[Healeys] [Fwd: Re: OFF WITH HER HEAD!!!]

[Dave Russell]

-------- Original Message --------
Subject: 	Re: [Healeys] OFF WITH HER HEAD!!!
Date: 	Sun, 25 Nov 2007 15:47:25 -0700
From: 	Dave Russell <Rusd at sitestar.net>
To: 	WILLIAM B LAWRENCE <ynotink at msn.com>
CC: 	Healey List <healeys at autox.team.net>
References: 	<BAY101-F26CB5850613AE904A3BF81A5740 at phx.gbl>



Hi Bill,

A few comments from personal experience. Attached is a pic of a cylinder 
head, a standard gasket laid on it, & a circle of white paper that is 
cut to exact cylinder bore diameter & positioned in the correct location 
of the cylinder bore.

Yes, the combustion chamber edges at the exhaust valves DO hang over the 
block (the chamber is wider than the cylinder bores). The gasket is 
scalloped accordingly to match the chamber contour. No part of the 
gasket is not backed up by the cylinder head surface. The gasket must be 
contoured to match the cylinder head not the block.

The Hundred Four does NOT have an optimum head bolt pattern & this makes 
the head to block fit very critical.
1- It is important that the head & block surfaces be PERFECTLY flat.

2- High strength studs, nuts, & hardened steel washers, such as the DWR 
set, will help assure that the head is firmly clamped & that it stays 
so. When using new studs, they should all be torqued to spec, loosened & 
retorqued, several times  to smooth up the threads  before final 
torquing.  Don't forget sealer on the studs which may extend into the 
water jackets. Upper stud threads should be lubricated.

3- The multi layer steel gasket from DWR is of the latest technology. 
The three steel layers are free to move against each other with 
temperature expansion changes & thus maintain a perfect seal under all 
conditions. Expensive?, yes, but well worth it in my opinion. This type 
of gasket DOES require a much smoother cylinder head & block face finish 
than the usual milling operation in order to work as it should. This 
gasket has the same contours as the correct standard gasket.

4- I recently rebuilt my Four using the DWR aluminum head, a compression 
ratio of 9.8:1, & the previously mentioned gasket,  studs, & milling.  
It has not needed retorquing & shows no signs of leakage of compression 
or of coolant.

Not sure how many  corners you may be able to cut without problems, but 
a good seal can be obtained. Don't overlook the fact that you just 
"might" have a crack in the cylinder head. The machine shop should be 
able to check before milling.

Good luck,
Dave Russell
BN2




WILLIAM B LAWRENCE wrote:

>For the second time in about 3000 miles my 100 has blown a head gasket 
>between #3 and #4 cylinders. I have the head off now and am having it 
>surfaced. I've checked the block with a straight edge and feeler guage and 
>it seems flat.
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