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MG MGA - Cross-Flow Cylinder Head from Moss Motors

Hi,

Has anyone used one of these:

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=47654&SortOrder=1

I can't tell for sure on the picture, but I think it says MSX. How would the performance compare to a HRG Derrington head. I'm just exploring options...

Thanks,

Darian
Darian Henderson

I have not used one, but I know a few people who have one, I know people who have done serious lab work and testing and some clean up on the casting, and I can offer a few notes. Do not lean too heavily on the phrase "computer generated gas flow design". Do read the caveats in the second paragraph of that ad.

I believe the MSX head is not as well thought out or refined as the HRG Derington head. I doubt there has been any significant change to the casting design in the past couple of years, so there will still be some significant internal flow problems. Anyone contemplating spending the money for one should read these articles written by experts:

OPTIMIZING AIR FLOW (Generic):
http://mgaguru.com/mgtech/power/pp401.htm

PORTING the MSX CROSS FLOW HEAD:
http://mgaguru.com/mgtech/power/pp402.htm

PORTED CYLINDER HEAD - Cutaway for Inspection:
http://mgaguru.com/mgtech/power/pp403.htm

The "Porting" article mentions a need and desire to do some internal welding to correct a serious port design problem that screws up the flow. They never did get to that step, as it was more expense the customer wasn't ready to cover. If you buy the MSX head, then pay someone to do some serious porting work, it may exceed the cost of a supercharger. And that's even before you add in the cost of intake manifold and carburetors.

If you are contemplating vintage racing, read the rule book first, as many race sanctioning organizations would not allow this head in a vintage race class.
Barney Gaylord

Thanks, I appreciate it. I guess I have to look for a machine shop to repair the head I've got...
Darian Henderson

Anyone used any of these heads:

http://www.britishclassiccarspares.com/engine.html

They say they are HRG...
Darian Henderson

It will be much cheaper to get your existing head fixed
dominic clancy

Darian,

Cameron sells MSX heads, not HRG.
Alexander M

Hi Alexander,

I've never dealt with this guy. I thought he had some kind of HRG head because of this from his page:

MGA/MGB STD - £POA
MGA/MGB PORTED & POLISHED FAST ROAD - £POA
MGA/MGB PORTED & POLISHED RALLY 44mm/34mm - £POA
MGA/MGB PORTED & POLISHED RACE 44mm/34mm - £POA
MGA/MGB CROSSFLOW STD HRG - £POA
MGA/MGB PORTED & POLISHED FAST ROAD HRG - £POA
MGA/MGB PORTED & POLISHED RALLY HRG - £POA
MGA/MGB PORTED & POLISHED RACE HRG - £POA

Darian Henderson

darin
i bought a hrg head from moss a few years ago, not an msx. the head needed a lot of work for eg the ports were too small and at 90 degrees. also the bits on the head didnt line up with the block. in other words off the shelf its total rubbish. i know of a guy who put one on an MGB standard engine and it made no diff on the dyno. however with a lot of head work it does produce better torque and breath better though you still only have 3 exhaust ports, very unsatisfactory. with a lot of bottom end work too and overbored with a piper 285 cam, the 300 is way too lumpy to drive on the road and its only about 10 to 15bhp at the top with a lot less at the bottom my engine builder managed to get 140bhp out of my 5 bearing MGB engine which has just gone into my A. unless you want to spend a lot more $'s on the HRG/MSX head i would buy a worked head off peter burgess which is what i would do next time. hope this helps
tim
t sullivan

Darian,

Cameron's site indicates it's an HRG head indeed, but he said it's actually an MSX head but that he wrote HRG because it's that "style of head".

Tim,

Peter Burgess modified the HRG head on my car, and combined with Piper 285 cam etc etc in the engine Chris Betson built, we saw 124 bhp at the wheel (+- 150 at the flywheel) at the dyno. Torque is very very good across the entire rev range as well. There's some numbers at the bottom of this page: http://www.octarine-services.co.uk/alex1950.htm
This is a car that's used on public roads, not the track.
What are the shortcomings for your engine then? 140 bhp doesn't seem that bad at all!

fwiw

Alex
Alexander M

Alex
The engine’s only just gone into the MGA so I haven’t driven it yet. I think it will perform well, I wanted an engine with torque not just high end BHP. The car will be road registered and I’ll use it for club track days and want to do some tarmac rallies like Targa Tasmania and Classic Adelaide. The motor’s got a nice flat torque curve from about 2,000 rpm producing about 30lb/ft over standard. My engine and yours look very similar to yours but you’re a slightly higher compression ratio, its hard getting high octane fuel here. You have to compare apples with apples when you talk about BHP on different dynos, as the same engine can even give different results on the same dyno when tested at different times and will certainly produce different figures on different dynos. It totally depends upon the calibration and how long ago the dyno was serviced. Even manufactures lie about BHP figures, Ferrari claim the 246GT produced 195BHP, but talk to the experts and they have never seen a standard engine produce more than 180BHP and even when worked its pushing to get to 200BHP. In other words i don't put much store in what people claim
Tim
Tim

This thread was discussed between 19/03/2007 and 24/03/2007

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