[simonmcnasty]

Hey guys,

Hope this is in the right section. I recently picked myself up a little project 67 pro street Camaro with a 355 and a 6-71 BDS on it. Was an old drag car that a guy bought to try and convert to street, he got so far and got financially strapped so sold it to me.

In my younger days I built myself several street cars and off road trucks within the budget I could afford back then. So I have turned wrenches before its just been about 20 years so rusty but willing to learn.

The guy I got if from knew nothing about the build but so far here's what I have been able to figure out.

Twin holley 650's on it, Victor Jr heads, ARP studs, comp blower cam and push rods, Jegs roller rockers, screw in guide plates and stud girdles. Was being overdriven 10% but plan on swapping pulleys and under driving it 10% under when I put it back together.

So after getting the car and trying to diagnose an overheating issue, (blew the bottom radiator hose off) I did a block check test and determined there were exhaust fumes in the coolant. No water in the oil however.

Did some reading and determined usual suspects were head gaskets, or cracked head or block especially with a blower motor. I went on into the tear down process. Just finished up a little while ago and have some questions.

First I could not find any obvious signs of a blown head gasket or any cracks I could see with my eyes. I did determine that the car was built with the block O-ringed and was running copper head gaskets, which gave me some relief as I had read where somewhere that copper headgaskets are suspect when it came to coolant sealing especially on a blown motor. One strange note is that the drivers head gasket mic'ed out at .0042 and the passenger was a .0032. I'm assuming that means that the drivers head was milled .0010 at some point? is that common place to run different gaskets instead of just milling both heads to match? Or possibly just got a mis-matched set of gaskets?

My main question until I get the heads checked by the machine shop is what is the best type of head gasket for a street driven blower motor? I searched on google and it seems a lot of people favor the MLS gaskets or the Fel Pros with the metal ring in it. Does the fact that the block is O-ringed dictate what type of gasket I have to use?

Also if the heads are milled different should I have them milled the same? or just get different head gaskets again?

This is my first blower motor and I only want to do this one time so any advice is appreciated.

[RWENUTS]

Question on your overheating issue?
Did you find out what it was that made the bottom hose blow off. Reason I ask is cause I've seen that before. Lack of a coil in the hose. Hose collapsed right by the suction on the water pump, started to leak and blew off.
Just wondering!!

[vinniekq2]

Its also a possibility that the engine has blown head gaskets before and when it was repair a different gasket ended up there.next time a situation like that comes up,put a rad pressure tester on the rad and run the engine to see if pressures build up fast when the engine is cold.
Is there any indication of one or 2 side by side pistons being steam cleaned?

[simonmcnasty]

As far as what blew the hose off, I cant say 100% but I did find that my overflow hose was kinked in half, cap tested fine, coil in hose, so my assumption is that the exhaust in the cooling system created enough pressure to blow it off if thats even possible.

I saw nothing on the pistons that jumped out at me when I took the heads off. I should have taken a little more time for inspection on them, but I was running late as it was to an appointment. I will reinspect again tomorrow but there was not anything obvious that just screamed "Look Here".

[1932bantam]

the mls gaskets are pretty good . I have took a grinder with a sanding pad and smoothed the copper oring flush with the block to run regular head gaskets .

[simonmcnasty]

Originally Posted by 1932bantam

the mls gaskets are pretty good . I have took a grinder with a sanding pad and smoothed the copper oring flush with the block to run regular head gaskets .

LOL, I had actually thought of that but my o rings are SS

[spinn]

Are they .042" gaskets and .032" thickness instead. 3 or 4 thousands is a little thin. Possible a mixed gasket set of left overs was installed. Personally I dont use shim type gaskets either. Factory commetic are good , do not like the shims.

No it is not common to have the sides different. Yes you can do it .

Exhaust in the coolant? You CLT it and found bubbles in the radiator. How did you check the block. Are the heads off, if so did you flux them.

Blowing the radiator hose off is from the supercharger. I run 10 psi on a 305 and although my heads have no cracks, I cannot see this happening. How much boost are you using?

[simonmcnasty]

Originally Posted by spinn

Are they .042" gaskets and .032" thickness instead. 3 or 4 thousands is a little thin. Possible a mixed gasket set of left overs was installed. Personally I dont use shim type gaskets either. Factory commetic are good , do not like the shims.

No it is not common to have the sides different. Yes you can do it .

Exhaust in the coolant? You CLT it and found bubbles in the radiator. How did you check the block. Are the heads off, if so did you flux them.

Blowing the radiator hose off is from the supercharger. I run 10 psi on a 305 and although my heads have no cracks, I cannot see this happening. How much boost are you using?

correct .042 and .032, typo.

Yes exhaust in the coolant, used the block check from NAPA, we used to use it all the time back in the day at the shop I worked at. detects exhaust gasses in the coolant system.

No the hose blowing off wouldnt be from the supercharger, my assumption was that with the overflow hose kinked off its no different than the cap not releasing pressure. exhaust fumes and gasses being forced into the coolant system would build pressure...at some point somethings got to give and I assumed that blowing the lower hose off is what gave.....not that it has any bearing on this issue but im running 10 pounds of boost.

heads are off and in my truck, Machine shop isnt open on weekends so still waiting to have them checked.

[1932bantam]

your stuck using the copper head gaskets if your oringed, there great but hard to seal around water, try using gaskacinch its good stuff we have done this. Are you using head bolts or studs? studs can be a pain sometimes about leaking

[simonmcnasty]

Originally Posted by 1932bantam

Are you using head bolts or studs? studs can be a pain sometimes about leaking

ARP Head Studs