Imp-Climax engine

[aeronca65t]

One of my racing friends, John S. lives in Quebec and owns two Ginettas. He's an ex-pat Brit who owns a business related to wine-processing.

John lets another pal Rick, race his second Ginetta in exchange for storage of the cars at Rick's place in Pennsylvania (plus, I think, some financial arangement). They do most of their racing in the US.
They have a third friend, Ross, who also keeps his Ginnetta at Rick's places. Ross lives in London, England and flies over to the US for our races.
Apparently it's cheaper to race in the US, even including the extra cost of an occasional airline ticket. :shocked:

So we have three of these little buzz-bombs to contend with in our small-bore races. They are great guys and fun to race with.

Anyway, I was talking with John recentley and asked him about the engines in these cars. They are all the rear-engine Ginettas with engines from Sunbeam/Hillman Imps.

And I asked him about the "connection" of the Imp engine to the Coventry-Climax engine.
I've had lots of folks tell me they are 'the same", but they don't exactly look the same to me.

But in fact, John told me that the two engines don't have a single, interchangeable part.
The myth of their "identical" relationaship was because the fellow who designed the Imp engine was "inspired" by the Coventry-Climax engine and sought to create a newer engine with many of the same good features of the original little, aluminum firepump motor. And he was able to review the original engineering drawings of the CC. So in that sense one might say the Imp is "derived" from the firepump engine.

By the way, the lead designer of the Imp engine was Mike Parkes, who is also well known as a former Ferrari driver (in both F1 and sports cars).

John also pointed out that when Rootes went bankrupt (during the time that Chrylser owned it) Peugeot bought off most of the Rootes inventory including the Imp engine tooling. Peugeot continued to build the Imp engine (for one of their small cars) until the late '90s, so there are still many spare parts for the Imp engines available via Peugeot. Also, as a result, John says that complete used Imp/Peugeot engines are available quite cheaply in the UK or Europe. *That* must be why he seems to shift his at 9000 rpm with careless abandon!

Interesting.....

 

[tony barnhill]

hmmmmmm...wonder if one of those engines that are so readily available in the UK would fit in an Imp?

 

[aeronca65t]

hmmmmmm...wonder if one of those engines that are so readily available in the UK would fit in an Imp?

Yes. No problem acording to John.

 

[tony barnhill]

hmmmmmmm.....I know where there's an Imp up on a stick that's only missing its engine & interior.

 

[sunbeammadd]

Apologies for dragging up an old thread. I haven't been here for quite a while and thought I should make a few comments.

The Imp engine was based specifically on the Coventry-Climax FWMA engine. The FWM was a descendent of the original Coventry-Climax FW fire pump engine, but the FWM was designed for marine applications. Coventry-Climax then developed the FWMA from the FWM for automotive use, and it was this design that they shared with Rootes for the Imp. Other FW variants, such as the FWE in the Lotus Elite, branched off from the FW earlier on and so are not directly related to the Imp.

While Mike Parkes and his colleague Tim Fry designed the Imp, the engine was designed by Leo Kuzmicki (previously of Vanwall and Norton) with assistance from Coventry-Climax themselves. I've never seen an Imp engine and an FWMA side-by-side, but I understand they do look very similar, even if not actually sharing any parts.

The Imp's production run ended in 1976 and it was replaced in 1977 by the new Sunbeam hatchback. This was completely different to the Imp being front engine/rear drive, but the base model used an Imp engine adapted for front mounting.

When Chrysler were on the ropes in the late 70s they sold Rootes (and Simca) to Peugeot-Citroen. In 1981 Peugeot closed Rootes' Scottish factory where the Imp had been built, and the new Sunbeam was being built. The closure coincided with the end of all the remaining Rootes-designed cars and the end of the Imp engine. Rootes' English factory continued until just recently as an assembler of Simcas, French Talbots and Peugeots.

No Imp engines were ever used in Peugeots, Citroens or French Talbots. Peugeot used engines of similar size, but these were a completely different design.

NOS Imp engines from the Sunbeam hatchback were still available up until the mid to late 90s though. I bought one of these myself and it's sitting in the back of my own Imp. It does require a little bit of modification before fitting to an Imp, but nothing very difficult.

The NOS supply has pretty much dried up now. Enthusiasts of the Sunbeam hatchbacks though tend to avoid the Imp-powered ones because the car was too heavy for the engine. The 1.6 litre and Lotus-powered 2.2 litre ones are much more desirable. That's great for us Imp owners though because we can make good use of them.