[hlweyl]

Greetings,

I have a 67 Camaro 350 .040 over. Edlebrock intake and heads, demon carb, headers, th350 trans. The engine was rebuilt by a professional mechanic (with my assistance) about 4000 miles ago. About 1000 miles ago, the passenger side head gasket started to leak.

I replaced it myself using fel-pro 1003 gasket and new arp bolts. I only replaced the side that was leaking. The head gasket was not blown and both the engine and the head were checked with a machined straight edge. Well, here we are another thousand miles later and they BOTH are leaking now. I'm 99% sure that I did the head gasket correctly.

I'm clueless as to why it is leaking again. The only thing I have noticed is that when I read the oil pressure today it read 50 psi at idle. 58 psi at 2000 rpm and 70 psi at 3000 rpm. The car used to idle around 25 psi.

Is it possible that the oil pressure is so high that it is blowing out of the head gasket? I was told with this combination, the bolts do not need to be re-torqued. Should I just get in the habit of re-torquing anyway? Final question, I didn't use any extra sealant when I installed the head gasket (felpro had some built-in blue sealant already), Do any of you add some sealant for good measure?

Thx in advance, and I did read several posts but none were specific to my problem.

[tresi]

I can assure that oil pressure had nothing to do with the head gaskets blowing. I hope that when you checked your block for flatness that you checked not only length wise but also diagonally. I would suspect that your problem is caused by the wrong head gaskets. Felpro 1003 gaskets have a steel wire ring seal sandwiched inside the stainless seal around each cylinder.
The steel ring can tend to brinell the aluminum heads. Felpro suggests using their 1010 gasket that uses a preflattened copper wire ring.
I would pull both heads and check the block for damage even if it was good when you put it together. If a motor runs too long with a blown gasket it will damage the block. You will need to get the heads surfaced if the steel ring has started to indent the heads. Install the Felpro 1010 gaskets with no sealer. You will need to put sealer on the threads of the bolts to ensure water doesn't get past the threads. Even if they are no re torque gaskets I re torque head gaskets on any performance motor.

[machine shop tom]

Are you leaking coolant or compression? Use no sealer on the head gaskets, but do use a non-hardening sealer on the head bolts. Re-torquing the bolts is always a good idea with a composition head gasket. Have the heads resurfaced, a straightedge doesn't tell the whole story. Most aftermarket heads are in need of straightening right out of the box.

[hlweyl]

Thx for the tips. Tom, I have not checked compression and I am leaking oil from the head gaskets, not coolant.

When I re-did the head gasket before, the gasket showed no signs of failure. On first rebuilt @4000 miles ago, I did have the block machined so I know it was flat and true.

I guess I will order the 1010 gaskets and hope for the best.

[k-star]

Is it leaking oil from both heads or only one??

Is the leak in the front or rear of the engine??

Is the leak the same place as last time???

Keith

[Wings]

Ahh, It's an oil leak you are concerned with.
That's good news. I don't think you can leak oil from the head gasket! There is no oil passage there. At least there better not be. Sounds like a leaky valve cover gasket with oil running down on the head. If your coolant is OK, you are not spiking a temp, & no coolant in your oil. I would bet you have a very easy fix on your hands. I certainly wouldn't rip off the heads for an oil leak!

[k-star]

Wings, the oil return holes go through the heads in a small block so there is a chance oil can leak through the head gasket. Even though is a very small chance.......

keith

[Wings]

Keith, The oil returns (pushrod holes) drain down under the intake and do not pass through the head gaskets. That is why I'm willing to go out on a limb and say that any oil leak you see has nothing to do with a leaky head gasket.

[hlweyl]

Originally posted by k-star
Is it leaking oil from both heads or only one??

Keith

It is leaking from both heads.

Originally posted by k-star


Is the leak in the front or rear of the engine??

Both leaks are closer to the rear of the engine.

Originally posted by k-star


Is the leak the same place as last time???

Yes and No. The passenger's side head leak seems to be in the same place(although last time it was leaking oil and coolant both cured with the new gasket for 1000 miles). Although visually it's very hard to tell as the starter is right in the way. The driver's side leak is new.

Thx very much.

Originally posted by Wings
Ahh, It's an oil leak you are concerned with.
That's good news. I don't think you can leak oil from the head gasket! There is no oil passage there. At least there better not be. Sounds like a leaky valve cover gasket with oil running down on the head. If your coolant is OK, you are not spiking a temp, & no coolant in your oil. I would bet you have a very easy fix on your hands. I certainly wouldn't rip off the heads for an oil leak!

Wings, I am sure the oil is not coming from the valve covers as I would be able to see it leaking. I also checked the rear of the intake manifold and it is dry as a whistle. The temp is running perfect, never been overheated.

[machine shop tom]

If it's oil leak, it's either a valve cover leak or an intake manifold leak. If you are using the rubber or cork end seals on the intake, there's your problem.

tom

[hlweyl]

Originally posted by machine shop tom
If it's oil leak, it's either a valve cover leak or an intake manifold leak. If you are using the rubber or cork end seals on the intake, there's your problem.

tom

Now I'm confused. I don't see how it could be the valve covers or the intake. You can see all the way around the valve cover and I would think I would be able to feel some oil on the back of the intake manifold... no? Are you saying if it is oil leaking, it cannot be from the head gasket?

For the intake manifold, I used fel-pro gaskets and prematex RTV sealant on the ends. Man, I hope you guys are right, I would much rather re-do intake or valve covers than the heads again.

Thanks.

[k-star]

Wings,
on the small block chevy the main oil drain back is the 2 holes at the front and rear of the head. These holes are about .470" in diameter. They do dump into the lifter galley. If you look at a head gasket these holes are the ones at the top of the gasket where the triangle part starts.

I hardly doubt this is where the leak is coming from, but it is possible to leak oil from this location......

hlweyl,
two things i would check if your sure it's not coming from the intake. Look real close at the top of the block where you have the oil pressure gauge hooked up. I have seen leaks at this location drive you crazy. The oil will follow the seam where the heads bolt to the block and it will look like the head gasket is leaking.

If thats not it and you take the heads off again check the holes where the locating dowels go into the head and make sure they are reamed deep enough that the head is not bottoming out on the dowels.

Keith

[hlweyl]

Originally posted by k-star


If thats not it and you take the heads off again check the holes where the locating dowels go into the head and make sure they are reamed deep enough that the head is not bottoming out on the dowels.

Keith

I appreciate all the suggestions. I will check the oil pressure hook up tonight.

If the heads are bottoming out on the locating dowels, would they leak from the get-go rather than surfacing 3000 miles later?

[k-star]

If the heads are bottoming out on the locating dowels, would they leak from the get-go rather than surfacing 3000 miles later? [/B][/QUOTE]

Yes i would think the oil leak would be instant but i have seen crazy stuff happen with engines. I was just thinking of things that might cause such a rare problem....... If you find out for sure that it's not coming from above and running down the head you need to be real careful when you take it apart again to look at the head gasket carefully to determin exactly where it's leaking.

Again i hardly doubt its coming from the head gasket!!!!

I find it hard to believe that both head gaskets would be leaking oil......

Keith

[machine shop tom]

k-star, we drill the dowel holes out when we do heads to make sure they aren't bottoming our on crap or burrs. Your advice to hlweyl is good advice.

tom