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BEC.. How Heavy is too Heavy?
BigDawgV8 - 19/2/23 at 07:20 AM

Morning All,

I have just finished all the bodywork on my steam-punk Morris Minor van and now turning my attention to the engine.

I would love fit a motorbike engine but fear that it is too heavy…..just over 700kg at standard weight all in.

Is that too heavy for a bec?

I already have a 2 litre Zetec waiting but now fancy something a bit different…

Thoughts appreciated!

Cheers

nick205 - 19/2/23 at 10:00 AM

BEC 7's usually seem a fair bit lighter, often 500kg or less.

Not used a bike engine in a car, but I'd imagine as the vehicle weight goes up the performance would go down. The work on the gearbox and clutch would be much heavier too.

What is it you're after, revs, sequential gearbox...?

jelly head - 19/2/23 at 10:01 AM

i suppose it depends on the engine, i imagine a hayabusa wouldn't struggle, z cars used to whack them in all sorts. I'm not sure how much a Smart weighs, but gsxr 1000s have been transplanted into them ok too. I suppose you've just got to factor in any extra costs in making it reliable (uprated clutch, sump etc).

TimC - 19/2/23 at 03:35 PM

There used to be a guy on the trackday circuit with a c.750kgs BEC Peugeot 205. It was crap. It’s been changed to car engine since.

BigDawgV8 - 19/2/23 at 03:49 PM

Thanks for all the replies people! Appreciated.

It sounds like this is NOT the right candidate for a BEC…..

Thanks again!

roadrunner - 20/2/23 at 06:58 AM

ZX12, ZX14 and a Busa engine would be fine with that weight.

gingerprince - 20/2/23 at 09:04 AM

Put 2 in, just to be safe

russbost - 20/2/23 at 09:15 AM

Do you mean current weight without engine is 700kg or is that with an engine of some sort already fitted, if it's the latter, then by the time you've removed existing engine & gearbox & replaced with BEC it's gonna be considerably under 700, if the former then substantially over by around 100kg

Even if the car's 800kg all up the ZZR1400 would easily handle it, it is, in many ways more like a tuned car engine in it's power delivery, pulls from relatively low revs, max power is at 9'500, but will continue with high power until 11,500, also has a good torque curve & delivers a max of 113 ft/lbs, which you then need to multiply by the reduction gearing, so around 170/180 in real terms. 190BHP with 170ft/lbs will move most things along pretty quickly & has a great soundtrack to go with it!

BigDawgV8 - 20/2/23 at 12:45 PM

Hi,

Thanks for the info.

That’s 700kg as it came out of the factory with all mechanicals, trim etc.

Mine has fibreglass panels, seats and minimal trim so should be a little under 700kg.

Cheers

Mr Whippy - 20/2/23 at 01:06 PM

unless you plan on putting in a heap of sound deadening I'd imagine a screaming bike engine in an old tin can van will sound horrendous

russbost - 20/2/23 at 01:29 PM

quote:
Originally posted by BigDawgV8
Hi,

Thanks for the info.

That’s 700kg as it came out of the factory with all mechanicals, trim etc.

Mine has fibreglass panels, seats and minimal trim so should be a little under 700kg.

Cheers


So what you have now can't weigh more than about 650kg, you're going to take out a heavy cast iron engine & gearbox & fit a lightweight alloy bike engine, the whole thing should now weigh around 675kg or so - my Furore weighed around 565kg & did 0-60 in around 3.5 seconds, there was no noticeable difference in performance when carrying a 100kg passenger - I don't think going BEC should prove any problem at all with a decent engine (NOT an old Fireblade!!!).

Re Mr. Whippy's comment "I'd imagine a screaming bike engine in an old tin can van will sound horrendous" I don't agree at all, the engine itself isn't noisy, only the exhaust which would be outside - also, the ZZR1400 as previously mentioned isn't really a screamer

Schrodinger - 20/2/23 at 05:14 PM

Don't forget to think about a reverse with the bike engine.

nick205 - 20/2/23 at 06:47 PM

quote:
Originally posted by Schrodinger
Don't forget to think about a reverse with the bike engine.



True

Isn't reverse an IVA requirement?

motorcycle_mayhem - 20/2/23 at 07:12 PM

Depends what you want, how you want it, what's important, what makes you smile. Life is short, so do something, don't think too long and hard.
My BEC's have been: Westfield (GSXR750), 403 Kg (slicks, race); Westfield (GSXR1000), 431 Kg (slicks, race and road), Westfield (GSXR1340), 489 Kg (road). Other race cars, Radical, ca. 500Kg, Hayabusa slicks and wings. Without exception, all went well.

The torque of the car engine is your friend. Your brick will make a very messy hole in the air, that won't matter if a high top speed isn't required. There is nothing quite like a bike engine, the big ones aren't my cup of tea, the smaller ones just howl beautifully. A bored out (1440) Hayabusa with some head work and heavy cams will sound (and go) rather well, but it'll always be better in a light race car (albeit aero/drag limited).

Radical still produce the SR3, a rather lardy thing, getting on for 650 Kg in full FIA crashworthy trim, 1500cc (long stroke) Hayabusa. Yes, it's not terribly quick in a comparative way with some other cars, but it still goes well.

If I was building a road going steel thing, it's be a car engine, solid gearbox architecture (with reverse), propshaft to rear axle. However, I'm not.
Zetec/Duratec/whatever. For a developmental future, one of those Egoboost (1.6) things. But, only YOU know what will light your fire.

perksy - 21/2/23 at 07:41 AM

Put the Zetec in it

Do it once, Fit and forget...