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Odd distributor leak repair and new aluminum valve covers.
My distributor has the oddest leak. It leaks oil up the shaft and into the distributor and then leaks out dripping on the bell housing. I have never seen a leak like this before on any distributor.
I took it out and took it apart and nothing looks unusual. I decided to try a fix by adding an o-ring to go between the cup on the shaft and the topp bushing on the housing. I used a .070" cs o-ring, greased it up good and when I put the shift in, it stopped short. Just a light push and I felt the o-ring go over the top of the bushing. It doesn't affect the lash and it didn't add much drag when turning it. Will it work? So far. I took it on a long drive and no oil leak yet. Will it last? To be determined.
I also got tired of fighting the chrome stamped steel valve covers and leaks from them. I have tried every type of gasket and sealer combo on them and even had the long torque spreaders on them, and the leaks stop for a while and then they return again and make a big mess and oil spots in my garage. I bought a pair of finned aluminum valve covers and used rubber with steel insert gaskets. So for dry as a bone.
So the big question, do the new finned valve covers look better or did the old chrome ones look better? I'm undecided yet.
Do not have a clue what the chrome stamped steel looked like but can find no fault of anything in your engine compartment; the valve covers look great. Judging by what I believe to be a hydro-boost and other things under the hood, appears to be a serious build; care to share some of the details?
Are you still located in Spring Park - google maps shows that to be on Lake Minnetonka? I often aim for that area when venturing out from the twin cities in my 69 convertible......on both nice days of the year.
At the top of the housing, isnt there supposed to be a felt washer and seal to prevent oil leaking out?
Look at some exploded diagrams of HEI distributors.
My distributor has the oddest leak. It leaks oil up the shaft and into the distributor and then leaks out dripping on the bell housing. I have never seen a leak like this before on any distributor.
I took it out and took it apart and nothing looks unusual. I decided to try a fix by adding an o-ring to go between the cup on the shaft and the topp bushing on the housing. I used a .070" cs o-ring, greased it up good and when I put the shift in, it stopped short. Just a light push and I felt the o-ring go over the top of the bushing. It doesn't affect the lash and it didn't add much drag when turning it. Will it work? So far. I took it on a long drive and no oil leak yet. Will it last? To be determined.
My guess is that you have a crankcase ventilation issue and it's is pressurizing and it's pushing the oil up the dizzy past the drain hole. Are you getting a fair amount of oil in the "CAN"? If so, that would be my guess again, too much pressure in crankcase.
I like the finned,. Never been a big fan of stamped steel valve covers. Cast aluminum is superior and that's why some covers are $19.95 and some covers are over $200.
I like your oil catch can, but I question why you have suction off of both valve covers in the first photo. One suction hose to the catch can and one suction hose to the air cleaner.
If both covers have a negative air pressure, how is fresh air being introduced and replacing the air that has been evacuated from the crankcase? In other words, you can't have two outlets without one inlet.
In the bottom photo, a valve cover breather is in place which would then be fresh air inlet.
The breather on the passenger side goes to the domed screen on the ac base, it has no vacuum to it. It breathes clean air from the filter at idle, cruise and breathes out to the carb at zero vacuum high throttle conditions. It is setup just like the L88's were.
Originally Posted by No Sweat
Mike,
Do not have a clue what the chrome stamped steel looked like but can find no fault of anything in your engine compartment; the valve covers look great. Judging by what I believe to be a hydro-boost and other things under the hood, appears to be a serious build; care to share some of the details?
Are you still located in Spring Park - google maps shows that to be on Lake Minnetonka? I often aim for that area when venturing out from the twin cities in my 69 convertible......on both nice days of the year.
Don
Yes I'm in Spring Park by Lake Minnetonka. You should come out on Thursday afternoon/evenings to the Minnetonka Drive In cruise night. Lots of cars show up. I go often as it's right around the corner from me.
There is still a photo of my chrome valve covers in my signature.
Originally Posted by MelWff
At the top of the housing, isnt there supposed to be a felt washer and seal to prevent oil leaking out?
Look at some exploded diagrams of HEI distributors.
There wasn't any felt washer in mine.
Originally Posted by Buccaneer
My guess is that you have a crankcase ventilation issue and it's is pressurizing and it's pushing the oil up the dizzy past the drain hole. Are you getting a fair amount of oil in the "CAN"? If so, that would be my guess again, too much pressure in crankcase.
No oil in the can, none at the air filter either. I've tested the PCV and it's good. I think Mell may have the answer with the lack of a felt washer in the top of my distributor. The casting is pretty much open up to the top bushing, so not much to stop oil from getting out the top.
And therein lies your problem. I've never seen a distributor that I recall that didn't have a felt washer and a thin nylon one on top of it.
Reference GM Parts Catalog Group 2.363/2.364 74-80 HEI Items 20 and 21
v2racing,
Your train of thought and mine are two different concepts. You say your passenger valve cover hose goes to the air cleaner base, no vacuum. But isn't the entire air cleaner under negative air pressure or in laymans terms, it IS under vacuum when engine is running? Your drivers side valve cover is under vacuum too, going to a oil catch can. The way I see it, BOTH valve covers are being sucked on by vacuum with no inlet available to allow fresh air in for the crankcase.
You see what I'm saying? Two outlets, no inlet. I like the catch can setup, but I don't believe yours is working at full potential.
v2racing,
Your train of thought and mine are two different concepts. You say your passenger valve cover hose goes to the air cleaner base, no vacuum. But isn't the entire air cleaner under negative air pressure or in laymans terms, it IS under vacuum when engine is running? Your drivers side valve cover is under vacuum too, going to a oil catch can. The way I see it, BOTH valve covers are being sucked on by vacuum with no inlet available to allow fresh air in for the crankcase.
You see what I'm saying? Two outlets, no inlet. I like the catch can setup, but I don't believe yours is working at full potential.
Hopefully there is no more than 1.5 inches at wide open throttle in the air cleaner, beyond that would be power loss. The engine idles at 9 inches in neutral and 7 inches in gear. It cruises at 20 inches, so there is far more vacuum on the PCV side in all conditions except high load/full throttle.
My guess is that you have a crankcase ventilation issue and it's is pressurizing and it's pushing the oil up the dizzy past the drain hole. Are you getting a fair amount of oil in the "CAN"? If so, that would be my guess again, too much pressure in crankcase.
v2racing,
Your train of thought and mine are two different concepts. You say your passenger valve cover hose goes to the air cleaner base, no vacuum. But isn't the entire air cleaner under negative air pressure or in laymans terms, it IS under vacuum when engine is running? Your drivers side valve cover is under vacuum too, going to a oil catch can. The way I see it, BOTH valve covers are being sucked on by vacuum with no inlet available to allow fresh air in for the crankcase.
You see what I'm saying? Two outlets, no inlet. I like the catch can setup, but I don't believe yours is working at full potential.
On my 69 427 the right side does go to the underside of the air cleaner base and the drivers side out the PCV to the base of the carb. Stock setup. Slight vacuum at the air cleaner base but the idea was to suck filtered air through the engine and the vacuum is much higher from the PCV side going into the intake. It also creates a slight negative pressure so no blow-by with wear.
Last edited by CanadaGrant; 05-25-2019 at 01:35 AM.
v2racing,
Your train of thought and mine are two different concepts. You say your passenger valve cover hose goes to the air cleaner base, no vacuum. But isn't the entire air cleaner under negative air pressure or in laymans terms, it IS under vacuum when engine is running? Your drivers side valve cover is under vacuum too, going to a oil catch can. The way I see it, BOTH valve covers are being sucked on by vacuum with no inlet available to allow fresh air in for the crankcase.
You see what I'm saying? Two outlets, no inlet. I like the catch can setup, but I don't believe yours is working at full potential.
Any reasonably efficient air intake set up only has 1”or 2” vacuum water column. His engine is at 9” to 7” vacuum mercury column.
It takes 13.6”of water to equal one inch of mercury. So the engine developers no less than 95 times more vacuum than the air intake assembly could hope to.
in other words its of zero concern.
at periods of WOT the flow will reverse and pressure will actually be produced due to blow by and non-existent vacuum, venting crankcase pressure out what would normally be the “intake” for the crank case ventilation. This is one reason why it’s connected to the air cleaner.
Hey V2Racing, myself and other have pointed out to you that you are missing parts concerning your oil leak but this fact seems to be drowned out by all the comments about your valve covers.
Hey V2Racing, myself and other have pointed out to you that you are missing parts concerning your oil leak but this fact seems to be drowned out by all the comments about your valve covers.
Yes. This is an aftermarket distributor and all it has in a nylon washer in the top. I have 2 of these distributors and they are both the same. The o-ring I put in the top seems to have cured the issue for now. I will keep a close eye on it and if it starts to leak again, I will find or make a felt washer.
Yes. This is an aftermarket distributor and all it has in a nylon washer in the top. I have 2 of these distributors and they are both the same. The o-ring I put in the top seems to have cured the issue for now. I will keep a close eye on it and if it starts to leak again, I will find or make a felt washer.
On second thought ... ridiculous prices on felt washer ... they must not be asian ... instead must be manufactured either JPL caltech or diamond district 47th st mid-manhattan
I think those finned v/c's look great. But like mentioned before if your concerned 'bout esthetics black hoses would look better than colored or clear.
Something that's not difficult to do but helpful for diagnosis of the crankcase ventilation is to tee into each line with a vacuum gauge to see what vacuum you really have at each location. Takes the guessing out of understanding the working system. And you may be surprised to find some positive pressure in locations where it should be under vacuum.
A vacuum gauge/test is often overlooked but it can show you restrictions in the intake ducting also. Any vacuum reading between the air cleaner and throttle body is a restriction. Any vacuum reading between the atmosphere and the air cleaner is a restriction in that duct also.
I think those finned v/c's look great. But like mentioned before if your concerned 'bout esthetics black hoses would look better than colored or clear.
Something that's not difficult to do but helpful for diagnosis of the crankcase ventilation is to tee into each line with a vacuum gauge to see what vacuum you really have at each location. Takes the guessing out of understanding the working system. And you may be surprised to find some positive pressure in locations where it should be under vacuum.
A vacuum gauge/test is often overlooked but it can show you restrictions in the intake ducting also. Any vacuum reading between the air cleaner and throttle body is a restriction. Any vacuum reading between the atmosphere and the air cleaner is a restriction in that duct also.
Hope this can help.
I have checked the crankcase ventilation. It is pulling in air through the passenger side breather at idle. Plug the breather and it creates a vacuum in the crankcase. I drove the Vette yesterday and the leak hasn't returned.
05-24-2019, 12:29 PM
Odd distributor leak repair and new aluminum valve covers.
