Head Gasket problem on wedge heads

I would like to ask a question concerning head gasket problems. I run an Indy Wedge set-up (Siamese center exhaust ports) using a KB stage 6 block re-drilled for wedge heads. I use a solid Indy Blown Alcohol head with ½ head bolts torque to 100ft/lbs. I use a .042-inch stainless O-ring in the head (.012-.014 protrusion out of head) with a receiver groove in the sleeve of the block. I use a .042-inch copper head gasket The blower makes 16-18lbs of boost (only 12-over). I have a MSD-12 set at 32-degrees of advance.

The problem is that the head gasket will fail between the center two cylinders (#3 and #5 or #4 and #6). The only solution I have found to eliminate this problem is to richen up the fuel mixture from 5.0:1 air to fuel ratio to 4.14:1 air to fuel ratio. This will burn just the electrode on the plugs instead of the entire flat. The problem is it also slows the car down from 191MPH to 184 MPH and makes the car act like it has a governor on it.

Do you feel the problem is mechanical (not enough O-ring protrusion out of head) or a tuning issue (too much spark advance or too lean). I did try to lower the spark advance but my ET suffered dramatically.

I know some small block Chevy racers (same Siamese center exhaust ports) and some wedge nitrous racers plumb water directly to the area in the center exhaust ports to reduce heat. I do not have this option with the solid head.

I would like to try to increase my boost to the 25-28lb range but feel I need to solve this problem first.

Another note: Thanks again to all who commented on my “slipping the tire to avoid tire shake” question. I was able to use some of the suggestions and solved the problem.

 

Wedge Gasket Problem

Is this perhaps a 4.500 Bore motor ? I built one of those things ( 477 " ) for a fellow in Hawaii that is in a Henry J . Gasoline, one Dominator, and it made 873 Horse on a Local Dyno that is not "souped up" Ran great but everytime he turns on th Nitrous Bottle it will lift the heads up and lose the Gaskets in the center cylinders......I know this is a Blown Alcohol site but I really doubt if you can get to the Boost you are talking about .....Someone on here without a doubt Knows how, maybe Mike Johnson looks in here sometimes ..He tried one of those Wedges on Alcohol in a Dragster, or maybe Tom Conway ! OH, I forgot, that Mopar made 1109 horse on a 250 Horse shot on the Dyno, but when he puts a real world load on it they say the gaskets go away....Maybe if Bob Meyer is still over there he will try to get into the Bellhousing ! ! ! ! * LOL * its a powerglide.......................Happy Trails, Larry.

 

The question that came to me was head bolts? Studs would allow a higher torque level and that might help your gasket issues. 100 #s doesnt seem like very much head torque. Dave Germain

 

I agree with Dave, 100lbs definetly doesn't sound like enough. On 1/2" studs in our blocks we take them to 120, and 130 on 9/16". Could also be the torquing pattern?

One other thing would be to check the width of the receiver grooves on the sleeves, I know some of the older sleeves we had were really narrow and we had to widen them to make a good seal.

 

I ran a blown alcohol chevy that I had a problem with it blowing the head gasket out. We found the problem to be the the receiver groove for the o-ring was not deep enough after having the heads cleaned up a couple of times. It was obvious what was happening as you could look at the gaskets, and see where the copper was squished and the imprint in the gasket from the receiver groove was not squared off at all. If my memory serves me correctly, the o-ring protruded from the block .014, and we made the receiver groove .025. I dont remember but we may also have made the receiver groove wider.

I hope that this helps.

Brian

 

Head gaskets

Sorry about the confusion but they are head studs. The bottom and middle row go down to the main webbing area (standard for a race KB hemi block) and the top row is a short stud that I installed when I plugged the hole for the hemi head and re-drilled for a wedge pattern. The bottom and middle row I think would have no problem increasing the torque value but the top concerns me a little. Would it be OK to increase the bottom and middle row to 120lbs and keep the top row at 100lbs?

 

Blown gaskets

I have a solution that I am in the process of getting a patent for if you are interested PM me.....I run a SBC with 23* heads runs 6.60's ran all last year without pulling heads.

 

look in the archives there is a guy named jerry magonical (hope I spelled it right) he will have an answer he is out in kansas if you have a national dragster layin around look in the back of it he is the guy that is making the cool cresent wrench for an fittings you can get a phone number there..good luck Dave