67 Skylark 300 Running Bad - Opinions Please

[Guest]

The Situation:<BR>My brother owns a '67 Skylark that run's pretty poorly, especially when hot. He has a new carb, coil, points and condenser. Timing is set at 8-10, we get about 18 hg with a vacuum gauge. We've tried tuning it for months. Still won't run very well, so we are considering getting a valve job done, and putting in a new cam/timing chain/gears. But, before dumping any money into this engine, we decided to do a compression test.<P>Compression Test Results:<BR>1967 300-2 (4 barrel manifold and carb)<P>1 - 140<BR>3 - 95 (120 wet)<BR>5 - 150<BR>7 - 140<P>2 - 190<BR>4 - 200<BR>6 - 175<BR>8 - 190<P>Obviously, we've got a problem. I'm seeking opinions on what to do next.<P>Questions:<BR>We're considering tearing into the motor and throwing in new rings and bearings along with the valve job, cam/timing gears/chain. We are hoping to avoid having any machine work done. Can we get away with this plan, or do we need to crack the heads off and take a look at the cylinders first?<P>We're also considering dropping a 350 in instead, but we might be looking at a similar situation with a junkyard motor. Any advantages with going this route?<P>Any thing I've completely missed?<P>BTW - He does not plan to race this car at all. He wants a fairly reliable and consistent motor with enough power to pass and get up hills without a problem.<P>Thanks in advance for your suggestions.<P>Ron

[Guest]

Without seeing all the "wet" readings, It would appear that you have a few burnt valves as the major contributor to your situation. Rings are probably bad on a few cyls also with a cracked ring a possibilty on your 95 psi cyl.<P>If you only wanted to spend the minimum I would pull the heads and inspect closely, are you getting a lot of blowby? How about plug deposits? Smoke out of the tailpipe?<P>I would carefully analyze the plugs under magnification to diagnose the problem further. Although I still feel a valve job is the primary consideration. Here's a visual guide to spark plug reading not the best but OK,<BR> <A HREF="http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html" TARGET=_blank>http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html</A> <P>Hope this helps.<P>I may be completely wrong, if so please disregard my opinion.

[56Roadmaster]

Hi, I agree<BR> Rings in your low cylinder, as to backyard rebuild, with the price of parts today (speaking from experienece) you are better off doing a complete correct rebuild. Buick parts are more expensive than the SB Chevy. If you are planning to keep the car a while the 1800-2500 you spend is worth it. <BR> think about this you will probably spend up 800 for a junker and unless you can drive it first you are asking for trouble, If you do back yard rebuild you will spend 600-1200 and if the crank is not round and the bores tapered and out of round you are wasting you money because in 10000 miles you'll be back to where you started. and you could replace the car but then you've got to register, inspect and other problems and a decent driver is going to cost.<BR> Finally if you do it right and keep up regular maintenance you will be spending less on the car per year to keep the engine going not mention you could feel confident in taking that out of state trip or the occasional stop light race.<BR> so save your money PAY STRICT ATTENTION to the ENGINE TOLERANCES and do it right once. <BR> PS check out your machinist get references ask guys who have 30K plus miles on engines do them, pick carefully. <BR> My take.

[Guest]

Thanks for your input, guys.<P>I totally forgot to mention plugs. They all looked good. Tan color, if anything maybe a little hot/lean.<P>Any good machine shops anyone can recommend in Los Angeles?<P>Ron

[Guest]

That's a good sign, maybe only a burnt valve. That can make a plug look lean.

[gbiggers]

Too bad your on the other end of the US,,I have a complete, good running 65 3004bl long block in my garage, and would love to see someone get it(cheap) that needs it. It will most likely be scraped, because of space limitations. Glen Biggers, GSCA, BCA member in TN.