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MG TD TF 1500 - Head

Would anyone know of a good un-milled head for an EPAG?

Trying to regain some compression ratio.

Thanks,
Mort
Mort 50 TD (Mobius)

Not sure what an EPAG is, but I have an unmilled, passed magnafluxing, banana port head that's just been gathering dust since I removed it from 'the53'. Bud
Bud Krueger

Unmilled head would have less compression.
JRN JIM

Mort,
I doublechecked and you have a new Moss supercharger. Are you trying to raise or lower your compression?

Unmilled head and dished pistons will lower it.

JRN JIM

Mort is trying to LOWER his compression, from 9.0:1 to in the low 8's, for safer use with his blower.

Tom Lange
MGT Repair
t lange

Before I pulled my head off I'd driven the car for 18 months without any problems until I blew a head gasket. I checked the head prior to replacing it & it had 147 thou removed (before I bought the car), way more than the max recommended 125 thou. The compression ratio must be well over 9 to 1. I was also advised to use a couple of head gaskets to reduce compression.
Cheers
Peter TD 5801
P Hehir

Sorry all, it was just a typo. It's our XPAG engine.

Thanks Tom, yes I am trying to lower the compression to about 8:1.

Bud, I will contact you via e mail.

Jim, I was told dished pistons were not available for this engine.

Mort
Mort 50 TD (Mobius)

Venolia Pistons in Long Beach, CA can make virtually any piston you need. But they would require a sample or a good technical drawing. Give them a call. You will find them most accommodating.
Lew Palmer

Mort, I don't know about thickness of soft solid copper gaskets for our engines, but for racing engines you can get them in various thicknesses, pretty much standard up to .062 to reduce compression using a blower. I would only assume one can be made for an XPEG as thick as you would need. I would rather do that than use double gaskets if available and would be a lot cheaper, plus different thicknesses can be easily changed for various compression ratios. Just an idea. We used them in race engines many moons ago. PJ
Paul S Jennings

Mort,

have you thought of changing the pulley of the charger?
A larger diameter one would reduce boost and nothing else would have to be changed on the engine to run at a lower effective CR.

The pulley can be fabricated at any machine shop at low costs.
The company that delivered your charger should be able to deliver a chart that shows pressure at different rpm. The rest is a simple calculation.
I think, that would be an easier way and should keep the rest of the engine close to stock without the need of special parts in case of service or repair.

With a calculated CR of 8:1 you'll end up lower when more radical cams are used. What cam are you running in your XPAG? The late symmetrical one, the early one or something else?

Ralph
R.S. Ralph Siebenhaar

Your best bet is definitely to lower compression rather than boost. Many piston manufacturers can make custom pistons.

I have a Moss supercharger also, for one of my MGBs. I got a set of custom dished pistons made for it to lower compression from 9:1 to 8.1:1. It didn't cost much more than a standard set, and the results are fantastic. I would personally prefer this to running double head gaskets. I'm getting ready to install a higher boost pulley (also a Moss Motors item) to take advantage of the lower compression ratio and other tweaks.
Steve Simmons

Mort, I had my pistons made by Venolia in Ca, per Lew. they built them special for me specifically for my supercharger. cost was about 700 bucks for four pistons. They will make them to your specs. I had mine made thicker due to heat buildup with the blower. the bottom is tapered also to expand when heated.
Tom Maine

I got a thicker, solid headgasket for the XPAG from 'Gasket Works USA': http://www.headgasket.com/gaskets.html

If you calculate the required thickness he can produce these standard material thicknesses .022,.032,.040,.043,.054,.063,.070, .086, .093, and .125 inches.
Willem van der Veer

Thank you all. Please see my thread on gasket questions.
Mort 50 TD (Mobius)

This thread was discussed on 21/01/2014

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