Over bore pistons

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bblock383

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Ok guys got a question. My engine is in the shop and guy is sayin im gonna have to bore my block. 040 over. I had a thought about maybe using different pistons instead of over size slant 6 pistons. Im planning to go turbo and uve heard stock replacement pistons aren't as good as the stock pistons. The idea I had was maybe using 2.2 turbo pistons. They will fit the new bore size perfect (3.44) and I know guys use these pistons on the long rod setup.
My questions are: will it be any cheaper using 2.2 pistons?

Will they fit on a 225 rod?

Will the compression ratio take a nose dive?

Any help would be be appreciated. Thanks.
 
ok for a turbo set up you have to choices... use the 2.2 turbo pistons or weisco pistons... the problem is they both take the 198 rod (longer than a 225 rod)

K1 makes the rod to fit for this swap...

obviously you do have other choices in pistons but i think past those two they would have to be custom...

also so you know slants can be bored over .140 and decked .100 on both the head and block... just to let you know where you have adjustment!
 
So kid are you saying the 2.2 piston will not work on a 225 rod? What exactly is the issue with the 225 rod that it wont work? I just figured if anything using the shorter 225 rod would just make the compression drop since the 2.2 piston is shorter.
 
Pishta I understand that there is a length difference. Im wanting to know if the 2.2 piston is compatible with the 225 rod. And if the compression will drop below the stock slant compression ratio. And if it will work would it be cheaper or close to replacement stock pistons?
 
bblock383 said:
Pishta I understand that there is a length difference. Im wanting to know if the 2.2 piston is compatible with the 225 rod. And if the compression will drop below the stock slant compression ratio. And if it will work would it be cheaper or close to replacement stock pistons?
Click to expand...

lol the stock compression is 7-8:1... with the piston anywhere from .140 to .210 down in the hole... also cc's of the head ranging from 54-58...

so if you do the math as me an SS were doing a little bit ago a 2.2 on the longer 198 rods/54 cc head gives you around 10:1 comp...

using 225 rod you would be -.3xx in the hole... or NO compression... so the 225 rods will kill your comp...

you can buy pistons from summit, stock style up to .080 over bore... im using the .080's with total seal rings and spin my motor to 6 grand... running 14's... and they are 12 bucks a piece!

BUT you said your looking for boost safe pieces so i didn't bring them up...

hope this is the info you were looking for
 

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Yes kid that's what I was looking for. Well it was an idea anyway but that's why I asked first before I did it. Im wanting something like the stock piston as it could take boost fine. Someone on the. Org I believe said that replacement pistons aren't as tough as the factory pistons.
 
bblock383 said:
Yes kid that's what I was looking for. Well it was an idea anyway but that's why I asked first before I did it. Im wanting something like the stock piston as it could take boost fine. Someone on the. Org I believe said that replacement pistons aren't as tough as the factory pistons.
Click to expand...

well the stockers are tin/aluminum cast... i know they can take a 125 shot for seasons... not on mine but ive seen it on the same pistons...

if your going boost just build it right and dont worry about it... or go NA and not worry about it lol...

this is the time to chose, at the beginning... as bill will say you can go really fast with a turbo slant. true... cheaper yes... guy running 12's on a STOCK bottom end, including pistons... think 21 psi lol
 
Shaker223 said:
good luck!!!
Click to expand...

Thanks, Tom. It;s 10:00 a.m., and already 88 degrees here... heading for 98, probably, and the car is now outside, so we MAY wait for a cooler day... we'll see.

Have you ever heard of this place: http://www.machdevelopment.com/page/page/238503.htm

It's a coating outfit that coats cams and lifters with a ceramic that apparently has much the same anti-wear properties of the Schubeck lifter lifter face material, and supposedly is impervious to the high unit loading damage incurred at the cam/lifter interface.

I have another cam here from Comp that is a 220/230 unit, and I may send it in for treatment (along with a set of lifters.) They charge $150 each, so it would total $300.00 (for the cam and a set of 12 new lifters.)

What do you think?

Kid; isn't this in your backyard???
 
Bill Dedman said:
Thanks, Tom. It;s 100:00 a.m., and already 88 degrees here... heading for 98, probably, and the car is now outside, so we MAY wait for a cooler day... we'll see.

Have you ever heard of this place: http://www.machdevelopment.com/page/page/238503.htm

It's a coating outfit that coats cams and lifters with a ceramic that apparently has much the same anti-wear properties of the Schubeck lifter lifter face material, and supposedly is impervious to the high unit loading damage incurred at the cam/lifter interface.

I have another cam here from Comp that is a 220/230 unit, and I may send it in for treatment (along with a set of lifters.) They charge $150 each, so it would total $300.00 (for the cam and a set of 12 new lifters.)

What do you think?

Kid; isn't this in your backyard???
Click to expand...

yea its about 40 mins away from the looks of it...
 
Glad to see you back Bill. One question on the Heads. What did you do to them?
 
805moparkid said:
lol gotcha... bill never told us what he did to it...
Click to expand...

When Fred and I started this /6 turbo project, we were fortunate to have some really good luck in several ways; one was to happen across a ported, big-valve cylinder head on ebay.. Buying a pig in a poke, for sure, but I went for it ($700.00) and when it arrived, I took it to my machine shop for analysis, and the head min there, said it was an A-1 porting job and that the valve job was a good one, so I had him check the casting for straightness (it was less than a thousandth of an inch "out") from end-to-end, so it didn't get milled. With shipping and the machinist's inspection and stamp of approval, it cost me about $900.00, which was about what I'd expected to pay for a workable race head.

The engine block was an engine that had never had the head off (never rebuilt) and had been in storage for 35 years (!), so we didn't deck (machine) any off the top of the block, either, (it was still "flat,") so compression should be optimal, with flat top pistons from Wiseco .167" down in the block.

I CC'd the head, added the gasket area dimensions and came up with 8.8:1, just about perfect for a turbo motor.

We're going to try to start it this weekend, if the weather will cooperate (and, when did that that ever happen???)

The valve clearance recommendation from the cam grinder (BULLET CAMS) for clearance is .016" for both intake and exhaust, HOT and running. We can't DO "hot and running" because we're starting the engine for the first time ever, and breaking in a new cam at 2,500 rpm for 30 minutes.

So, we'll have to set them cold. We were wondering what happens to the valve clearance in a slant 6, going from stone cold to hot.

Anybody got any information about that??

If we knew that we could set the valve clearance cold, with some confidence.

Anybody????
 
Bill Dedman said:
When Fred and I started this /6 turbo project, we were fortunate to have some really good luck in several ways; one was to happen across a ported, big-valve cylinder head on ebay.. Buying a pig in a poke, for sure, but I went for it ($700.00) and when it arrived, I took it to my machine shop for analysis, and the head min there, said it was an A-1 porting job and that the valve job was a good one, so I had him check it for straightness (it was less than a thousandth of an inch "out") from end-to-end, so it didn't get milled. With shipping and the machinist's inspection and stamp of approval, it cost me about $900.00, which was about what I'd expected to pay for a workable race head.

The engine block was aan engine that had never had the head off (never rebuilt) nd had been in storage for 35 years (!), so we didn't deck (machine) any off the top of the block, either, so compression should be optimal, with pistons from Wiseco .167" down in the block.

I CC'd the head, added the gasket area dimensions and came up with 8.8:1, just about perfect for a turbo motor.

We're going to try to start it this weekend, if the weather will cooperate (and, when that that ever happen???)

The valve clearance reccommendation from the cam grinder (BULLET CAMS) for clearance is .016" for both intake and exhaust HOT and running. We can't DO "Hot and running" because we're starting the engine for the first time ever, and breaking in a new cam at 2500 rpm for 30 minutes.

So, we'll have to set them cold. We were wondering what happens to the valve vlearance in a slant 6, going from stone cold to hot.

Anybody got any information about that?:-?

If we knew that we could set the valve clearance cold, with some confidence.

Anybody????
Click to expand...

did you get any flow numbers out of the head?? or pics?? i know your in boost but if its got bigger ports it will take more to fill them...

i just set mine .003 loose for inital startup, but i think mine tightened up about .004 if i remember...
 
805moparkid said:
did you get any flow numbers out of the head?? or pics?? i know your in boost but if its got bigger ports it will take more to fill them...

i just set mine .003 loose for inital startup, but i think mine tightened up about .004 if i remember...
Click to expand...


This is not an NHRA Stocker. This may be a revelation to you, but we are not made out of money, and our original intention was to build a car (turbo /6, early A body) out of junkyard parts, not buying anything new, for UNDER $2500.00.

We failed miserably, of course, but Ryan and Tom's cars were so DANGED appealing, that we decided to try to follow their lead, and at least, give the thing a chance, with the K-1 rods and the Wiseco piston/ring setup.

Buying a new tranny, converter, 8.75" rear, Cal Tracs, a roll bar, tubular front suspension, wheels and tires ($400.00 worth of slicks,) a $1,000.00 homebrew header, disc brakes for the front, and the fuel and ignition systems pretty much broke the bank for 2011.

We'd LOVE to send this head to Mike Jeffries for some meaningful flow bench analysis, and see how much he could improve it, but to tell you the truth, a new ball bearing turbo would probably do more for it than whatever improvements he could implement, and probably would cost about the same. Our turbo, though new, isn't the last word...

If we were rich, we'd do both! :)

So, no, we just took our machinist's word on the porting job on that head (he builds lots of race engines,) and will run it as is and hope for the best. If it's NOT "fast," we'll just crank up the boost... LOL!

That's what I love about bracket racing; no pressure to perform at any particular level... just pressure on yourself.:-?
 
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