180 Turbo Engine rebuild...

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acarlson
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Location: Dahlonega, GA

180 Turbo Engine rebuild...

Post by acarlson »

I have some issues with my Corsa turbo that will require pulling the engine, tranny and differential to fix. Here's the problems:
  • 2 of my cylinders are only pushing 85 PSI and the engine is burning oil.
  • The turbo is not operating so I'm only running on the carb
  • The clutch is slipping
  • The diffy axel seals are leaking
  • The exhaust pipes are heavily rusted
So it looks like a serious rebuild is in order.

Here's my reconstruction plan (I don't plan to split the case):
  • New forged pistons, rings, rods and head gaskets all around
  • New jugs all around
  • New connecting rods and bearings
  • New lifters
  • Turbo rebuild kit
  • New crossover, input and output exhaust pipes
  • New clutch and pressure plate
  • New seals for transmission and differential
So with all of this and with the drivetrain out of the car, my question is - what other components should I be paying attention to ? I don't want to have to pull it all out again for quite a while !!

All suggestions are welcome !!

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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thewolfe
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Re: 180 Turbo Engine rebuild...

Post by thewolfe »

Pilot bearing and crank seals. Don't get the viton ones! Are your lifters worn? If not and you're not replacing the cam I would leave them but mark which position they came from so they go back in the same spot. If you're going to the trouble to replace the rods and pistons you may as well split the case and check the cam and bearings for wear. Also check the oil pump clearance and wear. Check your push rods. Not uncommon to find slightly bent ones. Roll them on a flat surface and you will see. How fresh are your heads? May be a good time to go through those as well. You at least will want to replace the valve stem seals. Inspect the head gasket surfaces. Not uncommon for them to need a cleanup cut as the gaskets sink into the heads over time. Also deflash them if they have not been already. I would inspect the splines inside the pinion shaft of your differential for wear. These splines take a pounding and wear away. If your car has an original riveted flywheel you will want to either have it rebuilt or replaced with a bolted or hot riveted unit.
Nate Wolfe
65 Corsa 180
61 Lakewood 140
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terribleted
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Re: 180 Turbo Engine rebuild...

Post by terribleted »

I agree with everything thewolfe suggested.

I also would have concerns about replacing the rod bearings onto the existing crankshaft without any rod journal polishing or preparation. I would suggest that you (assuming the rod bearings do not show wear requiring replacement) re-install the existing rod bearings in their exact current locations onto the existing crank. Not a particularly great idea to put new bearings against a worn crank. They may not wear in nicely. If replacing main or rod bearings machining of the crank journals is normal procedure to assure good mating on wear-in. This would generally require removal of the crankshaft for machining.

Installing new lifters on a used cam can also sometimes cause problems due to wear-in issues. Current wear on the cam may not play nice with the new lifters and can in some instances cause camshaft failure (perhaps a 5% chance from my experience), hence thewolfe's suggestion to reuse the lifters and be sure each one is back in its original position. This position specific situation also applies to all pushrods and rocker arm and ball sets. It is a lot of work to go this deep in an engine and not be sure everything is right and then have to tear it down again because of it.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
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66vairguy
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Re: 180 Turbo Engine rebuild...

Post by 66vairguy »

So far some good recommendations. BEFORE you decide what to do with the crankshaft measure it (or have a good shop do it). Usually a nitrided Turbo crank will be within specification. If it is it can be professionally polished at a machine shop - NEVER INSTALL NEW BEARINGS ON A "DIRTY" CRANKSHAFT. If the crankshaft shows damage or unusually wear it will have to be cut and that removes the original nitrided surface. Not a big deal as the nitrided finish only reduces wear at the bearing surfaces, it doesn't make the crank any stronger.

Yous said new "jugs" and I assume you mean new cylinders from Clark's. Unless you get a matched pistons and cylinders you'll have to have the cylinders measured and honed for clearances to match the pistons. DO NOT USE THE CORVAIR MANUAL CLEARANCES that were for a cast piston. Typically a forged piston requires a greater clearance. BEWARE the old TRW forged piston instruction sheets. They called for a 0.0015" top of skirt clearance, BUT IT WAS FOR EACH SIDE - or a total clearance of 0.003" (bottom of skirt 0.001" each side or 0.002" total).

The other issue not mentioned is if you replace the camshaft you'll have to install a new cam gear. Use a forged cam gear, not a cast one. Also do not even consider install the cam gear yourself. I've run into broached gears, bent camshafts, etc. A special fixture is needed to heat (an keep the gear HOT) while installing the cam gear. I've had Jeff at Calif. Corvairs do mine without issue. Clark's says they also do it, but I have no experience with them. Fianally - timing the cam to the crankshaft is tricky during assembly since the cam gear timing mark is usually not well placed. You have to draw a centerline on the gear 90deg from the keyway and match that to the crank timing notch.

Good luck.
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acarlson
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Location: Dahlonega, GA

Re: 180 Turbo Engine rebuild...

Post by acarlson »

The cam may or may not be an issue. A previous owner bought an OTTO cam from Clarks (part C8803) back in 2009 and had Clarks install a new stock cam gear (part C783X). I assume he installed it so there's not a lot of mileage on it. The crank may also be relatively new - I won't know how good or bad it is till I open the engine up. I'll be getting all the parts from Clarks so the cylinders will match the pistons and rings and I'll have them install the connecting rods.I won't get this started till later in March but I'll post pictures and status as I go along...

Alec
Alec Carlson
Dahlonega, GA
1965 Regal Red Corsa 4 Speed Turbo Convertible
Restoration "In Progress"...
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thewolfe
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Re: 180 Turbo Engine rebuild...

Post by thewolfe »

Still best to check the piston to cylinder wall clearance. A set of bored and honed cylinders is going to need different clearances depending on the piston used. They are not a one size fits all sort of deal and I'm not sure if Clark's hones theirs differently for either cast or forged pistons. You may ask them that and what the clearance is. Generally when you are going over bore you take the pistons and block or cylinders you intend to use to a machine shop and have them bored and honed to fit with the specified clearance. Corvair cylinders must be honed with a torque plate and many shops are not set up to do this.
Nate Wolfe
65 Corsa 180
61 Lakewood 140
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Re: 180 Turbo Engine rebuild...

Post by terribleted »

Clark's does their cylinder finishing in the proper fixture with pressure applied. I have never found an error in piston to cylinder clearance from Clark's when ordered as a set, and I have installed a few sets. (measure anyway just in case, but, just sayin). They hone to different grits based on the type of rings to be installed. When ordering pistons and rods from Clark's they have an install service that is very nice. Full set rods installed to pistons for like $32 and they come out of the box ready to install with out fooling around with a press or chasing to a machine shop for this service.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
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Located in Snellville, Georgia
Scott V
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Joined: Wed Jun 30, 2010 2:31 am

Re: 180 Turbo Engine rebuild...

Post by Scott V »

thewolfe wrote: Tue Feb 28, 2017 12:09 pmCorvair cylinders must be honed with a torque plate and many shops are not set up to do this.
terribleted wrote: Tue Feb 28, 2017 2:02 pm Clark's does their cylinder finishing in the proper fixture with pressure applied.
a torque plate is different than a fixture that holds the cylinder. looking @ the clarks picture......it doenst look like a torque plate. clarks does a nice job on their cylinders - torque plate or no torque plate.

http://www.corvair.com/user-cgi/catalog ... w_page=23A

-Scott V.
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