Anybody ever have a 350 that doesn't leak?

[ubtripn]

I know that most do but I found a good crate motor and I would love not to worry about liquid levels. has anybody ever had one that doesn't dripfrom anywhere?

[Longhorn 70]

In the beginning, none leak. After a while, most do. Just keep oil changed and replace gaskets as need be. You just have to stay on top of them.

[flashed]

I put a 290 HP crate motor in my wifes 72 Malibu convertible several years ago that does not leak ,yet.

[vectorit]

Does this meen you are changing your handle from "ubtripn" to "ubdripn"?

[mrein3]

Every one I built doesn't leak a drop.

[D.PASSMORE]

On a local rebuild, the rear main seal is usually a leaker.

[OSM 70 C20]

They only leak until they are empty

[special-K]

I've had several that don't. These motors aren't known for having leak problems any more than anything else. In fact,less than most...such as Fords and Dodges

[ubtripn]

Thanks all, lol - I like ubdripn

[jus2qwk]

If it didn't have oil under it I wouldn't think it had oil in it!

[MARKDTN]

Yes, a 1-piece rear seal one. The 2-piece seal ones always leak eventually. There is a reason that Chevy went to 2-bolt valve covers and 1-pc rear main seals. They are worth it if you are swapping motors.

[Dunenutt]

It's not leaking, It's marking it's territory!

[Madtat]

It's not leaking, it's sweat from the horsepower!

[truckster]

Given enough time and use, any engine will eventually leak. But I've had a lot of success using 3M Super Weatherstrip Adhesive (black) to seal gaskets.

Seals can benefit from careful installation and a coat of lubrication before mating with rotating parts.

[TBONE1964]

Originally Posted by Dunenutt

It's not leaking, It's marking it's territory!

ha-ha-ha-ha, That's what I say.

[LEEVON]

I won't have leakers in my driveway. That said, it's not easy to get there! The thick blue rubber felpro gasket for the oil pan, when installed correctly does not leak. Don't use the valley gaskets on the ends of the manifold, but RTV instead. For the valve covers, here is the deal:

1. 5/16" cork gaskets. Yes cork, not rubber there is a reason!
2. Make sure your valve covers are flat and true. Chrome sucks, don't use it!
3. Apply a liberal amount of the "right stuff" gasket maker to the valve cover.
4. Place the cork on the valve cover.
5. Set the whole thing down on the flattest surface you can find. I'm talking mirror flat. Set some weight on top of the valve covers while the right stuff cures.

The surface that mates to the head will now be as flat as the surface you put it on. They key here is FLAT-TO-FLAT!!! Any imperfections were taken up in the cork material and the sealant. The sealer will "squish" just enough at humps or "fill" at bellies. Use load spreaders, and just snug the bolts. Not tight!

Worst oil leak I ever chased was on an '87 TBI 305. It looked like the rear main, but wouldn't leak at idle where I could see but only after it was good and hot and at higher speed (thus coating the whole underside of the truck). Clean, drive, inspect, clean, drive, inspect, clean, drive, inspect. Replaced the rear main seal and oil pan gasket. Still leaked. Went ahead and did the timing cover, intake and valve cover gaskets along with the distributor JUST TO BE SURE. Still leaked. Looked like the rear main, maybe I didn't get it perfect? PULLED THE WHOLE ENGINE! Went over everything again. Still leaked. I was about to burn the thing down. Then for some reason I thought to remove each of the bellhousing bolts and inspect them. Sure enough one was about 1/4" longer than the rest. I shined a light in the hole and couldn't see the bottom. Turns out it had busted into an oil galley. One tiny squirt of sealant on the bolt fixed the whole dang thing. When I sold it, I told the guy how hard I had worked and he says "It don't matter to me, I park on gravel and dirt all the time". DANGIT MAN, give me some credit here!!!

[see ten]

It's not so much "leaking" as "seeping" ... it's an engine design that was put into use in the 50s.... Old cars "seeped"... remember how black the center of the traffic lanes used to be from cars dripping as they went down the road?

[brad_man_72]

I use "hondabond" sealer. Go ahead and laugh, when's the last time you heard a joke about a honda leaking oil......
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[Mister-B]

The oil you use can make a difference in leaking. I like full synthetic oil, but it is more prone to leaking than regular dyno oil. I like Mobil 1 High Mileage full synthetic. It has seal and gasket conditioners in it that help with leaks. I was originally using a different brand full synthetic, and when I switched to this one, I don't have to add nearly as much oil between oil changes.

Here's one positive to a slow leak: you're adding fresh oil to the engine here and there, and so it freshens up the oil in the engine, vs someone that never needs to add oil between oil changes
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[Longhorn 70]

My Corvette, which is a 383 LT4 still uses the same basic setup as Joe 350 except there are a few more places to leak. I run Mobil1 5w30 all year around. Doesn't leak a drop. I make sure with a piece of cardboard where I park. One drop of oil on the cardboard turns into a 3" circle.

My wife's 2008 Rav4 with a V6 has had the engine pulled to replace seals in it under warranty with only 50K on the clock.

Give me a GM motor anyday.

[BruthaMan]

A friend that helped me on my '78 build had '84 that leaked pretty bad. I used to tell him to put a maxi-pad under his truck when he came over.

My '72 has started leaking a little more than usual. Have heard that putting a thicker oil in can solve the problem. Valvoline Max Life, in fact...was just reading about it earlier this week. Supposed to help with oil leaks.

[Mister-B]

Originally Posted by BruthaMan

A friend that helped me on my '78 build had '84 that leaked pretty bad. I used to tell him to put a maxi-pad under his truck when he came over.

My '72 has started leaking a little more than usual. Have heard that putting a thicker oil in can solve the problem. Valvoline Max Life, in fact...was just reading about it earlier this week. Supposed to help with oil leaks.

Maxi Pad. That's funny

Yeah, that Valvoline Max Life is good stuff. I prefer the full synthetic Mobil 1 High Mileage though
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[Hawssie]

86 up blocks don't leak that much. Gm did a major improvement on the rear main seal and valve cover gasket designs as mention earlier including the one piece M.S. design.. Never had one of the 85 down that didnt leak some.

[BruthaMan]

Originally Posted by Mister-B

Maxi Pad. That's funny

Yeah, that Valvoline Max Life is good stuff. I prefer the full synthetic Mobil 1 High Mileage though

That's what I've been using, is Mobil 1. It's a GM crate motor with about 15k miles on it. Rear main.

I have a number of "stop leak" products I picked up on Amazon, just to keep around and try out between oil changes, to see which one worked best.

Leak isn't bad, just annoying.

[ubtripn]

Thanks for all the info!