Brainfarting a combo

[Tom Meyer]

The 2002 j bodies came with both a vin 4 push rod and vin F OHC. The pushrod block is steel and comes with a roller cam and rockers with a heavy crankshaft. The OHC block is aluminum, crankshaft is lighter and knife eged and will turn more rpm faster. It also has 1 point more compression. On a wheel dyno OHC motor was 40 hp better. I feel the OHC motor was easyer to get hp out of. Also trans gear ratos are better with OHC stick . Tom

[Billy Nees]

Hi Tom, what intrigues me about the combo is that they came with the 4T40E transaxle. I didn't know that. That gives it the access to the same final drives and low gearsets as the Ecotec. 20 less HP? It might be worth a closer look.

[Tom Meyer]

You are right. TH125,1st 284,2nd1.60 3rd1.0, FD3.18. 4t40 1st 2.96,2nd 1.63,3rd1.0 FD 3.91. Lots more weight spinning in the 4t40 verse gearing in a low hp and toque combo. Some tranny guy could take weight out? 125 is 125 lbs 4t40 is 150. Look what putting a 200 or a pro trans does for the RWD stocker does. But I am looking at paper and you are running a car. Tom

[Billy Nees]

Originally Posted by Tom Meyer

Lots more weight spinning in the 4t40 verse gearing in a low hp and toque combo. Tom

I don't know just how much more rotating mass there would be. Not everything is spinning at one time. One interesting thing that we learned is that the line pressure is adjustable with a laptop! We have taken advantage of that!