<VV> Dropped valve

[tony underwood]

On 8/19/2024 9:30 AM, Jeffrey Hennessey via VirtualVairs wrote:
> Folks…
>
> I am despondent. My 1963 Spyder Coupe, that I have owned for 24 years is currently a static display in my garage. My local guy did the troubleshooting. He has determined that I have a dropped exhaust valve. The problem is in the middle cylinder passenger side. Compression zero. All others 150. I’m in Massachusetts. I am at a loss as to how to tackle this. I’m looking for some guidance. Have any of my fellow Corvair people dealt with this?
> Jeff
> Sent from my iPad


This has happened to every Corvair enthusiast who actually drove 
Corvairs.  Spyders and Corsas tend to lose more seats than the grocery 
getter types.


If you have been around Corvairs for a quarter-century you already know 
the drill... take the head off, bring it to your favorite auto machine 
shop and show it to them.  They will fix it.  Corvair heads used to be a 
bit of a mystery to many machine shop guys because they were used to 
dealing with iron stuff. Today, vast numbers of engines have aluminum 
heads and seat inserts, no mystery anymore.

If you aren't mechanically inclined, perhaps your local guy would be 
willing to yank the head and take it to a machine shop for repairs. 
Being the passenger side head, it's a bit more complicated to r&r since 
the turbocharger bolts to it, but it's still doable without a lot of 
heartache. NO, you do not have to remove the turbocharger, it can just 
hang there although you will need to wiggle the turbo's oil return tube 
a bit to get it out of the head. I've had two Spyders (Still have one, a 
project) and I drove them somewhat aggressively along the way and had 
seats come out of both heads of both cars, yanked the heads each time 
and took them to the shop and had new seats pressed in. Later, I took to 
staking the good seats to help insure they stayed in place (not always 
successfully) but I was never "set back" over it since I always do all 
my own work that is doable. It's what many people do with vintage 
vehicles; it's part of the mystique of owning one.

That said... I won't try to replace a valve seat in a head; I'm not a 
machine shop.

I'm sure there are multitudes of people in here who could give you step 
by step details on how to remove the head as well as putting it back 
once it's repaired. It helps to have someone on hand who has done it 
before, but you Can do it yourself if you can handle basic tools and own 
a torque wrench. Or... enlist help from someone who's good at twisting 
wrenches. And, my opinion only, you do not need to arbitrarily replace 
every single valve seat if one comes out. Some people insist that you 
do; I'm not one of them. Have the shop check the rest for potential fail 
evidence. They should be able to give you a good idea of the head's 
expected performance once they have it apart, before it's repaired.

Clark's is your friend.

You'll need a head gasket, a valve cover gasket, intake manifold to head 
inlet port (aka carb mount) gasket (the gasket not the spacer the 
carb'ed cars use), exhaust manifold gaskets (three smaller ones to the 
exhaust tubes and the larger one between the exhaust manifold and the 
head pipe), a set of pushrod tube seals vitons of course, and maybe a 
turbocharger exhaust outlet gasket, along with whatever else you might 
need to replace along the way that wasn't anticipated. That should be 
about it for the r&r parts, iirc. Everything else is nuts and bolts. 
You'll have a better idea of what you need to do after you remove that 
section of passenger side engine bay tin (upper and lower shrouds) and 
the muffler and heat shield (you'll see it) along with the cooling 
damper doors and vents at the rear of the engine. You will need to make 
sure you get all the shrouding bolts and screws off the head so it will 
actually come off the car. Pushrods and the pushrod tubes will need to 
come out also, make sure you note which end of each pushrod has a small 
hole in the side which is there to oil the rocker arms. Don't put the 
pushrods in backwards. The crankcase/cylinder studs may give you some 
grief, maybe requiring you loosen the rear motor mount and block up the 
rear of the engine with a floor jack to allow it to drop down just 
enough to allow the head to clear the engine bay - wheel well sheet 
metal. Wave a camera around the stricken area during the disassembly to 
document progress and keep a fresh viewpoint on how it goes back 
together. The head is bolted in with 9/16 nuts and 13/16 rocker stud 
nuts, along with the misc hardware that attaches the engine bay tin and 
associated sheet metal. Rocker arm nuts are 5/8. Valve cover bolts are 
7/16. Shroud hardware includes 5/16, 3/8, and 1/2 sockets. In other 
words, basically a full compliment of sockets and the occasional misc. 
wrench. As Mike Rowe says, "prepare to get dirty".

Putting it all back together is also going to involve valve 
adjustments... that can be dealt with in this forum after the head is 
back on the car. Now, all this is a basic description of what to expect. 
It is not a substitute for a service manual or a specialty Corvair 
repair manual like the Tech Guide etc.

Don't be discouraged.

tony..

PS: if I missed anything important, the viewing masses are free to jump in


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