I am trying to decide whether I should bore my ZC block .02 (.5mm) over with my turbo setup. I am weighing between the advantage of having a clean bore for 75.5mm pistons and the fact that I am loosing material that would help with strength. I will be boosting between 10-12psi. I can use 75mm pistons, but I already have 70K on my ZC (D series) block, and I am concerned that the exsisting wear is enough to create a less than perfect seal. All opinons are welcome. Thank you.

 

you'll be fine, its not much off, but if you really wanna keep most of the sleeve there just go and flex hone it. I say save up for resleeving job

 

Sorry for posting in both forums.... here is a continuation.

Have you been boosting on your stock cylinders? If so, you probably need to bore to get good ring seal again. Not sure how that can affect the strength of your stock bore, however. You certainly would not want to go any larger than 75.5mm on a boosted block.

Yes there is about 10k boosted miles on the non-built block already with a 92-95 greddy kit. I am switching to an Apexi kit and building a bit (rebuilt head P&P, JE 9.1:1 pistons with stock 75mm bore or the same with 75.5mm bore, eagle rods, zdyne ecu and 450cc injectors, walbro fuel pump)
I have been leaning towards getting it bored to get a good seal but started to be concerned with the strength of the block @ 12 psi. I think it will all be OK with the proper tuning, but I wanted to see if some others had an opinon on this from experience.

As far as resleeving I think I will wait untill I am using a B series motor. I want the D series ZC to get 200+ whp and then just keep it tuned and drive it a lot. I'm not sure if it's woth it to invest in the D any more than what was mentioned.


[Modified by azulito, 6:38 PM 2/6/2003]


[Modified by azulito, 8:19 PM 2/6/2003]

 

You should be able to boost more then 10-12 psi if your bottom end is built and your top end is as well. More like 15-17psi with built internals and correct fuel management.

Blaze

 

It seems to me that 15-17 psi on my ZC would be a bit optimistic without more building than I mentioned. At the most when the block is at the machinist getting bored I might have the crank and flywheel balanced and maybe the pistons and rods as well, depending on cost. It's all a matter of priority as to where to spend the budget. Neither have I heard of anyone trying to run that IHI/Apexi turbo that high yet.

 

I'd get a bit nervous with those boost levels on stock sleeves too, but I suppose if you're tuned properly and not detonating it should be OK.

 

What 1/4 mile times do you think you'll get with that kind of boost on a zc?