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Re: Derrington Cross-flow Head

To: <Editorgary@aol.com>, "MG List" <mgs@autox.team.net>
Subject: Re: Derrington Cross-flow Head
From: Steve Morris <smorris@en.com>
Date: Fri, 6 Oct 2000 20:11:57 -0400
On 10/6/00 7:01 PM, Editorgary@aol.com  <Editorgary@aol.com> wrote:

>I've just bought an MGA 1600 for vintage racing.  It is fitted with a 
>cross-flow head that the previous owner says is an "original Derrington" 
>head. The only identifying marks on the head are the initials HRG cast into 
>the top on the right front. Can anyone shed any light on this accessory -- 
>when it might have been used originally and if there is any way of verifying 
>its originality?


Gary,

The July/August 2000 issue of NAMGAR's MGA! magazine has a whole article 
by Mike Ash on the HRG-Derrington head (page 12-14.) It tells the history 
of the company, and quotes and analyzes a couple reviews of the heads 
from 1958 "The Motor" and a late 50's issue of "Motor Sport" magazines. 
They started making the heads after their car manufacturing was bought by 
Singer and then Rootes Group in 1955, so the head was time appropriate 
for your 1600. The HRG Engineering Company went out of business in 1966.

Cost of the head was "58 pounds 10 shillings including valves and 
springs." (or about $150-$200 USD which comes to about $1200 of today's 
dollars; about what a new cross flow costs.) "Flat top high compression 
pistons and a special Derrington extractor exhaust give an additional 2 
bhp."

On a 1500 MGA "The HRG head renders the engine extreme flexibility - top 
gear range was 10-100 mph!"

"We believe that up to 70 mph, the HRG headed MGA will beat a normal MGA 
by 5 seconds."


If you can't find a copy of the issue, let ne know and I will send it to 
you.

HTH,
Steve
 

Steve Morris     Avon, Ohio
1958 MGA 1500    Red/Black
NAMGAR #5987
http://www.en.com/users/smorris/mga/


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