70ChargerRT
Well-Known Member
Do they still Make It?
Fat Fish Rear Main Seal
- Thread starter 70ChargerRT
- Start date
steve340
Well-Known Member
Yes it is Fast Fish
70ChargerRT
Well-Known Member
Ok thanks! Was thinking about giving it a try, hadn’t found no post in a long time about them and was wondering. Engine is out, crank is in. I’ll look them up and give ‘em a call.
steve340
Well-Known Member
The one piece seal is a good idea I think. I like his retainer that eliminates those side seals.
I did a Ford 428 FE years ago and home modified the rear seal system on that to use just sealer no side seals and it worked out well. That FE Ford engine is notorious for rear main leaks like the Mopar big block.
I am thinking maybe most folks have a leak from the seal retainer housing rather than the crank seal itself.
Let me know how it works out.
I did a Ford 428 FE years ago and home modified the rear seal system on that to use just sealer no side seals and it worked out well. That FE Ford engine is notorious for rear main leaks like the Mopar big block.
I am thinking maybe most folks have a leak from the seal retainer housing rather than the crank seal itself.
Let me know how it works out.
70ChargerRT
Well-Known Member
Well I built this engine 4 years ago and it has leaked from day one. The motor doesn’t even have 500 miles on it but that’s another story. Me and the engine builder talked and he guaranteed it wasn’t the crank seal but the factory retainer and I agreed also so I didn’t take it out. I put a Mancini rear in it Friday evening and it went in beautifully. Sunday morning i put 6 quarts of 0w20 in it. Hooked it to an engine puller and leaned the motor way back putting the oil against all of the rear. Well it leaked. It Didn’t leak out the sides or the bottom of the retainer. It looked like the crankshaft block seal was leaking. It was oil soaked bad and it pushed out with little resistance. Now I will add, he didn’t have it clocked but I had the seals glued together with Right Stuff and he had used a rubber felcro seal with factory retainer.
Geoff 2
Well-Known Member
I built a 440 last year & the owner bought a new seal housing [ from 440 source ]. The fit/sizing was not as good as the factory housing. So I used the factory housing. Also, I never use the side seals. I fill the slots with silicon & leave for a day or two to harden. Then silicon the sides & base & install. Engine has not been started yet.
70ChargerRT
Well-Known Member
My Mancini was perfect. I did use the 2 small o-ring side seals but I used Black Right Stuff on everything. I don’t like Ultra Grey, never did, it’s not made for oil but Ultra black is. It did not leak on the sides or the bottom part of the retainer. Leaning the motor back filled with 0w20 trick works. I also turned the crank a few times. I had the seals glued together and it was leaking at the block crank seal. I easily pushed it out and it was soaked with oil. I’m thinking about just using Right Stuff instead of the oil rings this time.
gkent
Well-Known Member
How does it not use side seals ??
Challenger340
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Yep.... we 'hang' every BB Mopar engine we assemble here with just the Crank/Seal installed and completely submerged in Oil for a few hours before proceeding with the rest of the assembly.
If it's gonna leak ?.... we want to know BEFORE we run it on the Dyno !
Forget the side seals, we use the side to side 'play' in the retainer and move/drag the seal half side that doesn't seal against the crank over into contact(BB Mopars are notorious for that).... then tighten the Bolts and just silicon the sides up.
Factory retainers, stock seals.... never an issue.
May I ask why you are using 0W20 Oil for anything ?
If it's gonna leak ?.... we want to know BEFORE we run it on the Dyno !
Forget the side seals, we use the side to side 'play' in the retainer and move/drag the seal half side that doesn't seal against the crank over into contact(BB Mopars are notorious for that).... then tighten the Bolts and just silicon the sides up.
Factory retainers, stock seals.... never an issue.
May I ask why you are using 0W20 Oil for anything ?
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70ChargerRT
Well-Known Member
70ChargerRT
Well-Known Member
0w20 is the oil I use to submerge my seals with because if any oil will find a leak 0w20 will. Are you confident enough in your process that you go ahead and install all of the gaskets on your oil pan and windage tray?
70ChargerRT
Well-Known Member
Got the Fast Fish rear main seal in this evening. I really like this set up. Double lipped, the retainer is notched out for my APR cap bolts and nuts, the inside bolt holes had plenty of play to keep the retainer center on the seal itself and the No side seals is genius. I put the seal in with the motor out without loosening the cap.This is a lot better set up than the Mancini I used the last time in my opinion. I’ll give her an oil bath tomorrow and see if she leaks or not.
70ChargerRT
Well-Known Member
Well looks like I have a clearance problem where the crank sets in the block. The oil looks like it’s bypassing in between the seal and the block retainer if that’s what you call it. Dry as a bone on the side and it’s dry on the retainer side. I pulled the fast fish seal out and put a 2 piece in. Glued it together on both sides, let it dry amd clocked it 6 and 12 and got the same
Results. The oil is bypassing the upper seal. The only thing I can do now I guess is put a rope seal in it without pulling the crank.
Results. The oil is bypassing the upper seal. The only thing I can do now I guess is put a rope seal in it without pulling the crank.
I just installed one in mine while in the car. So we will see here as well. Did you put ANY sealant on the seal itself between the seal and the retainer groove whether in the aluminum retainer or the upper part in the block? The directions tell you to. I never give up so if mine leaks I will remove, clean, and reinstall. Whatever you do is never quit. I come from BBC Chevelles and I detest rear main seal leaks. UNLIKE MOPARs I had to pull the engine to change them for my set up. I did it 4 times in my Chevelle before I was successful. It ended up being that the VITON seals were too stiff and the cheaper blue silicon seals worked the best. It was dry as a bone before I sold it. Same here with the Hemi I bought. Ray Barton engine and has a Mopar performance billet aluminum retainer. The FAST FISH set up is way better. The seal itself is more pliable and does not have a steel core and is also made by the guy at FAST FISH/ Double lipped and if you notice fits the groove perfectly. The seal in my old one was not close and was also just sitting in there, no other sealant. Just because it leaks this time try it again with the same stuff. You will get it.
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I guess with respect to the big block Chevy you must be talking about a newer block made after 86 with the one piece seal. On my 66 427 Vette it was just a matter of dropping the pan and removing the rear main cap.
But anyway, I just installed a Hughes Engines rear retainer and their seal kit in my 66 Hemi and it seems to be sealed up. It appeared to have been leaking past the side seals with the old composite material style ones previously. I put tracer dye in the oil and its good so far back there. Now the valve covers are next.
But anyway, I just installed a Hughes Engines rear retainer and their seal kit in my 66 Hemi and it seems to be sealed up. It appeared to have been leaking past the side seals with the old composite material style ones previously. I put tracer dye in the oil and its good so far back there. Now the valve covers are next.
You were not dropping the kicked out pan on mine with full length headers, scatter shield etc. I even had to loosen a header to get the oil filter out.
Yup, doing my valve covers too. Went to a silicon based gasket. We will see.
70ChargerRT
Well-Known Member
My engine builder originally put RTV in the upper part of the retainer but the leak was coming from the retainer rear main seal because it didn’t have enough crush because he bottomed out the original retainer on my ARP bolt nuts
Why didn’t he see this I’ll never know. If i would have known it was going to leak toward the block side I would have left the rubber seal in it and would have tried to glue another seal to it but since he didn’t clock it that bugged the crap out of me so I jerked it out . My rope seal will be home Monday but I won’t be able to install it till Friday night. If this doesn’t work I’m going to jerk the crank out.steve340
Well-Known Member
Rope seals "crush in" and kind of need to be smoothed out. I don't think they will go in with the crank in place.
I fitted a few when I was an apprentice but that 40 years ago.
They also are very tight on the crank.
I fitted a few when I was an apprentice but that 40 years ago.
They also are very tight on the crank.
70ChargerRT
Well-Known Member
Planned on smoothing it or forming it out in the retainer cap. Then loosen the cap bolts and raising up the crank just enough to get ahold of it with the sneaky Pete tool. My buddy had the exact problem with his 440 15 years ago and the rope seal with this method worked for him and he is still leak free. Maybe it’ll work for me, maybe it won’t, maybe he just got lucky. If it don’t feel right I’ll just go ahead and jerk the crank out.
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