2.4 valves hit?

[marine sniper]

I have a 1973 T bottom end with Schmidt 84.97mm pistons and cylinders and 73 E heads and cams installed. All 6 exhaust valves hit the pistons exactly at the small releif cut. The cam timing is at 2.7mm. No known work ever done to the bottom end. Any thoughts on the obvious?

[Tim Walsh]

you can't clear E cams with T pistons or S cams with E pistons etc. shaved heads will do it as well along with a few other things. hmm.. what cams are you running and what pistons? Was this motor running or are you just now building it?

[marine sniper]

Sorry for the size on the pistons. The are the cast iron Schmidt 83.97 original T Cylinders /pistons and the cams are the 73 E cams.

[Tim Walsh]

AHH that would do it. You can't clear E cams with T pistons. A machine shop can deepen the valve pockets for you for not a whole lot of money (well under 200)

[marine sniper]

This was put together by some other person to replace a stock 73 T engine that had blown up. I thought the valves would hit, however I was told by this person that you could put any combination of 2.4 T E and S parts together . So E cams will hit T heads and S to E etc?

[Tim Walsh]

Yes they will hit if timed properly. You CAN get away with timing them in some unusual way that they won't hit but your powerband will be way off. That's just what I've heard though. The official line and my experience is you can't run T pistons and E cams.

[911parts]

Last summer I built a nice running motor with 2.2E piston with S cams, using E cams will also work but if your building the motor you have to improve the 7.5:1 compression of those 2.4 T pistons