[Healeys] A90 Head Update

Wed Feb 3 11:44:34 MST 2021

This is what I used on my BN2 head gasket.  Licensed by Rolls Royce.
Mike MacLean

    On Wednesday, February 3, 2021, 9:27:07 AM PST, <gradea1 at charter.net> wrote:  

 Alan-did not get another description from Permatex other than this which, if true, addresses your concerns:
Prev Product
Permatex® Ultra Rubber Gasket Sealant & Dressing
US Part Number: 80697
Canada Part Number: 58985
Permatex® Copper Spray-A-Gasket® Hi-Temp Sealant

Category: Gasket Sealants
Fast-drying, metallic copper sealant helps dissipate heat, prevents gasket burnout and improves heat transfer. Fills minor surface irregularities. Seals instantly. Fills hot spots and surface imperfections. Temperature range -50°F to 500°F (-45°C to 260°C); resists all types of automotive fluids, especially gasoline. Level 3

 Buy Online

I did have to remove a head for another reason, which had this coating, and it was not a problem.  I guess time and mileage will tell how effective this product is. So far, I have been pleased to not have any issues with installed heads.  Can't stress more strongly how overheating is the death knell for these engines. Hank

----------------------------------------------------------------------------------------------------------------

From: "Alan Seigrist"----------
 To: gradea1 at charter.net
Cc: "Bob Spidell", "Healey list"
Sent: Tuesday February 2 2021 7:54:17PM
Subject: Re: [Healeys] A90 Head Update

Hank -
Is the spray on sealant silicone, or is it a non hardeningkind like hylomar?  I'm a little concerned to use this as itmay make disassembly difficult later if I have to strip the enginedown again.  What is your experience?
Thanks,
Alan
On Wed, Feb 3, 2021 at 10:46 AM<gradea1 at charter.net>wrote:

Alan-two questions: do you know if the car overheated at anytime after the replacement of the head?
Secondly, do you have any idea what torque they used totighten the head, even if they did not go in order?
A couple of us, who have been doing this for awhile, decidedon about 80 FT LBS. as max torque. There is no book spec. That is aspec for that size stud and nut. The tightening order in theworkshop manual is strictly adhered to, and the torque is broughtup in 1/3 increments.
Again, I sprayed  both sides of my copper gasket with alight coating of Permatex copper seal.I used a Payen gasket which was marked top/front. Yea, thegood old days...Hank

-----------------------------------------
From: "Alan Seigrist"
To: "Bob Spidell"
Cc: "Healey list"
Sent: Tuesday February 2 2021 6:07:37PM
Subject: Re: [Healeys] A90 Head Update

Hi Bob -
This gasket was put on the car only about 5K miles ago if youcan believe it, but the car sat for about 10 yearsafterwards...  I've checked both the head and deck with arectifier (see pic), both are very nicely flat and do not need togo to the machinist.  Both are flat to within 1/1000 on thesurface... which is less than the error on the rectifier!
I have the previously removed very old copper gasket which Isaved and it has no signs of gas leaking between cylinders comparedto this newer gasket that I just removed.  Idiscovered a few things:   
   - The old gasket is made with better quality, softer copper, andis thicker than the newer gasket that was put on.  The oldgasket that showed no problems is 1.8mm thick after beinginstalled, the new gasket that failed is 1.5mm thick after beinginstalled.  The old gasket is very nicely marked as toorientation, directions, copper compression rings are thicker,etc., etc.,  Clearly the older gasket was made to work incircumstances where the mating surfaces weren't always perfectlyflat.
   - I highly suspect the mechanics that installed the head lasttime did not torque the head in the proper sequence, quite possiblyworking from the outside in.  
   - The head stud mount holes on the deck were raised a bit incouple places and may have caused the head to deflect a little,possibly, but they don't seem to have been enough to make adifference... I have already filed those holes down.  MichealSalter has told me to run a countersink to debur the hole.
It's a weird one, I think possibly a combination of all threeissues above.  Let's see how she goes after I finish thejob.  Ultimately one thing I learned is I cannot anymore relyon mechanics that I do not know well to do work on my car... I endup having to redo everything.
Best,
Alan
On 2/1/2021 11:23 PM, Alan Seigrist wrote:
> All -
>
> Got the head off.  Sure enough the gasket blew between3&4 .  some
> evidence of gas flow between 1&2 as well. Last pic is ofme standing
> in the engine compartment lifting the head off, just to makeall of
> you jealous ... :D
>
> Cheers,
>
> Alan
>

_______________________________________________
Support Team.Net http://www.team.net/donate.html
Suggested annual donation  $12.75

Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive

Healeys at autox.team.net
http://autox.team.net/mailman/listinfo/healeys

Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/healey.nut@gmail.com

_______________________________________________
Support Team.Net http://www.team.net/donate.html
Suggested annual donation  $12.75

Archive: http://www.team.net/pipermail/healeys http://autox.team.net/archive

Healeys at autox.team.net
http://autox.team.net/mailman/listinfo/healeys

Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/rrengineer.mike@att.net

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20210203/108a43e5/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hylomar.jpg
Type: image/jpeg
Size: 61100 bytes
Desc: not available
URL: <http://autox.team.net/pipermail/healeys/attachments/20210203/108a43e5/attachment.jpg>