Blue smoke upon shift

[brucejohn]

I am noticing a puff of blue smoke as I let out the clutch and accelerate upon shifting and upon start up in the morning. I assume rings? She does not use a lot of oil in my opinion, a quart every 1,000 miles or so.

My vacuum gauge reads steady 18 (inches) at idle. Drops to 1-2 at snap acceleration, rising back to 18, jumps to 23 upon release and returns to 18 again at idle. The ranch is at almost exactly 2000 feet above sea level.

Haven't pulled the plugs to check compression yet.

[gudjeon]

With vacuum readings like that, I wouldn't worry too much. Likely valve guide seals letting oil in under high vacuum situations. Like sudden closing of throttle and going downhill under deceleration. I have seen motors go 60-80,000 miles running like that. Try a synthetic oil, it sometimes helps. I know if I use too light a viscosity, even a freshly rebuilt 2.25 will puff the odd time.

[brucejohn]

Thanks gudjeon! That is good to hear.

My helper (my 11 year old I hope loves tinkering as much as I do) and I did a compression test this afternoon. My inexpensive gauge picked up at Napa recently has 5 inch increments and that needle moves fast, too fast for my eye, but each appeared consistently near 130#.

If the gauge is accurate 130# would be toward the low side for an 8:1 head, right? (I assume she has an 8:1 head as the block serial number starts with 361... and I believe it is the original head).

Any thoughts appreciated, though I think for an almost 30 year old engine that as far as I know has never been gone through she is in good shape.

[gudjeon]

I would leave well enough alone at 130. Unless you plan on taking it apart for other reasons like making unleaded conversion. Near 100, or wildly uneven among the four, then I would be concerned.

[brucejohn]

Thanks again Gudjeon.

I guess next adjust tappets and then timing, points, etc..

I appreciate your help.

[marsjess]

I think if you have a 8:1 the number 8 is stamped on the head across from the carb. Mine is a 7:1 and has a 7 stamped there. It is also a 74 rover which I think should have had an 8:1 so better check.

[brucejohn]

I think if you have a 8:1 the number 8 is stamped on the head across from the carb. Mine is a 7:1 and has a 7 stamped there. It is also a 74 rover which I think should have had an 8:1 so better check.

According to what I have read there are heads that have the flat dog next to the carb, without a stamp. These heads could be either 7:1 or 8:1. Supposedly all heads have the compression ratio on the side, but I have yet to locate same. My engine block serial number is one that was originally built with an 8:1 head.

Part of the fun is fitting the pieces to the puzzle together. Thanks for your thoughts, keep them coming.