british-cars
[Top] [All Lists]

Re: Lotus Europa

To: kburtch@pts.mot.com
Subject: Re: Lotus Europa
From: megatest!bldg2fs1!sfisher@uu2.psi.com (Scott Fisher)
Date: Fri, 22 Oct 93 10:26:26 PDT
> I'm wondering if anyone could answer some questions. I've always liked the
> Europas, and only seen one up close.

I'll let PhilE and a few others supply the specs.  

> What engines do people drop into them? It seems all are 4-bangers, usually
> Renault.

Well, that's what the factory used in most of them, with some getting the
twin cam used in the Elan and Cortina (Lotus 26 and 28, respectively)

> Has anyone ever dropped a 3.5 Rover aluminum V-8 into one? 

Colin Chapman did, and Graham Hill drove it in tests.  He is reputed to
have climbed out after a few hot laps saying, "It needs more brakes."  By
that time, the Lotus sports-racing cars were all developing along different
evolutionary lines than the street-sports cars, so nothing much came of it.

> How about a rotary? 

I saw an Esprit with a rotary once, in the repair bay of the shop that
rebuilt my Lotus Cortina's motor.  Looked very tidy in there.  The biggest
problem I can see with the Rotary is heat; they are very susceptible to
power losses when they get up near the top of their temperature range 
(could be because the rotor housing expands enough to cause sealing
problems, I've never heard that but I wonder if it's part of the problem?)
Anyway, if you keep them cool enough they'd be a good choice.

I spec'ed out a rotary conversion once and found some interesting facts
about it.  My technical source was Craig Nagler, owner of Tri-Point
Engineering and currently the SCCA's Solo II National champion in the
RX7 turbo he built at his shop.  Craig's comment was that rotaries are
happiest in light cars that can run very low (numerically high) final
drive ratios, because the rotary doesn't make mas uch power on each pulse
as a nice torquey long-stroke British motor, but it makes so many
pulses so close together because it spins so quickly.  So the object is to 
gear the car aggressively and then run it to 10,000 or 14,000 RPM.  (No
valves to float!)

Also, where the transmission's input shaft slides into the engine on a
Rotary is somewhat higher than in most piston-engined cars.  This means
the engine can mount lower -- which is good for CG, but bad for GC (where
they stand for Center of Gravity and Ground Clearance, respectively).  It 
can also lead to problems with adapting rotaries to existing gearboxes,
and as a result, most front-engine/rear-drive cars use the Mazda box as
it's usually easier to adapt the transmission mounts than the bellhousing.
Obviously, that won't do in a Europa, unless you can get a Webster 
gearbox or whatever it is they use in the Jim Russell Formula Mazda cars.

Just to get you salivating, there are two basic flavors of rotary engine:
the 12A, which has something like 1100cc of swept area, and the 13B, which
has about 1300.  Parts are interchangeable to some extent between the two,
and I understand that a "12-1/2B" is a very potent street performer as it
uses the smaller ports of the 12A with the larger rotor volume (and crank
to fit, of course) of the 13B.  Since port size is inversely proportional
to intake velocity, this gives *lots* of low-end power, and if you flow
the ports correctly you can still get most of the top end that the 13B has.

In any case, stock non-turbocharged rotaries in the last year of the 
second-generation RX7 were producing about 150 bhp with full smog 
equipment, and 220 in turbo form; the current twin-turbo is rated at
255 bhp.  With free-flow exhaust and a properly sized and jetted carb,
Craig was getting 185 bhp out of his naturally aspirated 13Bs (I never
heard Craig talk about the 12.5B hack).  I don't know what it's like in
a Europa, but it's completely bloody breathtaking in a Frogeye.

I've considered on a number of occasions making a "green" sports car by
fitting a complete 1987-92 RX7 drivetrain, with EFI, cat, and the works, 
in an early MGB bodyshell.  150 bhp in a B would be adequate, especially
if you dropped the engine weight by, oh, 300 pounds. :-)  That way I'd 
have an engine that produced no more emissions than a modern car, but
it'd be open, it'd "just feel right" (heh :-), and it'd also go like the
proverbial bat out of you-know-where.  The engineering work to install a
rotary in most older front-engine/rear-drive sports cars is about $1000,
I can almost guarantee it will be more in a Europa, and the motor will
run about $1500 or so if you have it built for 175-180 bhp.

On the other hand, a full-race Twincam rebuild won't run much more than
that, and it'll end up being a much more valuable car than a rotarized
Europa (though it *does* lend itself to a great license plate, EUROTA).
And you can get 175 bhp out of a Twincam.  Just some things to consider...

(Personally, I would hesitate to convert a small-volume sports car to
a non-original engine.  As much as I love Bs and Midgets, there are 
enough of them around that I wouldn't feel as bad about cutting one up.
Though for the B, I think a nice torquey six would be just the thing.
Hey, Rob, you still have that '72 shell hanging around?  Maybe I ought 
to look for a rusted-out Z Car and start taking parts off of it... :-)

--Scott "Just what I need, more (and more complex) project cars!" Fisher


<Prev in Thread] Current Thread [Next in Thread>