1936 BUICK ENGINE PROBLEMS

[Guest LarsG]

Hello:

My 1936 Series 40 coupe has just got new rings, honed cylinders and cylinder head work including valve seats.

(Bottom end was checked and as it was ok, left as is.)

Prior to this the engine ran fine, smooth, with plenty power etc. (despite the fact that the reason for the ring job was uneven compression and some oil smoke).

Here is my problem: the engine will simply not run smoothly anymore. It will start and idle reasonable well and also pull well in the lower range (both when at steady speed or when accelerating) BUT if I try to accelerate suddenly or if I try keeping a steady speed in the higher rpm range the engine will sound strange (like there was no air filter on the intake) and the power is simply not there; simultaneaously I get the feeling of no vacumm advance in the distributor. I even tried another similar distributor but there was no change at all; also another carb.

What could be the problem considering the engine ran fine previously and that nothing other that what I mentioned was done to it?

Has anyone experienced this problem before??

Thanks,

Lars

[Guest Ron3660]

Try checking the vac. line. I had a small crack in mine. I replaced the whole line and fittings. No more problem.

[hchris]

Sure sounds like a vacuum leak, you need to go back and tighten every nut and bolt in the intake system, check that gaskets are all intact and the intake manifold is down tight and snug

[Mark Shaw]

You might also re-check your valve settings now that it has been run awhile....

[Guest LarsG]

Ron3660, Hchris and Mark:

many thanks to all of you for the suggestions. They all sound obvious and very worth a try!

Further to my original message, I was thinking it could be weak valve springs....but would they suddenly get weak??

Thanks!

Lars

[critterpainter]

Check for a restricted or plugged exhaust system.

bill

[hchris]

No I dont think the valve springs would get weak on you all of a sudden, however did you take the valves / cam etc. apart ? The thought occured to me you might have reinstalled the cam one tooth out when it all went back together

[Guest captbrian38]

check the butterfly in the exhaust manifold. Had a similar problem that was discussed on this forum back in april with a rebuilt 248 tried everthing that will be and was mentioned here including the plugged or restricted exhaust. The butterfly must have operated the first time I ran the engine and when I shut it down to fix a manifold exhaust leak couldn't for the life of me get the engine to run again. It would start and run for a few seconds and stall. The butterfly was jammed closed, I mean jammed shut finally opened it with a crobar and now it's stuck open and the engine runs like a top. So drop that engine pipe and look up in the manifold with a mirror and see what you can see. Any degree of closure might be causing you problem.

Brian K.

capibrian38

[Guest LarsG]

Thanks!

The exhaust is not to blame in my case (checked it).

Hchris: I only worked on the head itself but the cam was left in situ.

Could it be the valves springs were alraedy weak and that the the slight work on the seats resulted in just the minute additional clearance to make the springs too short (or too weak)? Sounds far fetched but...

I would discard the cam being one tooth off.

Brian K.:

that`s an interesting variation of a problem you mention there!

I think the valve you mention is actually missing in my particular engine but will certainly check it soonest I can!

Thanks again to all of you!!

Lars

[Mark Shaw]

It seems like a timing problem... Have you checked it with a timing light? If not, I suggest you loosen the distributor and try rotating it with the engine running to see if it improves either way.

[Guest LarsG]

Hi there to all who helped me with good suggestions:

I am very pleased to tell you that my old Buick is now running like a youngster again! In fact it does since the last 3 weeks or so and I had forgotten to thank you all!!!

Do you know what the main problem was? Yes, the cam sprocket was in fact one tooth off.

Yes, I know one of you told me and I said "no" because I had already asked my mechanic and he said he had not touched the cam...hmmmmm...

I am red in the face!!

So, thank you fellows so much!!!

Lars