Does anyone out there know what compression readings I should be getting on a middle age 454? I strongly suspect that the route of my oil comsumption problem is valve guides not the lower end. Any experience at rebuilding one of these? Suggestions and comments would be appreciated.
Thanks

Eric, a compression test will tell you more about the condition of your engine's compression rings than the oil control rings. The compression rings can be good, but the oil rings can be tired or sludged up.
A compression guage is not as good as a differential pressure tester. That said, look for something over 100 pounds, but it is more important that all cylinders be within 5 to 10 pounds of each other than the absolute value. You can squirt carburetor cleaner on each intake valve stem while the engine idles to check for a suction leak. There are rubber umbrellas or spring loaded seals that can be installed on the intake valves with the heads in place. With the heads removed, the valve guides can be machined to accept teflon seals. It probably wouldn't be a bad idea to pull the heads and have a valve job done if your engine is high mileage.
How much oil does your engine use? A quart of oil every tankful of gas is not a big deal.

Thanks for the feedback Bill. I just purchased this unit knowing full well that a new engine would be in its future sometime. I picked it up in Seattle and drove it to Portland ME., and it ran flawlessly accept for the Oil consumption. It had 10/30 oil in it when I picked it up (Way to thin for the heat in these engines), and 20/50 by the end of the trip. One Qt of oil every 200 miles dissapeared, no leaks, no smokeing. the compression check came out: 167/170, 160/160, 156/160, 154/160. I have changed the PCV valve, oil and filter, and added a pint of additive that I use in some real tired diesels that I own, but I have not run it enough to really see what it is doing. I will be taking it to NY next weekend so I will get a better idea of what is going on.
I guess the question I am looking to answer is; new motor or full rebuld, or just the top end of this one. Any input would be greatfully appreciated. Oh yes it has 76,000 on it.

[This message has been edited by eric (edited November 24, 2001).]

Let's see, a quart of is one dollar every 200 miles. At 7 mpg, at 1.10 per gallon, gas is $31.42 for 200 miles. So your oil consumption is adding 3% to your petroleum consumption. Of course, you are polluting a bit, but perhaps not as much as a jet ski, snowmobile or leaf blower.

With that kind of compression, your bore is probably pretty good, as are your compression rings. I don't know what kind of additive you are using, but it may loosen up the sludge in your oil rings if there is any there. Give it time.

That said, a valve job seems like a good idea. Do the carb cleaner down the valve stem thing. Listen to the engine and have a spotter watch the exhaust. Will you be doing your own work? If so, you can drop the crossmember and front suspension to remove the pan. Then push the pistons out and re ring them, mike the crank and replace bearings. You can get .001 .002 etc undersize to take up a little wear. Be sure to ream the ridge before pushing the pistons out. Then mike the bore for taper.

This should give your engine a new lease on life, and you will know what you have. Confidence is a wonderful thing.

Eric, I should mention that plastigage is best for checking main bearing clearance with the crank installed. It is hard to mike main journals installed.

Thanks for the advise Bill. I am mechanically inclined enough to cause real damage. >grin< But I have lots of friends and a real big heated garage. I think we are going to use your methodology for a blue print to do the job.

Thanks, Eric