10 replies to this topic

[G'Racy]

Does anyone on here know what the engine specification would have been for the Speedwell 1150, I’m assuming it started life as a 998?

[MiNiKiN]

If I were you, I would start a research at Mark's speedwell library http://mk1-performan...l_documents.htm

[G'Racy]

That’s great thank you, I would never have guessed such a thing existed.

[Cooperman]

'Speedwell' was a company in North London started by Graham Hill and John Sprinzel. John was a very well-known rally driver who drove for BMC mainly and, of course, Graham was F1 World Champion eventually.

Basically you could have whatever state of tune you wanted for the use you intended to put your car to. There was the 'Sebring Sprite' which had the over-size engine and again they were buit for either race or rally use, with different states of engine tune.

Typically, a rally engine would have had a 544 cam, well gas-flowed head with bigger valves, twin H4 carbs, fully balanced, lighter flywheel, better inlet & ex. manifolds.

Speedwell were well regarded for quality and performance. I often called in there for a cuppa as John is a friend of mine. He now lives in Hawaii, but comes to England sometimes for reunions, etc.

By the way, the company was not called 'Speedwell' because it implie performance, it was because the London telephone number was 'Speedwell xxxxx'

[G'Racy]

Happy memories Cooperman

[whistler]

A 1098 with +0.60 overbore would give you just under 1150cc. Back then Hillman Imp pistons were used when going off-piste with nonstandard overboring.

[wzd345]

Ken Lee drove a Speedwell Cooper very effectively in those early days.  Engine capacity was 1152cc and it was fed by twin Amal carbs.  Well featured at the time in motoring press.

[Cooperman]

A few years ago I was asked if I could build a powerful engine for a Mk.1 Sprite for historic rallying. I said that it was not a problem and that it could probably go out to around 1140 cc. The regulations insisted that any modifications had to have been used before the end of 1962. The owner was concerned that such an engine might be deemed 'illegal', but I checked with John Sprinzel who confirmed that he had built & rallied Mk.1 Sprites in 1962 with a bored out engine, so that is what I built. It had a 295 head, twin H4's, etc., etc.. I think I used a 276 cam to keep peak power down to a safe level for the long-stroke crank. The engine came from a Morris Minor 1098.

With a CR gearbox and a very low final drive ratio it certainly went well. It was noted when entering rallies that it was modified to Speedwell specification and everyone was happy with that. 

Speedwell certainly did achieve good results with their cars in both their own hands and those of their many customers.

[ACDodd]

Yes you can also squeeze this into an 850 block!

Ac

[timmy850]

The Speedwell 1152 was based on a Cooper 997 engine stroke of 81.3mm and a bigger bore of 67.1mm

They also made an 1182 TR5 which used the crank from an 1100 which is 83.7mm

My engine is a 1098 with a 83.7mm stroke and +080 pistons (which is 66.6mm) which makes it 1166cc. I’d definitely recommend starting with an 1100 bottom end to make a fun small bore engine

[mk1mark]

Sorry to be a pedant, but most of the above reply is incorrect.

 

'Speedwell' was a company in North London started by Graham Hill and John Sprinzel.

No it wasn't.  It was started by John Sprinzel, Len Adams & George Hulbert. Graham Hill bought John Sprinzel's shares when John left to set up his own company "John Sprinzel Ltd".

 

Basically you could have whatever state of tune you wanted for the use you intended to put your car to.

This is only partially true.  99% of the A Series engines & kits supplied by Speedwell were specific sets made to standardised specs.  Custom engine builds from Speedwell were VERY rare indeed.  From as early as 1959 most of the arguments between directors were along the lines of whether they should be a "proper" tuning company or specialise in selling shiny stuff & kits of bits to the masses, this was in actual fact the split that caused JS to leave only 2 years after the company had been formed..  The latter faction eventually prevailed.

 

All the engine development work was carried out by Dave Jones who while working for Speedwell also did development work for the likes of BRM & Cosworth.

 

 

There was the 'Sebring Sprite' which had the over-size engine and again they were buit for either race or rally use, with different states of engine tune.

The Sebring Sprite was produced by John Sprinzel after he left Speedwell.  There was a similar car called a "Speedwell Sprite" & although this was "similar" it did not have the success in competition that the Sprinzel offering did.

 

http://www.sebringsprite.com/

 

http://mk1-performan...prite_outer.jpg

 

 

Typically, a rally engine would have had a 544 cam,

No it didn't.  Speedwell used all their own cam profiles designed by Dave Jones, a rally type cam would have been a CS2 which is more akin to a modern high torque / MG mertro type profile.

 

well gas-flowed head with bigger valves, twin H4 carbs, fully balanced, lighter flywheel, better inlet & ex. manifolds.

Speedwell offered Alloy 5 port heads as well as modified cast iron heads.  On almost all their small bore conversions the "standard" head supplied would have been a Clubman spec alloy head.

 

There is masses of accurate info on Speedwell on the web, a lot can be found here;

 

http://mk1-performan....uk/spdhist.htm

 

The vast majority is from contemporary accounts & sources that don't rely on 50+ year old memories.

 

As I say, I don't mean to be a pedant, but accurate info is easily available & I don't see the point in recirculating the same old myths.

 

As a matter of interest, I own the original Speedwell 1275 S demonstrator LGW 123D as well as a Standard Mini fitted with a Speedwell 1152 conversion.

 

Mark F

Edited by mk1mark, 12 November 2020 - 11:38 AM.