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ghofstetter
10-27-2006, 05:34 AM
Need any help or suggestions prior to rebuild this winter.
1963 R2 Avanti. Burning Oil and Rear Main Seal leak. Please advise.

George Hofstetter

wagone
10-27-2006, 10:32 AM
How much oil is the engine using (miles per quart)? There have been cases where a full engine overhaul does NOT rectify the situation. By full I mean FULL (bored, new pistons/rings, new valve guides/stem seals, etc). As the experts have stated it is very difficult, if faced with this dilemna, to determine the cause. Many people will (probably) advise to pull the engine and trans together. However, I feel that you will need a lot of head room in the garage to do this on an Avanti. I had barely eight feet when I pulled mine and this was to the ceiling and when substracting the needed room for the engine hoist I felt that this would be a problem.....so I pulled the engine and left the four speed T-10 under the car. I don't see this as a problem....but I'm always concerned that the cap screws (some say BOLTS) are not pulling up evenly when it goes back together and hence something is being cocked in the process (input shaft, clutch, bell housing, etc.) and hence undue stress is present. Once when tightening things up I heard a loud crack (I think this was on a Corvette with an aluminum bell housing and trans case and feared I'd cracked one of the two...but it never gave any problems). Also it can be difficult to get the proper torque on these SCREWS as it is hard to find enough room for wrenches under there. If an automatic I can't advise, but it may be more advisable to pull both than in a manual trans situation. Standard advice is to find a shop which has experience with the Sude V8 as they may be able to avoid the assumed pit falls of the Stude engine. Why there should be any unusual issues with the Stude engine I'm not sure. Boring one V8 ought not to be any different than any other....now that may sound naive as the block is fairly hard which could cause an issue, I suppose, or rhe right hone may not be used to get the right final finish. But ANY competent shop ought to be able to deal with the few issues which appear to be of concern. I told the shop that did mine that the Stude iron was harder than many and asked whether that was a concern. My '63 R2 runs quite strong in my opiunion, but even after a $3300 complete overhaul is still not the easiest on oil. But the plugs don't foul and it doesn't smoke so I'm going to live with it. The shop needs to understand that if they disassemble the rocker shafts that they've got to go back exactly as they came apart and then go back on the bank they came off of....failure to do this could easily result in NO oil to the shafts and rockers.....NOT a good situation. Please ask specific questions and I or others more knowledgeable will help. Good luck and ask questions and get all issues resolved ahead of time (if possible)....this is a major undertaking and not CHEAP! OBVIOUSLY.

wagone and the '63 R2 Avanti

Rosstude
10-27-2006, 12:25 PM
With the cost of overhaul being high, one should do some home work prior to condemning an engine. If you have, please disregard. A compression / leak down check are one place to start. Does it smoke, if so under what conditions? Oil l can run down the back of the engine from the rocker covers, distributor, oil gauge pressure line, etc. A good cleaning and then some detective work will track down the source(s).
The 259 V/8 in our Provincial was going through a quart of oil each 300 to 500 miles. It leaked like a sieve, from what would have appeared to be the rear main seal, it was not, and a pan gasket was all that was needed. It smoked upon deceleration from highway speed, and upon pulling away from a stop after said deceleration, and a bit at start up when hot, this was valve seals. I replaced the valve seals, and the smoking stopped, and the plugs cleared right up.
Anyway, the engine now has gone 1600 miles and has used less than ˝ quart, much better. I did the work myself, and the parts were less than $50. The pan gasket was a bear to do, so I can imagine that labor could add up—still cheaper than a rebuild.


Ross.
Riverside, Ca.
1957 Provincial X2
1958 Transtar
1963 Lark. F.S.

John Kirchhoff
10-27-2006, 12:31 PM
Take a look at my posts on page 2 under something like "!Avanti R1 engine back pressure" at how to check compression. I'd never pull a running engine for a ring job without doing so. Adding the oil is what will pretty much tell you if you need a ring job. Sure, it helps determine compression ring wear but rare is the time when an oil ring is worn out but the compresion rings are in good shape and vice versa. As wagone said, there's a lot of things that can cause oil usage. Different ring designs can affect oil usage and some engines are expected to use oil. Whennew, some older Oliver tractors with the Waukesha engine were expected to use a quart a day when under heavy load but hardly any when under light load. That was straight from the manufacturer.

If your car puffs out a good bit of blue oil smoke when you first start it but then it clears up, you can bet the valve guides and/or valve stem seals are shot. You can replace the seals without pulling the head. Get one of the hoses from a compression gauge or bust the porcelain part out, braze a pipe to it and put a air hose fitting on that. Remove the spark plug, screw in the air hose and turn on the air (with a good air compressor). With the cylinder under pressure, the valves stay in place and you can remove the valve springs and replace the seals. I believe the teflon seals I used were for a 350 Chevy. The little guys with the metal spring are very much better than the miserable old style "umbrella" seals. You will also hear air escaping past the rings and into the crankcase. Without you having more experience, I can't really describe what sounds ok and what sounds excessive. With the valve springs off, grasp the end of the valve stem with your fingers and see if you can wiggle it. (Don't pound on it with a hammer and loose air pressure or you'll be taking the head off to fish out the valve.) If so, the guides are pretty worn. On really worn ones you can even see the hole in the guide as being oblong shaped compared to the round valve stem. If they're slightly worn, they can be knurled and helps tighten things up. If you'er that far into it however, new guides is preferable as knurling is a short term fix.

If your car smokes a lot under high vacuum conditions such as idle or coasting but clears up when accelerating hard, it's guides or seals. If it smokes more under hard acceleration, it's probably rings.

Make sure you're not loosing oil from valve cover gaskets, crankshaft seals, oil pressure line or the gasket around the fuel pump. To figure out where leaks are, get a big old cardboard refrigerator box and cut several big wide slabs out of it. Drive the car to get it warmed up good and then slip the cardboard under it while you let it run for fome time. 10-15 minutes or so. Any oil leaks will show up on the cardboard and you can get a better idea of where they're at as opposed to a 60 mph wind blowing oil every where. Keep in mind the fan blade could move the oil some. After you've shut it off for a while, put another piece under it and let it set overnight. If the fan is blowing the oil, that can sometimes help you determine where the leak really is. It can also help determine if it leaks all the time or only with the engine running.

The last thing you want to do as wagone says is overhaul the engine and then find the leak is actually the fuel pump gasket. Sorry for the long manifesto!

Roscomacaw
10-27-2006, 07:23 PM
Actually, I find alot of times a leaky engine is summarily diagnosed as "burning oil". It might just be LEAKING oil, but not "burning" it.
George didn't say if he's seeing blue smoke or seeing oil-fouled plugs. So.... George? Care to elaborate?:)

Miscreant adrift in
the BerStuda Triangle!!

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

ghofstetter
10-27-2006, 08:07 PM
Thanks to the four good people. Burning oil out exhaust,fouling plugs,leaking from rear main seal. I have learned a lot from the comments. A lot of checking to do before a engine removal. I need a real good mechanic.

George Hofstetter

rockne10
10-27-2006, 08:58 PM
I'm not a mechanic but I know distinct oil pressure drop when you release the accelerator can indicate worn bearings. Lots of good advice here and much to consider.

None of us wants to see you do a triple backflip off a one meter board.:D

sbca96
10-27-2006, 09:08 PM
I replied to your post on AOAI site, probably a repeat of the good
advice you already got on this thread. - Tom

http://www.aoai.org/forums/index.php?showtopic=548

The same basic rules apply to Studebakers as any other brand, I would first
find out WHY its burning oil. Usually there are two main causes of oil burning
one is valve seals (can be done on the car) and two is rings (rebuild time).
You can help to figure out which by paying attention to WHEN you see smoke
out the tail pipes. If you see smoke whenever you accelerate, and during
idle, and you have low compression 125 psi or less, then its probably rings.
If you see smoke when you have left the car sit after driving it, & when you
fire it back up (say sitting for 30 mins to 2 hours), and notice smoke out the
tail pipes when you let off on the gas and reapply on the freeway, then it is
valve seals. These are NOT definate, but are simple rules of thumb. The oil
leak you notice from the rear seal COULD be coming from above at the oil
pressure rubber line, or could be from an oil pan that has loosened over the
years. Sometimes retorqueing the pan bolts according to the shop manual
will solve (or seriously reduce) an oil leak. Studebakers are going to leak
pretty much regardless, so if you can fix it without pulling everything apart
thats a better plan. Also make sure that the oil is not leaking from the FRONT
seal and running back down the engine to leak off the rear of the pan.

I wouldnt go rebuilding it until you know whats wrong, is the oil pressure
good? How does it run other then fouling plugs?

Tom

'63 Avanti, zinc plated drilled & slotted 03 Mustang Cobra 13" front disc/98 GT rear brakes, 03 Cobra 17" wheels, GM alt, 97 Z28 leather seats, soon: 97 Z28 T-56 6-spd, Ported heads w/SST full flow valves, 'R3' 276 cam, Edelbrock AFB Carb, GM HEI distributor, 8.8mm plug wires