I wouldn't even call that a leak. One frigging drop in 24 hours and it hasn't even fell off? Come on! Probably the gaskets haven't taken a set yet. I'd go back over the bolts while the engine was warm, just put a wrench on them to make sure they were snug and not loose. Unless it's the rear main seal, it will probably seal itself as it goes through a few more heat cycles since it's no more of a leak than that.
^^^Yeah, I'd be elated with a single drop in 24 hours. I don't think anyone mentioned the engine builder's trick of sealing the engine, then hooking up a shop vac to it, then going over any "vacuum" leaks with RTV, which gets sucked into the "leak" and seals it.
Reading the comments on this has a comforting effect. Although I am highly irritated with a leaky freshly rebuilt engine, at least Im not alone. I was super paranoid with having the Flat Tappet cam, upon reading internet stories. But its all I could afford. Im driving the first 500 miles presently. While bogged with that in my mind a leaky SBC left my mind.
This is exactly why I posted here. To see if there was a sort of “settling-in” process in the gaskets. Also to get answers like this before I called him. Thank you, and yes a leak is an overstatement maybe a dribble is better?
Maybe the next time I have one on the stand. I'm going to clean up my engine, do 1 thing at a time. Like the pan, then timing case cover, etc. Get it squeaky clean then run some RTV down the sides of everything, let it cure 24 hours and see how it goes. I had a major oil leak at my oil pressure line tee, valve covers I mentioned and the o-ring where my dipstick tube went in the pan (Chevy II style). I just went around the aluminum intake and snugged up all the bolts. The end ones tend to get loose.
Don't worry about it being flat tappet. They've been around a lot longer than rollers have, with by this point billions of miles collectively. You'll learn they're just fine.
Seems passenger side valve cover has a drip in the back, where they all do. Starter had some oil on it. Appears cork gasket for valve covers. Oil pan leak is still there, hasnt increased. Just have to keep an eye on it.
I only had one 355 Chevy that did not leak ( for the first couple thousand miles). Thees cork gaskets seem to set themselves, I always rtv them in on both sides and tighten them from time to time. This seems to help. If your builder used an older crankshaft it may have a little rust pitting on the sealing surface of the rear main seal. I had this problem on a 312 Y Block and an 327 Chevy. I can´t count how often I replaced the rear main seals with no success. The solution woul be to buy a new crank. So I lived with that little drop under the oilpan. It´s ok.
There was a rash of Datsuns that leaked from the block/oil pan mating surfaces. New cars, freshly Pre-Delivery Inspected, so the factory authorized some 'stop leak' to be added to the oil of the 'chronic' ones. A young Associate Technician obtained a can from Parts, and in a short time, returned it. The Parts Mgr. asked how he knew it didn't work...it was only a 15 minute window. The tech showed him the can, with its gaping 1" hole. "Soon as I punched the hole, the Stop Leak stopped leaking. Wouldn't come out of the CAN! " Good stuff...
Pulled dust cover... more oil than I thought would or should be in there. I cinched up the bolts by rear main seal, then all around. Back by the seal, they took almost one complete turn. Im hoping this is normal after a its first few hot/cold cycles. If not you can only tighten so much, hopefully not ruining the gasket. That splash is right when the oil hit the ground. So maybe hard to tell just how much. But it didnt have much time to expand
I like these valve cover gaskets........... https://www.speedwaymotors.com/Spee...ts-Pre-1986,1872.html?OriginalQuery=910-17001
The only American made 40-60's engine I have that don't leak have an Aero Space Industries vacuum pump on it. PCV systems help and so do Zero gap or Total Seal rings.
Presently it has cork. We’ll see what happens after another drive. Hopefully re-tightening down the oil pan bolts does the trick. Valve cover may br adding but, I dont see any trail from above. But, there is some oil back there when I run my fingers, so..... The joys of small blocks...
Would the same be said for blocks after that time as well? Is the entire run of Small blocks, just leaky and the few who have onesthat dont leak are just lucky?
They figured out how to stop most of the leaks on the 1987 redesign of the small block, with the different valve covers, and the (actually 1986) one piece rear main seal.
I run a Vortec block with the 1 piece rear main seal and have replaced said seal twice already and it's leaking again. Doesn't leak from anywhere else. As has been said, I've never owned a SBC that didn't leak.
I fought a similar leak on a SBC for some time. The oil was seeping out of the lower rear corner of the DS valve cover. Tried every sort of gasket and sealer known to mankind with no success. I finally upgraded to a better pair of valve covers and the leak went away.
24hrs later, here we are. I wouldnt make the claim “i stand behind my work” then not respond “wont leak a drop of oil” then it does. Granted, in the grand scheme of things its not bad. Just the claims made to reality, is what irritates me. Youtube “myvintageiron7512” is the builder: not posting to flame just to show, the guy knows what he is doing. Not some random novice engine builder. https://m.youtube.com/channel/UC8XUoWoA03a4-YKEMtUqUbQ Continuing to post to somewhat document this issue.
After all this lol... I forgot to even ask. Is it possible to stop this without dropping the pan? Maybe spread some “right stuff” sealer around. Or is that just not going to cut it?
The Jalopy Journal
