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Possibly time for engine rebuild.
Posted by: rotted65 ()
Date: September 17, 2022 07:50AM

Due to the large amounts of oil my 140 4 speed is burning, I think it’s time for a rebuild. The car runs ok, not great but ok, doesn’t leak much. There is noticeable blow by. What should I be focusing on. I was thinking of replacing the pistons, rings, and cylinders. And wanted to know if there is anyone on the Philadelphia area that can go over my heads. I drive it a little on the harder side. Are full fin cylinders worth the extra? What pistons should I consider? I can do the work, that’s not the problem. I just don’t know what parts I should use. Basically I want to go through this engine and build it right the first time now so that I’m not doing it again. Thanks for any input.

69 monza 110 PG gone many years ago
65 corsa vert 4spd gone
New toy 66 monza vert 140 4spd

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Re: Possibly time for engine rebuild.
Posted by: Marco_a_p ()
Date: September 17, 2022 08:18AM

fist off, make sure you are sure what engine size working with. I say this because over the years I have had cars come into the shop that had all the markings of a 140hp motor, yet it was running a 145ci crank. You will need to mic the crank as well to see if what size bearings you will need.

with the new clark's full finned cyclinders, I would go straight to 60 over. Forged pistons always over cast if available. With stock original cylinders I would try to keep it at 40 over. You can possibly get one more build out of those 40 overs in the future.

make sure to select cam that will meet your driving needs. Sounds like a 270 or OT20 would be a good fit. New Fail Safe gear. always. Viton seals everywhere except for the Crank seal and Harmonic balancer seal.

goo luck with your build.

Marco
A 2nd Gen Monza Wagon, a 2nd Gen GB 8door, a 2nd Gen (61's were 1st Gen) R/s and a 62nd Gen Turbo coupe..

Hanging out with the scorpions, king snakes, road runners, coyotes and quails In the southern desert of the silver state
Mesquite NV 89024

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Re: Possibly time for engine rebuild.
Posted by: Colorsarge ()
Date: September 17, 2022 08:37AM

Contact Jeff at Corvair Ranch in Gettysburg about your cylinder heads.

Frankford, De., eight miles north of Ocean City, Md.
1966 Corsa convt.

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Re: Possibly time for engine rebuild.
Posted by: Unsafe140 ()
Date: September 17, 2022 04:22PM

keep us informed if you do a teardown...

Joel
Cave Creek, AZ
1965 Corsa 140 tele

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Re: Possibly time for engine rebuild.
Posted by: Caraholic4life ()
Date: September 17, 2022 04:42PM

Colorsarge Wrote:
-------------------------------------------------------
> Contact Jeff at Corvair Ranch in Gettysburg about your cylinder heads.



I'll second that and add the following:

IF the motor in the car is not the original one to the car and or, if it makes no difference to you, it might be possible to have them build you a fresh motor from inventory and trade in your current engine as a core.

In theory, you could continue to enjoy the car while they build you a motor then once it is ready for pick up, pull your motor, drive to the Ranch and swap the existing core motor for the freshly rebuilt one, go back home and install it. This would eliminate the down time for the car.

There is a good chance they could build an engine with a correct block code if they have one on hand. Getting a correct date code might be tougher. In the end, it would depend on your preferences.

They are very busy at the Corvair Ranch. If you would like the engine work done by them, plan ahead. IF you prefer to build the motor yourself, they can do as much or as little of the machine work as you want.

1962 95 F.C. Van
1964 Greenbrier Deluxe
1965 Monza Coupe
1965 Monza Convertible
Westminster, Maryland

MID ENG enthusiast &
prior Kelmark owner.

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Re: Possibly time for engine rebuild.
Posted by: RobertC ()
Date: September 18, 2022 12:25AM

What does "large amounts of oil" mean? Miles per quart?

Are spark plugs fouling?

Compression test?

Has the engine been rebuilt before?

Any pulled head studs?

An engine rebuild competently done with stock cylinders - and even original GM cast pistons - should last 100,000 miles (or more).

Just depends on what you want...

If you are building a race engine, then, the parameters (and life of engine) are different.



Edited 1 time(s). Last edit at 09/18/2022 12:28AM by RobertC.

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Re: Possibly time for engine rebuild.
Posted by: rotted65 ()
Date: September 18, 2022 09:32AM

I want to do as much of the work myself. No idea as to former life of car. I got it off of a flipper. Plugs aren’t fouling badly but I can see that they are starting to foul. Vacuum is goofy when timing is set correctly. I have a suspicion that the timing gear has moved. Car won’t run correctly unless it’s about 30* advanced at idle. Compression close to even at about 110 each, IIRC, give or take a little. Not building a race motor but definitely want a healthy strong motor. I will pull the motor out of the car hopefully within the next couple weeks. I will post tear down pics. I have to spend some considerable time in the garage getting garage ready first. Downtime with the car isn’t that big of a deal. It’s getting ready to be too cold for the car. It’s a convertible and the top hasn’t been up in several years.

69 monza 110 PG gone many years ago
65 corsa vert 4spd gone
New toy 66 monza vert 140 4spd

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Re: Possibly time for engine rebuild.
Posted by: steve c goodman ()
Date: September 18, 2022 11:35AM

Check the crank gear too. The woodruff key can shear and the engine will still run at least to a point. If cam gear is loose the engine will not continue to run for long. Good luck too I hope the new engine turns out perfect

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: Possibly time for engine rebuild.
Posted by: RexJohnson ()
Date: September 18, 2022 02:03PM

I have seen a weak coil cause the need for the timing to very advanced so make sure that it is not that simple. I agree with Steve that a loose cam gear will not last long but a crank gear that moved a little bit might.

RJ tools
Salem,Oregon

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Re: Possibly time for engine rebuild.
Posted by: gbullman ()
Date: September 19, 2022 07:00AM

Also curious about your miles per quart. I know my car was driven very little for the 30 years before I bought it (but from the maintenance records appears to have been driven some each year). When I first started driving it I was getting around 100 miles per quart, maybe less. Now almost 2 years and 8K miles later I’m up over 500 miles per quart, hopefully more (just changed the oil and haven’t driven enough to get a good sense of consumption yet). I’ve been running back to back treatments of AutoRx and it seems to be helping.

As far as timing, is there any chance your harmonic balancer has slipped and 30 degrees is not accurate?

If I do need major engine work at some point I’d probably take it to Corvair Ranch.


Gary
1966 Corsa Convertible
Northern New Jersey


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Re: Possibly time for engine rebuild.
Posted by: rotted65 ()
Date: September 19, 2022 07:33PM

Crank pulley is a new unit from 1 of our venders. Key way looks good. Coil isn't problem. It is also new after the newish 1 cracked several weeks ago. Hot coil and open engine compartment when raining I think was the culprit. Problem was there before and after coil incident. Now I have gone and made situation worse. I dropped the air cleaner wing nut down into fan. After several hours of several people looking with magnets, flashlights, and borescopes, no joy. so that means at least the shroud is coming off. I think this is going to turn into one of those "while I'm this far I might as well do this since I'm here" situations A visit to Jeff at Corvair Ranch is definitely in my future.

69 monza 110 PG gone many years ago
65 corsa vert 4spd gone
New toy 66 monza vert 140 4spd

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Re: Possibly time for engine rebuild.
Posted by: RexJohnson ()
Date: September 20, 2022 10:10AM

The wing nut will sit there a long time without hurting anything. Visiting Jeff is always a good time no matter the reason.

RJ tools
Salem,Oregon

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