<VV> Changing Things

[corvairduval at cox.net]

145 vs 164 differences are just in the stroke of the crank. I mean the
displacement change is from the stroke of the crank. To stroke the engine,
GM had to change:

Crankshaft (longer throw on rod journals, dimentions are the same)

Pistons (shorter distance from top of piston to first ring land and piston
pin is also closer to top)

Rings (match groove size of new pistons)

Cylinders (bore is the same, added a notch at the bottom to clear the rod
at bottom of stroke)

You cannot put 164 pistons on a 145 crank, and get the same compression
ratio. They will fit and run, just lower power.

To find out if your YR is 145 or 164, pull a head and measure stroke. 

If the rings fell through the barrel, measure EVERYTHING for wear.

Frank DuVal

Original email:
-----------------
From: Mark Durham 62vair at gmail.com
Date: Mon, 24 Jun 2013 14:45:00 -0700
To: duallycc at gmail.com, VirtualVairs at corvair.org
Subject: Re: <VV> Changing Things


Gary, if there was that much wear in the cylinders, I would wonder about
how the bearings look. I would suggest you pull at least one rod off, at
the front of the engine where there could be less oil flow, and see what
they look like. Bearings are cheap, and in my mind its easy to pull the rod
caps and keep the cylinder/piston/ring assy from the donor engine intact to
prevent any damage and to keep the units together. Also, you are then
keeping a known piston in its cylinder and you don't have to worry about
clearances.
Mark Durham

On Mon, Jun 24, 2013 at 12:32 PM, Gary Berry <duallycc at gmail.com> wrote:

> Hey All;
>
>    I have a reverse-rotation Corvair engine in my fiberglass dunebuggy.
I'm
> pretty sure that I sanded it the last time out at Pismo Beach. I have
> pulled the barrels and rings. I went to check the end gap on the rings,
and
> they just fall through the barrel. Oh, this engine has a YR on it's id
> number which indicates it's a 145ci(?). I have measured the pistons, and
> they come out to 3.44 inches on the diameter which is strange to me cause
> the book I have says it should be 3.1 or close to that. Anyway, I have
> another engine (164ci) here that runs good and I'm thinking about swapping
> the barrels and rings from it to the reverse-rotation engine if the
pistons
> are the same size. Any problems with this idea? If need be, I can also
swap
> the rods and pistons over and throw some new rod bearings at it. I really
> don't want to split the case. Just wondering. Thanks.
>
> GaryB in Prosser, WA

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