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ChadS
11-02-2004 09:52:42
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Re: Farmall Tractor Pulling in reply to Dr.Evil, 11-02-2004 08:43:28
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Stock RPM. The problem in the 350 sleeves in the H block is the top ridge on the 350 sleeves. The H has a flange size of 3.783 and the outside bore of the H sleeve is right at 3.5625, which is the bore of the H block with the sleeves removed. With out looking at the block,, the C-175 engines, the top flange was just at 4 inches, and the block bore is 3-3/4, or close to it. The H block can take the barrel size, but not the flange at the top. What has to be done is the 350 flange has to be machined down to the H flange specs so you dont have that problem with overboring the top of the block to fit the sleeve. I used a lathe to cut the flanges down, before I bored the block, that way, they have to match up the block to the sleeve, instead of vice versa. Any H good H block can be bored to 3-13/16 straight thru, and still have meat in the block to run. (FYI) Anything below 3-13/16 is no problem as long as the block is not cracked along the bores. Yes, in 55 they made the casting change, the Super H was just a bored out sleeved H engine with the good cyl head and camshaft, and the big carb and intake. the C-169 and up were totally different in the block bore casting, much bigger, and you can bore them more than the H block and still run on the block. still same outside appaerance,, (kinda) as the H, but the bearings, and the sleeves were bigger on the C-169 and up, super H 164, was just the crank, head and cam update same block casting as the H. OK ,you can aslo bore the H block, (no sleeves) to 3-5/8 which is the economy route, but you still have the sleeve flange at the top of the block deck. It makes it a pain to drop the pistons in the bores with out fighting the rings slipping out of the compressor upon installation of the piston/rod assembly in the block bore. and you lose area in the compression chamber, and gasket sealing area when you do that as well, but,, there is ways to fill in the gap, or run it without the flange,and still seal the head gasket. you could either A.. Cut the top of the flange off the H sleeve, press it back in to the block and bore the flange to 3-5/8, or B just have the flange made and installed. there is shops that make them, will post that info at a different time,, or C, run with out it. Only thing that has to be done, when running without the flange, is to use the C-175 head gasket. it has a larger fire ring diameter than the H head gasket, and will cover the gap and get a good seal on the fire ring. It will seal on the block, instead of the top of the sleeve flange. I am not one puller to rev up these old engines, unless they have been redesigned for the rpm range I set them to. I have an H that is well over 100hp,at 540 and runs about 3000 rpm and that was alot of careful balance work on the crank and flywheel, rarely does this engine see 3000 rpm, but it is good to know that the safety steps involved were done for safety reasons. On a farm tractor,, I would say that 15-20% over stock rpms is safe to run on an IH, I say that for engines that have been freshly rebuilt only,, because they have been torn down and everything should be up to par as far as all the torque specs are concerned. Older tractors, that have alot of use on them, I would say no more than 10% over on stock rpms. Some, just aint as tight as they used to be ya know,, Only one pulling engine I have is balanced to run high rpm,, the others are not over 10%, and that is with a stroker. Just no need for those to rap the rpms, they have power enough to spare at stock rpms. Now for a few facts on HP readings. Fact or fiction for one to belive it is the gains I look at from modifications, not just hp gains, but compression gains, properly matched parts to match that particular engines out put. I think you will find that the carb, distributor, and the governor will yeild you more HP for your $$ than doing expensive stroke work, head work, or custom cams. We have quite a few Super H's running round our family of pullers, I have one that has a stock, but dyno tuned C-164 that makes 45 hp, at 150 psi of compression. The other puller Super H has a 350 piston/sleeve kit in it. It has 50-52 hp at 165 psi. Both have almost identical torque curves onthe dyno, just the 175cuin Super H has a bit more HP at 540 than the stock C-164 in the other. And the 175 engine head has not been milled,, yet,,, or really dyno tuned to where my super H is to get 45. Lot more room for HP in the 175 super H we have. any questions? just ask.. ChadS
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