Recent content by efi-diy

For all things 4200 performance related https://sites.google.com/view/vortec4200wiki/home

Only with forged custom made pistons and the increase in skirt length is about 1.5mm. GM fixed the piston slap issue with the 06 up connecting rods that have a oil squirter hole in them. But to ensure proper oiling the crank needs to be cross drilled.

We now have billet flywheels with ring gears in stock.

We have these in stock. emtechmotorsports.com

Quick update - due to popular demand MT flywheels are in stock.

It all looks good. This should improve the exh flow by 50 cfm to 210 cfm based on my prior flow testing.

The 06 up cranks are not fully counterweighted and cause a dynamic loading issue on the rod bearings (beats the piss out of the rod bearing)- I know this first hand. Once I changed to an 05 crank the problem went away. The 05 crank can be machined to accept the 58t tone ring from a 08/09 crank...

If you open the rod bearing clearances to 0.0021/0.0023" and run the BHJ damper + external oil feed - much better chance to get the engine to live.

Best way to get hold of me is email info@emtechmotorsports.com

There are a number of MT flywheels from the group buy available. (as of Dec. 2020) check on the FB page https://www.facebook.com/groups/1964263467156690 for details. Flywheel has a dual clutch bolt pattern for the pressure plate - colorado 5 cylinder and 10.5" SBC.

The '02 pan had factory installed baffles.

I don't come in here very often - but this thread has some useful tidbits. If your going to lean hard on the 4200 - the external oil feed to the main oil gallery is good insurance. Also 1 person (not me) on the 4200 facebook page is trying get a min order for billet cam blanks together.

Call and ask......

What 4200 cams - call bullet cams - they are spendy but add a ported head and cams + good exhaust == 400HP NA.

4200 flywheel These were never releases by GM. The ring gears are not available in USA. This is your chance to get a MT flywheel.