12 replies to this topic

[Sharman]

I know that HRG made a twin-cam conversion to fit a Singer 1500 block, I recall seeing the car at Oulton in the 50s. (54?). I have now found an alloy cross flow head for a BMC "B" series. Does anybody have further and better particulars, why wasn't the twin cam successful and how many cross flows were made for the B series?

[Cirrus]

I'm no expert, but the HRG crossflow head for the B Series was a fairly popular conversion for the MGA and MGB engines. I don't think it's homologated for MG's in historic racing, but I'm pretty sure it is for the TVR Grantura.

[Allan Lupton]

Originally posted by Sharman
I know that HRG made a twin-cam conversion to fit a Singer 1500 block, I recall seeing the car at Oulton in the 50s. (54?). I have now found an alloy cross flow head for a BMC "B" series. Does anybody have further and better particulars, why wasn't the twin cam successful and how many cross flows were made for the B series?

Like Cirrus, I remember the HRG-Derrington head for the B series as widely used where the regulations allowed. The cross-flow aspect was perhaps its best feature as it permitted four ports for inlet and exhaust so you could put a couple of twin-choke Webers and a 4-2-1 manifold on and go racing!

The Singer twincam was used in a limited way as a production car, the Hunter saloon from about 1955 (just before the Rootes take-over).

[Sharman]

Allen
I don't think that the twin cam ever made it into production in a Hunter. Was the desgn of the engine by HRG or by the factory. It went into the all enveloping HRG which I recall as quite a pretty car. I had photos which went the way of the rest of my memorabilia in 1978, can anybody post one? Cirrus was right about homologation on TVRs.
John

[Allan Lupton]

I could be wrong, but I'm sure I remember that the Hunter (Singer, not Hillman) did have a twin-cam engine, and my memory is that it was the HRG head.
But then memory is an elusive thing these days and it may just have been a show model.

[David McKinney]

According to Georgano, a twin-cam head was an option on the Singer Hunter

[Gerr]

The car was the Singer Hunter 75....as in 75 bhp....announced in October 1955.

The twin cam head on the saloon was an iron, non-crossflow design, with two Solex carbs mounted vertically above the intake valves. In the HRG it was an alloy crossflow with side-drafts.

The Hunter 75 was abandoned around January 1956, with the Rootes take over. Only about 20 engines were built for Singer.

[Allan Lupton]

Originally posted by Gerr
The car was the Singer Hunter 75....as in 75 bhp....announced in October 1955.

The twin cam head on the saloon was an iron, non-crossflow design, with two Solex carbs mounted vertically above the intake valves. In the HRG it was an alloy crossflow with side-drafts.

I said memory was elusive.
Certainly, now I come to look, Motor Sport (November 1955) tells me it was a "cast-iron edition of the 1½ litre twin-o.h.c. cylinder head evolved for the Singer engine in the sports HRG"
No mention that it was changed to a downdraught layout.
In July 1956 Bill Boddy reported being told that the PRO of Singer Motors had told him that the Hunter 75 "never got as far as the production stage and now it never will"

[roadmap]

They only made 5 alloy twin cam heads its believed in total . The two cars that raced were very quick but time was against HRG, They spent so much developing the cars even the disc brakes were state of the art, their core business suffered and they made their last car in 1956, although they continued to make accessories for many performance cars, their car building days were over.

There is a story that they made a few iron twincam heads for several singers that went to the States but I have not seen or heard of one, so it may never have actually happened.

My car has been out a few times recently at Aintree, Silverstone and Le Mans 24 hr support race last year and there is another car that ran at Goodwood in 55 and alongside mine in 56 being rebuilt. These are the only original cars left out of the three actually produced.

See picture below.


http://www.roadmap.c.....0Mans 190.htm

[Sharman]

We were discussing on another thread the paucity of engines in the lower categories during the mid fifties. I wonder why nobody picked up on this configuration for an easily available road engine. What sort of output was/is available. It would seem to have been a better bet than the Butterworth in 1500cc guise.

[roadmap]

Original bhp quoted ex factory was around 110 at 5750 rpm in 1955. They did get a lot more when the two cats were out and about. We were getting close of 147 last year and its due to go on the dyno within a fortnight. I didnt want to push it too far as I only have the one head.

[Sharman]

Do you have any plans for cntinental excursions, Pau for example?

[roadmap]

May do depending on my programme.