[FC] Mikes dropped valve seat

Fri Mar 5 12:23:21 EST 2010

Good points Ken - I guess it's just been my experience that many (most) used parts I use were taken off cars that were parted out in the 70s and have just been sitting around for decades - or parts cars that have been out of service since the Nixon administration.  Others may not be that lucky.  With heads though, a guy can make an educated evaluation based on valve guide tightness, wear on valve tips, how much HG surface is deformed, sludge appearance... you just can't see how hot it's been.  It would be interesting to do a survey of sorts on total corvair miles driven in the past 5 years vs. number of dropped valve seats (small valve / non-turbo applications)  My guess would be relatively few failures relative to many, many miles driven.  You probably have a better sense of it given your exposure and repair business - mine is just personal experience and our small local club.  Of course it's a calculated risk / bet... most everything in life is. 

As for the cost...  I will use your pricelist as a baseline since I know you do top-notch work

Weld head for seat repair           $30
Valve seats installed (6)@35      $210
Valve guides installed (6)@25     $150
Valve Grind 3 Angle per head      $82 
Shipping 2 ways (estimated)       $25
1-2 weeks downtime (minimum)   Free
---------------------------------------
 - - - - - - - - - - - - - - - ->    $497 for damaged head,   $467 for other.  Add for bronze guides, HG resurface, new valves or springs (might as well).

With good oil and no overheating, you will have a set of heads that will provide hundreds of thousands of miles of worry free performance.  Cost per mile is negligible.  That piece of mind can be priceless.  I know the feeling of being scared to shut the engine off for fear of the dreaded hammering upon restarting (mainly 140s)... fear quotient directly proportional to # of miles from home.  You just have to ask yourself if that is the goal for the particular application.  Believe me, I have had many Corvairs where the powertrain cost far exceeded the price paid for the shell.

As for adjusting lifters Ken, I always do them dry on the bench by feel and never have any problems.  I just know many people still swear by adjusting them running.  Seems Clark's even strongly suggests it.  We don't even need to start a lifter discussion... not without including David at TheSource and LonWall anyway :)  That reference may be from another board - I forget.

PLEASE DO NOT take this as a personal attack Ken - I truly value your insights and passion for keeping the Corvair hobby alive.  Not trying to butt Heads! (pun intended)

Maybe OK core to build here on ebay (it's even a drivers side Mike)  http://cgi.ebay.com/ebaymotors/Single-3878566-Corvair-110HP-Head-1965-67_W0QQcmdZViewItemQQhashZitem563a2c4804QQitemZ370343168004QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Andy

 > To: corvanatics at corvair.org
> Date: Fri, 5 Mar 2010 10:14:12 -0500
> From: vairmech at aol.com
> Subject: Re: [FC] Mikes dropped valve seat
> 
> 
> OK, IF you have NO money and are strapped for something to drive I just might agree with you on a lot of your points because I have done most of what was said below. That was 30 years ago and the parts were a little newer and you could still get low time semi virgin used parts. That is rare today. Not to long ago I put a used head on a on an engine and guess what? It proceeded to drop a valve seat! I had to do the job over and provide another head at my cost.
> 
> I don't know about taking the other head off myself but with the one head the one seat can be repaired for a little more than a used head and be guaranteed for the seat not to come out! Here is where I go a little farther and say replace all the seats and then put the worry of dropping valve seats behind you for that head. 
> 
> And, Sorry, adjusting lifters running is like living in the dark ages. Any valve can be adjusted with the engine NOT running and NO mess, well, a couple of drops of oil.
> 
> 
> 
> Ken Hand
> 248-613-8586
> www.corvairmechanic.com
> 
> 
> 
> 
> -----Original Message-----
> From: Andy . <rumbleseat66 at hotmail.com>
> To: corvanatics at corvair.org
> Sent: Thu, Mar 4, 2010 5:42 pm
> Subject: [FC] Mikes dropped valve seat
> 
> 
> 
> I just can't join the chorus and suggest taking the other head off just for the 
> heck of it. To say that the passenger head is on the brink of dropping a seat 
> after 45 years just because the drivers side just did is questionable logic to 
> me. Seems like a waste of time and money to mess with the bank with perfect, 
> even compression and no known problems (I assume). Not to mention the risk of 
> pulling a head stud out of the block. That opens a whole 'nother can of worms.
> 
> A fresh valve job and cleaning of the combustion chamber on a good-running-order 
> head I bet will not net you 1-2 additional horsepower. I would even suggest 
> that an aggressive valve grind by a ham fisted non-Corvair machine shop could 
> even increase the likelihood of future seat failure. Grinding/twisting of a 
> valve seat cannot be beneficial. Staking can be though I guess.
> 
> Given this is one of three or more corvairs he has, probably none being primary 
> transportation, this motor might not see 5,000 miles a year. The signature is 
> listed as a 110hp 65 van, but he is looking for a 95hp head??? 
> 
> If that were the case (relative few miles/year), and it was mine, I would find a 
> decent used head with tight guides, lap the valves by hand, check for full 
> contact / pattern of valve and valve seat with machinist dye or a magic marker, 
> reuse my viton orings, put the sucker on and enjoy the van another 10 years. 
> And have the warm feeling that I made it run like new again for < $100.
> 
> But if I found that I could stick my thumb down the valve guides of the busted 
> head indicating a million miles and the passenger side needed a valve cover 
> gasket and pushrod tube o-rings replaced anyway, then I could see tearing the 
> other side off. 
> 
> Also, if you adjust your lifters running and you are not an ace at it... 6 
> lifters hammering is a lot easier to deal with than 12 lifters pecking (or 
> "peckers lifting" as my Dad would always say). That fancy 3 angle valve job you 
> got is not worth a damn if you run a valve into a piston trying to decipher the 
> difference in sound of 11 hammers banging anvils vs. 12 banging... LOL And of 
> course, assuming factory exhaust, the driver's side is far easier to adjust 
> (more room, less exhaust noise, no 500 degree hand warmer / skin-melter aka 
> muffler)
> 
> If you have both heads off and the blower housing off (as suggested to service 
> bearing and gaskets) then you are only 12 little rod nuts away from honing and 
> re-ringing the darn thing and replacing those rod bearings..... where does it 
> stop????? Might as well thermal coat those piston tops while they're out... 
> after fly-cutting them and milling the heads for optimal quench... hello custom 
> pushrods... also better replace those tired valvesprings so an extra 100 rpm 
> can be squeezed out of 3rd gear when you are climbing a steep hill on a 2 lane 
> road with 19 cars behind you... pedal to the floor, knowing 4th gear would be a 
> speed-losing proposition.
> 
> With all this said, some tongue-in-cheek, I spend many hours prepping any head I 
> use. Of course, if the motor is sick and needs it, by all means do it. But 
> just for the "fun" of it? No. Cleaning and deflashing can be done fairly 
> completely on an installed head. IMHO, the odds are heavily in your favor of 
> NOT dropping another seat anytime soon.
> 
> Also, I just heard on MSNBC the other day that all dropped valve seats prior to 
> August 30, 2010 are officially George. W. Bush's fault. There will be no more 
> dropped seats after that date. But if any are dropped, it will still be GWB's 
> fault.
> 
> 
> 
> YMMV
> 
> 
> _______________________________________________
> Corvanatics mailing list
> Corvanatics at corvair.org
> http://www.vv.corvair.org/mailman/listinfo/corvanatics
> This list sponsored by the Corvair Society of America, http://www.corvair.org/

_________________________________________________________________
Your E-mail and More On-the-Go. Get Windows Live Hotmail Free.
http://clk.atdmt.com/GBL/go/201469229/direct/01/