F3 engines

[tinweevil]

Title edited, probably helps to ask about something that exists!

Anyone know any good technical info on the F3 Sprint engines or know any websites that do?

Ta
Tinweevil

[tinweevil]

So far all I can find out is that the cars were March 763 tho I doubt it was March that built the engines.

They sat upright in the chassis (why? width?). Smifters post provides a few more clues but begs some questions too. Starting with are the Cossie pistons custom for the job or an off the shelf part? Given March's budget I'd guess the latter.

I havn't even been able to find any power figures for it.

Tinweevil

[xvivalve]

Probably sat upright in the chassis because a) they weren't too interested in reducing bore wear over tens of thousands of miles (which is why Triumph kilted it over) and b) as it was located behind the driver it made the least frontal area when combining those two largest components of a racing car...?

Long time since I saw the one at Gaydon, but doesn't the dizzy get driven directly off the end of the camshaft?

Fuel injected from beneath the manifold

I could do things with one of the transaxles!

[Sprint36]

Slightly bigger valves than standard.

Usually had DNF by it in the results.

David

[xvivalve]

...and didn't the 763 have a toyota 2 litre engine, the 773 was the one Needel drove...

[Jon Tilson]

I thought it was canted over because it was half a V8....
It was aslo designed by coventry climax wasnt it? Used in a fire pump...
Has a lot of obvious design similarity with the imp engine, also CC sourced.

Jonners

[tinweevil]

...and didn't the 763 have a toyota 2 litre engine, the 773 was the one Needel drove...

The March site I linked above isn't totally clear but it looks like more than one engine went in 763 chassis. Triumph isn't shown against 773.

Um.... Earth calling planet Tilson? Come in Tilson?

Tinweevil

[tinweevil]

The Gaydon stock list shows their car as 1978. The March archive doesn't list any Triumph engined cars built that year so there's definately some duff data floating about.

Tinweevil

[Lewis]

Coventry Climax designed the firepump, which later became the Imp engine - without much redesign, it using a single-carburettor ex-Coventry Climax engine which was one of their tuned up firepumps. The firepump that wins races!

There's no real link between our slant and theirs.

The Triumph Slant-4 is an engine developed by Triumph. According to Triumph historians Graham Robson and Richard Langworth in Triumph Cars, the complete story, the engine was developed in-house by a design team led by Lewis Dawtry and Harry Webster.

The UK engineering and consultancy company Ricardo, which did have a general engine-development contract with Triumph, was not directly involved with its design, but was usually kept informed of anything new being planned.

Ricardo was involved in developing a new engine for Saab, as a replacement for their aging two-stroke units. When that development proved too expensive and risky to produce, Ricardo, knowing the Slant-4 was almost ready for production, brought Saab into contact with Triumph.

Saab first used the Triumph Slant-4 at 1.7 L (1709 cc) for the Saab 99. Only later, as production capacity increased, did it become available in Triumphs. Development continued into the 1990s. The engine is a straight-4 with the cylinders tilted at 45 degrees which bears many design features and components shared with the later Stag V8.

Variants of the design were also used in the Triumph Dolomite 1850 and Sprint, early Triumph Stag, Triumph TR7 and Panther Rio (1975-1977).

I always thought the engine was a Ricardo design but I'm not sure about that now May have been totally in-house. Anyone?

[slant4]

ricaro did some work for triumph. I thought was based around the generic v8. Straightened up for weight distribution. Got an article on it somewhere at home think its the 75 years of triumph book

[xvivalve]

http://www.teamdan.com/archive/www2/ukf3/77bpvf3.html

http://www.teamdan.com/archive/www2/ukf3/76bpvf3.html

Ahh, both is the answer, but most of the '76 cars were toyota powered with a greater predominance of Triumph engines in the '77 season - note the '74 and '75 season cars still being campaigned in the same later races.

Didn't know Dron had driven one...

[tinweevil]

Slant4: I'd be very interested in a scan of that article.

Alun: Re Tony Dron, nor did I. I wonder what Holbay's involvement was.

Tinweevil

[grelley]

The engines in the March cars were built by Swindon. I have a Holbay F3 based engine in my car. I am unsure if Holbay engines were raced. I think they just built development engines. The Holbay motors had Holbay steel cranks and rods and Hepolite forged pistons with 1.0 mm rings. The heads were profiled and polished and run very high compression. They were designed to produce around 160 - 170 hp @ 6500 rpm with a restrictor, so gave very good torque. The camshaft had a relatively mild grind on it and they were dry sumped and fuel injected. The oil filter housing on the block was totally machined away. Holbay experimented with different grinds on the rockers to try to alter the exhaust timing.

[triumphlux]

This car should have an F3 based engine !? It is supposed to have 270 bhp and wins for the second year the 2 litre class in the fully modified STT series in Germany.
The cars performance is very impressive and the driver is really excellent.
I saw it once on a wet race and it was faster than modern Porsches and the like ...

http://www.sprint-racing.de/

http://www.spezial-tourenwagen-trophy.de/