<VV> Video of Noisy 110 Engine 1965 Monza

chaz at properproper.com chaz at properproper.com
Mon Jul 20 21:49:47 EDT 2015

Mark and VV'ers ~

I may not have mention it, but this rapping noise started
instantaneously while driving normally (after 5000+ miles of quiet
performance), so it did not "build up" to being noisy, just "all of a
sudden" rapping, even startling me, like I hit something (which I

Also, the compression, which I've checked twice now, is consistently
100-125 on all cylinders.

I watched the valve stems (eyeballed against the head) for any visibly
noticeable difference in lift as in the videos, but saw nothing.

I'll stethoscope it next and look for a good, conclusive reason to pull
the head off, only if necessary.

Thanks for the insights

From: MarK Durham [mailto:62vair at gmail.com] 
Sent: Monday, July 20, 2015 5:36 PM
To: Charles Lee
Subject: Re: <VV> Video of Noisy 110 Engine 1965 Monza

It's not a lifter. None of the noise is lifter tapping from a lifter
internal failure. It's more of a thump.

Having said that, I suspect you have one of those cams that were ground
incorrectly that
have a hump on the ramp. if so, normally there will be damage to the
bottom of the lifter(s)

A second choice would be piston slap, but frankly it does not sound like
piston slap to me.

You could verify piston problems by pulling the case top cover and
inspecting the piston skirts at bottom travel and cylinder walls
scraping at top of travel. You could also inspect the cam lobes to look
for any uneven wear marks.

Properly worn in cam lobe surfaces should have a grey appearance with no
nicks, scratches or sharp edges. Look for any flat topped lobes. Any
surface on a cam lobe that is shiny is wearing fast and needs further

I have assumed you have taken a stethoscope and listened to the engine
at various locations to determine the exact location of the noise? If
not, you need to. Even a long extension or a long screwdrive up to the
ear will work, but not s effective. 

Mark Durham
Hauser, Idaho
62 Monza coupe Red/Red 4 speed

> -------- Original Message --------
> Subject: Video of Noisy 110 Engine 1965 Monza
> From: <chaz at properproper.com>
> Date: Mon, July 20, 2015 3:19 pm
> To: virtualvairs at corvair.org
> Here are some video diagnostics of the noise:
> Noisy when running, no (unusual) noise when cranking.
> Rapping noise with engine running :
> Composite Video of Corvair diagnosis of Noisy 110 Engine Running and
> Cranking  
> www.youtube.com/watch?v=fL8xudLHYNY
> Watching the valve train for deviant rocker arm lift:
> -----------------------------------------------------
> Right Side Valve Train Lift 1 3 5 
> www.youtube.com/watch?v=7B6Yg2FtCVA
> Left Side Valve Train Lift 2 4 6 
> www.youtube.com/watch?v=JyvW-04A9VI

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