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GT2EvoGuy GT2EvoGuy is offline
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Join Date: Jun 2008
Location: Connecticut
Posts: 121
8000rpm bottom end rebuild - what do I need to do?

I want some qualified advice on what I will need to build my 930 bottom end to withstand 8000rpm bursts. Im thinking about having my local builder dig into the engine this winter but before I plunk down any money I really want to get advice from some fellow forum members who are successfully spinning their motors this high.

The engine right now is a 3.4L stroker 930 engine laying down 585whp at 1.2 bar with Motec EFI. The car is still street driven currently, but I ultimately intend to retire it from street service and run it in PCA racing. Id like to build the motor to a higher spec in 2 stages. First stage would be to bulletproof the bottom end and have the heads reworked a bit while retaining my 3.6 plastic intake setup and streetable GT2 Evo cams. The second stage would be to go to ITBs with much larger ports in the head and custom racing cams. In this second stage Id be looking to rev the motor to 8k.

Here are the specs of the bottom end currently:
3.3L 930 case stroked to 3.4L via a 964 crank
Stock rods shot peened and prepped with ARP bolts
964 oil pump
Stock 3.3 P&Cs
Shuffle pinned

This setup with my current heads, cams, intake have been fine for a 7000 redline but obviously above 7000 things have to be changed considerably.

My builder (Auto Associates) is recommending:

*Have the 964 crank race prepped with oiling and other mods (does anyone know what must be done specifically to live at high revs?)
*Motorsport bearings - maybe the ones sold by Smart Racing?
*Carillo rods (is there a specific rod length I should go with?)
*Custom 98mm CP pistons 7.5:1 - the motor will be boosted up to 1.4bar
*Have the OEM cylinders bored and re-Nicked to accept the larger pistons
*Upgrade from 964 to GT3R oil pump

Are there any other things that should be considered re the bottom end of the motor? Looking to get this done right the second time around and be done with it once and for all. Wasted a lot of money by having to go into it a second time
Old 11-26-2009, 08:09 AM
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