Climax Engine

[Wrightpayne]

Having watched the lovely Coventry Climax powered seven in Ivan's Garage on youtube, it has got me interested in the engine.

Does anyone have any knowledge of the unit and whether there are similarities between a water pump engine and a car engine that enable them to be interchangeable?

This was somewhat driven by a Green Goddess auxiliary water pump engine (Climax) appearing on ebay for £400 BIN a few weeks ago. Sacrilege to repurpose it, but I thought it was cheap if it can be fitted fairly easily in a car (custom backplate, flywheel, appropriate gearbox etc which could make the package expensive, not to mention a nice early Lotus or Caterham to put it in!)

 

Any thoughts? 

 

[Mcalvert]

There's some history here from a Lowflying article by John Watson that may be of interest?  here   

 

[oilyhands]

The Hillman imp engine is based on the Coventry Climax, how closely I'm not sure, but I have worked on both (many years apart) and a few bits were definitely interchangeable.

Oily

[revilla]

My Mum used to have a Hillman Imp, she used to take me to swimming lessons in it when I was a kid! Seeing this made me look up the Imp on Wikipedia and the article contains this throw-away line without further detail: "The Imp used a derivative of the Climax FWMA engine whereas the Lotus cars used an FWMC engine which had an entirely different cylinder head.".

[Golf Juliet Tango]

If I remember correctly, the requirements of the pump included running well & at full power from cold start-up. Obviously putting particular demands on lubrication.

[Baggiebird]

Some interesting history on the linked page here, under the paragraph 'Proper Motor' https://www.imps4ever.info/algemeen/history.html

My first car, in 1977, was a secondhand Hillman Husky which was then a small estate based on the Imp, with the rear mounted 875cc engine under a hatch in the rear floor.  Had a lot of fun with that car, including changing the transaxle/gearbox and Rotoflex doughnut couplings!!  That was easily done in an afternoon amazingly by Dad and I.  Dad also made some reinforcing plates for the front suspension mounts and the sills were done as well as a new steering rack.  I can also remember setting up the camshaft clearances using variable thickness shims.

The engine never suffered with HGF either, despite the reputation.  Cars were so simple then, compared to the almost state of the art we have now, though of course safety has been  much improved.

My first company car, in 1979, was a Chrysler Sunbeam, which had a stroked version (still under 1000cc) of the Imp Engine but installed at the front!!

Nice memories.

[p.mole1]

The Coventry Climax engine was indeed a fire pump engine and it was designed to be able to run flat out once started. I think it was not quite ideal as a car engine as the clearances were quite slack to enable them to run at full power from cold. It was ideal as portable fire pump engine as it was very light. 

We used to have LPP's  (Light portable pumps) when I was in the Fire service they used Nissan Micra engines. I don't know who classified it as an LPP as it was defiantly not light! but it nearly had the same pumping capacity as a Fire appliance from what I can remember, but they took some abuse. 

[rj]

We had VW air cooled based pumps when I was a fireman. And we had a Godiva... Heavy as... and not portable at all...

 

[russjones]

The fire pump and the FWA and FWE were different but genetically connected engines. 

[paul_w]

First thing to note is that there are two types of Climax fire pump, the far more common one on eBay being the smaller 750cc unit that is like a scaled-down FWA and used in period (apart from a couple of Le Mans specials for the Index of Performance). There is a lot of work and expense to convert a pump engine but it can be done. I was told I'd have to budget around £10k for a half-decent Climax motor which is why my S1 has an A-series in it! Mike Brotherwood supplies flywheels, sumps etc.

 

Lower spec engines have been done for less, but one of the challenges is that the compression ratio is low on the pump engines and I think the heads are usually welded up and the combustion chambers reshaped to resolve this. I have pondered whether a cheap AMR500 supercharger bolted on a pump engine would be the way to go for budget fun but I've too many projects as it is...

[Mrp]

My 1st car was a standard imp van (my dad bought it for £25 when I passed my test at 17 and 3 weeks)  the engine was quite advanced (mine was knackered) and I learnt a lot about engines (1977) but as long as you got the cooling sorted is was really good and revved smoothly like hell. I graduated to Minis but I still have a fond love for the Imp as I really learnt a lot about engines and cars and now I can see even more that given time and resources you could really build a sleeper screamer car. Of course you would also not have to pay the mini/mini cooper tax on building one. Just to add I also in my day did a lot of Minis as well. My last was a countryman when I was at tech school which I built a super hot Cooper S engine in to scare Escort Mexico owners.

Sorry evening ramblings.

Happy days

Mrp

[paul_w]

For some reason it won't let me correct my post above despite several attempts - I meant to say that the 750 pump unit was not used in period. They are eligible for use now in 750MC historics but I don't think they get used much.

[Mcalvert]

Enjoyable YouTube video with some great Climax engine sounds and a fair bit of engineering in "Ivan's Shed" video