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-   -   Oil Leak on SBC....please help. (https://www.racingjunk.com/forums/showthread.php?t=20484)

altune 04-10-2008 06:56 PM

We had the same problem an an engine from a well known builder.
it was the rear allen next to the cam plug, use some plumbers liquid seal.
screw those in as far as they will go.
we did the same, thought it was the pan.
asked if the dydo room had any oil on the floor after our 8 pulls and they said , our dyno floor is always oil free, oh well

degnitz_3732 04-10-2008 08:11 PM


Originally Posted by suicidebomb
Make sure that the plug and hole are not threaded with different threads. ie NPT & SAE.

suicidebomb

I ran a 1/4 NPT tap into the hole and it seemed pretty loose even when it was completely turned into the threads?? Would and SAE thread be a straight thread? It wouldn't be tapped to 1/4 NPS (National Pipe Straight) would it????? I'm pretty confident that the plug is tapered.....but i did question if it was indeed tapped with a tapered thread. Any suggestions??

suicidebomb 04-10-2008 08:33 PM

SAE threads are straight threads. Some NPT&SAE threads are close enough to screw together, but they probably wont seal under pressure. I have seen NPT threads screwed into holes with SAE threads & vice versa. Did this answer your question? If not holler
NPT threads are a tapered thread, They are tapered 3/4 inch to the foot. I don't know why I know this but I do.


suicidebomb

cepx111 04-10-2008 11:43 PM

"I don't know why I know this but I do" thats scary dude...lol

Serioulsy if the fitting doesnt seem like it wants to tighten up , put alittle extra teflon tape on it or just toss it and try a new fitting, sometimes they get alittle carried away tapping them fittings and run it to far down the fitting which will keep it from being able to tighten up all the way. I prefer the shouldered brass set plugs over those allen ones and also I use a combination of telfon tape and pipe dope.
Goodluck, Charles

degnitz_3732 04-11-2008 05:12 AM


Originally Posted by cepx111
"I don't know why I know this but I do" thats scary dude...lol

Serioulsy if the fitting doesnt seem like it wants to tighten up , put alittle extra teflon tape on it or just toss it and try a new fitting, sometimes they get alittle carried away tapping them fittings and run it to far down the fitting which will keep it from being able to tighten up all the way. I prefer the shouldered brass set plugs over those allen ones and also I use a combination of telfon tape and pipe dope.
Goodluck, Charles

Yeah....do you think it's a possiblility that they put a straight tap in there?? If so....would you need a shouldered bolt to seal it off?? And about the teflon tape.....that is what we did the last try. We cleaned everything and tefloned it and used some sealer on it also. One more question.....can you use a brass plug in a steel block??? Thanks for everyones input. Derek

performanceengin 04-11-2008 05:48 AM

the dart little m uses 1/4 npt. on rear plugs. remove all 3 plugs, check them close or pitch snd install new ones. use pst thread sealant and tighten good. you can use steel or brass. this block has priority oil system in it and they don't recommend restricters. also check plugs to see if they may have a small hole through the center, have had that problem before..

degnitz_3732 04-11-2008 02:32 PM

So tomorrow we will be taking the transmission and converter out of the car and starting the motor so we can see exactly where the oil is coming from. Out of curiousity has anyone changed the rear seal before? Will we know if it is in backwards? We are obviously going to have our motor builder do this for us, but i'm curious how it works. I was told that you might get away with just loosening up the rear main cap???? Or will he have to take of all four caps? Is this not a good practice? Let me know if you have any suggestions.
Derek

Racefab57 04-12-2008 05:44 AM

On the rear main seal, if you change it, the seal lip has to point IN towards the frt of the motor! The other part of the rear main's seal is the dust seal Its a straight lip seal. You'll see it and tell the difference between the two lips. Long story short, the seal thats at an angle is the rear main -IT POINTS IN!!!!!!!!!!!! David. Pm me any time !

degnitz_3732 04-13-2008 03:11 PM

Well....for anyone who is curious, we think we finally have it fixed. There is another 1/4 npt plug in the bottom of the block that is on the oil filter side. So we dropped the pan and cleaned the threads out and used loctite thread sealant on all of these. Started the motor again and had it running for about 20 minutes ( got the oil temp up nice) and we couldn't see any oil coming out of anything. Basically it seems that if there was a little more time spent on sealing these plugs this would have been alot easier!! Thanks for everyones help. Derek


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