oil seal problems

[ljbarryiv]

I just finish a full rebuild of a bigport bluetop 4age for my ae86. Everything was fine until I did a track day at NJMP this week end. I had to cut my day short because oil was leaking out the front pully seal. I lost about 1/2 quart of oil during the 20 min run. As soon as the oil cooled off it stoped leaking. I drove the 4 hours home with no leaks. I cleaned the engine bay and then warmed it up and drove it hard for a few min. Still no leak. The engine has been completly rebuilt. New seals, oil pump. Is this seal know for leaking? I was running regular 10w40 oil with working stock oil cooler. And yes I greased the lips of all the seals when I put them in. No other seals are leaking that I can see. The seals came from toyota. Maybe I just got a bad seal?

[oldeskewltoy]

sometimes the previous seal puts a small groove into the crankshft. if the new seal is in the exact location... the seal can leak

[ljbarryiv]

I checked the crank the wear mark was barely noticeable. I don't think that it.

[rick q]

I had a seal fail in mine shortly after rebuilding an engine - but it kept leaking after coming off the track as there was a whole piece missing.

My guess would be that you might have venting or blowby issues. Since the leak only occurred when the engine was being thrashed [when blowby is highest], you may either have too much blowby [rings haven't sealed] or either your PCV valve or the vent at the rear of the head is blocked.

The subsequent build up in pressure in the crankcase finds the paths of least resistance [the seals] and as it squeezes out there it takes oil with it. Might pay you to see if there's an oil leak showing at the bellhousing in case it's also leaking through the rear seal.

[ljbarryiv]

That was a possibility I thought. The engine was rebuilt to OEM specs. It has no noticeable oil burn and runs very strong. Its got now maybe 2-3k on it. The machine work was done at a very high quality shop known for their build quality. The motor made 130whp in my ae86 on a mustang dyno. The motor has stock high comp pistons from a redtop and 264 poncams. The motor is fresh and runs strong. I would think with high case pressure it would have pushed the dipstick out first. I had a friend who drifts his ae86 hard and said his pops the dipstick out sometimes. It looked like mine was still in but when I saw the oil all over I pulled the dipstick out right away to see if I hurt the motor and now I am not 100% sure if it was still all the way down. There was oil inside the lower timing cover so I am sure the seal was leaking. Is there a case venting problem on the 4age? I have seen some cars running two passage side valve covers for more venting? Anyone else have this problem? I plan on bringing this motor to 8,000 RPM on the track as soon as I get the Megasquirt installed. When I get time I am going to check the rear main seal as well just to be sure. How about oil? Maybe I just need thinker? I have a 93 mr2 with a 3sgte making 360whp and it has never leaked oil since I rebuilt it 2 years ago. I beat the crap out of it last year at Pocono and no leaks. I was running 10w30 full synthetic Castrol.

[ljbarryiv]

Oh I did check and the vent hose was venting. Didn't notice any larger amount pressure flow but is there away to check case pressure? Wasn't pushing oil into the intake which is what my broken ringland did on my 3stge.

[gotzoom?]

Ring seating has nothing to do with the quality of the shop or work. That comes from breaking in the engine properly. You have only a short period of time to get the rings seated until the sharp edges of the hone are worn off. If you miss your chance, you'll never get the rings to seat properly without a re-hone (and rebuild that goes with it.)

IMO, babying the engine for some amount of miles is not a good approach for breakin. You need crankcase pressure in order to force the rings into the cylinder walls to get them seated. The easiest way to do that is by lugging the engine. My preferred method of breakin is to go to may favorite mountain road immediately after engine install, put the transmission in 4th gear and drive the whole thing in 4th, which keeps the revs under 4k, but much of the time, it is between 1000 and 2000rpm. When you put your foot to the floor at low revs, it creates good crankcase pressure which seats the rings quickly. Then you can do an oil change and baby the engine for 1000 miles or whatever you feel good about.

[ljbarryiv]

I didn't baby it. I made sure I loaded the engine up. I did quick pulls of full throttle. This isn't my first engine build but I am not saying I am an expert either. To many opinions on how to breakin a motor out there. Most end up fine.