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Robatr0n

Original Poster:

11,781 posts

102 months

[news] 
Monday 31st March 2008 quote quote all
I've been tapping into google this morning to see if anyone has done this before and whilst there seems to be a few there doesn't seem to be any solid write ups on it.

Basically I'm looking for the total cost to complete the conversion and what's involved. Ideally if I could find a photo diary that would be great!

Does anybody know of a project like this?

trackcar

6,453 posts

112 months

[news] 
Monday 31st March 2008 quote quote all
Can't help you on this except that the other way around there was a very succesful imp engined racing motorbike/sidecar that was so fast it was banned I think. why do you want to get rid o the Imp engine anyway? they're screamers - or is it that you like something different and over 150hp beckons (can't fault that reasoning anyway)

Foolish Dave

2,077 posts

142 months

[news] 
Monday 31st March 2008 quote quote all
Fantastic idea!
I have no pointers, but I remember my dad's old Imp, would be great (but very scary) with a 600-700cc 3 cylinder bike engine!
Good luck!

Robatr0n

Original Poster:

11,781 posts

102 months

[news] 
Monday 31st March 2008 quote quote all
From my understanding, the only advantage of the bike engine would be the horsepower.

I am aware that the imp engines can rev to something silly like 10,000rpm but I'm not aware of them being tuned/modified to gain huge BHP. If however they can then I would be more than willing to chuck money at the engine rather than spending endless hours attempting to fit a bike engine.

Sam_68

9,939 posts

131 months

[news] 
Monday 31st March 2008 quote quote all
There was an unfinished project BEC Imp for sale here on PistonHeads not so long ago, so it's at least been partly done! They were asking stupid money, so I don't know if it sold.

Try asking on the Imp Club forums for more information.

The Imp is a fairly heavy car for a bike engine, so don't expect the performance to be too startling (though of course the standard engine has a lot in common with a bike unit, anyway, and a full race Imp is reasonably brisk)
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Sam_68

9,939 posts

131 months

[news] 
Monday 31st March 2008 quote quote all
Robatr0n said:
I am aware that the imp engines can rev to something silly like 10,000rpm but I'm not aware of them being tuned/modified to gain huge BHP. If however they can then I would be more than willing to chuck money at the engine rather than spending endless hours attempting to fit a bike engine.
Without getting into very expensive mods, the Imp engine has a sensible rev limit of 8,000rpm, but they can indeed be made to rev to 10K+ if you have enough budget.

You can also get up to around 130bhp, with enough work, but such an engine would be expensive, unreliable, and have foul manners for road use. I used to help run a 1000cc Imp engined hydroplane when I was younger, which produced a genuine 130bhp, but IIRC we ended up spending something like £7K getting to that point (and this was at late 1980's prices yikes). 130bhp Imp engines are like 155bhp Crossflows... everyones engine makes that sort of power until they put it on a dyno. wink

The sensible limit for a road driveable Imp engine is around 95-100 bhp.

Furyblade_Lee

3,370 posts

110 months

[news] 
Monday 31st March 2008 quote quote all
A mate of mine is currently fitting a VVC K-series in the back of his Imp. Should give upto 170 bhp and go like stink!
For any bike engine conversion, I would speak to Chris Allanson at Z-Cars. I imagine it would be possible to adapt one of his mini-kits to the Imp shell, it comes pre-mounted in a roll-cage structure with suspension ect already fitted. Not the cheapest option by far, but will be a 100% pukka job. He does off the shelf kits for R1, Hayabusa and Type-R, inc Supercharged........

Sam_68

9,939 posts

131 months

[news] 
Monday 31st March 2008 quote quote all
Furyblade_Lee said:
A mate of mine is currently fitting a VVC K-series in the back of his Imp. Should give upto 170 bhp and go like stink!
VVC K-series is a nice choice, for sure.

What gearbox is he using, though? The standard Imp box will tear itself to pieces in no time flat with that sort of power and torque!


Joe T

487 posts

110 months

[news] 
Monday 31st March 2008 quote quote all
I would have thought the 1.4 K series would be ideal for that conversion I think they make about 95bhp and cheap plus available.

There used to be a lot of fibregalss panels for imps, I think it was Fibrefab who made them, complete flip fronts etc, this would reduce the weight quite a bit.


Robatr0n

Original Poster:

11,781 posts

102 months

[news] 
Monday 31st March 2008 quote quote all
I'm quite liking the VVC K-series engine idea!

Fibre glass panels would be a must given that the Imp isn't really the lightest car for it's size.

alex_p

210 posts

91 months

[news] 
Monday 31st March 2008 quote quote all
I nearly put an identical post on here myself about two weeks ago! I had a bit of a look round on google and found a couple of Imp owners clubs with forum areas dedicated to engine transplants.

I'd thought of a bike engine and wondered if I was being foolish but believe me, once you've looked at some of the V8 conversions, a 1000cc bike engine seems like a fairly sensible proposition...

I did think that the imp may be a bit heavy for the torque from a 4 cylinder bike engine and that 10,000 rpm might get a bit much on the motorway (was thinking of a daily driver/Q car) so how about a lower revving, more tractable V twin or an alfa boxer?

rhinochopig

17,061 posts

84 months

[news] 
Monday 31st March 2008 quote quote all
I'd stay clear of a BE swap for the imp. BECs are quite heavy on their gearboxes and an imp is a chunk heavier than a 400-450kg caterfield.

Sam_68

9,939 posts

131 months

[news] 
Monday 31st March 2008 quote quote all
Joe T said:
There used to be a lot of fibreglass panels for Imps, I think it was Fibrefab who made them, complete flip fronts etc, this would reduce the weight quite a bit.
Flip fronts for an Imp?! I've never come across them - and I suspect they would be quite difficult structurally, bearing in mind the way the suspension loads are fed into the shell at the front of an Imp. You could certainly get fibreglass bonnets, engine lids and doors, though.

There were several Imp 'Special Saloons', with fibreglass look-alike bodies mounted on spaceframe chassis (eg. the Maguire, Davrian and Rawlson cars) and there was a bike engined (Yamaha FZR1000, IIRC) Sunbeam Stiletto special saloon built by Jedi a few years ago. I've got a copy of CCC with quite a detailed article about it.

Joe T

487 posts

110 months

[news] 
Monday 31st March 2008 quote quote all
Sam_68 said:
Flip fronts for an Imp?! I've never come across them - and I suspect they would be quite difficult structurally, bearing in mind the way the suspension loads are fed into the shell at the front of an Imp. You could certainly get fibreglass bonnets, engine lids and doors, though.

There were several Imp 'Special Saloons', with fibreglass look-alike bodies mounted on spaceframe chassis (eg. the Maguire, Davrian and Rawlson cars) and there was a bike engined (Yamaha FZR1000, IIRC) Sunbeam Stiletto special saloon built by Jedi a few years ago. I've got a copy of CCC with quite a detailed article about it.
Now you have got me thinking, I did look over the car and it did have a flip front, I beleive the inner wings and other internals were all there. I actually bought some derrington parts off the guy for another project, this was in the early 80's though, so my menory may be playing tricks on me.

Furyblade_Lee

3,370 posts

110 months

[news] 
Tuesday 1st April 2008 quote quote all
I imagine he is using PG1 gearbox as found with the k-series. He works for Talon Sportscars, which specialises in fitting 160bhp VVC engines into Metros. And 220bhp supercharged ones.

Sam_68

9,939 posts

131 months

[news] 
Tuesday 1st April 2008 quote quote all
OK... he's doing it as a mid-engined installation, then, rather than sticking with the original rear-engined layout?

Jon Ison

1,157 posts

119 months

[news] 
Tuesday 1st April 2008 quote quote all
For info if you check out locostbuilders you will find a guy on there with a ZX12 powered imp, I believe he is currently fitting a turbo to it as we speak.

Think his user name is "imp Paul"

Robatr0n

Original Poster:

11,781 posts

102 months

[news] 
Wednesday 2nd April 2008 quote quote all
Thanks guys!

It looks as though I have an awful lot of reading to do! biggrin

Robatr0n

Original Poster:

11,781 posts

102 months

[news] 
Monday 2nd June 2008 quote quote all
Just thought I would pop in and update this.

As was the case when I originally started, I am still in the process of costing this up to get a realistic idea on price....however a spanner has been thrown into the works!

Charlie (Vixpy1) has now told me that a Subaru Impreza engine will fit a treat into the back of a hillman imp and what with these engines not costing a fortune it could well be a viable option. Obviously weight distribution would need to be looked at, i.e. removing the rear bench seat and having the engine sat just behind the driver as opposed to having all the weight over the back of the car.

The biggest problem at the moment would be finding a suitable gearbox to mate to the engine as the hillman imp gearbox would no doubt blow up and the standard Impreza gearbox would be far too big, so I need to find a suitable alternative that could handle around 300bhp.

One possibility would be a Porsche X50 gearbox but they do cost alot of money and they are also quite a lump to start with.

Would anybody be able to offer some advice in regards to the gearbox?

rhinochopig

17,061 posts

84 months

[news] 
Monday 2nd June 2008 quote quote all
Robatr0n said:
Just thought I would pop in and update this.

As was the case when I originally started, I am still in the process of costing this up to get a realistic idea on price....however a spanner has been thrown into the works!

Charlie (Vixpy1) has now told me that a Subaru Impreza engine will fit a treat into the back of a hillman imp and what with these engines not costing a fortune it could well be a viable option. Obviously weight distribution would need to be looked at, i.e. removing the rear bench seat and having the engine sat just behind the driver as opposed to having all the weight over the back of the car.

The biggest problem at the moment would be finding a suitable gearbox to mate to the engine as the hillman imp gearbox would no doubt blow up and the standard Impreza gearbox would be far too big, so I need to find a suitable alternative that could handle around 300bhp.

One possibility would be a Porsche X50 gearbox but they do cost alot of money and they are also quite a lump to start with.

Would anybody be able to offer some advice in regards to the gearbox?
Slightly off topic - sorry - Why not try a conversion in the same style as the z cars mini. Civic type r engine and box with its own space frame mounted mid-engine. 260bhp with their ecu, pipe, and TBs. Chris took me out in one of his demo cars and they are superb - two-up it felt faster than my Blackbird westy, which is not exactly slow. The build quality is also second to none. A million times better than EVERY other kit car manufacturer.

have a look.

http://www.zcars.org.uk/mini/civic.htm
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