Hay fellas... I had a previous post on an oil leak and where it was possibly comming from... We thought it could be the intake manifold area in the rear. I pulled the intake off, cleaned and resealed/reinstalled as recomended, however, it WASNT the problem... Is it possible for oil to leak from the head gasket area of a 1962 327 SBC Corvette engine???? It seems to be dripping of both sides where the head and block meet... i can plainly see the oil dripping off an area at the rear cornors of where the block and heads meet. The motor/heads have been machined/rebuilt... Any oil galleys or areas that I should know about around the head/block? HELP GUYS... I am not going to move forward with this project until I isolate this problem and fix it... Thanks, Jefe
there is one plug on the drivers side under the head, near the top of the block at the very back of the deck surface, I dont know how it could get over to the other side, though.
oil leaks can be a *****...they can appear to be from a certain spot , but in reality may be coming from somewhere else have you checked you valve cover gaskets? oil pressure sender?
I believe '62 was the last year for the road draft tube. If you are using it and it's clogged it may build up enough pressure and possibly force oil out of the back of the valve covers,and down the back of the heads.
I don't know about the '62 327's but the '65's have a place in the top back of the block where the PCV hose plugs in from the carb.Maybe on the older ones,it's where the vent breather would be.Could this be leaking?
Jefe, In your previous post on this, I stated to check the oil plug thet is under the drivers side head. Early style blocks (265,283,307,327,..) have this hole while newer ones (350,305,400,...) do not. If the block was hot tanked or deck work done, they pull all the plugs to get the engine completely clean or machine. It is common to forget to replace that plug, I have forgotten a few times and learned my lesson. Also the plug is sometimes threaded or a soft freeze plug, if it is there, replace and use a sealant on it. Some leaks are as less obvious than just an intake gasket.
Hi. Oil does not p*** through the head gasket on a 327. Possible places are valve cover gasket, the vent tube behind the intake manifold, oil pressure fiting back there too, and distributor gasket. There is also a plug behind the camshaft that can get knocked out if you jammed the cam in, unlikely though and you would see oil out of the bellhousing bottom. Is the block is vented properly? Excessive internal pressure could be forcing oil out. A 62 would have the rear vent tube drawing air from the air filter, and I think a vented oil fill tube? Or a draft tube? I can't remember. My 64 had a primitive pcv valve under the carb drawing air through the block from the oil fill. Fresh air came through the airfilter into the block from the rear vent. Hope this helps, John
On some engines you need to put some Permatex on the threads of the intake manifold bolts as sometimes oil can sluice right up the bolt and out from under the head of the bolt, not m***ive quan***ies, but annoying.
A black light and some of that leak view stuff might help pinpoint it. Can you run the engine on a bench so you can easiliy view the back of the engine?
"Hi. Oil does not p*** through the head gasket on a 327." Uhh,,,yes it does,but I doubt thats where the leak is.
I think Hemiguy is on the money with the dizzy gasket. A buddy's redneck truck had a mystery oil leak that his mechanic couldn't find. He brought it over and we started to pull the intake, of course you pull the dizzy to pull the intake, there was no gasket on the dizzy. The only high flow spot that is easy to access with the engine in the vehicle is the oil pressure sender. I hope one of these two is your leak.
Thanks for all the help guys, it's vented correvtly with a pcv to the carb and breather. The draft tube was removed and plugged with a freeze plug. I put ARP thread sealer on both the oil pres. sender and ARP intake bolts. Checked and recheck the valve cover gaskets with my dental mirror and finger. After a few burns from my headers, nothing there either. Distributor gasket is clean as well... Whats weird is that its comming from both p*** and driver side, WTF, over!!! The plug that jrblack is talking about "If the block was hot tanked or deck work done, they pull all the plugs to get the engine completely clean or machine. It is common to forget to replace that plug." Where is this plug at? Do i need to take the heads off, is it on both sides? Could it be a head bolt leaking down into the head gasket area. I know im reaching but I can make sence of this... Thanks Guys, Jefe
Uhh,,,yes it does,but I doubt thats where the leak is.[/quote] I don't think it does, goes up the pushrods and drains back into the lifter valley. Only water goes through the head.
Hi. If you plugged the vent hole in the back of the block you need vented valve covers, if you are drawing air in from someplace like the oil fill tube, you need to let fresh air in someplace else. Although if you were drawing a vacuum in the motor I wouldn't expect oil to be leaking, just burning... I think the plug in the back of the block is for the oil gallerys, so if it was out you would have a geyser of oil. Head bolts go into the water jacket, so if the threads are not sealed sometimes water will come up. A head bolt leaking oil then migrating between the gasket and head surface and out is possible, but unlikely. I would expect to see water leaking out as well if the head gasket was not sealing.
Three things come to mind as possibilities: 1. Did you use the "rubber" rail gasket? If so, this is a very common leak problem, especially with machining... was any decking work done? With decking, the "crush" is changed and the gasket can easily be pushed out or split which will make a leak. 2. If you used the "rubber" rail gasket, did you use RTV at the corners where the intake gasket and the rail gasket meet? and did you layer the two properly? 2. Did you omit the "rubber" rail gasket and instead use a bead of RTV? If so, did you use high-temp RTV? did you completely clean and degrease both mating surfaces and allow ample time for the RTV to cure?
i'm guessing its the intake gasket, even though you said you resealed it, you also said you had machine work done,this can mess up the proper clearence from a stock gasket, my advice is go to your local honda dealer and buy a can of ultraflange and use this instead of a gasket.I used this on the last 427 i took the heads off of for this exact reason, the machine work wouldn't allow a regular gasket to seal.We race all last season with this engine with no troublesome leaks. good luck
No rubber on the intake just high temp BLACK RTV. Cleaned the mating surfaces with brake-clean. There was ZERO OIL or gasket material left behind. Both valve covers are vented, one with a pcv valve to the from of the carb va***e and the other is just a breather. Im baffled guys... I even went with the #1205 FelPro aluminum intake (recomended by edelbrock for the intake) gaskets. I'm going to have the machinest/engine builder (my buddy) come down and take a peek. Whats that additive to the oil some of you guys talked about? Maybe that'll help. Jefe
do you think oil would make it to the p*** side as well as the drivers side if this was the issue? I can see oil on both sides where the head and block meet up.
the only engine where I've had that plug leaking it was pretty obvious it was on the driver side. how fast is the leak? like how many drips/second/minute?
I had a small leak yrs ago at the plug Squirrel pointed out.Seems I forgot to tighten it after machining.Had to pull the head.
Many years ago a oldtimer mechanic told me that after rebuilding a engine he would seal off the carb hole and any other holes that air could enter and would then hook a va***e to the fill tube. He would then go around all gasket/mating areas with a mechanics stethascope(spl.?) and listen for air being ****ed in. Said it saved him rework and unhappy customers. Never tried it myself and can't vouch for it but as a last resort ???
squirrle - about 1 or 2 drip a min from the drivers side and a slow seeping from the p*** side. I know it dont sond like much but it drips onto the exahust and then comes the white smoke... In addition, ITS A NEW/REBUILT motor, I allways wanted a no drip no leak motor, looks like I've yet to have one. Jeff
i'll do what i have to do, like pull the heads - but man, i just wanna drive this baby, ya know!! my wife's getting pissy, she wants to roll around town and I have yet to take her!
I doubt it's head/block related. IF you are absolutely certain it's not coming from the intake/block/dizzy... it almost has to be coming from the valve covers/gaskets. What kind of covers and gaskets are you running? This is a simple and inexpensive check - pull the worst side valve cover and do an inspection for warpage, cracks, misaligned gasket, cracked gasket, crushed gasket, etc. Pay particular attention to wet spots on the mating surfaces.
Running new finned alum. valve covers, thick cork felpro gasket AND a nice bead of RTV to boot. Valve covers arent leaking, i'm sure of it. I even tried the rubber gaskets with no leaks as well but I feel better with good old cork... Funny thing just happened, I ran the car at idle for about 5 mins and then another 5 mins at 2000 rpms and the leak was BARLEY noticable. Nothing off the p***engr side and about a full drop off the drivers side. If I can get my 700R4 dialed in i'll take a test drive and report back to ya. Do you think driving the car would make a bigger diffrence?
"Do you think driving the car would make a bigger diffrence?" I can't EVER recall having an annoying problem get better with time and by ignoring them......had a lot of 'em get WORSE, but never better.
thin fel-pro rubber gaskets work great with cast valve covers, thick gaskets + silicone =leaks. now with ****py old stamped ones with spreader bars, thick cork is the way to go. can you pull the dizzy and run a primer on the pump? then you could watch for leaks without the heat, vibration, noise and fan blowing.
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