Will 0.020 over bore on a gen 2 be ok?

[Wheysted]

Have a gen 2 0.20 over bore
Has Modular head shop cylinder supports
Will be pushing around 900hp

Is this a bad idea... or is 0.020 still safe enough with cylinder supports?

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[WildHorse]

2/10 of a inch ? Umm no. Now if you meant .020" as long as you can get pistons ur golden.

 

[Wheysted]

2/10 of a inch ? Umm no. Now if you meant .020" as long as you can get pistons ur golden.

O yea, .020 thanks

 

[Jackson1320]

I built these block all the time at .020 but that is considered the limit. I have built them at .030 but for a close to stock rebuild. Just remember you at your limit next time you will need another block

 

[Wheysted]

I built these block all the time at .020 but that is considered the limit. I have built them at .030 but for a close to stock rebuild. Just remember you at your limit next time you will need another block

Do you think the cylinder supports will do their job? Did you have success with your blocks at .020?
Really don't want it to crack after doing 1 pass haha

 

[Jackson1320]

I have a .020 over gen2 with cylinder supports right now making over 900 wheel. I can’t say it will be fine because I didn’t build it. If you have problems It most likely will not have anything to do with the cylinder thickness

 

[Wheysted]

I have a .020 over gen2 with cylinder supports right now making over 900 wheel. I can’t say it will be fine because I didn’t build it. If you have problems It most likely will not have anything to do with the cylinder thickness

Thanks for the input appreciate.. that makes me feel better at least haha

 

[Angrey]

If you're sleeving, absolutely. I don't see how you're going to bore it if you're not, because sending it off to have it plasma coated would be interesting/costly.

 

[NASteve]

If you're sleeving, absolutely. I don't see how you're going to bore it if you're not, because sending it off to have it plasma coated would be interesting/costly.

Gen 2 block not Gen 3.

 

[Angrey]

Gen 2 block not Gen 3.

I'm not understanding. They're both plasma coated. If you bore it, you're removing the plasma coating so unless you're gonna recoat it, you have to sleeve it.

 

[NASteve]

I'm not understanding. They're both plasma coated. If you bore it, you're removing the plasma coating so unless you're gonna recoat it, you have to sleeve it.

I don't recall Gen 2 having the coating sprayed in, I think that was a Gen 3 block only.

 

[Angrey]

I don't recall Gen 2 having the coating sprayed in, I think that was a Gen 3 block only.

Indeed you are correct. Must have factory sleeves, which I guess would be okay to bore slightly. Obviously the proper way would be to yank the sleeves, bore the holes and then install slightly larger sleeves (to maintain the sleeve wall dimension).

 

[Jackson1320]

Indeed you are correct. Must have factory sleeves, which I guess would be okay to bore slightly. Obviously the proper way would be to yank the sleeves, bore the holes and then install slightly larger sleeves (to maintain the sleeve wall dimension).

What makes this the proper way? They sell over sized pistons for a reason. There’s no reason to sleeve until the are past.020 and in that case it is cheaper to just purchase a new block

 

[NASteve]

Indeed you are correct. Must have factory sleeves, which I guess would be okay to bore slightly. Obviously the proper way would be to yank the sleeves, bore the holes and then install slightly larger sleeves (to maintain the sleeve wall dimension).

Min over bore like the OP is discussing is OK, but to cut out the old sleeves and install aftermarket ones isn't cheap, unless he is going to really push it which doesn't sound like it then he will be OK. Anything over 4 digit wheel HP I would sleeve the block, at that point its just a matter of time before the factory block with factory sleeves fail.

 

[Angrey]

Min over bore like the OP is discussing is OK, but to cut out the old sleeves and install aftermarket ones isn't cheap, unless he is going to really push it which doesn't sound like it then he will be OK. Anything over 4 digit wheel HP I would sleeve the block, at that point its just a matter of time before the factory block with factory sleeves fail.

So it begs the question, if you're not going 4 digit power, what's the point of going .020" over? What are you really gaining? Unless you've gotten some steal of a deal on pistons that are overbore (even then) I don't see the point in it unless you have big big plans and are trying to squeeze out every last drop of power.

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