XPAG and XPEG Head gasket dimensions

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Graeme Louk
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Location: Sydney, Australia

XPAG and XPEG Head gasket dimensions

Post by Graeme Louk » Mon Dec 14, 2015 6:32 pm

Greetings All,
Can someone please tell me where to find or give me dimensions for XPAG and XPEG head gaskets if they are available. I'm after accurate stud and bore spacings. I don't need coolant passages but if they are on the drawing even better. I have the opportunity to have torque plates water cut.
I have found variation in the hole spacing in head gaskets I've measured.
Many Thanks,
Graeme Louk
Sydney
Australia

Tom Lange, MGT Repair
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Joined: Mon Jan 07, 2013 10:14 am

Re: XPAG and XPEG Head gasket dimensions

Post by Tom Lange, MGT Repair » Tue Dec 15, 2015 5:23 am

I have always thought that there are simply too many variables for a torque plate to have any effect at all. You would have to use the exact fasteners with both torque plate and engine, since clamping forces would be different with different head studs. Also, you would need to use the exact same head gasket with both torque plate and engine, since there are so many variables in head gasket design and manufacture - you would inevitably have your sealing force distributed differently over the engine with a different head gasket.

Seems to me to be a lot of work and expense for 1 or 2 percent gain..

Tom Lange
MGT Repair

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Kameron M
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Location: South Bend

Re: XPAG and XPEG Head gasket dimensions

Post by Kameron M » Mon Feb 15, 2016 6:27 pm

400hp engine with an aluminum block might be a job well needing a torque plate for a hone.

I have a gut feeling that on a small bore cast iron block engine that the torque plate will do absolutely nothing.

Factory didn't use a torque plate.

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Alan Jones
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Location: UK

Re: XPAG and XPEG Head gasket dimensions

Post by Alan Jones » Wed Jul 21, 2021 12:25 am

Hi, the original question was in regard of the dimensions of an XPAG gasket which is what I am looking for to enable a special solid copper gasket to be laser cut.
The dimensions of the block / head holes including the combustion chamber would suffice too.
Please.

Tom Lange, MGT Repair
Posts: 305
Joined: Mon Jan 07, 2013 10:14 am

Re: XPAG and XPEG Head gasket dimensions

Post by Tom Lange, MGT Repair » Wed Jul 21, 2021 2:26 am

There are early and late XPAG engines, with oblong or round cooling passages, so you must distinguish between the two, no matter where you go. There are copper-gasket suppliers (Hussey Copper in Pennsylvania) who already have patterns, so there is no need to re-invent the wheel. Also try headgasket.com. If you need a new pattern, you can do no better than by sending off a head gasket for copying.

But my real question is why you need a solid copper gasket? I use a standard gasket whenever possible, as copper gaskets have presented sealing issues for me in the past, as have using two head gaskets. I strongly recommend the Cometic gasket, available from Manley Ford.

Pistons stand proud? Have them machined down. CR too high? Get a different head.

Tom Lange
MGT Repair

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Duncan M
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Location: Northern California

Re: XPAG and XPEG Head gasket dimensions

Post by Duncan M » Wed Jul 21, 2021 9:40 am

A few of the early pro racers used XPAG/XPEG with no head gasket.

Tom Lange, MGT Repair
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Joined: Mon Jan 07, 2013 10:14 am

Re: XPAG and XPEG Head gasket dimensions

Post by Tom Lange, MGT Repair » Wed Jul 21, 2021 5:51 pm

Duncan - I believe you refer to EX-176, a 1,466cc dry-deck engine used at the 1954 Bonneville Land Speed Record attempt, when a streamliner with that engine went over 153MPH. Racers like Ken Miles also used that engine, and some racers still do - Steve Konson and Don Martine, for two. MG made all the advertizing hay possible when it claimed the TF1500 used that same "race-winning" engine - they were actually quite different. I have two EX-176 engines, one in a TD, and one from a Lotus IX originally raced in California by Rex Huddleston - it was removed and replaced by an 1,100cc Maserati engine the car still competes with to this day!

It was also possible to home-make dry-deck engines, and Ludvigsen and Chrfisty describe how in their MG Guide. Factory EX-176 engines put out 75HP out of the box, and could easily be bumped up to 100HP unsupercharged.

Tom Lange
MGT Repair

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