<VV> FW: Cam? engine woes venting

[kevin nash]

From: wrokit at hotmail.com
To: wrokit at hotmail.com
Subject: RE: Cam? engine woes venting
Date: Thu, 26 Nov 2009 11:41:12 -0800




 


From: wrokit at hotmail.com
To: virtualvairs at corvair.org
Subject: RE: VirtualVairs Digest, Vol 58, Issue 101
Date: Thu, 26 Nov 2009 11:39:25 -0800




 
> Message: 3
> Date: Thu, 26 Nov 2009 10:22:17 EST
> From: N2VZD at aol.com
> Subject: Re: <VV> CAM? engine WOES venting
> To: virtualvairs at corvair.org
> Message-ID: <c26.6cb28e28.383ff729 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
> 
> just a short story about my lost summer. (missing a lot of details!)
> engine for my rampy was assembled last winter with the greatest of care and 
> components , hoping for a very good performing , long lasting motor to 
> travel anywhere with...(dreaming again?).
> things went well on the bench , everything seemed to run good and adjust 
> properly. i had cam lube on the cam , lucas breakin additive in the oil , 
> yada yada etc. i have put many motors together over the years , but never 
> bothered with a new cam before. this time i went with the highly recommended 
> OT10 cam. anyhow as time progressed , the valve train always seemed noisy 
> like an early fuel injected vette with solid lifters. i adjusted the valves a 
> few times , but they were squirrley , like about 1/4 turn or less between 
> noisey and skip (too loose to too tight). they all seemed about the same. 
> sooo i put another set of another brand lifters on one side only. this did 
> not change anything. all pushrods and rockers were checked and / or changed.
> finally i gave up and tore this new motor down after less than 500 miles 
> yesterday. 
> my shop is now full of engines in pieces (wow the pictures!) , the coupe 
> tossed a valve seat because it overheated (sender terminal was broken , so no 
> real indication in time ) apparently because the wrong shroud piece was 
> installed on the right rear (hidden by the A/C bracket , leaving a 1 inch gap 
> for air escape around cylinder number 1 , which lost the valve seat 
> closest to the hot area.not bad for an engine that we thought was bad @2500 miles 
> ago when i bought it!
> so now i want to prove the cam in my truck was bad when installed , i 
> really dont think i did anything incorrect. playing with harbor freight digital 
> calipers , i find interesting dimensions comparing the 9889 cam to this one 
> , plus a couple of lobes look porous (spots on the high part of the lobe ).
> any of you expert engine guys have any similar past situations?
> i had very strong magnets on the oil pickups in the motors as usual, that 
> came up with nothing but normal small amount of break in mud.
> next year WILL be different!
> regards , very tired tim colson
> HAPPY TURKEY DAY
> 
  Tim- I've been running a TB-10 on my early turbo, and what you describe doesnt sound that much different than what mine sounds like-quite a bit louder than a stock cammed
stock lifter corvair, not as loud as a rhodes lifter, but as loud as a vw that needs its
valves adjusted. I thought I might have got dirt in the lifters, so I changed them out, and
tried the flat plate check valve type, which seemed slightly quieter than the previous set,
but nothing I've tried so far (various lifter adjustments, pushrod lengths, oil viscosity...)
has really helped enough to matter. The only thing that has quieted down my noisey
valves have been to let the car sit for 2 or three days!, It will then stay quiet for about
15 minutes of driving, and then gradually get as loud as it usually is. Also, when warm,
the ticks go away when the rpms are kept above 3000 or so. I believe that the problem
is that either the bleed rates are wrong ( ticks go away above 3k) or that the type of
lifters that we have to use nowdays (non-inertia valve type) are somehow more prone
to collecting oil foam, and the more radical cams make these problems worse.
I've heard old chev 235's that were converted to hydraulic lifters that sounded as loud
as what I've got (and apparently you) and the 235's were also prone to oil foaming causing noisey lifters. 
    Kevin Nash, Efi early turbo, daily driver



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