Subject: [Fot] TR head cracks

From: [email-masked]
Date: Tue, 23 Dec 2014 08:30:19 -0500

I need advice on repairing some cracks on a TR4 head between #2 and 3  
cylinders. Is it common and is it a real concern? Can it be  repaired?
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From: Rich <[email-masked]>
Date: Tue, 23 Dec 2014 16:51:51 -0500

This is not the "usual" situation.  There are two cracks which have grown to
the point they are on the edge of the sealing area.

I can send a picture...

Rich Rock
________________________________
From: Tony Drews
Sent: 12/23/2014 11:44 AM
To: [email-masked]; [email-masked]
Cc: [email-masked]
Subject: Re: [Fot] TR head cracks

Crack between the two water passages between 2 and 3 is common and
can be ignored.  It's not a sealing surface.

Cheers, Tony Drews

At 07:30 AM 12/23/2014, [email-masked] wrote:
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From: Doug Mitchell <[email-masked]>
Date: Wed, 24 Dec 2014 13:03:52 -0500

You might check into an old-school technique of cold stitching. Not sure if it works on a head, but have seen it done on blocks. Not cheap and intensive work, but it can recover a block.

Doug
[email-masked]
Sent from my mobile phone

-------- Original message --------
From: Tony Drews <[email-masked]> 
Date: 12/24/2014  12:27 PM  (GMT-05:00) 
To: [email-masked] 
Subject: Re: [Fot] TR head cracks 
 
I received a picture of the head - the crack is to the point where if 
it grows any further there will be definite sealing issues on #2 and 
probably #3.B  I like this suggestion - a hole to stop the propagation 
and silver solder to seal it back up.B  I'll have to remember that one!

When I went through the "cracked head" issue (mine wasn't 
repairable), someone suggested "stitching" which is a series of 
threaded plugs run through the crack.B  That's the only other fix that 
comes to mind.

Cheers, Tony Drews

At 05:53 AM 12/24/2014, MadMarx wrote:
>You can stop the crack with a hole at its end and solder the crack with
>silver solder.
>Seems to work fine with a good success rate.
>
>Cheers
>Chris

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From: Mike Mehl <[email-masked]>
Date: Wed, 24 Dec 2014 20:49:32 +0000 (UTC)

I have unfortunately hadB experience with stitching a head.B  My first TR4
race motor had a stitched head (the guy who built itB repaired the head and
did notB tell me).B  It seems that with the added stress of a higher
compression race engine at high revsB the head flexed and caused blown head
gaskets.B  It might be OK to stitch a head on a street motor buy my experience
was not good on a race motor.B  I had a geyser squirting out of the
overflowB bottle.
Mike MehlB 
B       From: Tony Drews <[email-masked]>
 To: [email-masked]
 Sent: Wednesday, December 24, 2014 9:27 AM
 Subject: Re: [Fot] TR head cracks

Cheers, Tony Drews

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From: "MadMarx" <[email-masked]>
Date: Wed, 24 Dec 2014 23:01:33 +0100

Ah,

seen the cracks.

These are on the edge of being too late for rescue.

The only thing which might cure is staking the head as Kas Kastner shown in
his books and to put one screw just on the end of this crack.

But getting a new head is okay too.

Cheers

Chris

Von: Rich [mailto:[email-masked]]
Gesendet: Mittwoch, 24. Dezember 2014 15:58
An: MadMarx
Betreff: RE: [Fot] TR head cracks

Chris,

Wasn't sure if you had seen the cracks...

Rich

  _____

From: MadMarx
Sent: 12/24/2014 6:58 AM
To: [email-masked]

Cheers
Chris

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From: Rich <[email-masked]>
Date: Fri, 26 Dec 2014 18:40:41 -0500

Thanks to everyone who offered suggestions!

Here's the plan for repair:

First, the head will get magnafluxed to determine if it has any other cracks.
If the head passes that test, the repair to the two troubling cracks will be
done by "stitching".

My  machinist has a fair amount of experience with this process which involves
drilling and tapping a series of holes along the centerline of the entire
crack.  This will be done one at a time, starting with the end closest to the
combustion chamber.

The hole gets tapped using a special tap similar to a pipe thread tap and the
special (cast iron) tapered bolt gets threaded in and cut off near the head
surface, to be made even with the surface when the final machining is done.

The holes get drilled so that each successive bolt has some contact with the
preceding bolt near the head surface, and each bolt gets coated with a special
epoxy before being threaded in.

Wherever possible, the bolts will be installed so that they bottom out, and
act as "stakes" just as Kas details in his book.  Additional stakes will also
be installed away from the crack in an effort to stop any further collapse of
this already thin (shaved about .150") head  in this area and hopefully add
even more stability to the repair.

We'll see how it turns out.

Thanks again,

Rich Rock
________________________________
From: michael
Sent: 12/24/2014 3:39 PM
To: Doug Mitchell; Tony Drews; [email-masked]
Subject: Re: [Fot] TR head cracks

Years ago, I remember taking a TR3 head to a place in Long Island City, New
York called Cool Weld.  Using a process called "cold welding" they patched a
combustion chamber. This wasn't a crack, it was a hole but it worked on
cracks
as well.

That was my back-up head and it worked fine for several races and also for
the
guy who bought the car.

Mike Cook

> Date: Wed, 24 Dec 2014 13:03:52 -0500
> From: [email-masked]
> To: [email-masked]; [email-masked]
> You might check into an old-school technique of cold stitching. Not sure if
it works on a head, but have seen it done on blocks. Not cheap and intensive
work, but it can recover a block.
> >Seems to work fine with a good success rate.
http://autox.team.net/mailman/options/fot/[email-masked]
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From: Kas Kastner <[email-masked]>
Date: Fri, 26 Dec 2014 17:04:54 -0800

I had this type of repair completed on a head and also a block for the 1967
GT-6, the first in he country that I was working with without too much
success.  That pair of castings went on to live throughout the work.  The
repair is GOOD.

*Never be beaten by equipment.*

On Fri, Dec 26, 2014 at 3:40 PM, Rich <[email-masked]> wrote:

> http://autox.team.net/mailman/options/fot/[email-masked]