I have a 250 chevy completely rebuilt(bored.040 over) 2400 miles ago in my '67 c10. It has a head with cut bosses(done professionally). I run a holley 390 with offenhauser intake and headers. It started leaking water into the head, had it magnafluxed, it's ok. Put it back on twice now and I think its leaking through the back two intake head bolts still. Using permatex 59214 with black allen head bolts and washers. Any advise to seal it better? Thanks.

Try some Ultra Black RTV. Tom

Some people might consider that a Hillbilly way of water injection!

haha, well I do plan on a turbo this winter if I can get the thing to seal up!

Is that sold at most parts stores?

Remember that a turbo is going to require that seal in both directions, or the intake charge will pressurize the water jacket.
I don't know any easy tests, but you'll see "rainbows" in your radiator if it happens, due to gasoline.

Run a boosted engine for a short while with out the water pump and no radiator cap and if you have any leaks like that you'll know in a hurry. Just a little boost is all it takes to look like a fountain.

Ok. well I'm going to try the Ultra black rtv this time. I'll let you guys know the outcome in about a week. Hopefully the block isn't cracked, the water seems to only be leaking in the 3-4 and 5-6 intake ports.

Find some tubing (Stainless Steel works best) with an ID slightly larger than the head bolt. Then ream the head bolt hole so the tubing is a press fit. Coat the tubing with Locktite and press it in the hole. Let it set 24 hours. Install the head bolts.

We have to do this all the time when we port heads and break into the water jacket or intake port.

I hope this helps.

Ron

Assuming engine has intake removed and cooling system is still together.
Wouldn't a radiator pressure checker show where the leaks are?

Thanks for the help guys. I'll have to check into the radiator pressure checker once everything is bolted together.

Sleeving the hole like Ron mentioned is the permanent fix for that head.

If it is from the head bolt holes.

If you need it back together and it's from the head bolt holes, I would use "right stuff".

It's a newer "brand name" (Permatex product I think, ? ) and it seems to seal in a less perfect environment than the various forms of RTV seem to.

I get mine form any of the 3 national parts stores (O'Reileys, NAPA and CarQuest).

See it here: http://www.permatex.com/brand_right_stuff.htm

It can be a mite pricey, it might be cheaper to find some stainless tube and sleeve the hole, if it's just 2 of them.

If you can plug off the water connections to and from the engine a bicycle pump can be used to pressurise the engine; if it's assembled.

Be carefull if you use another source of air than something human powered (ie an air compressor) as somewhere above your system operating pressure (whatever the cap is rated for) it can spit a freeze plug out (possibly at high speed ).


Good Luck.

Erik...Nice to see your still kicking.

Ron

Well turns out the head was cracked where the bolt boss was cut too close to the water jacket. I have a spare head for it. I decided to finally go ahead and turbo this motor. I probably wont cut the bosses, not sure if I trust that anymore for reliability. I'll start a new thread once I sell off my other parts and get started on it. Should be fun!

That's too bad,did you remove the boss w/a sawzall or an end mill?

MBHD

the machinist cut them.Looks milled.