Hey guys, I’m putting a 235 out of a 57 Chevy car in my 50 Chevy truck. I bought engine kit from summit and rear seal was rope design.I tried installing it but it put too much resistance on crankshaft. Without doing the one piece machine work, what’s my best option for a new seal?
You got the wrong seal in your kit. By 57, all the blocks were machined for the rubber (neoprene, maybe?) seal, and the groove in the block and main bearing cap isn't machined as deep. There's no room for a rope seal to work right. Either use the 2 piece lip seal, or machine the block for a full circle type. I believe Best Gasket is making a neoprene type seal now. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Jerry, do you think the seal that Jim Carter has is a “best gasket “? It is pricey at 70dollars after shipping.
Since I have the equipment to machine blocks for a full circle seal, it's a moot point. I haven't used a 2-piece seal of any kind in a long time. I just wish the GMC engines I'm about to start working on had a similar capability. All of them use a bigger flywheel flange than a Chevy, so it's impossible to use that type of seal. I'll probably scavenge up as many of the old original equipment rope seals with asbestos in them as I can find. They're still available on Ebay at times, and just about any OEM rope seal can be used, no matter what engine it was designed to fit. Yes, I know- - - -get anywhere within half a mile of any kind of asbestos, and all of your kids will be born naked- - - - -I don't care! Anything that's resold by the resto-ripoff guys has an outrageous markup. I buy directly from the manufacturers whenever possible. LOL Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The rubber (people call it neoprene but it was more close to viton according to what Fel-Pro told me years ago) is the best option unless you're going to have the block machined as Jerry mentioned. If you use the rubber 2 piece seal be certain to use a Speedi-sleeve to restore the rear crank surface. It will very likely be chewed up and if it is, it will not work right. If you have the crank ground and that rear area polished, you'll need to shim the rubber seal to make it seal correctly. You'll probably need to add .006" to .008" underneath it. Also if you have the crank ground, make certain the work is done so that the bearing clearance is right on the lowest of the factory suggested clearance. Which is .001". That will keep that long wobbly crank from moving around as much and keep as much oil from shooting out of that bearing to crank area. Good luck!
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
The thin stainless steel strip that holds some windshield wipers together makes a good shim to put under a rubber seal to tighten it up when running it in a groove designed for a rope. Stick it into place with some green LocTite "stud and bearing mount" before installing the seal. That's simpler and less expensive than using a speedy sleeve if the seal surface isn't rough or scored. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
That strip is very good for that purpose. Just be certain to inspect the rear crank surface really well. Below is the last one I saw and it is a fine example of what a rope seal will do over time in a very humid climate...it will absorb and wick moisture to that area and you'll wind up with a pitted mess. Good luck!
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
It's a 3 7/8 inch sleeve (3.875) that slightly increases the diameter of the surface it's installed on, and makes the seal grip the shaft a little tighter. It also is made of stainless steel, which is more rust resistant than the original crankshaft material. The raised lip is intended to be removed after the sleeve is installed, but if there are no clearance problems involved it can be retained to act as an oil slinger to help keep the seal from being flooded with oil that escapes from the main bearing. Using a small amount of red Loctite during installation can also be done to assure a tight fit. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The rear surface of the crank is in really good shape. I think I’ll try the 2 piece rubber seal and see what happens. Thanks for all the help guys Rick
Good...here is what I do, Rick: set the block upside down (main bearings pointing upward). Set in place the bearing insert halves and half of the rubber seal in place in the slot for it. Then cut a common piece of copy paper about 1" wide by 7" long or so. Set this over the rubber seal (in the middle and just so it covers the seal...not on the bearing surface) and then carefully set the crankshaft in place. With the crankshaft sitting on its weight, pull the strip of copy paper out the back end and note the amount of drag involved. If there is drag present, you'll probably be okay. If there is no drag present, lift the crank out, remove that piece of rubber seal and cut a strip of self-adhesive foil tape (the kind the HVAC guys use on ductwork). Cut it the same width as the bottom of the seal slot, apply it to the back side of the rubber seal, trim carefully at the ends and put everything back as before. Now check the drag and keep doing this until you feel resistance when you try to remove the piece of copy paper. The copy paper and the aluminum foil will each be .004" thick. You'll just be moving the seal lip toward the crank surface .004" at a time until it touches and that will give you enough contact to make it all Jake until the seal wears out (15,000 miles or so...hopefully longer) and you'll get to do the same thing again but probably with the engine in the truck. Don't make it too tight, however. Attached are a couple of digital images I took of a seal removed from an engine with about 60,000 miles on it and also a brand new seal piece. You can see how the seal has been worn. That's another reason you want the rear main bearing as close to .001" as possible. Good luck!
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Check the fit of the seal by pinching a 1/2" wide strip of copier paper between the bottom of the seal and the crankshaft hub as you install the rear main cap. With the bolts snug, but not yet torqued, there should be a firm drag on the paper as you pull it out. If it slides freely, add shims between the seal and the block and the main cap. It looks like Jon beat me to the seal shimming suggestion! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The neoprene seal made its first appearance for the 1956 model line. At least the pass cars. So you can find a block cast as early as late August 55 that has the rear cap machined for the new seal. What I have not been able to determine with any kind of confidence is whether the truck blocks, 56-63 came with the neoprene seal or came with rope seals. I ave seen them both ways but never a truck block that had not been rebuilt so I don’t know one way or another for certain. I have seen 57 and up blocks with the rope seal. For a while that neoprene seal was really hard to come by. The original seals were an asbestos based seal, new are fiberglass graphite affair and don’t really work all that well. If you have a 57 block, hold out for the neoprene seal. It will still mark its spot, just not as bad, lol!
I believe it might be possible to adapt a larger diameter version of the lip seal to GMC sixes by fabricating a seal holder that surrounds the flywheel flange on the crankshaft and bolts to the back of the engine block. It would require a seal about 6 inches in diameter to work on a GMC engine, I believe. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
