Compression check OK?

[my5thmopar]

1964 Slant 225. I followed the FSM and here is what I have. First stroke on all cylinders at about 65psi and builds quickly from 2nd to 4th stroke 140psi. If I let it go 6-7 strokes a few more it will hit 155 psi. All cylinders are within 5psi.

Does this engine sound healthy? I didn't really want to rebuild it but, I am considering doing the frame off? I can't see doing any unnecessary repair since the engine doesn't smoke, leak or seem to have any other issues. Craig

 

[CUDA69]

Did you have the throttle plate wide open during cranking? Were all of the plugs out? It might go up another 10 PSI, but that 225 should be fine.

 

[my5thmopar]

Did you have the throttle plate wide open during cranking? Were all of the plugs out? It might go up another 10 PSI, but that 225 should be fine.

Yes, Yes followed FSM. BTW the oil pressure is 47-48psi. And found one bolt missing and one broke on engine mount right side. Also found a drip on bottom of water pump.

 

[my68barracuda]

those are good numbers,
maybe too good to be true on an original 64 motor,
do you know the engine's history?

 

[my5thmopar]

Not sure of history other than odometer says 41K. Truck was parked in 1988 but someone had done a quick restore by recovering seats, doors and did a repaint. Its possible someone may have rebuilt the engine.

 

[BillGrissom]

Excellent numbers, better than I recall measuring on a rebuilt engine. Compression pressure depends on many things besides cylinder sealing, most importantly the camshaft used. Try turning it over by hand, and see if you can feel strong resistance from each cylinder. If it takes >5 sec to leak down (hear the hissing), the sealing is excellent.

A new water pump is $19 w/ free shipping on ebay.

You can't do a true "frame off" on a unibody. To do it on a rotisserie, you would remove the K-frame w/ engine/tranny, suspension & steering, plus all interior. You can find photos here. If only surface rust, you can treat and paint with engine installed. I did, with almost everything in the engine bay removed except the engine itself.