2.4T Compression 80 x 6 - ok?
 

I know compression on 2.7, 3.0, and 3.2 motors, but unclear as to what a 1973 2.4T motor should be. The one available to me reads 80 across the board before putting carbs on. Is this acceptable?

Should be closer to 120, but maybe their gauge reads different. Or it could be an engine that is shot and needs a rebuild.

Does it run?

How does it run?

Has it been sitting idle for a long time?

When was the last time it ran?

If it runs and sounds decent, put a few miles on it and then adjust the valves. You may get a different reading.

Yes, it does run. Sat for about 5 years. Run well? That I don't know. Thoughts?

80 is very low. My lawnmower is more than that. I would do a leakdown just to verify. If the 80 is accurate I would expect a leakdown to be over 20% and be VERY close to rebuild time.

My bet is closed throttle plates giving a low compression test.

Did you do the test with the throttle wide open?

With individual throttle bodies you have to have the throttle wide open to get a proper reading. And a fresh battery too.

way too low

- culprits can be bad rings, not enuf pump strokes (6 needed ), closed throttle, weak cranking, or (unlikely) universally and equally leaking valves - a leakdown will tell a story , cold or otherwise

my 2.7 8.5 CR pumps 165 with solex cams - cool block - OAT = 85 at 2800 altitude (readings 2 weeks ago)

I had that engine dyno'd today - it makes 125 rear wheel HP and flat 112 torque curve from 2800 to 6500 rpm with webers and stock distributor curve

Larry I agree with everything you said. But more importantly, I LOVE your signature.

The older I get, the better I was. Just classic!!

Bruce Anderson writes in Performance Handbook 2 that a good 911 engine will show 130-170 psi

our guru Wayne Dempsy's book has a complete procedure outlined on page 14 and uses 150 as an example reading