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By Hoosier Hurricane - 14 Years Ago
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Guys, I promised some of you I would let you know what I found out about the head gasket after my problem at Columbus. Here's what I have so far. I pulled the head again, used a dial indicator to check the block and head for flatness. No problem there. When I first built the engine, I had the block decked a minimum amount, just enough to make it square and equal. There had been some rust at the top of #1 which left a discolored spot. I didn't think it would hurt. Does rust make cast iron soft? Careful cleaning and inspection of that area showed some small pits. I got some Devcon steel putty and put it on that area, and filed it flat. That stuff is tough, dulled my file. Re-assembled it with a Detroit gasket that I had, one of Gary Burnette's specials he had made. The Detroit has a wider fire ring than the others I looked at, and it also had two perforated sheets as foundation for the composition, the others had one sheet. I thought it might support the fire ring better. Haven't had it to the track yet, my car hauler has been converted to a soy bean hauler, the beans aren't done yet. More to come.
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By yblock32deuce - 14 Years Ago
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thanks for the update john, been waiting as i am sure alot of us were to hear if you found anything. hope this is it.
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By Ted - 14 Years Ago
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John. Thanks for the update. I did receive the two new Best Gasket big bore head gaskets back from you the other day so thanks for that also. Based on the note of dimensions included with the gaskets, it looks like you did quite a bit of measuring on the various brands of gaskets. Fingers are crossed on my end that you’ve eliminated the gasket blowing problem. But if that indeed cures the problem, then it makes me wonder where the fine line is between the various brands of gaskets when stepping up the combustion pressures.
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By Hoosier Hurricane - 14 Years Ago
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I noticed something else in measuring the fire rings in the gaskets. The gasket I installed at Columbus, I gave an extra 5 ft.lbs. of torque, "just because". When I compared the gasket I took off at Columbus to the replacement I took off at home, I noticed that the fire ring was .002 thinner near the head bolts on the "extra 5#" gasket than the other. But, the fire ring at the top of the cylinder was the same on both gaskets. I had apparently induced .002 distortion by overtorquing. Also, some of you saw and chuckled at my redneck 1/2" extension I was using to torque the head. I offered the theory that whatever touque was applied to the top would also be applied at the bottom. I still believe that. However, with my "clicker" touque wrench, some springiness in the extension must have come into play. While torquing at home, I found that after I torqued them with the extension, I could put a 4" extension on instead of the long one, and the bolts moved. Torque was about 5# less with the long extention.
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By Fordy Guy - 14 Years Ago
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John, do you know if the Detroit gasket is thicker than the others when compressed?
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By John Mummert - 14 Years Ago
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John, cast iron will distort. I was at a shop one day while the engine builder was finishing up a vintage road race 289. He was performing a leak down test just before shipping the engine and found some leakage at the #5 exhaust, as I recall. He found that when he back-off the closest head bolt the leakage went away. Torquing down the head bolt distorted the valve seat. The variation in gasket thickness looks like the head was distorting near the head bolt. Regarding the extension, I know my impact wrench has less power when I use an extension but is a torque wrench a "static load". Under a static load the twisting force should be the same at both ends, I think.
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By pegleg - 14 Years Ago
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Feistritzer may have something in the spring of the extension. With a clicker anyhow. I'm thinkin' that won't affect a bar type wrench though. I have noticed the same thing when i re-torqued the heads on the red car. I was too lazy to go get my extension for the lower (outer bolts) and they all checked 4 or 5 lbs less where I'd used the 12" extension. But the real problem for the Hurricane occours in an area that doesn't seem to cause me any trouble with the Best Gaskets. The other bank of the hurricane is OK also. It's something to do with a weak spot in this particular block. And, any metal will distort with enough force on it, that's why they have to use The bolt on bore/honing fixtures on blocks with the head bolts on the side of the cylinders. Not us of course! Cast iron has very little Yield, it just breaks.
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By Hoosier Hurricane - 14 Years Ago
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Fordy Guy: I checked used Detroit and Best gaskets. The Detroit averages .043, the Best .047. They have been torqued to 85 ft.lbs. with 1/2" head bolts. Don't expect to find this particular Detroit, Gary had a run of them made, then Detroit claimed they lost the dies in a move and can't make them any more.
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By Don Woodruff - 14 Years Ago
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Some builders countersink, for lack of a better word, the threaded bolt holes in the block to avoid "pullup" around the torqued bolt hole.
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By Hoosier Hurricane - 14 Years Ago
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Good point, Don. I have been doing that for years, but some of our younger Y Blockers may not be familiar with that operation. Thanks for posting.
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By Hoosier Hurricane - 14 Years Ago
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Took the car to the track today to try the head gasket again. Never unloaded the car. Rain. I'm not too bummed, we despately need the rain here.
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By yblock32deuce - 14 Years Ago
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reckon you 're getting what just finished with us john. since last monday rain guage has recorded 22in. here. we needed it too,so know how you feel. 
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By Hoosier Hurricane - 14 Years Ago
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Now for the rest of the saga. Took the car to the track Saturday. Went 12.03 and 12.07 in my only two time runs. Both at nearly 112 mph with a stiff side wind. Lot of cars there, and first round was about 9:30 pm, I knew it would pick up. Dialed it 11.99, and on a double breakout race I ran 11.86 and 114+ to lose. All seemed well with the car. Sunday I got the bright idea to check my radiator catch can. It had considerable water in it. Today I ran a leakdown, and #1 (the problem cylinder at Columbus) and #3 each showed a very small leakage into the cooling system. Checked the bolt touque, they had relaxed. After the re-torque I re-checked #1, same result, so I drained the water and aired up the slicks for its long winter nap. I'll build another block this winter. Something's going on with this one. I'll use it someday on a NA car, I would be comfortable with that.
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By charliemccraney - 14 Years Ago
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Could it just be time to replace the bolts?
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By Hoosier Hurricane - 14 Years Ago
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Charlie: Good point, but the left side bolts are the same age, and there is no problem on that side. They are 1/2" grade 8 bolts.
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