Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“Performance
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum The fastest message board... ever.
Corvair Center 
Pages: Previous12
Current Page: 2 of 2
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: Wagon Master ()
Date: May 19, 2017 05:57AM

On the majority of my builds, when pistons are replaced, regardless of manufacturer, a piston with a .010 taller compression height would be beneficial.

'64 Monza Coupe 140 4 speed
'61 700 Lakewood 95 4 speed
'69 Monza Convert. 140 Auto.

Been aircooled since 1973
Northwest Ohio

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: Phil Dally ()
Date: May 19, 2017 06:11AM

Baddest 2.8 I ever saw was in a Kellison at Bonneville.

Yep...in a Kellison like Brian's car with a blower.

The car was for sale with triple Webers.


[corvaircenter.com]

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: JimBrandberg ()
Date: May 19, 2017 06:18AM

Well that's interesting. Arguably .0625 is sort of getting out there regarding cylinder wall thickness, maybe 60 full fin cylinders would be a good idea if building another one.
Does the piston protrude from the cylinder with stock .006 cylinder base gaskets? 8 CCs volume for the dish is a good piece of information for figuring C/R. Looks like you've still got some step in the head gasket surfaces.
When building engines for my road racing Corvair I could never seem to get enough compression, my recent activities find me constantly concerned with too much.
It seems like pistons with a bowl were not favorable for good flame travel back in the day but they are considered good practice in new engines today. Any discussion on what happens with a bowl on the bottom and a squish on the top?
Jim Brandberg
Isanti, MN
CorvairRepair.com

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: cnicol ()
Date: May 19, 2017 06:44AM

I just measured the deck height and it's .008" (Top of the piston is .008" below the cylinder's head gasket surface.)

On a quick check of specs in the manual, I didn't find one for deck height but I'm remembering measurements of .010" on previous builds. Bottom line - deck height looks fine IMO.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
60 Monza coupe (sold, sniff sniff)
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: didget69 ()
Date: May 19, 2017 07:29AM

Looks like Pin Diameter is .9055"...

bnc

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: JimBrandberg ()
Date: May 19, 2017 07:37AM

I'm not much of a Rockauto guy but I searched there for the Mahle part # above and discovered that is .030 oversize on closeout with only 2 left. The 2.0 engine came up on a 1983 search but not 1982.
They have a Sealed Power Std piston on closeout, putting 12 in the Cart didn't faze it. The Info shows .9055 pin size not .800.
They list Hastings rings on closeout and putting 3 sets in the Cart didn't faze it. Makes me nervous that they didn't allow you to choose the size.
I don't know that I'm excited enough to pull the $203 trigger for closeout stock, especially if the rods need to be reworked for bigger pins although the price is nice for 3 engines worth.
I usually need to calm down in these situations and remember that I've got a ton of stuff that was a good deal but how good is the deal if you're not using it?
Any follow-up on the pin size? Was .800 perhaps on the previous generation, was it 1.9 litre?
Interesting stuff.
Jim Brandberg
Isanti, MN
CorvairRepair.com

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: JimBrandberg ()
Date: May 19, 2017 08:11AM

I went back to Rockauto and looked at 1.9 which looks like Isuzu which scared me.
Regan recalled using 2.0 pistons with .800 pins but I suppose opening up rods to .9055 isn't a deal breaker, although .800 would be easier.
I don't know that we determined for sure that Craig's pistons are 2.0 and not 2.8 as he was told. I will shut up and wait for more follow-up information.
Jim Brandberg
Isanti, MN
CorvairRepair.com

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: Wagon Master ()
Date: May 19, 2017 08:14AM

Jim, my fuzzy math says putting 12 pistons in your cart is only enough for 2 engines. Unless you're going for manual cylinder deactivation.

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: JimBrandberg ()
Date: June 06, 2017 05:15AM

teddbrown has a similar thread I saw recently. It mentions Clarks having full fin cylinders with a large overbore for the airplane guys. It's not a new thread but is currently on Page 1 due to recent activity.
Did we ever decide if we're taking about 2.8 6 cylinder or 2.0 4 cylinder pistons here?
Jim Brandberg
Isanti, MN
CorvairRepair.com

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: teddbrown ()
Date: June 06, 2017 02:07PM

This piston in the pic looks like the 1985 GM 2.0 piston. It has the proper pin diam (.08002) and compression height. I put a set in Loadside engine at the start because I was to impatient to wait for my oversized rods. They ran fine, but it was a low compression monster, so I installed the 2.8 flats and it really made a difference. Both piston were oversized to 1.0mm which became 179 cu in. I currently run a set in the Loadside.

The pistons I wanted special made were the 2.0 pistons with a flat top or the 2.8 pistons with a .8002 pin. These pistons are pretty much the same except for those differences. Either way the manufacturer (www.uempistons.com) would not make a run lower than 280 pistons. After rings, shipping, etc... I was going to have a pretty good investment. Then I had to have Clark's provide the overbored cylinders. I also have some info on the www.Corvai-efi.com website

I have it all mapped out in C/R as I am a math nut, but again, without any interest, I was not going to invest 7k for a product that didn't seem to have much excitement.

Ted Brown
Anderson, SC
68 Convert 110/PG/EFI/DIS
61 Loadside 102/PG/EFI/Dist
61 Rampside 4 speed (Restoration starts Nov 2015)
130HP/PG/Honda Engine Project
67 Monza Cpe
61 Greenbrier
**UPDATED** Corvair Fuel Injection and DIS Page




Edited 3 time(s). Last edit at 06/06/2017 02:11PM by teddbrown.

Options: ReplyQuote
Re: Some seller stories are true. S-10 2.8 pistons in a Corvair!
Posted by: teddbrown ()
Date: June 06, 2017 02:38PM


Options: ReplyQuote
Pages: Previous12
Current Page: 2 of 2


Sorry, only registered users may post in this forum.
This forum powered by Phorum.