Technical He's got some SBC woes

So I get this SBC 350 powered car here. It belongs to an elderly gentleman who's been dicked around and passed around by a series of backyard buddies, hillbillies, hacks, and ball droppers for 15 years. He just wants to enjoy the car. He now has a few elderly issues and can't remember who did what or why or what parts are in it exactly.

It runs strong, really strong. Most of the time.
Thromp the throttle and all off it goes. Shifts into second and busts the tire loose, shifts into 3rd and really gets with the program.
Sounds great right?

Well sometimes it just Boggs and falls down and stalls-wont start back up until it cools off. and I'm pretty sure that's a fuel delivery problem someplace between the tank and the carb.

Oil pressure on the gauge is great.

Now ,,,,
The valve train is really noisy on passenger side but not when it's cold. Only when its good and warmed up does it start the clatter. Pull the valve cover and found a nice set of parts. RHS heads, screw in studs, guide plates, roller tip rockers, Poly locks.

So Planned to adjusted the valves while running using a stethoscope. Took the valve cover off and fired it up. Nice and smooth no noises. First thing I noticed was that there was very little oil getting to the top end anywhere- not good. More than 1/2 the rockers on the passenger side received no oil for several minuets- not good. After about 5 mins the clatter just started. Around 15 mins is was a full blown cacophonous tappet orchestra. While waiting for the music to start I checked the pushrod rotation. #8 intake is turning @ 1/4 the speed of the others- not good. Now #8 intake is the noisiest one and the best oiling on this side - puzzling coincidence or related?

Grab the stethoscope and adjust the valves till they shut up. Nice and quiet, running good, snappy throttle. Still not much oil to the top end - not good. I shut it down and left it sit for a few hours to get cold again. Started it back up and it won't idle smooth, really flat on the throttle - lifters are adjusted too tight for this engine cold, couldn't spin any pushrods -also not good. As the engine warmed up the running got better and better till it was once again running pretty good.

My assumption is that there's some sort of oil delivery problem to the lifters on the passenger side & the Easiest to check thing is the dizzy's transfer grove. #2 oils poorly but much better than # 4. # 6 Intake oils better than the exhaust . Also puzzling.

Im also in assumption about #8 not spinning that there's a problem with that lifter/cam lobe.


I'm seeing some Kinda weird stuff and not having any history ontop of a bunch of new stuff makes me wonder what to do to help the guy.
I'm thinking you guys might be able to help too.

 

if the engine once has roller rockers,maybe there are oil restrictors inside. Maybe the hydralic lifters are collapsing.

 

missing galley plug? (for oil issue)

 

I doubt it's it but I seem to remember different distributors being used in the early sbc and somehow completed the oil galley passage

Also I remember a friend in highschool had some kinda hybred 351 , boss headed ford bastard motor .. Anyway the thing ran hard but the valve geometry was fucked ( or we thought anyway) an kept messing up lifters .... Saw one with a hole wore through the bottom of it he put probably about 5000 miles on it and replaced 20 lifters every time a valve got noisy a new lifter went in...

He got sick of it ... Pulled the motor and put something else in

 

Bump for the morning crowd

 

Not a Chevy guy but ran around with a few of the nuts years ago.
I remember some of the old guys would put pipe cleaners in the push rods to restrict oil flow to the top end.
Another thing to check would be if the lifters are matched to the cam style. Solid lifter cam, hydro lifters. Really screws things up. If something like this has taken place the parts may all be junk.
Cam bearings may not have been installed correctly also.
Just a few things to look at.
GS

 

rear cam bearing has spun

 

Cam bearing was my 1st thought. Look at an oil-flow diagram for a SBC to see if it makes sense. To me, it sounds like it should come apart to ultimately sort it out. Definitely should replace the cam & lifters and look over everything closely.

 

Well 31vicky if your scratching your head I'll be as helpfull as tits on a bull!! Don't have a clue but I hope You find the problem! I enjoy threads like this when its carried thru and a answer is found(I know the owner is not happy) You will fix it I,m sure(Hope it doesn't hurt to much) Pete

 

Definitely not solid lifters? Dumb question but you probly wondered yourself at some point..

 

As mentioned above check to see if someone put restrictors in the rear oil galley. You can sometimes see it if you pull the distributor out and check the oil galley on the back side of the engine. A spun cam bearing isn't usually an issue in most small block chevy's because of the full groove behind the bearings. It is usually only an issue in the 64 and earlier blocks where the cam had a flat spot in the journal for oiling.
You also might be able to see an oil restrictor by looking above the flywheel or flexplate while under the vehicle and shining a light up. Their is also a 1/2" freeze plug under the rear main that many people forget to put back in if they take it out. This usually causes lots of oiling issues.

 

Several years ago a lifter manufacturer had a bad run of Chevy lifters. Wouldn't push oil through pushrods. If engine hasn't been run much, and nothing else obvious maybe he has a bad set of lifters.

 

Sure, I wonder about all sorts of stuff.

Found a bit more useless information.
Some guy installed the engine and Trans, but he couldn't get it running. So it got shipped over to a different some guy who did get it running. Then to yet a different some guy to get it running better and tuned up, he found a smashed fuel line and ran rubber from pump to carb. Maybe some other stuff.

Some coaxing and jogging from his cousin,

 

The very early 283/265 motor had a specific distributer and it had to be clocked right to properly oil the top end. By the time the 350 rolled out all the dizzies were the same and it didn't really matter how you stabbed them.

Vicky
I have run into top end oiling issues with small blocks and on the latter engines it usually boils down to either bad lifters or cam bushings (bearings) set wrong. Sometimes its one of the plugs into the oil galleys I the rear of the motor but I would take a look at the lifters first. I had one dealing me a fit several years back and I finally bit the bullet and got into it. I don't know why but I took a lifter apart and found chips in it. Then I started checking and found most of the lifters had crap in them that would follow the plunger up and down and sometimes block the oil hole. My guess is that the ones I was dealing with were offshore lifters.

I have also got way into them and found a cam bushing spun or installed wrong and the oil hole was blocked or partially blocked.

 

I think it will have to be torn down. Sounds like a multitude of problems ! Cam bearing? Junk in a oil passage ? The oil flow now caused damage to lifters? Cam? or both most likely ?

 

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Lifter bore problem? Dennis

 

aluminum heads??? we had the same noise when hot and when adjusted hot would collapse the lifter and make it a solid when cold and when they pumped up it ran like Crap. the valve train will change .006-.010 because of head expansion . and might not be allowing the lifter to transfer oil due to pump up or being collapsed . I know there was a special way we had to adjust them . also check the rollers on the rockers to make sure there is no flat spots too . as they can cause problems also .

 

Just a thought..For a while SBF lifters could not be bled down while running, not sure if OEM or not...You had to put them in empty and adjust valves with out running the engine..

 

I once got a set of lifters and while installing them I discovered that I had 8 solids and 8 hydraulic. The guy that I got them from said that the engine they were in didn't run right? Amazing that.

 

I'm sure this isn't the issue here, but in the early 70's I put a 355 together, among the standard go-fast parts I bought were some new fangled, trick pushrods, had what I thought was a lifter/oiling issue, come to find out; one of the inserted ends on one of the pushrods never got drilled all the way through. Replaced it and the motor was quite happy.

 

Whats up Doc!! Did the patient die!! Updates? Pete

 

No. 8 exhaust lifter gets oil first , missing / loose oil journal plug at front ,right bank ???
dave

 

I'm by no means a SBC expert, but I've always been told, if the engine has one simple problem, diagnose, fix and drive away.

If it's this complex, pull it inspect it, and if you have a dry top end, it needs checking real fast.

 

The other side oils the same way, but it stays quiet.

 

just to be clear, minimal/no oil through the pushrods on both banks, right? see 7. unless the back journal on the cam is fragged, cam/lifters is probably ok. cam bearing may have been installed wrong.

 

I had a customer 350 in here once with oiling problems and found that the plug that goes under the rear main was left out - you can check it from the top by measuring down into the oil pressure hole at the rear of the block, seems it needed to be 8 3/8" down from there that your measuring tool (welding rod) stopped but don't quote me on the dimension, it was a while ago.

 

If that plug is left out, you'll see it on the gauge, big time. If the guys been driving it for a while, hell, you'll see it on the drain plug...

 

Falcon George, are you saying there will be a noticeable drop in oil pressure? I had always been told that the only result was that it allowed the oil flow to bypass the filter. Was I given bogus info?

 

Just so everyone knows it doesn't matter where the hole in the cam bearing goes on most stock block small block Chevy's. There is a full groove behind the cam bearings and the hole will feed oil to the cam journal in any position, the only ones that are the exception to this rule are the early about 1965 and earlier as the rear cam housing is different and utilizes a flat spot on the journal for oiling.