Help me build a motor for my '72T part two: P&C's/Cams

[jim72911t]

Hi all,

Some of you may have seen my earlier post here:

help me build an engine for my 72T. 2.4? (2.7?)

Quick question about pistons and cylinders: Does anyone know whether 2.2T P&C's can be used in a 2.4 with E cams? (BTW Wayne, I'm using the chart in your rebuild book as a guide, but would replace 2.2E P&C's with 2.2T P&C's) I am looking for the compression boost they would provide but am concerned that the valve pockets would not be deep enough for the higher lift E cams. The car would retain MFI. If the valve pockets are an issue, is there sufficient material to deepen them slightly?

The reason I'm curious is that the rebuild budget has been pinched a bit due to a recent decision to buy my first house. I've located a good used set of 2.2T P&C's for a great price, and I'd like to get the motor together with a slight performance boost, before the move. The 2.7RS spec motor I was planning will have to wait a couple of years

Thanks,
Jim

[rvanderpyl]

I would think you would be OK with T P/C as the lower compression ratio from these is due to the lowered piston height. However you are going to have fun trying to figure out your jetting if you are running Carbs, and if you still have your MFI it might not match up very well.

[BK911]

The 2.2T pistons in a 2.4E will give you about half a point increase in CR. But the pistons weigh a lot more. I can't remember how much more and if this will negate the performance gain from the CR increase. Regardless of which pistons you use, check all clearances.

[jluetjen]

If you have a set of calipers and a straight edge you should be able to get an idea of how space you have. The other option is to build up one cylinder with the heads and valves on, but no cam. Put some clay in the area where the reliefs are and turn the engine over once. (BTW - leave the spark plug out so that it will turn). Alternatively you can put the piston at TDC and the using a micrometer measure how much each valve can move down with finger pressure.

I doubt that the difference in CR will make a huge difference to the MFI -- I suspect that you could adjust around it using the part throttle adjustment. If you were to use carbs, it should be even less of an issue.Here's a thread that contains a lot of different weber configurations. If you look at the successful combinations, I'm somewhat surprised by how they don't vary a whole lot.