.030 overbore.....good? bad? do's? donts?

[Dub4Life]

Long story short, blew a motor and need a new set of pistons, i am redoing the bottom end again only this time i was thinking of going with a .030 overbore instead of the .020 JE's i had. Just wondered if this was a bad idea in terms of cylinder wallss, cooling etc. Any input is greatly appreciated.

Side notes, i am running the FP3052 and will be working towards 20-23 psi on pump. Didnt know if that might have an effect on wall thickness and heat etc....

Mike

 

[RuBiCaNT5X]

I am no expert on the subject, but a .020 might be a better choice... If your cylinder walls go south after this rebuild, you can bore them out again to .030 and get a fresh start... .040 is pretty much the bleeding edge so you are still in good shape with the .030..

 

[Suparata]

I believe he already has the block .020” over and needs to go to the next size over available, right? You will be perfectly fine with both .030” or .040” over so don’t worry about it; it’s really a matter of which pistons you want to use.

 

[RuBiCaNT5X]

I believe he already has the block .020” over and needs to go to the next size over available, right? You will be perfectly fine with both .030” or .040” over so don’t worry about it; it’s really a matter of which pistons you want to use.

I guess I misread what he said... Oops... I'll shut up now..

 

[Dub4Life]

yeah, the motor now is .020 over and my friend has a set of pistons that are .030 over and will give them to me cheap...brand new. So i figure i can save some cost and take them from him as long as i wasnt going to run into any issues with going .030 over. Thats why i wanted to post here to see if there was anything i should be aware of before doing it.

Mike

 

[eclipsegs98911]

yea man go .030 over you will be fine. i would never go .040 over just because I feel it is too much with the pressure we build in our engines at 20lbs of boost

 

[Dub4Life]

yeah, thats what i am pretty surei will be doing. I called the shop today and they are going to disassemble and reassemble the bottom end and bore and hone the block for 185 bucks. I will be doing new bearing all around and they are going to check clearances and all etc. So i am jumping on top of this since i was expecting hte price to be much higher.

If there is any other input, all is appreciated.

Thanks guys

Mike

 

[gritsak]

with a .030+ overbore..has anyone ever looked into seeing if the head also needs bored out? an overbored block with the flat part of the head in the cylinders can cause hot spots -----> detonation..worth checking out before a problem comes up

 

[Dub4Life]

hmmm....never crossed my mind...i guess its possible....anyone hear anything about this? My head is bored .020 over from the last time so i'll assume that the difference would be .010. But assuming is never really a good thing.

 

[BlackTalonSi]

Dub4Life, where exactly in FL are you located???....I'm fixin' to have my block rebuilt, and $185 sounds pretty good to me as well....I'm in south GA, a hour or so from the FL line, so it may be worth the drive...let me know on this thread or PM me.....thanks man