midman Posted October 17, 2016 Share Posted October 17, 2016 I might be opening up a hornets nest but I want some opinions on the racket my engine makes. Here is some history. I bought the car 4 years ago. It had been sitting since the mid 60's supposedly after an engine rebuild. When I got it it needed a cosmetic restoration after a halted one. The engine ran well and quiet. I drove it around for a short distance and the car overheated. I shut it down as soon as I noticed the temperature spiking. A rebuilt radiator fixed the overheating. Fast forward to me finishing the cosmetic resto along with replacing all tune up parts. I struggled with the dual point setup a little and still am not comfortable with the second set of points. I can get them close but there is not enough adjustment to get them perfect. Anyway it starts, runs and after some tweaking of the carb does not backfire anymore but it sounds like a freight train now. All cylinders are right around 60 pounds, good oil pressure at idle. I know I have a small exhaust leak at the butterfly valve (I welded shut the pipe but there is blowby around it), but the noise sounds more to me like valves (though my compression is good). It is quieter at start up and gets louder as it warms up. The engine is filled it with 30 weight oil. I uploaded a YouTube video and would appreciate any help with diagnosing the problem. Thanks Link to comment Share on other sites More sharing options...
Grimy Posted October 17, 2016 Share Posted October 17, 2016 Valve lash within spec? Getting oil to rocker arms (remove cover and check while it's idling)? Oiling to roller lifters? Play in those rollers? Have you had pan off to verify it's clean? Link to comment Share on other sites More sharing options...
edinmass Posted October 17, 2016 Share Posted October 17, 2016 (edited) Nice car. Idle is way too fast. Disconnect the fan and idle it down very low, it's easier to identify the noise. Make sure it doesn't overheat. Then repost the video with the motor at a slow idle. From your video it sounds like valve noise. I am not familiar with this vintage Buicks valve adjustment. I would as the Buick boys in the Buick section of this Fourm. Is oil getting to the top end? What series is it? 60 pounds of compression seems low to me for a Buick, I would have thought 90. Edited October 17, 2016 by edinmass (see edit history) Link to comment Share on other sites More sharing options...
Grimy Posted October 17, 2016 Share Posted October 17, 2016 Ed, compression ratio is about 4.5 to 1, if memory serves. At sea level (14.7 psi) that would be 66 psi OPTIMAL compression at cranking speed. As I recall from my 1934 Buick (subject to correction), the rocker arm oil feed is through a small diameter fitting and line entering the rear of the rocker shaft. That oil supply route should be verified to be clear, as it can easily be clogged. Link to comment Share on other sites More sharing options...
Spinneyhill Posted October 17, 2016 Share Posted October 17, 2016 Hopefully non-detergent oil isn't behind the problems. Link to comment Share on other sites More sharing options...
edinmass Posted October 17, 2016 Share Posted October 17, 2016 (edited) I checked the compression chart posted a few weeks ago, range for a 31 Buick is 63 to 70 pounds, mid thirties it climbs up to 100. Edited October 17, 2016 by edinmass (see edit history) Link to comment Share on other sites More sharing options...
midman Posted October 18, 2016 Author Share Posted October 18, 2016 Thanks for the input so far. To answer some of the questions: It is a 90 series, I had checked the oil feed when I first put the car back together and I was getting good flow but I'll check it again this weekend. The idle was up by hand throttle, actual idle is much lower. I had the pan off and the bottom end was spotless which led me to believe the engine build story, or at least someone cleaned it up 50 years ago. I had not checked valves yet, so I'll check them this weekend as well. Ill post what I find, thanks again. Chuck Link to comment Share on other sites More sharing options...
midman Posted October 23, 2016 Author Share Posted October 23, 2016 Well Houston we have a problem. I figured I'd warm the car up a little before checking the valve lash and pulled the cover, right away I knew I was in trouble. Oily foam was sprouting from just a few of the ports the rest were not letting oil through at all. Obviously there was water in the oil. I just checked the oil a couple of weeks ago and no water showed on the dipstick so something happened once I noticed the clatter. First suspect is of course the oil cooler so I pulled it and plugged one end and filled it with water. Nothing coming out the oil ports so I think I am OK there. On closer examination of the engine I noticed some oil seeping out around the head gasket so I am going to pull the head next and see what I can see. I did take the time to check the valve clearance and 4 were out so that may have contributed to the noise but lack of lube/ contamination is the obvious issue. I did not run the engine much at all after noticing the clatter so hopefully no major damage involved. I'll post what I find. Link to comment Share on other sites More sharing options...
keiser31 Posted October 24, 2016 Share Posted October 24, 2016 It may have just been a case of re-torquing down the cylinder head. Link to comment Share on other sites More sharing options...
JACK M Posted October 25, 2016 Share Posted October 25, 2016 On 10/23/2016 at 6:16 PM, keiser31 said: It may have just been a case of re-torquing down the cylinder head. Our great minds are thinking alike. Link to comment Share on other sites More sharing options...
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