Question about 66 mustang...

Ive got a 66 coupe with a 289 that is running decently except for some blowby. I know its being caused by bad rings, and a mechanic friend told me that if i drain the oil and run it with some ATF for about 20 minutes, then drain and refill with regular oil, i could clean up some gunk on the rings that might not be causig them to seal properly. Does this really work? Or will it seriously mess somethign else up?

Ive rebuilt the heads and taken off and checked the oil pan (replaced the gaskets and seals too). I will replace the bearings and rings during my winter break, but that is in 2 months and i need the car to get me from Reno to Las Vegas so i want it to be able to make it. How long can i expect it to take me to replace the rings and bearings and can i do it with the engine in the car?

Reply to
Errol Smith
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Reply to
Bill S.

Its your car. Personally, I'd live with the blowby for the distance you have to drive, or replace the oil cap you have, and replace it with a cap for a "closed system" and attach a piece of heater hose that will run down below the engine and let the oil fall to the ground. Just check your oil often and keep it full. The engine could be damaged if you ran straight tranny fluid for 20 minutes... If you're really blowing alot of oil, a tow might be prudent.

Reply to
Mustang_66

I wouldn't run ATF in it or replace the cap as mentioned below. One, I've never heard of doing this. It might be perfectly acceptable, but it sounds scary to me. Second, if it's cleaning off old gunk around the rings I imagine it's cleaning out other sludge deposits. Where is it going to go? Will it make it through the pump without damaging or clogging it? What other damns is it going to break free in a 30 year old motor? Might have a Jonestown flood on your hands! If by chance you really are loosing oil through the breather, just keep it wiped off. I suspect you are really having more issues burning the oil than loosing it in liquid form. Anyway, how many miles to the quart are you getting? Can you still see behind you through the blue smoke? :-) A leakdown test would help tell you how bad you really are. Personally I would find another block and have it properly cleaned, machined, re-ringed and have new bearings installed. Magnafluxing is always a good idea before you buy it to make sure it's sound. After that you only have a weekend project in store to swap it out especially if you have help. As for doing it all in the car, it might be possible to just swap stuff out but to do it right it will have to come out and go to a machine shop.

Reply to
Bard

I wouldn't run straifght ATF, but I have heard of using it to clean out sludge and build-up. I've always heard it suggested as adding 1-2 quarts of ATF to your oil before an oil change and letting the engine idle for 15-20 minutes. It should loosen things up and what loosens up should mostly drain out of the pan (the oil may be thicker apparently, from the gunk coming loose). I've never tried it, but I've heard people who ahve and reported success. I wouldn't count on it helping your rings seal better, but if you noticed lots of gunk in your engine when you did the heads it may be worth a try. Just wahtever you do don't rev the engine or drive the car with the ATF in it. It's not the same as oil, it has lots more detergents and such as I am told, which is why when used _in combination with_ oil it is supposed to be a safe way to clean out the engine. Supposedly switching to synthetic oil will eventually get you the same results, but that's not practical for you to be spending that much money on synthetic to top it off all the time.

My '68 had a bad blowby due to bad rings, particularly in two cylinders and also due to old beat heads with burnt exhaust valves and worn valve guides. I just kept buying the cheapest oil I could find to top it off at every gas-up until the engine finally had enough. Now it's rebuild time. :) it got my by until I could get my '67 running again, which got me by driving 400+ miles/week and now I've got a little Prelude to drive until next summer when I'll hopefully fix the '68. I'm thinking 351W... Maybe I can find a cheap low mileage one from a truck, as money is tight and I'd rather not have to build an engine, though it would be nice to have my summer cruiser back (with a little more pep to boot!).

Cory

Reply to
Cory Dunkle

Check the pcv valve and make sure it has good vacuum. Also make sure the pcv hose and fittings are not plugged with sludge. If the pcv is not working, you will have excessive blowby and oil consumption.

To CHECK: At engine idle, lightly pinch the hose connecting the PCV Valve to the Intake Manifold. If there is a clicking sound coming from the PCV valve, it is fine. If not, you may need to replace the PCV Valve.

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Reply to
RonK

Thanks everyone for the insight. Im glad i asked before i made the mistake of trying this. I dont yet have the time or facilities to do a full rebuild which is why i wanted to just replace the rings and bearings. I know that i SHOULD rebuild the whole motor or get a new

289 block, but i cant for awhile so im just going to overhaul it with new rings and bearings and ill hone the cylinders. The heads actually looked pretty good when i pulled them off. The old seals were still soft. The valves were covered in carbon deposits though. When i took the oil pan off, everything looked good inside. The oil pump screen was clear and the bearings looked alright. I didnt gauge them or anything but it all looked decent. Anyways....if you dont have anything nice to say then please shut up. Thank you.
Reply to
Errol Smith

You'de be surprised what those Windsor engines will put up with. I used to have a '69 GT with a 351W. It ran OK, but burned a lot of oil at 125,000 miles or so. I drove it across country anyway; from west TX to NY, then stored it for 2 years while I was in Europe, and then drove it to Ohio. When I got to Ohio, I added a can of Restore to the the new Penzoil. That seemed to help quite a bit. Not as much smoke when I hit the gas, didn't burn as much oil as I drove it back and forth to work every day. After about a year or so - with about 145,000 miles on the odometer - I decided it was finally time to restore the whole car. When I removed the pistons, the rings from three cylinders literally fell off in my hands. Who knows how long they had been broken. I also found 2 rods that were bent. No clue how that happened. One of the main bearings was deeply scored, and the rest were pretty thin. Now I have '65, with a '76 302. How many miles? No clue. About

10,000 miles ago I overhauled the engine. New rings and bearings, new cam, lifters, timing chain, and oil pump. I honed the cylinders using a drill motor and one of those dingle ball things. I used the same pistons, rods, and crank, just cleaned them up. I still drive it quite a bit, and it still runs good. Someday I'll replace the motor with a roller EFI. But for now it's very reliable and fun to drive - it's just not a rocket. And it doesn't burn a drop of oil. Actually, I don't even bother to change the oil because I expect to replace the whole thing in another 10K miles or so. The point is, those Ford small blocks are pretty darn tough, and will keep running long after you would expect them to explode.
Reply to
.boB

lol! thats good to know! Last time i made the trip from Reno to vegas was in june. I got about 3/4 of the way there and had to tow it. When i pulled the heads, i found 2 bent valves, and one was so covered with carbon deposits that it wasnt seating right. I know after you do the top, the increased compression usually finishes off the bottom.

Reply to
Errol Smith

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