34 replies to this topic

[Ray Bell]

Just looking over a site for Imp owners...

http://www.imps4ever...h/cov_clim.html

It gives a sort of potted history about Climax engines in racing and cars generally, and while it almost ignores the FPF altogether and denies the existence of the FPE, I'm more worried about this paragraph:

The absolute capacity limit for the block was represented by the FWB, of which only a few were made. These engines, that contained nearly 1500cc, were raced in 1956 by Coopers. And it was one of these cars that won the British Grand Prix of that year.

Well, there's a nice boo-boo there about the British GP, but what about the designation 'FWB'?

I always thought there were 1100cc FWBs, or at least 1220cc FWBs... but this says that this designation belonged only to the 1500 single cam engine.

Anyone know for sure?

[Dick Willis]

Ray, I think an FWA is an 1100, FWB is a 1500 and an FWE is a 1220 as in a Lotus Elite.

[David McKinney]

That's my understanding too. Single-cam engines all.
Strangely, although CC used different designations for the various sizes of single-cam engine, the FPF designation was used for all twin-cam sizes - 1500, 1660, 1700, 1750, 1960, 2014, 2208, 2500, 2700 - what have I missed?

[Ray Bell]

Matich's Lotus 19 had a 2600 (or thereabouts).

And wasn't it 2495? The '2.7' was variously entered as 2751 and 2752, while Dan Gurney's Eagle had one that was even bigger, IIRC...

[Dick Willis]

My understanding of FPF's is that the numbers after the FPF part of the engine number identify the original size of the engine and the application, ie. sports or racing.
For instance, mine is FPF 430/27/1243, another that I had was FPF430/4/1005, the 1243 and 1005 being the actual engine number, but can anyone explain the exact significance of the other numbers. I know I read it somewhere once but now can't recall just where.

[Peter Morley]

The FW series engines were developed from the lightweight firepump that Climax made, so FW stans for Featherweight.
FWA is 1,100 cc.
FWE is 1,220 cc and was built mainly for the Lotus Elite (e.g. Featherweight Elite engine).
FWB is 1,500 cc and used the longer stroke of the FWE with the bigger bore of the FWA, it was basically just a combination of the two other engines.

FWB & FWE blocks are the same with bulges on the side to clear the rods on the longer stroke crank, so that is indeed the capacity limit for that block (FWA block will have a lower capacity limit).

They also made some other variants such as the 750cc version used by Lotus at le-Mans in the index of Performance.

The Imp engine is very similar to these single cam engines.

The FP series of engines were Climax's first purpose built racing engines - the FP part of the description supposedly referring to Firepump as cover while they were working on it!!

The first was the FPE (Firepump Experimental!) which was the 2.5 litre V8 from the mid 50's.
After that was shelved they used half of that engine to make a 1,500 cc 4 cylinder for Formula 2 (which later became F1).

The 1,500 cc FPF engine was slowly stretched upto nearly 3 litres (but the block was different by then!) - 2 litre, 2.2 litre, 2.5 litre being the most common sizes, with a few 2.7 litres being built for Cooper's indycar project (and then a few more for favoured customers).

Can't remember if the F in FPF was for Formula or simply the next letter after E.

Of course they called the 60's 1.5 litre V8 engine the FWMV - but there is of course no similarity between that series and the earlier single cam FWs.

[Ray Bell]

Surely the E and the F in the FP engines stand for 'four' and 'eight'?

It seems to fit anyway... and there was no FP A, B, C or D...

How about the bore spacing of the FWMs and the FWMV? Are they the same, perchance?

[D-Type]

Can somebody please clarify the original c.c. of each of these engines. As period programmes often (but not always) had the correct capacity it is a useful, but not infallible, tool for identifying which engine was in a particular car. For example there were 1097 and 1098 "1100's" and 1460 and 1475 4-cylinder "1500's". When the 1960cc FPF was originally there were different variants of the enlargement to "2.2 litres" - Walker did a 2015 and then they had a 2.2 that was different from the Climax one.

Wasn't the V8 called the FWMV as it was developed from two of the 750 (FWM?) blocks.

[Macca]

My understanding was that FWMV was another misleading cover designation while they were developing it: FeatherWeight Marine Vee.

I don't suppose anyone ever used it in a boat though!

[Peter Morley]

Have reverted to printed matter (Climax in Coventry):

Firepump was an FW (Featherweight - 1,020 cc).

FWA - the A stands for Automobile - (697 made), 1,098 cc (72.4 mm x 66.7 mm)

FWB - 1,460 cc (only 35 made - because they were worried about reliability) (76.2 mm x 80 mm)
FWBP - firepump version of the 1,500

FWE - E for Elite - (1,000 made) 1,216 cc (76.2 mm x 66.7 mm)

FWM Featherweight Marine = 745cc
not used for marine applications but later used for firepumps.

FWMA - Automobile version built for Lotus Le-Mans 1957
This was adopted & modified for the Hillman Imp.

FWMC (FWM twin Cam) - development twin cam head version of FWMA (e.g. half the 1.5 litre V8), used in an Elite at Le-Mans 1961

FWMV (featherweight marine V-8!) - the 60's 1.5 litre V8 F1 engine.

FPE - code for Fire Pump Engine (in case any directors asked questions!)

FPF as FWB just the next letter in sequence.

FPE 76.2 mm x 67.94 mm = 2,477 cc

FPF mark 1

81.2 mm x 71.1 mm = 1,475 cc

86.4mm x 83.8 mm = 1,960 cc

1 off, overbored, 2,015 cc engine for Rob Walker

4 off, 88.9mm x 88.9 mm = 2,207 cc

FPF mark 2

94.0 mm x 89.9 mm = 2,495 cc

81.8mm x 71.1 mm = 1.5 litre

14 off 2.7 litre even bigger bore & longer stroke

In total 273 FPF engines of 9 different capacities - 159 1.5 litre, 48 2.5 litre

[David Beard]

Originally posted by Peter Morley
FPF mark 1

81.2 mm x 71.1 mm = 1,475 cc

86.4mm x 83.8 mm = 1,960 cc

1 off, overbored, 2,015 cc engine for Rob Walker

4 off, 88.9mm x 88.9 mm = 2,207 cc

FPF mark 2

94.0 mm x 89.9 mm = 2,495 cc

81.8mm x 71.1 mm = 1.5 litre

14 off 2.7 litre even bigger bore & longer stroke

In total 273 FPF engines of 9 different capacities - 159 1.5 litre, 48 2.5 litre

Any idea how many FPFs had twin plug heads?

[Peter Morley]

I'm not aware of any FPFs running twin plug heads.
There is provision for a 2nd plug in one of the head castings (not sure whether that is on a Mark 1 or 2 though).
I've never seen a twin plug FPF, and in my quick skim through the book didn't notice anything about them.

[Dick Willis]

My Mark 2 definitely has provision in the casting for a second spark plug, but I think, from memory the Mk 1 also had it.

[Peter Morley]

I just checked photos of my (Shannon's) FPE (it is in the UK, on its way to an engine builder) and it only has single plug heads, no provision for twin plug in the way the FPF does.

I really can't remember if my mark 1 FPF had provision or not for a 2nd plug.

[David Beard]

I know that there was definitely at least one FPF with twin plugs. A Mk1 I would think.
The car that contained it was stolen....so if you ever see one....

[Don Capps]

Originally posted by Dick Willis
My understanding of FPF's is that the numbers after the FPF part of the engine number identify the original size of the engine and the application, ie. sports or racing.
For instance, mine is FPF 430/27/1243, another that I had was FPF430/4/1005, the 1243 and 1005 being the actual engine number, but can anyone explain the exact significance of the other numbers. I know I read it somewhere once but now can't recall just where.

I always meant to get the information as to what the numbers meant between the 430 and the individual engine block number on the FPF engines. I worked on sorting some of it out years ago, but haven't a clue what I did with my notes. Incidentially, was there ever a listing of the FPF and FWMV engines made by CC and at least their initial customers? Just one of those items that would be interesting to eyeball...

[David Beard]

Originally posted by Don Capps

Incidentially, was there ever a listing of the FPF and FWMV engines made by CC and at least their initial customers? Just one of those items that would be interesting to eyeball...

Doesn't Tony Mantle of Climax Engine Services retain something like this?

[Roger Clark]

Karl Ludvigsen, in Classic Racing Engines says: ".. the head had always provided for dual ignition, which was never needed"

I am confused about the Mark I/Mark II nomenclature. Several posts above seem to imply that the full 2.5-litre engines were the Mark IIs. Yey Classic Racing Engines, and Doug Nye's "History of the Grand Prix Car" both say that a new cylinder head, the Mark II was inreoduced in late 1959. The implication is that the early 2.5 litre engines were Mark Is, despite aving a substantially redesigned bottom end.

To make matters worse, the 1.5-litre FPFs introduced in 1961 were always referred to as Mark IIs - or was this a case of the design of the small engine catching up with big brother?

[Don Capps]

Originally posted by Roger Clark
I am confused about the Mark I/Mark II nomenclature..... To make matters worse, the 1.5-litre FPFs introduced in 1961 were always referred to as Mark IIs - or was this a case of the design of the small engine catching up with big brother?

I have come to the conclusion that the 1961 Mark I and Mark II (or was it Mk. 1 and Mk. 2?) versions of the FPF referred to the differences between the FPF's built specifically to the 1,500cc specification -- the ?? in the 430/??/nnnn equation. However, having been dead wrong in the past....

[Ray Bell]

Somewhere I feel that I've read that the Mk 2 revved higher...

And I'm sure that any announcements mentioning Mk 2 were made only in 1961. Of course, it's possible that Mk 2 denoted the 2.5 head on the 1.5 bottom end or something, but it might also include cross-bolting the main bearing caps.

There were 2.5s with and without this feature...

[dretceterini]

Any idea how many FWMs were built (especially twin cam units)??

[Ray Bell]

I seem to recall that there were two of the twin cam FWMs...

Lotus had pressed to get one and then C-C made one for Cooper so as to avoid any claims of favoritism... that's as I recall it anyway.

[Roger Clark]

Originally posted by Ray Bell
Somewhere I feel that I've read that the Mk 2 revved higher...

And I'm sure that any announcements mentioning Mk 2 were made only in 1961. Of course, it's possible that Mk 2 denoted the 2.5 head on the 1.5 bottom end or something, but it might also include cross-bolting the main bearing caps.

There were 2.5s with and without this feature...

Doug Nye wrote in "History of the Grand Prix Car": "The entire bottom end of the later (1961) 1500cc Mark II and full 2 1/2-litre form was robustly cross-braced by studs screwed horizontally through the five main bearing caps, there being eight such studs on each side of the engine."

Denis Jenkinson wrote, in the 1961 Monaco Grand Prix report: "The MkII does not produce much more in the way of maximum bhp than the earlier engines, but it revs higher and has a better torque curve as well as being more robust, the lower half being developed from the 2 1/2-litre engine"

I inferred from this that the 2 1/2-litre engines always had cross-bolting but it ain't necessarily so.

A revised cylinder head for the 2 1/2-litre engine was introduced at the 1959 German Grand Prix (Brabham and Moss). It had larger inlet valves and changes to the inlet manifold to line up the ports more accurately with the carburattors. DSJ said that it gave an additional 12-15 bhp. It was this that Ludvigsen and Nye appear to have referred to as the Mark II cylinder head.

[Ray Bell]

Yes. Roger, I know for a fact that the 2.5 engine in the Lotus 15 works car that had the A-Series BMC differential wasn't cross-bolted.

Or, at least, the engine fitted to it when it was sent to Australia wasn't...

From memory, that was the first 2.5 engine in Australia, certainly the first 2.5 engine to run in the Australian Grand Prix. Even 2.2s were almost unheard of here in June, 1960, when that year's AGP took place.

When one looks at the numbers of engines makers turn out today for GP racing, and the complexity of those engines, and the cost, it's almost laughable to think that Coventry-Climax took as long as they did to progress from 1760 to 2495, and that when they did, it was difficult to get an engine out of their production run anyway.

In the days of the 2.5 formula, these engines were rare, very rare, and I guess the only reason Matich got his in the 15 was because it didn't have the cross-bolting that was then a part of production.

I wonder, too, how many of these engines were turned out at Repco when they bought the patterns (since destroyed...) so they could keep up supply for the Australian and New Zealand entrants in the Tasman Cup and the Gold Star?

Their later developments, by the way, included a short stroke version of the 2.5, presumably using the bore size of the 2.7.

And I wonder what the story was with that 2.6 engine Matich had in the 19? That was a UDT-Laystall car, wasn't it? I know Moss had driven it... John Ellacott has photos of it as it first arrived with the tall windscreen, even a soft top clipped between the screen and the engine cover, with a hood bow keeping it up off the driver's head!

There are also pics of Moss trying it out at Warwick Farm...

[D-Type]

I'm not sure about the FWM and FWMA.

David Hodges's Le Mans history (1963) has the 1957 Index winning Lotus as 744cc and the 1958 750cc Lotuses as 741cc.

But in the report of the 1958 race he says "The two Lotuses in the 750 c.c. category should have been strong handicap contenders, but a main bearing cap of the new Coventry Climax FWMA of the works car broke in practice and a 1957 engine was substituted for the race."

On this evidence the FWM must have been the 1957 engine and the FWMA the 1958 one.

Was it WB who said "Pity the poor historian"?

[conjohn]

Originally posted by Dick Willis
My understanding of FPF's is that the numbers after the FPF part of the engine number identify the original size of the engine and the application, ie. sports or racing.
For instance, mine is FPF 430/27/1243, another that I had was FPF430/4/1005, the 1243 and 1005 being the actual engine number, but can anyone explain the exact significance of the other numbers. I know I read it somewhere once but now can't recall just where.

Doug Nye, in Cooper Cars (1983 ed) has this explaination (in appendix five) :
"Climax engine numbers show basic type, then third section serial reveals spec. of engine fittings, eg. F2 single-seater or sports with dynamo, etc. Final four-digit number is individual unit serial."

There are no explainations as to what e.g. 4 or 27 stands for...

[Roger Clark]

Originally posted by D-Type
I'm not sure about the FWM and FWMA.

David Hodges's Le Mans history (1963) has the 1957 Index winning Lotus as 744cc and the 1958 750cc Lotuses as 741cc.

But in the report of the 1958 race he says "The two Lotuses in the 750 c.c. category should have been strong handicap contenders, but a main bearing cap of the new Coventry Climax FWMA of the works car broke in practice and a 1957 engine was substituted for the race."

On this evidence the FWM must have been the 1957 engine and the FWMA the 1958 one.

Was it WB who said "Pity the poor historian"?

I don't know about the names, but I think the 1957 750cc engine was a short stroke version of the 1100, while the 1958 was an enlarged version of a 650cc engine. Climax were very concerned about the reliability of the 1957 engine but it was completely reliable in the 24-hours.

[David Beard]

Originally posted by Roger Clark

Denis Jenkinson wrote, in the 1961 Monaco Grand Prix report: "The MkII does not produce much more in the way of maximum bhp than the earlier engines, but it revs higher and has a better torque curve as well as being more robust, the lower half being developed from the 2 1/2-litre engine"

I inferred from this that the 2 1/2-litre engines always had cross-bolting but it ain't necessarily so.

The following is from a paper by Wally Hassan presented to the SAE at Cleveland Ohio..

When it came to the question of the 21/2 litres which was
required to have a real crack at the Grand Prix races,
we were faced with a problem of considerable modification
but with the necessity of retaining the ability to machine the
major components on existing jigging. We
were, therefore, tied to the existing cylinder centres, main
bearing stud centres, and only a very small variation in
cylinder head stud centres.
It was decided to overcome the crankcase failures by
reducing the skipping rope effect. of the underbalanced
shaft by utilising the rather expensive heavy alloy
marketed by the G.E.C. This is a sintered tungsten having
a specific gravity 1.6 times that of lead. By this means we
were able to re-establish 100 per cent rotating weight
counterbalance within the crankcase walls. We also made
the main bearing caps of 40ton steel, which gave improved
rigidity, and the facility of arranging studs through the crankcase
side walls into the bearing caps, effectively tying the crankcase
and the bearing caps together in the horizontal plane.

This gives the impression that the full 2 1/2 litre motor was cross bolted from the outset, does it not?
(Which leaves a bit of a puzzle with the Derek Jolly motor mentioned by Ray)

[Ray Bell]

Originally posted by David Beard
.....This gives the impression that the full 2 1/2 litre motor was cross bolted from the outset, does it not?
(Which leaves a bit of a puzzle with the Derek Jolly motor mentioned by Ray)

No, not me... I never mentioned the Derek Jolly engine at all.

His was a 2-litre... it was the 2.5 engine in Frank Matich's Leaton Motors 15 I mentioned... recall that I specifically said it had the A-series BMC diff? Jolly's car had the queerbox, with its integral diff, and I've mentioned that before on this forum as well.

[David Beard]

Originally posted by Ray Bell


No, not me... I never mentioned the Derek Jolly engine at all.

Ooops, sorry Ray. Must pay attention.

[David McKinney]

Easy mistake to make:

1959: the first 2.5 Lotus XV races at Le Mans, driven by Graham Hill and Derek Jolly
1960: Jolly races a Lotus XV in Australia. A 2.5 Lotus XV races in Australia

[Roger Clark]

David's observation is still valid, applied to the Matich car. I'm also intrigued by its having a BMC "A"-series diff. I know that some 15s had a "B"-series gearbox, but an "A" sounds a bit puny for a 2.5-litre Climax.

[David Beard]

While we are discussing FPFs....
I have been confused for some time about the low and high level water pumps. Exactly which variants had which, or was it an option on all of them?

[Peter Morley]

Originally posted by David Beard
While we are discussing FPFs....
I have been confused for some time about the low and high level water pumps. Exactly which variants had which, or was it an option on all of them?

FPE had high water pumps, so early FPFs had high water pumps.

Not sure when they introduced low pumps - probably fairly early (e.g. well before Mark 2s) since bleeding the water system was a pain (also the high pump tends to be in the region of an upper chassis rail, making installation tricky).

But I'm sure they'd have gladly supplied anyone who wanted one a high pump engine later on.

[Ray Bell]

Originally posted by David McKinney
Easy mistake to make:

1959: the first 2.5 Lotus XV races at Le Mans, driven by Graham Hill and Derek Jolly
1960: Jolly races a Lotus XV in Australia. A 2.5 Lotus XV races in Australia

Was it a 2.5 at Le Mans?

It only ever raced in Australia as a 2-litre...

Originally posted by Roger Clark
David's observation is still valid, applied to the Matich car. I'm also intrigued by its having a BMC "A"-series diff. I know that some 15s had a "B"-series gearbox, but an "A" sounds a bit puny for a 2.5-litre Climax.

I'm told that the Matich 15 had a ZF gearbox, but I'm not sure about that. But I know it had the A-series differential, and that this was frequently changed. Every race, sometimes.

The Jolly car also had a differential problem... in the time of the Gibsons' ownership it wore out crownwheels, which weren't readily available. I think it might have been a case of Lotus saying, "You can get replacements from the makers," while the makers were saying, "It's up to Lotus to carry spares for that gearbox, as it's made exclusively for them."

So old Hoot had to deal with it all in his own way. 'Foreign orders' from GMH were involved... the story is contained in this post:

http://forums.atlasf...=&postid=269322