360 now 408 stroker oil pan still leaks!!

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fuzzman

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I have had this motor for ten years. It used to leak at the rear of the motor and I changed the gasket twice and still could not get it to stop leaking. Than this winter rebuilt motor to a stroker 408 and it started leaking in the rear again so I tried to go through and tighten all the bolts now it is leaking on the front seal. Before I take the pan off this winter is there any secrets that anyone has to stop the oil pan from leaking? A one piece ruberized gasket would be nice for our beloved small block's.
Help!
Pat Faley
1967 Barracuda Notchback
Peoria IL
 
I have had this motor for ten years. It used to leak at the rear of the motor and I changed the gasket twice and still could not get it to stop leaking. Than this winter rebuilt motor to a stroker 408 and it started leaking in the rear again so I tried to go through and tighten all the bolts now it is leaking on the front seal. Before I take the pan off this winter is there any secrets that anyone has to stop the oil pan from leaking? A one piece ruberized gasket would be nice for our beloved small block's.
Help!
Pat Faley
1967 Barracuda Notchback
Peoria IL

It sounds like maybe you should just get a new pan? sounds like it is warped.
 
pull the pan knock the bolt hole back, you might have over tighten them. use a good cork gasket set and clean the pan and block. apply a good skincoat of RTV let set sould be ok O72D
 
Are you running a PCV valve? If not, try it out. If you are, change the valve. I'm thinking that you're having pressure building up in the crankcase, pushing oil out of the crank and pan seals.
 
Fuzzman-

What machine shop did your stroker work? I am interested in stroking my 318 and could use some advice...
 
There is a one piece rubberized pan gasket available for a 360 small block, I have one. I bought it some years ago. I can't remember were I bought it. It may be an MP part.

Chuck
 
Are you running a PCV valve? If not, try it out. If you are, change the valve. I'm thinking that you're having pressure building up in the crankcase, pushing oil out of the crank and pan seals.

Great point, this is often overlooked. I just had the same issue on my new little roller 318, changed the PCV valve, leak stopped.
If you run a HV oil pump, it even makes it more difficult on some of the sealing.
 
Use black RTV on all oil gasket surfaces. I had the same problem but it turned out the header was blocking the valve cover from sealing in the back near the fire wall and when I launched a small stream of oil was running down the space between the head and the block but looked like the oil pan was leaking. I felt like an idiot after I found it but would have bet money the rear seal on the pan was leaking.
 
this is funny cuz i have a slight oil leak but from the front of the pan on my 408. for right now ill live with it since id rather keep the car on the road. let us know how it goes though cuz ill have to do the same.
 
Chenoweth speed and machine I highly recommend them. They have a very shop and you can read about them in Mopar Muscle they placed second in the engine building contest for building a big block. They are in this years contest to build a killer small block.
 
I did put a new pan on it and I had the same problem and when I put the new gasket on the new pan I also checked to make sure all the holes were straight and not pushed in.
 
Are you running a PCV valve? If not, try it out. If you are, change the valve. I'm thinking that you're having pressure building up in the crankcase, pushing oil out of the crank and pan seals.
I still have the original pcv valve and I'm planning on putting it back in. I picked up a chrome one from a speed shop this summer and have been using it and that might be one of the problems. Thanks
 
Use black RTV on all oil gasket surfaces. I had the same problem but it turned out the header was blocking the valve cover from sealing in the back near the fire wall and when I launched a small stream of oil was running down the space between the head and the block but looked like the oil pan was leaking. I felt like an idiot after I found it but would have bet money the rear seal on the pan was leaking.
I will pick up some black RTV and give it a try when I change out the gasket this winter. I use the black wrinkle mopar performance valve covers and I had a problem before with the valve covers leaking using the cork gaskets so, I went with the rubberized ones and it solved my leaking valve cover gasket problems. Thanks
 
Great point, this is often overlooked. I just had the same issue on my new little roller 318, changed the PCV valve, leak stopped.
If you run a HV oil pump, it even makes it more difficult on some of the sealing.
I may try that and see if that solves it. thanks .My next project car is a 69 rag top red with a white top: is yours a 68? Nice Car!
 
Great point, this is often overlooked. I just had the same issue on my new little roller 318, changed the PCV valve, leak stopped.
If you run a HV oil pump, it even makes it more difficult on some of the sealing.
I'm also running a stock Oil pump but, with high oil pressure at 1000 rpm I'm running 45LB and at 3000rpm I'm up to 60 to 80lb. I have good oil pressure.
 
are you sure it aint the rear main seal

have the same problem and it end up being the rear main seal
 
Not sure if someone has said this...but when you line hone the mains, the pan end seals are...too long and like to buckle and leak...

It all depends on how much was honed out, usually only .005 or so but who knows what they did, and how many times.

If you see the seal bulging out just a hair...thats a good indicator.
 
Not sure if someone has said this...but when you line hone the mains, the pan end seals are...too long and like to buckle and leak...

It all depends on how much was honed out, usually only .005 or so but who knows what they did, and how many times.

If you see the seal bulging out just a hair...thats a good indicator.


What are you talking about?? The seal rides on the main cap and the block rails, how would line honing change that? Maybe I am not getting what you mean?
 
Not sure if someone has said this...but when you line hone the mains, the pan end seals are...too long and like to buckle and leak...

It all depends on how much was honed out, usually only .005 or so but who knows what they did, and how many times.

If you see the seal bulging out just a hair...thats a good indicator.

You know now that you said that the front main in the middle where the oil is leaking the rubber is pushed outward just a tad and the paint isn't on that part of the seal anymore. Right at first the rear started leaking just enough that when I drove it oil would coat the bottom of the dust shield on the trans. I asked the motor builder about it and he told me to tighten up the pan bolts so i have a little at a time. Than I notice another oil spot on the garage floor and sure enough the front started leaking and just like you said it looks just like the middle of the seal has a slight bulge where the paint is gone and you can see the blue ATV sealer showing. It seams to leak more when the motor is running, because it is right behind the fan and it blows it all over the front of the oil pan. I looked up the torque value of the oil pan and it says to torque them to 15 ft lb which translates to 180 inch lb. I have a inch lb torque wrench but I haven't gone that route yet to check them with a torque wrench. So what is the answer if the rubber gaskets are to long? Can you trim them down? or use alot of sealant on the ends? My plan is to try this winter and take the oil pan off and change the gasket and try a Felpro(rubberized) or a Milodon (crush proof) Gaskets. Sorry for the long post.

Pat Faley
67 NB Barracuda S Clone
Peoria IL
 
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