Corvair Forum

Hello Guys, I am doing a top half engine refresh on my '65 Corsa Convert, 180 Turbo. I've been to the Hastings online website and have determined that I will be needing Hastings #2M669030 piston rings. The 'M' indicates Moly and the 030 indicates .030 the overbore as marked on each piston top. My question is ...Am I looking at the correct piston rings? As I've noted the engine is a Turbo, should I go with the Moly or will cast rings do the the job just fine? As I understand it, Cast rings seat faster and were used by GM on all Corvair's except for turbos were GM used the Moly rings.

Thanks in advance,
Steve
'63 Monza Vert
'65 Monza Coupe (project)
'65 Corsa Vert (project)

If you are just re-ringing the pistons and not going with new pistons and cylinders the cast iron rings are best suited for that purpose.
However ,the fact that this a turbo engine you need to go with moly rings. I would not just re-ring a turbo engine. The pistons are subjected to a lot of abuse on a turbo engine. I personally would not go that route. I do realize that people are on a budget and a re-ring is the economy way to go. Maybe some would just re-ring with the moly rings and go with it . You need to CLOSELY inspect the pistons for signs of damage and make sure that they are still in tolerance along with the cylinders. If you find that everything is still in tolerance and in good shape, then I guess that you can hone the cylinders and go with moly -rings. You need a good cross hatch pattern for the rings to seat properly. Some rings say to have a different hone patterns to use with their rings. I only use forged pistons on my turbo rebuilds and make sure that I have the right clearances on my pistons and cylinders to prevent scuffing and premature wear.

Thanks Fred, Cylinders,Pistons and heads are at the machinist. Cylinders and Pistons are being checked for roundness, are within tolerance,proper piston to cylinder clearance, honing and producing the hatch pattern and in general good condition. Heads are being evaluated and CC'd.

I purchased this car last fall, from a friend who had purchased the car 3 years prior and never did anything with it. In the 3 years of having the car he only started the car once, never drove it. When I came along, I got the car started, but could not get the car into gear. I concluded the clutch was frozen. Sure enough when I removed the power pack, I found the flywheel/clutch/pressure plate all rusted together. With the power pack removed, I decided to investigate the engines condition. The heads, valves, springs, cylinders, pistons all look as though a recent rebuild had been performed. However one cylinder shows evidence of oil burning. The machinist is like I said, checking for condition.

I expect the Machinist to tell me to replace the one cylinder/piston , machine to match the others. replace all rings and put the engine back together.

I've had the Turbo rebuilt (Steve Goodman) and the Weber Carb is being rebuilt (Ray Sedman) and with the machinist cost, I am about out of budget. Hence my question about the Hasting Rings, Moly #2M669 or Cast #2C669 and are these the right numbers.

Steve D.

Sounds like you are covering all of your bases. The fact that the engine was recently rebuilt and then sat for other mechanical reasons is good to know. I personally would recommend Steve Goodman and Ray Sedman as being more than qualified to assist in any capacity during your rebuild. As you may already know, Steve is the go to guy when it comes to anything concerning Corvairs ,especially turbos. Ray has done the progressive Weber Carb modification on a few Webers for me and sold me his proprietary Safeguard for my Corsa. Ray had also sold me a special cam grind ( torquer cam) for my Greenbrier engine rebuild. I really love the lowend and midrange ability of my van after my rebuild. I am glad that you have enlisted two of Corvairs' finest to help you in your endeavors I can't wait to see the final results. Good luck, and happy Vairing

I have used Hastings rings in a bunch of SBC and never a problem .