GG, that soft seal with high oil pressure is a no go. Those traditional seals were used for more than 70 years! Go with proven every time you can! Great intervention video! Congrats on the fix!
Gaskets or rtv, rarely both. In 1987 built a 440 bored 30 over, 2 piece rear main seal with side seals no rtv and still good today. Oil pan gaskets with windage tray and 7 quart oil pan, and no rtv.
Im glad you got it i watch nicks garage and he is the mopar man he always uses factory style rear main seals and he freaks out when people use rtv with gaskets and seals.
On old style cork gaskets it was recommended to install the cork dry as when the engine oil permeates it the cork will swell up and seal. Of course after many years of use and the cork gets hard it will fail to seal even with the tightening of the fasteners (unless the fasteners have worked loose and the cork is still pliable). I had a V6 engine in a Dodge Caravan that had a real bad oil leak at the rear main and there was a groove cut in the crankshaft sealing surface that just caused the seal to not seal. I put one of those seal savers on the crankshaft sealing surface but to no avail (had to pull the engine as there was no way to change the seal, it was a one piece job). So finally i consulted the fellow that I do business with in automotive machine shop and he found me a teflon seal through Felpro and it was also offset so that the seal ran on another part of the crankshaft that was not worn. Also teflon seals are not to be lubricated as they are designed to run dry. If you do lubricate them they will leak. This solved the problem. We had teflon seals in the 6.9 liter International engines and that was the recommended procedure as well. I have used the Permatex on the backsides of seals but it has to be dry and you have to give it time to adhere to the surface. I donot know what was used on SBC engines but when you disassemble and engine that is factory original there seems to be some sort of sealant on the mating surface where the seal sets in the grooves. Biggest problem is people use too much RTV when assembling parts and you either use RTV metal to metal (both surfaces have to be clean and void of any lubricant) or using gaskets and RTV. The RTV hampers the design of the gasket to do its job. I had a friend of mine who would always use RTV along with the gasket on rear axle covers and they always leaked. You know if some is good more is better.
Put the old school seal in,no silicone. Nick's Garage did a whole video rear main seal on a big block rear main seal. Good for you folks! Happy you got the leak taken care of!
Enjoy watching your figure out your problems. I was never a Mopar person I love SBC but I had friends who would trade their first born for a good 440 block. Keep up the good work
Great job, engine sounds really healthy, I'm a Chevy man, but when i was younger lots of my friends had big block mopars, oil leaks never seemed to be an issue with factory seals . Love watching your channel ❤❤❤
It's great that you've showed your work from beginning to end in the last two vids and not have broken the process down into multiple teaser vids as some do. Glad you figured it out and solved it with the two piece seal. Really a wise idea to have run the engine on the stand to find issues prior to installation. I had a 68' Charger in my youth but sadly, it only had a 318. It looked good though with being red, black interior and and a black vinyl top.
double up your header gaskets, they never leak, been on my big block for ten years, just check your header bolts every spring,, good luck, the crazy canuck, winnipeg canada
use the old-style seal, they work. Sounds great, it's hard to sleep when you have a lot of money into something and its not working right, feels great to get those problems fixed.
Old school, the best way! Before throwing gaskets and sealants at the header flange, check the flange at each tube and make sure they’re truly flat…I’ve found many are not right out the box! There’s a chunk of flange between the outer tubes and the inner set of tubes that can be removed, gives more flexibility for sealing. Good luck!
I have been working on a 383 with a friend of mine who is an excellent mechanic, and rebuilt many racing engines and other things, and we are restomoding a 1970 Dodge Challenger that has been a total pain in the ass and dealing with problem after problem with it. I hate Chrysler and Dodge products for a reason even though I know they made some really strong cars, I'm just a GM man by heart! We also had a rear seal leak, but the seal plate was broken and was the cause. We replaced that bad part and installed a two piece seal staggering the seal just a little bit on each side of the seem, and used RTV on it, and have not had any more problems with that yet.
Seeing you stretch that seal so much and it didnt let go made me wonder if it could have stayed in one piece and streched over the crankshaft? But as so many already said, if the old way have worked for such long time there's no need going modern 🙂
I been meaning to say I have never seen a run in stand with the engine pointed that way, the brace you have the bell housing bolted to is used for a radiator support and the back end braces the Bell housing to the bottom, I guess if i works LOL. You're getting stuff done!
I've had best luck using a 2 piece viton seal kit with a thin film of silicone on the cap surface, a dot in the corners, and thin film on the side seals to help seat the cap. Also, some aftermarket billet retainers have had the seal groove machined too deep. I would use an OEM seal retainer.
If you use that seal again (you have to cut it to put it on the crank right?) I would put a drop of Super Glue on the cut ends & glue them together on the crank 1st. It works surprisingly well. No oil on it of course. Then the rtv. 😉 Edit: nev mind. Danny.. "Sometimes ya just gotta go old school." 😎👍
Happy to see it's working at Nick's garage he had one big block Mopar he had to replace it a times it was because of a line horn issue when they honed lying horned the man's have a great day thanks to the
DON’T USE RTV ON A REAR MAIN SEAL!! That’s your problem. The RTV in the groove behind the seal has no way to get out and distorts the seal. Plus, that tiny bit at the butt joint makes it impossible to seal. You must pull the crank (it can be done without pulling pistons and heads) and clean every bit of sealant from behind the seal. Clean all surfaces with acetone. Install the new seal dry! Use a SMALL dab of Gasgasinch on the butt ends. I’ve been building engines since the’70s. Before RTV. In my opinion it’s a scourge on the automotive industry. Gasgacinch is great for oil pans and valve covers too.
It couldn't hurt to go with the old school 2 piece seal - they have better rigid support and never were a problem. I wonder if the cylinder rust formed after the engine was built, before it ran on the engine stand. Somehow moisture (high humidity) built up on the dry cylinder? (Yeah, that cam gives it great sound and giddy up.)
I'm very curious if you didn't have the wrong 12 O'clock when you installed the rear main seal, it might have been on the side of when you installed the oil pan side 😊
Had trouble on my last build, a 261 cu.in solid lifter dual carb six banger in a 53 chev truck. Oil pressure and then oil leaks with the new one piece seal. So I tore it all back apart, changed the pump, went back to the old school seal. Been running it now for three years, problems solved. So stuff happens as they say, I would go old school and tear the whole thing down and re-do.
We found that some aftermarket rear-main seals had been off because of the age of the manufacturers tooling; also we also mandatory swipe pattern test on rear main seals and can add shimming under the outside perimeter of seal to to improve wipe the pattern/contact.
Whoo hoo you's done did it. I think u have the right diagnosis on both issue's. Permetex looked to be in seal groove and outside permetex may have put more pressure in one area causing an egg shape. Thank's for trying the one piece seal, now we know not to use it. And the rust made me think it didn't get up to temputure, but like a house window with hot tempeture inside and cold outside causes condensation, same idea.
Gloves !!!! If it eats solvent you surely don't want to spray it on your skin so it is absorbed into the bloodstream. "Be kind to the old man you will one day be." - My grandfather
I would have to say that possibly there was too much sealant used in this application and that may have caused the sealant to squish out at the parting line on the seal and of course affecting the performance of the seal. A friend of mine who worked in dealerships in the early seventies when RTV sealant was just coming into use told me that you do not have to put much on the surfaces as it will just squish out and cause problems elsewhere. A man who did assembly work on engines at the machine shop I did business with told me that a lot of failed engines that someone else assembled were the result of too much RTV being used and the stuff would break loose and clog up oil pump screens and passages and of course cause bearing failure. I would have been skeptical of having to using a seal that had that one cut line although the regular seal uses two as a matter of installation. On SBC where this is a problem builders would put the seal in where the parting line was offset and that of course changed where the possibility of leaks coming from both the seal and the cap at the parting line. Way back in the late seventies a fellow told me that trick while I was in a bar in Monroe Louisianna. On Cummins engines they have a special tool that locates the rear seal plate as there is a one piece seal used but I have always just let the pressure from the seal center the plate up (that tool is quite expensive and I did not use it enough to justify the cost). I will say this though oil leaks can be the most aggravating and actually I learned from a mechanic at a dealership that rear main oil seal leaks were the biggest warranty problem that dealers had at Chevrolet dealerships hence the introduction of the one piece rear seal. The old engines had the rope style seal and there was a tool available to seat the seal but most people had to sue the crankshaft to seat the seal. You had to install the seal in the block cut it with a little sticking up on the ends and the same on the cap. you did this before final crankshaft assembly. Done properly those seals did a pretty good job. Anyway enough of this and I hope that your sealing woes have gone away.
Very strange leak as you both are so serious on the mount,..it is almost like the crankcase compression had pushed the oil out at the seal,..but this would not be the case cos everything is new and crankcase ventilation has probably been sufficient,..ok silly suggestion from me, Maybe the oldskool seal do it better,..wish you luck
Is it possible to rotate the engine 180 degrees on the run stand? I never seen a run stand where most of the heat is close to the battery and the gas tank. Maybe it's just me.
There is no need for RTV anywhere on that engine, it will always end up in your pickup screen and will make future repairs more difficult. Good quality gaskets and proper torqueing procedures will work just fine
The rust is just surface because of no lubricant on the walls you gotta remember thats bare metal it rust easy just wipe it with a clean blue paper towel with brake cleaner and oil it down and next time you run it YOU MUST put it under a load those rings need to bite otherwise you will have oil burning and blow by.
Where you cut the seal and RTVed the cut, maybe you should waited for the RTV to dry before installing the crankshaft? That wasn`t in your video.If you pushed it down it could have pulled apart and the gap stayed a gap.
Over on nicks garage channel he’s a Mopar guy and he revealed a 440 and it literally leaked from the same exact spot five times he had to tear that thing back apart and he says that’s happened over the years several times I have no clue why but I hope yours is easier to figure out than his was
You need a radiator on your run stand... you cant properly bring the engine up to temp. with a water hose dumping cold water in the engine with no thermostat... it does look like ya`ll did a good job putting the engine together... good luck
