Overbore Z129 kits

pudland · Jul 31, 2020

Hi all!
Just got a '52 TO-30(wifey got it for my bday)...

Looking at overhaul kits and they all say overbore to 3 3/8". I have a few questions so thanks in advance.
1) Why are they all overbore instead of stock?
2) I take it that's boring out the cylinder wall for a larger O.D sleeve?
3) If the blocks not already cracked (which I read they are prone to)... Will boring seriously weaken the block?

Thanks sooo much!
Adam

Dieseltech · Jul 31, 2020

No block boring needed, the wet SLEEVE is thinner...

pudland · Jul 31, 2020

Thanks!

Not sure if that's good or bad though.
Thats like an 1/8" added to the combustion chamber volume. I'll have to do the math but I wonder if I have to "tune the carb" to make up for the added volume....

Thanks again!

Bruce(OR) · Jul 31, 2020

Bolt it on and see what you get. That carb has already been tuned to make up for weaker compression for how long?
Once it is running, then look at it.
If it ain't broke, don't fix it.

pudland · Jul 31, 2020

(quoted from post at 19:12:49 07/31/20) Bolt it on and see what you get. That carb has already been tuned to make up for weaker compression for how long?
Once it is running, then look at it.
If it ain't broke, don't fix it.

True true.... It's not like it's a 4bbl right! 🤣

Bruce(OR) · Jul 31, 2020

4bbl about 600 CFM good for most engines. Bigger carb generally needs a bigger cam and larger valves don't hurt either. Whereas there is no
replacement for displacement, you still need gears for go. Hence the newer vehicles with transmissions larger than the engines.
Here's your 2.0 with a turbo and a 10 speed trans. Hit your power band and shift all the way up.

Overbore Z129 kits

pudland

New User

Dieseltech

Well-known Member

pudland

New User

Bruce(OR)

Well-known Member

pudland

New User

Bruce(OR)

Well-known Member

Similar threads