MGB MGB Head Mods

[kyreb1862]

Well I recently discovered I had a small coolant leak in my cylinder head above the number 2 spark plug. For the time being I'm going to use a little sealant to get me by. I know that I am going to have to replace the head eventually so my question is, what mods would be the best to make to my new head to get improved horse power?

 

[DrEntropy]

I'll reiterate what I posted in DieselBrad's post: "The Special Tuning Manual" and books by Clive Trickey and David Vizard are great for info on reworking and tweaking the engines.

Reprofiling the 'squish points', cleaning up the inlet and exhaust runners, "cc'ing" the chambers and port matching are of most benefit in my experience. Makes them noticeably smoother running and boosts output.

 

[Bob Claffie]

Why a new head? This leak could be as simple as a bad gasket or a warped head or block. The head could be cured with a surfacing operation of a few thousanths. The block fix would be much more $ and time. Only look at replacement if cracked. Why is everybody so quick to spend big $$$? Bob

 

[kyreb1862]

It actually is a crack Bob. Its located about 2 inches above the No. 2 plug. I wish there was an easy way to fix it because the engine runs great. believe me when I tell you I'm not one to run out and spend big $$$ for no reason, that stuff is just to hard to come by. /ubbthreads/images/graemlins/grin.gif

 

[AlanT]

Remove the valve cover and clean the head and you will see the crack from the valve guide to the spark plug hole. FWIW , I've run one like that for six to eight years. Obviously look for an uncracked head to modify.

Alan T

 

[kyreb1862]

[ QUOTE ]
Remove the valve cover and clean the head and you will see the crack from the valve guide to the spark plug hole. FWIW , I've run one like that for six to eight years. Obviously look for an uncracked head to modify.

Alan T

[/ QUOTE ]

What have you done to your head to stop the coolant leak to the outside?

 

[AlanT]

I installed a can of K&W block/head sealer. Sometimes it works.....Sometimes it doesn't.

Alan T

 

[kyreb1862]

I'll try it. The leak is not that bad yet, just shows up under pressure. Thanks

 

[DrEntropy]

The K&W stuff is usually pretty effective. I took from your first post that the leak was coming from a cracked head, seen plenty with just what you (and now AlanT) have. If it doesn't get an "overheat treatment" it can last quite a while. Just monitor the coolant level and the gauge.

The stuff I suggested is NOT expensive, and most of it can be done with "hand tools" and patience (with guidance from Visard's book). Good used heads are still around at reasonable cost, too. With the proper drifts you can even replace the guides yourself as well. The only expense would be having a machine shop cut three-angle seats.

 

[kyreb1862]

I couldn't find the K&W stuff so I got some made by Prestone instead. It was successful. Now I no longer have the leak. Thanks for all the input guys. Merry Christmas! /ubbthreads/images/graemlins/thumbsup.gif

 

[jlaird]

I ran a plymouth with a leak many years with that stuff in it. No problems.