My Beast blew a Gasket...

Denny S. · #1 (**permalink**) 03-29-2002, 09:34 PM

WAs running great, but today it decided to blow a head gasket
( I hope) No compression two cylinders side by side Wooshing noise with Comp tester in one and no plug in the next. Oh well
NOW Give me the sum of your expertise on Head gasket choices along with Intake and Exhaust to headers.. It's a 65 428...
Forged Pistons, Comp CAm, Stainless valves, 428 SCJ Crank,
Iron heads. Maybe it was my 40 mile trip down the interstate yesterday at 100 plus that did it.... But I wanna put it back together to stay this time. Engine only has 1800 miles on it..
Talk to Me ...

Whaler · #2 (**permalink**) 03-29-2002, 11:09 PM

Hi
This makes me wonder about the theory that we should retorque heads and intakes after the motor has been broken in..with only 1800 miles on it I wonder if this would have helped??

I have yet to start mine for break in..so I am wondering. I have aluminum heads and intake.

Tim

searanch · #3 (**permalink**) 03-29-2002, 11:31 PM

Hey Whaler,

You making any progress on that beautiful CanAm cobra? Post some pictures and give us an update - enquiring minds want to know...

Your Yankee Naybore

Whaler · #4 (**permalink**) 03-30-2002, 11:29 AM

Hello
Yes making some progress be it slowly. Have not flashed it up yet awaiting jethot coating of pipies and headers, as well as gauges/dash electrics.
Driveshaft being built in Vancouver as we speak.
Its coming a little slower than I wished as my builder is still working on the build manual (after 4 months since I picked the car up) You still chasing your dream??
I want to be on the road by June/July

Tim

427sharpe · #5 (**permalink**) 03-31-2002, 12:55 PM

Just to try to get back to the line that was posted....
I highly recc'd FelPro blue gaskets, hi performance. I would avoid Detroit Gaskets like the clap. I use FelPro on my 535CID big block, and have never had a problem (11.75:1 compression). From what you say about where the leak happened, when you pull the head, check (recheck??) both it AND THE BLOCK SURFACE for absolute true---meaning flat. If the head or the block has a 'crown' in it, you'll never get a gasket to seal! Then check for any cracks in the head or the block (prayer is helpful here!). Also, after running the engine in for 150-200 miles, RETORQUE all the gaskets and recheck valve lash! FelPro says this is unneccessary, but it is cheap insurance. It sounds as if there is excessive gap between the head and the block on that side of the motor for the gasket to blow that fast, IF the gasket was properly torqued in the first place. Make sure you follow the correct torque sequence as well! Good luck!

Cobra20646 · #6 (**permalink**) 04-01-2002, 05:38 AM

To add to the good info that 427 said above.....
Don't reuse your head bolts. I've heard stories both for and against this reuse thing, but if in doubt, just replace the things. Again, like 427 said, cheap insurance.
Good luck.
- Jim -

HighPlainsDrifter · #7 (**permalink**) 04-01-2002, 09:42 AM

The main cause of such gasket failures is detonation. Anything over 9.5 or 10 to 1 is too high for pump gas. If you have 11.0 to 1 you will keep having troubles. A band aid fix is to retard your timing to 32 degrees total. Also on the old engines the vacuum advance was on 'ported' vacuum instead of constant vacuum at idle. Ported vacuum has no advance at idle and high advance the higher the engine is revved. So if you were hauling down the freeway you would have maximum advance and were probably detonating.Sort out your timing before you hit the gas again.
Perry.

Denny S. · #8 (**permalink**) 04-01-2002, 09:59 AM

My ignition is MSD and so is my Distributor. My initial is at 10 degrees. I just found out the guy I bought the car from got it hot on initial run. And it got hot on me once also. So I'm assuming that getting it hot didn't help the gasket situation much. I run only 93 octane it in. According to the builder it's 10-1.

HighPlainsDrifter · #9 (**permalink**) 04-01-2002, 08:11 PM

You still have to determine how much mechanical advance is in the distributor. Many come with 28 degrees, add that to your initial and that's 38 total, too much. There are 2 small springs in the distributor that can change the mechanical advance. You should have 20 to 22 degrees in your distributor. If you do not know how to change it I would suggest taking the distributor to a shop to 'curve' your distributor.
Perry.