Re: Ur-Q hydraulic head conversion questions...

[JustaxPHX@aol.com]

> . I can cite my datapoints ... When I pulled the head from my WX engine
>  ... unknown mileage, but the head removal was a result of a project that
>  started as an attempt to repair a turbo with leaky seals ... :)  On this
>  head I had several cylinders that had cracks from valve seat to valve seat
>  and from valve seat to spark plug hole.

My original head had five cracks, one on each cylinder, all from valve seat 
to valve seat....

>  I've also got the MC head I pulled from my '88 5kCSQA, with about 120K 
miles ... not the slightest signs of a
>  crack.  I also have another MC head which has perhaps 70K miles (I forget 
now) that has no visible cracks.  

I'm guess this head has 137k on it and there were no cracks that I could see. 
 However, I talked with Scott Justusson this morning about my plans and he 
said I should also look for cracks inside the intake and exhaust ports since 
this is where the MC heads typically crack.  He said he's replaced a total of 
8 heads recently that had this problem so I have called the machinist and 
told him to magnaflux the casting once he's stripped and cleaned it ... we'll 
see.

Personally, I have never seen an MC head with cracks (except for one that was 
overheated) whereas every Ur-Q owner that I know has replaced the head at 
least once and in one case, twice.  If my conversion really works, it'll be a 
cheap and easy way to address the Ur-Q's cracking problem since these heads 
are readily available for $100-150 each and I have yet to find an uncracked 
Ur-Q head for less than $400...

JG


JG