283 rear seal leaks on new build

[realsteelGM]

Just finished a complete rebuild on a 1958-283, on break in had major oil leak out rear of block. Used "Best Gasket #3711" in place of rope gasket. Are there any other oil plugs on this year of block that could have blown out? Installed a high volume oil pump also. Installed a new re-conditioned crank, would this be ground down to a smaller diameter at the real seal section on the crank?

[MARKDTN]

Can't exactly answer your question but early 283s oil a little different than later ones. I thought 58 was the first year but may be wrong.

[RustyPile]

1955 265 V8s did not have an integrated oil filter. The filter assembly was externally mounted on a bracket attached to the upper engine. Also, the rear bearing surface on the camshaft had a notch that allowed oil flow to the lifter bores. In 1958, this "notch" was machined in the block under the rear cam bearing.. In 1959, the rear seal was changed from the rope type to neoprene. Over the years, several gasket manufacturers have offered a replacement for the rope seal..

Here's a very good video about the proper method for installing the rear seal..

https://www.bing.com/videos/rivervie...4DF8&FORM=VIRE

The seal surface on the crankshaft is never reground, it's only polished.. Are you sure the seal is leaking?? The oil could be coming from one of the oil passage plugs at the rear of the block.

[chris mc bride]

1957 first year for 283, 55 wqs 265 and 327 in 62. May not know what day a war happened trhat meant something but remeber my car history.Hell Car craft,super chevy,poplar hot rodding or super stock was in my history book.

[realsteelGM]

Originally Posted by RustyPile

1955 265 V8s did not have an integrated oil filter. The filter assembly was externally mounted on a bracket attached to the upper engine. Also, the rear bearing surface on the camshaft had a notch that allowed oil flow to the lifter bores. In 1958, this "notch" was machined in the block under the rear cam bearing.. In 1959, the rear seal was changed from the rope type to neoprene. Over the years, several gasket manufacturers have offered a replacement for the rope seal..

Here's a very good video about the proper method for installing the rear seal..

https://www.bing.com/videos/rivervie...4DF8&FORM=VIRE

The seal surface on the crankshaft is never reground, it's only polished.. Are you sure the seal is leaking?? The oil could be coming from one of the oil passage plugs at the rear of the block.

I have pictures to show of the rear bearing with new neoprene seal to upload, the site wouldn't let me load them. Would the high volume oil pump open up one of the rear oil plugs? Where are they located? Are they the 3 plugs located close to the rear of the cam that screw in with allen keys? The only other place I could see would be the blue problem solver gasket, it's broken in two at the rear corner of the oil pan. I mended it with "Right Stuff" silicone before putting oil pan back in place. Would there be increased oil pressure pushing out two or three quarts of oil at the weak part of the pan gasket in just 40 minutes of break in due to adding high volume oil pump? Can this 1958 block handle a high volume oil pump? Thanks for chiming in!

[geezer#99]

Make your pics smaller. Then they’ll upload.
And yes those are the plugs.

[RustyPile]

Originally Posted by realsteelGM

I have pictures to show of the rear bearing with new neoprene seal to upload, the site wouldn't let me load them. Would the high volume oil pump open up one of the rear oil plugs? Where are they located? Are they the 3 plugs located close to the rear of the cam that screw in with allen keys? The only other place I could see would be the blue problem solver gasket, it's broken in two at the rear corner of the oil pan. I mended it with "Right Stuff" silicone before putting oil pan back in place. Would there be increased oil pressure pushing out two or three quarts of oil at the weak part of the pan gasket in just 40 minutes of break in due to adding high volume oil pump? Can this 1958 block handle a high volume oil pump? Thanks for chiming in!

When I was racing, I built many, many 283s, 301s, and 327s. A stock Mellings oil pump at 7K RPM provided plenty of lubrication. I see no need for a high volume oil pump on a basically stock or even a mildly modified 283.. Warmed up and ready to go oil pressure at idle should be around 15 - 20 lbs. Highway speed oil pressure should be 35 - 45 lbs.. What is your oil pressure under those conditions???

Yes those three small plugs plus the large plug, (looks like a freeze plug) at the rear of the camshaft. Three quarts in 40 minutes makes me believe it's a pressurized leak.. However, that broken gasket is also suspect. Replace it.

[realsteelGM]

Originally Posted by MARKDTN

Can't exactly answer your question but early 283s oil a little different than later ones. I thought 58 was the first year but may be wrong.

1957-1959 I believe came with a forged steel crank. These blocks are different for sure as I tried to place a 1960's crank in mine and it would'nt fit. Thanks for the chiming in!

[realsteelGM]

Originally Posted by geezer#99

Make your pics smaller. Then they’ll upload.
And yes those are the plugs.

Thanks for the info on pictures!

[realsteelGM]

Originally Posted by RustyPile

When I was racing, I built many, many 283s, 301s, and 327s. A stock Mellings oil pump at 7K RPM provided plenty of lubrication. I see no need for a high volume oil pump on a basically stock or even a mildly modified 283.. Warmed up and ready to go oil pressure at idle should be around 15 - 20 lbs. Highway speed oil pressure should be 35 - 45 lbs.. What is your oil pressure under those conditions???

Yes those three small plugs plus the large plug, (looks like a freeze plug) at the rear of the camshaft. Three quarts in 40 minutes makes me believe it's a pressurized leak.. However, that broken gasket is also suspect. Replace it.

The oil pressure gauge was maxed right out at 3000 rpm, all the oil was splashed over the clutch I can't see that coming from the oil pan gasket. I didn't drive it at highway speed, just used the manual transmission to vary my rpm for "break in". I followed several videos and was meticulous about installing neoprene rear seal. My first build on this engine was 14 years ago and all things checked out A-1 with a rope seal, however it constantly dripped and sprayed oil in clutch housing. How can I find out where this oil is coming from without dismanteling the entire block?

[kwmech]

Repeatedly I've seen people install the neoprene seal backwards in the main cap. Lip forward in the block, but somehow manage to flip it around in the cap. Also, staggering the seal by a 1/4'' on the split is recommended. If it is "gushing out" there may be a different issue. Can you remove the transmission and start it?

[57taskforce]

You would almost have to have no rear main seal in place for it to leak like that. I too would bet it’s a pressurized leak of some sort… galley plugs, etc.

[realsteelGM]

Originally Posted by kwmech

Repeatedly I've seen people install the neoprene seal backwards in the main cap. Lip forward in the block, but somehow manage to flip it around in the cap. Also, staggering the seal by a 1/4'' on the split is recommended. If it is "gushing out" there may be a different issue. Can you remove the transmission and start it?

Yes checked and made sure seal was facing proper direction, and staggered about 1/4 inch with sealant on ends. I can't see why I would'nt be able to start it with the trans SM-420 intact. Would I have to take the clutch and pressure plate off also to scan for oil leaks?

[realsteelGM]

Originally Posted by 57taskforce

You would almost have to have no rear main seal in place for it to leak like that. I too would bet it’s a pressurized leak of some sort… galley plugs, etc.

How do you diagnose galley plug leaks without the engine running?

[RustyPile]

Originally Posted by realsteelGM

How do you diagnose galley plug leaks without the engine running?

"Pegged oil pressure gauge"?? I repeat, get rid of that high volume oil pump.

I suggest removing the engine. Remove the clutch, flywheel and bell housing. When you find the source of the leak, you'll probably need to do this anyway.. Using a variety of "plumbing" adaptors, connect an air hose at the location of the oil pressure gauge. Using an air compressor, adjust the air pressure to about 50 pounds. Open the valve and look for air leaks.. This won't do anything toward checking that broken gasket, but it will show any pressurized leaks. My money is on leaking plugs at the rear of the engine.

[geezer#99]

What did you use for a gasket on the china wall at the back of the intake?

[MySons68C20]

Pull the distributor and spin the oil pump with a priming tool. With the volume you are leaking it should be obvious where it is coming from.Will be a lot easier to see without the engine running.

[realsteelGM]

Originally Posted by RustyPile

"Pegged oil pressure gauge"?? I repeat, get rid of that high volume oil pump.

I suggest removing the engine. Remove the clutch, flywheel and bell housing. When you find the source of the leak, you'll probably need to do this anyway.. Using a variety of "plumbing" adaptors, connect an air hose at the location of the oil pressure gauge. Using an air compressor, adjust the air pressure to about 50 pounds. Open the valve and look for air leaks.. This won't do anything toward checking that broken gasket, but it will show any pressurized leaks. My money is on leaking plugs at the rear of the engine.

I'll get back to you later on hopefully with smaller format pictures of the oil plugs when I did the build.

[realsteelGM]

Originally Posted by geezer#99

What did you use for a gasket on the china wall at the back of the intake?

"Right Stuff" silicone.

[geezer#99]

What intake did you use?
Some don’t clear the road draft canister

[realsteelGM]

Originally Posted by geezer#99

What intake did you use?
Some don’t clear the road draft canister

Edelbrock 2116 never had an issue with it in 14 years.

[1970-CST]

Was the block line honed? Not sure on the 283, but the 327 / 350 etc if the mains are line honed there is a different part number for the rear main seal.

Do you have a PVC system installed and if so is it hooked up correctly and working?