<VV> Valve adjustment
joel at joelsplace.com
Thu Feb 15 01:00:18 EST 2018
The only thing I see that can be a problem is defining "The pushrod will be hard to turn." The only time the pushrod feels hard to turn to me is after it stops at the point that the lifter is full. If it's been run at zero preload then the lifters will be full and hard to turn when preloaded but if the lifters are half full or empty then the pushrod won't get hard to turn until the lifter is half collapsed (when half full) or fully collapsed (when empty). I would call the zero lash point a slight drag on the pushrod where the clearance has just been taken out.
From: VirtualVairs [mailto:virtualvairs-bounces at corvair.org] On Behalf Of Hugo Miller via VirtualVairs
Sent: Wednesday, February 14, 2018 3:29 PM
To: Seth Emerson <sethracer at aol.com>; virtualvairs at corvair.org
Subject: Re: <VV> Valve adjustment
#### It wasn’t my question! I just expressed surprise at the answer – took me a while to catch up. Hydraulic lifters are a bit new-fangled for me – as a Brit, I’m sure British cars of that era never had such things, not till much later.
In the meantime I looked online for Corvair valve adjustment and found a lot of info that contradicted the ‘official’ settings, to the point that I would say there is a consensus that it is better to wind the rockers in less than specified by Chevrolet (quarter or half a turn, or maybe 3/4, seems to be the average recommendation).
Although I have four running Corvairs, a (restored) 1960 Impala with a 348 and a 1961 Corvette with a 283 (undergoing restoration), I have never yet had to lay a spanner on a Chevy engine (other than to change a water pump), so please don’t think I’m offering advice or telling others what to do – I’m just reporting what I found on the internet.
From: Seth Emerson
Sent: Wednesday, February 14, 2018 8:12 PM
To: Hugo at aruncoaches.co.uk ; virtualvairs at corvair.org
Subject: Valve adjustment
Hugo - You asked for a procedure. You got a procedure. Buy the shop manual. It is easily available (a little expensive through the mail for you) It will answer almost all of your questions. -Seth
From: Hugo Miller via VirtualVairs <virtualvairs at corvair.org>
To: virtualvairs <virtualvairs at corvair.org>
Sent: Wed, Feb 14, 2018 5:50 am
Subject: Re: <VV> uneven vacuum
#### Ah, you are actually pushing against the spring loading in the lifters, are you not? That would make more sense of things.
From: Seth Emerson via VirtualVairs
Sent: Wednesday, February 14, 2018 2:10 AM
To: virtualvairs at corvair.org
Subject: Re: uneven vacuum
Joe - The cold adjustment involves setting the engine to TDC (at the end of
the compression stroke) for each cylinder and go through the firing order.
1-4-5-2-3-6. When the cylinder is at TDC, you back off the valve adjusters
(both) until you can easily spin the pushrods between your fingers (Thumb
and pointer). Then tighten them down until you take out the slack. The
pushrod will be hard to turn. Then give it your pre-determined preload,
often 1/2 a turn. Do both the intake and the exhaust, then move to the next
cylinder. That is it.
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