Well, i just bought a build h22 short block and i've realized that three of the cylinders are bored over .0040, which i knew about, but one of the cylinder is bored over .0051!!! Now, my tuner, who is putting in the engine, told me that the cons of this mistake is that:


1.) AT start up, the engine will make some noise> I have to wait for the engine to warm. He told me once the motor heats up, the metals will expand and eliminate the .0011 difference in that one cylinder.

IT MAKES SENSE, BUT IS SAFE OR WILL THE MOTOR GIVE UP ON ME IN TWO MONTHS


Modified by peakboosth22 at 1:19 PM 8/29/2006

 

So your tuner says it's ok to have .010" extra piston to wall clearance in 1 hole?

 

hE SAID that it is definitly not ideal or recommended, but he said that it should be o.k

 

Well what's the piston to wall clearance on the rest of the holes? What pistons?

 

wtf, 10 thou is way too much, expansion will not make up the difference.

 

im not sure about the clearence, but the pistons are .40 over arias pistons with 9:2 compression ratio

 

ask ur tuner how he plans on building compression in a sleeve thats .50 over and a slug thats .40 over? blowby anyone? mass oil consumption perhaps? n/a ur rings will b in danger and they dont stand a chance against boost. just lookin out man, i dont want ur pride and joy to give out a couple months down the road. just my $0.02

 

Basically, it's a very bad idea, don't do it...

 

to tony1 for the backup

 

um..who bored it for you? thats messed up shop work man..get ur money back...

no dont run it like that. get them bored out the same and get new overbored pistons.

 

I had a kid with a build D series come in for a tune one time. I did a compression test prior the tune and cylinder 3 read 30psi or 40psi lower for some reason than the other cylinders if I remember correctly.

Anyways, I tuned the engine and on top of the other 10 problems the car had it did so-so on the dyno. The engine then spun a bearing about 6 weeks afterwards then he had me come over to inspect the block. Immediately I looked at the number 3 cylinder and for some reason the piston looked funny. It turned out he was running a stock bore piston in a 20 over wall in cylinder 3. He failed to mention to me prior that he dropped a single piston on the install and had to order a new one. He ordered the wrong one and didn't notice it upon assembly, lol.

So yea it will run... but it's probably the dumbest thing you can do.

 

SOOOORRRY guys!!!!


That one cylinder has been over to .0052 as comared to the other three cylinders, which are at .004

Now, will this contrast cause a problem or will the engine be o.k

 

All around it is just a terrible idea and more then likely you will have major oil consumption. WHy would you even take the time to put a motor together you know is not right? I would take it back to whereever you got it machined or bought it from and get your money back and start with a fresh block. .012 is even worse the the .010 in the original post.

 

no, it's not the difference is not .012. Its .0012

 

Im pretty dure that you added one to many zeros in there, Cylinders are usually bored in .010 increments. I dont even think they sell pistons in .0040 oversizes.

 

I'm not trying to be a ********... but you really need to have someone who knows what they are doing assemble your engine. Seriously, your machinest/builder is having you scour the internet for info that he should already know. I doubt he is even going to check your ring end gap, bearing clearances, etc.