<VV> Re: valve seat set screw retention/tap sizes

[Tony]

At 1049 04/20/2004 -0400, Bruce Schug wrote:
>
>This thread has turned into a somewhat interesting thread on threads 
>(?). But, I have to ask, is this a viable way to get reliable valve 
>seats in a Corvair? 

Well, for the folks on a budget who don't mind the DIYS methods, yes it is.   

>I've heard it mentioned from time-to-time but I 
>continue to hear that the best way to solve this problem is to:
>
>1. Heat the whole head to remove stress (I think that's what it does)
>2. Remove all the old seats
>3. Machine the head for DEEPER seats
>4 Heat the head and install the new deep seats with a significant 
>interference fit.

Nice fix, good for the duration, never have to worry much about a seat coming
out again.  But...   

How much dos this cost today?   


>I will add that Bob Coffin installed bullit-proof seats in my heads in 
>1986 when he was still in Mass. I have never had a problem with them 
>through all kinds of driving conditions: rallys, autocrosses, VIR in 
>90+ degree heat, economy runs, street driving with the air-conditioning 
>on, etc. Why try to invent the wheel, this wheel works fine for me!

I don't think anyone was trying to reinvent the wheel, just trying to keep the
existing wheel rolling without going broke.   

I've done the Cromwell setscrew trick and it works... and it cost me about 15
bucks for the hardware to do 4 heads.   Make sure the guides are OK and the
seats will stay put.   So far, so good.   


tony..