[Fot] TR4 head crack between water holes

[Tim Murphy]

Thanks Tony, good info!  My machinist was concerned about that and now I
have some more info for him.

Tim

-----Original Message-----
From: fot-bounces at autox.team.net [mailto:fot-bounces at autox.team.net] On
Behalf Of Tony Drews
Sent: Saturday, May 12, 2012 12:36 PM
To: fot at autox.team.net
Subject: Re: [Fot] TR4 head crack between water holes

Subject was "[Fot] TR4 Valve spring - pressure, assembled height, suppliers"

I think we're talking about different areas of the head.

The area Richard was talking about is between the two water holes in 
the head between Cyl #2 and #3.

There's a picture of my (old) head here:
http://www.tonydrews.com/2008-9Rebuild/DSCN0536.jpg
It pretty clearly shows this area of the head, and you can also see 
the lines that are the edges of where the head gasket runs.

There is no gasket surface area near that particular crack, and the 
other side of the water jacket (to run the pin / peg against) is far, 
far away, very deep into the head.

On the other hand, there is the idea of "pinning" the head when you 
mill a bunch off.  THAT may have prevented the crack in the head 
which caused me to have to have a new one prepared.  There's some 
detail about that at the bottom of this otherwise unrelated page:
http://www.tonydrews.com/Tony_Car.htm

For that, you drill and tap holes around the periphery of the 
combustion chamber on the opposite side from the valves, screw 
something through the holes against the other side of the water 
jacket with some threadlocker, cut them off and have the surface 
ground / milled smooth.

There is also a method of fixing cracks using overlapping screw-type 
pegs "stitching" I think it's called - that was one possible 
suggestion for an attempted repair of this crack:
http://www.tonydrews.com/Test%20Pics/2012_0331Head_Crack0007.JPG

There may be some value in fixing a crack between the water holes 
between Cylinders 2 and 3, but I'm not seeing it, and "Uncle" Jack 
always considered that to be a total non-issue.  Cracks between the 
valve seats (another common problem) ARE a big deal.

Tony

At 11:17 AM 5/12/2012, Joe Alexander wrote:
>TeriAnn is right.
>
>It might be in one of Kas' books, I think.  TeriAnn's comprehensive website
on
>heads is back up, according to TeriAnn.  Another great resource that we
have
>on the FOT LIST, regardless of competition status.
>
>There is a suggestion that this area can flutter and perhaps can disturb
the
>gasket seal.
>
>The fix is something like drilling and tapping this area and running a
screw
>down to a solid point in the water passage.....then milling flush.
>
>The FOT list is very much alive and well. The Mitty provided some stimulus,
>methinks.
>
>
>
>
>
>Joe Alexander
>A. R. E.
>645 1st Street
>Jesup, Iowa 50648
>319.464.4711  (cell)
>n197tr4 at cs.com
>
>
>
>
>
>-----Original Message-----
>From: TeriAnn J. Wakeman <tjwakeman at gmail.com>
>To: fot <fot at autox.team.net>
>Sent: Sat, May 12, 2012 10:37 am
>Subject: Re: [Fot] TR4 Valve spring - pressure, assembled height, suppliers
>
>
>On 5/11/12 7:53 PM, Tony Drews wrote:
> > Richard, the crack between #2 and #3 cylinders between the water holes
> > is no big deal, don't worry about it.
> >
>Shouldn't you at least peg the crack?
>
>Teriann
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