Technical SBC Distributor whine

I finally finished my '50 Chevy project and have taken it about 300+ miles now. All is going ok with the car other than my ears will not stop ringing after I get out of it. There is a high pitched whine coming from the distributor.

I have an HEI in it and its a 355 SBC. It doesn't seem to effect its ability to run like it should but it is getting annoying. First I pulled the cap and see no signs of anything rubbing. Then I swapped to another distributor.. the problem still continued. So I shimmed it up with the largest Teflon shim in the Moroso kit. Still whines constantly. The noise does go away when I get on the gas. So it is really a 1000 - 2500 RPM issue

Any help or suggestions would be appreciated.

 

I'm not really sure of which goes where or with what but there is a condition with sbc cam distributor drive gears and distributor gears. It's a late vs early discrepancy with those gears. Might be worth looking into . That or cam walk

 

Just a guess,do you have a cam button on the end of the cam,it might be walking in the block

 

The cam walk idea is possible. I didn't build this one so I am unsure what is under the timing cover. Ill have to pull the cover to see what I have

 

your cam is not walking unless it's a roller---you could lap the gears but it has to come apart to do it...

 

Drain the oil and check for any metallic flake, the high pitch whine sounds like metal on metal, could be cam walk, could be incompatible dist gear to cam, I'm guessing something inside the engine is eating itself throwing shavings.

 

Drained oil and no signs of anything other than oil. Noise goes away when under a load. It seems to be at its worst under idle.

I really don't want to pull this thing apart after finally finishing it after a year and a half of working on it. Might just have to though

 

could it be the flywheel cover rubbing?

 

Did you put a high volume oil pump in this engine by any chance?

 

Does the noise change pitch as the rpm increases? If its constant without a pitch change, make sure you don't have a vacuum leak (may be the source)

 

The flywheel cover is still on the shelf still so I don't think it'll be rubbing.

I am not sure which oil pump it was built with. The guy I bought it from didn't know much about the build details.

I did have a tough time getting the timing and air/ fuel mix correct. When I first fired it up, the exhaust was running EXTREMELY hot. I have it running a little rich right now to keep the exhaust temp down while at idle. It cools down when driving.

 

It does have a pitch change when rpms go up and is silent when over about 3000 rpm's

 

If it has a high volume oil pump in it and the crank bearings were not clearanced as required, then you may have too much oil pressure - causing the oil pump drive to whine. I have experienced this many times over the years, mostly with sbc's...probably only because they are so popular and hv oil pumps for them are cheap. Lots of people think they can just slap one on and go - not the case. If this is what's going with your engine, it will tear up your cam/dist gear and maybe even ruin the engine. Check your oil pressure with a mechanical gauge first. If its much more than 55lbs at speed, hot, then you probably have a problem.

 

It's not the distributor as you swapped them and didn't solve the problem. High exhaust temp is usually retarded timing, and if you have an automatic it could be the pump. Disconnect all the belts and start it to rule out alternator, water pump, fan, p/s pump etc. As to the oil pump, what is the oil reassure? Drain your oil and put 5/20 in it and see if that helps. Thin oil doesn't build pressure like heavier oil, see if that makes the noise go away.

 

Not sure if it helps but the oil pressure gauge in the car stays steady at about 50 lbs at speed.

 

Is it an electric or a mechanical gauge? Some electric gauges aren't very accurate at all...many won't even read above 50lbs. Anytime I am troubleshooting an oil pressure issue I always connect a mechanical gauge.

 

Quick rundown of parts.

• Hooker headers
• HEI distributor
• 2101 style Edelbrock intake
• 1405 Edelbrock carb.
• 993 heads, stock style rockers
• Supposedly it is a .030 over block
• NV3500 5-speed transmission

New alternator, water pump, belt all in the last week. Tried 2 different HEI distributors, 2 different alternators, swapped replaced all accessories and still whines

 

Mechanical oil pressure gauge

 

Try the thin oil suggestion - it's easy and doesn't cost much. You could even use diesel fuel if you wanted to, just for a short run test (unloaded), won't hurt anything.

 

Did you try a new distributor cap? I've seen a cracked cap leak secondary voltage to the closest ground. It makes a whine sound.

 

Running 10-30 now. Temp stays steady at about 180. Idles like it should.

I can give it a go, its easy enough to swap oil and see if it makes a difference but it sounds more like a metal rubbing squeal.

 

Not a new one but a different one off my stock car. No squeal on stock car.. like a pig on this engine

 

Are u sure the dist is getting enough oil? I think a sbc has a plug that needs to be in place (or was that on my early hemi?)

 

Never really heard of a plug to be in place on the chevs. Plenty of oil on the shaft when I took it out though.

 

Thanks for all the help, I'll try a few things tomorrow and see how it goes.

 

Here's what I was talking about

http://www.youtube.com/watch?v=EJ6K98affAs

 

I've got strong oil pressure so I'm guessing the plug is in there in this case.

But at least I learn something new today.. never knew that there was a plug in there.