AM   #28
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Dont know when I'd use it either, but who knows...

Jeff, since you know the guy maybe you can get more info on it? Like how accurate it is, etc? Maybe his would be available....unless a new one has that many more features that we'd want it.

Also thinking there are a lot of people in the other forum threads that might be interested...........and quality people still over on the other forum too.
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Old 05-18-10, 12:08PM   #29
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Hey guys. I just caught up to the post. The car was originally built with no intention of turbocharging. All original intent was N/A and then nitrous. But with complete street intentions. So the 9.25 compression was a N/A street compromise. When the turbo bug bit (and bit hard, heh)I built a complete 400 for my turbo plans. The engine never got assembled but it is a '73 400, .030 over, I bought specially dished (20cc) Ross forged, with the full expectaion of using those 6X-8s at 97cc. That combination would have put me well down in the mid to high 7s for compression. Also knowing that I would be using a turbo friendly milder narrow CL cam therefore retianing most of the compression I had. As I accumulated the turbo and the guts to put it on, I decided that I would build it on the 455 as it sat to see if I could get a viable system. If all went well I would finish the build on the 400 and swap out the 455. But it ran so well on the 455 using intercoolers to help with any compression issues, I never got the 400 built. The pistons from that 400 are the ones now going into the 389 build. Such is the history behind the present combination. Once I decided to retain the 455 I felt that the higher compression was not a deteritment, as long as you respect it and design your tune for it. You have to remember that the turbo builds compression. The forced induction is what becomes higher compression. I have a stinking suspicion that the aluminum rods may actually have dropped the pistons down further in the hole than I required. I asked that the machinest build the deck height to zero using the rods manufacturing specs as growing .010. Which means the piston should sit .010 down in the hole and should grow to zero deck. I never checked the actual deck height when I assembled the short block figuring that the man knew what he was doing and should be right. During this time my son had graduated college and was working at the speed shop where I had the work done. The machinest had machined my sons 4 valve chrysler 4 cylinder head and had done some really great work on it. So I trusted him. But on the 400 as I do on all my blocks, I had him cut the deck for o-rings. The block sat for several years and one day I decided to install the o-ring wire. It turned out that instead of cutting the grooves to pass next to each other between the cylinders he actuall cut them so the groove matches at the intersection and to lay the wires in you have to cut them to fit, they would not lay next to each other to create a continuous ring. The groove center is the same at the groove intersections. So I wonder when he did the work on the 455, if he was as thorough on the 455 as I thought. The 455 originally had blueprinted cast rods. I added the aluminum rods to the existing TRW pistons (still in the 455) and expected him to machine down the deck to match. I just wonder if they never did a thing and charged me for the decking and I assembled it not checking. After my son having worked there and his eye witness reports of some of the things the owner slipped through and short cuts he did to customers stuff I have to figure the compression is not what it should be. The only good thing is I feel if that be the case, the compression will be lower rather than higher than thought.
So the short answers is, the engine was really designed for N/A and nitrous. Converted to turbo duty. Sorry for the long story. MArk L
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Old 05-18-10, 12:19PM   #30
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See??? Then I really COULD use a shot at that compression gauge that can actually give me a real compression ratio. LOL. I wish I knew how much it has been decked, but I guess no way to know that without taking it apart. Makes me wonder......Sims over on PY sells roller camshaft retainers, but he sells the timing chains to go with it in stock size, and undercut too. What is it that requires you to buy an undercut timing chain?
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