Engine with the biggest 'Power to weight' ratio?

[sirhc]

What is the engine with the biggest power to weight ratio?
Or torque come to that?
Before anybody suggests any turbo engines, how bought if we also include all their required bits n bobs as well (turbos, superchargers, manifolds, intercoolers, pipework, ect).
Not so clear cut now then eh.
Maybe there should be categorys to guide car builders & home tuners.
200,400,600,800,1000 BHP ect.
What do ya reckon?
All running on regular fuel of course & before the laughin gas goes on.
Ive heard of 800BHP Evo's n Scooby's,
1300BHP Skylines,
1000BHP 5 pot Audis,
1000BHP 6 pot Beamers,
600BHP 4 pot Hondas,
800BHP Cossie's ect.
400BHP H'busa's,
No dought almost every USA V8 will make 1000BHP+ in the right hands to.

All far cheaper alternatives to a 987BHP quad turbo Bugatti mill, probably lighter too when you factor in its double figure count of radiators!!

So genlemen & women start your thinkin.

[stevesingo]

RX7 rotary turbo from the 1993MY. They can make some pretty good power and can't be too heavy.

Or 2strokes from the 500cc GP bikes of old.

Steve

[eliot]

800 bhp from a 4 pot scooby/evo on pump gas....dont think so somehow. They put race gas in them, crank the boost up and do 1 dyno pull. Same goes for some of those other engines.

[sirhc]

Thought you might have something with real balls from your answer so
just checked out ya profile.
That Dakar jobbys a beast.
Bet thats not short of a few stallions n torques.
You appologise for it's weight at 1800kg's but that is lighter than alot of the other supercars out there!
I say 'other' supercars cos thats wot your monster is.
Could start a whole new thread 'wot defines a supercar'?
Something thats at the top of the tree when it comes to being built for its purpose maybe.
I.e your Dakar.
Aerodynamics don't really come into play til 60-70MPH anyway.
So bricks are fine by me.

[Snake the Sniper]

For weight to BHP, it's gotta be a turbo'd busa. 450+bhp for about 65-70kgs, maybe more depending upon intercooler.
For weight to torque, things aren't so clear cut. I'd probably guess at a supercharged ally block V8, maybe the UFZE (if I've got that right, the toyota jobbie) with twin turbos.

[Zad]

As a comparison, the (Rolls Royce) Allison 250-C40B turboshaft weighs 127kg and has a takeoff rating of 715 shaft horsepower.

[Trooper2]

Team Infinity Samuri 528 engine:

Displacement = 4.58 c.c's
Weight = 353 grams
H.P. = 2.8 @ 40,000 RPMs



There are RC nitro engines that make more horsepower from a similar displacement but I couldn't find weights on them. These things are unbeatable for power to weight ratio..

[chuntington101]

eliot said:

800 bhp from a 4 pot scooby/evo on pump gas....dont think so somehow. They put race gas in them, crank the boost up and do 1 dyno pull. Same goes for some of those other engines.

come on eilot thats a bit harsh. there are serveral UK companies that could take a 4g63 out to over 800bhp and have it hold together for a long time. check out Norris Designs. there is also RC Developments thats running some serious stuff and its holding together.

and i think stevieturbo on here has worked on some mental scoobies with big power to!

back to the original post, have you looked at a bike engine???? hehehehehe

Chris.

[Foolish Dave]

Trooper2 said:

Team Infinity Samuri 528 engine:

Displacement = 4.58 c.c's
Weight = 353 grams
H.P. = 2.8 @ 40,000 RPMs



There are RC nitro engines that make more horsepower from a similar displacement but I couldn't find weights on them. These things are unbeatable for power to weight ratio..

Nearly 8 bhp/kg? Wow! Wonder how long it would run at 40krpm for

I was thinking the 200bhp V4 2-stroke you an get from the US for skidoo racing (link on another thread once I find it again)
IIRC - 198bhp @ 44kg (can't remember displacement, but somthing like 1litre) = 4.5bhp/kg

ETA -

Found it (thanks go to hugoagogo for the original link):
http://www.aaenperformance.com/V4_racing_engine.as...

Actual values:
V-4 Drag 74 X 58.5 1025cc 275 @ 10,000
If you dig around the site a bit more, 44kg is mentioned, so that's 6.25bhp/kg They don't cost silly amounts wither - about £5k for that engine IRRC!

ETA2 -
Snake the sniper 'busa engine: 450bhp @ 65kg is 6.9 bhp/kg Which I think is pretty amazing for a real-world 4 stroke IMHO.

Maybe we should split it into 2-strokers (do we need to go NA/blown/diesel ), 4 stroke NA and 4 stroke blown?

Edited by Foolish Dave on Monday 16th July 09:23

[eliot]

chuntington101 said:

come on eilot thats a bit harsh. ...check out Norris Designs. there is also RC Developments thats running some serious stuff and its holding together.
Chris.

Not disputing the figure, but o/p said: "All running on regular fuel of course"

I have looked at Norris Designs website before - from memory anything over about 500bhp was race gas.


Such as:
http://www.norrisdesigns.com/demo8.asp
http://www.norrisdesigns.com/demo9.asp (928 bhp is impressive by anyones standards)

Although this one manages 587 on SUL:
http://www.norrisdesigns.com/demo5.asp

Hate to think how much those cost, Should we be considering "power to wallet ratio" too?

Edited by eliot on Monday 16th July 15:33

[sirhc]

I agree there could be all sorts of off shoots for this subject.
Most useful would definutely be BHP per £, then you could cross referance with the weights for the best budget option.
Hard to see any engines beating the Yank V8's for BHP per £ though.
Not so well in the weights catergory eh.

If we are talking 'torque' then i think the diesel boys may have the upper hand.
Again though diesels are heavy old bits of kit.
But whats it best to have , lots of power or lots of torque??
Knew i should of payed attention in physics at school!!!


Still along the lines of weight saving.
Im sure there's some clever mathematicians out there who could calculate the size brakes needed for a given weight car too.
Massive brakes are all very well n look the nuts but if ya don't need 'supersize' it's all extra weight int it.

Can feel some new threads coming on!!!

[chuntington101]

chris, i think im going to name you the thread starter! lol

if you want to keep it a car engine and one thats readly avaliable then have you thought about slighty larger units but running them N/A???

for example the cough rover cough k series??? very light, pretty small and can make good power! or the ford Zetec. LOADS to dig out of any recent ford at the scrappers, pretty bomb proof (you can get 300bhp form a stock block with a turbo and a spacer plate), loads of tuning parts (dont forget the USA get these engines to so there is everything from superchargers to turbo kits out for them) and cheap.

for some others there is the Pug/Cit 1.6 as used in the 106 and saxo. agian loads of them. there are honda units but they will be more exspencive i recon. the Vauxhall Ecotec engines are pretty impresive if a bit tall.

and how about this the ford CVH??? with a few choice components you can easly see over 250bhp out of one!

just a few ideas

Chris.

[benyeats]

As road car engines go the Rover K is pretty good as it is very light, with uprated cams etc I would think it would be one of the best.

Ben

[sirhc]

Cheers for the sugestions.
The only thing that niggles/scares me bout the K is it's liking for a head gasket ( but then dont all Rovers, i know me 220 turbo did).
PPC have an article this month bout the K h/gask but it doesnt really do much to reassure me.
So saying, it still has lots going for it though.
1. Lots of them about.
2. Lots of people have tuned them.
3. Come as N/A or with turbo from factory.
4. Light weight.
5.(My personal favorite) Come in both front & mid mounted options.

And probably ideal for a twin engine set up, as both Rover & Lotus have already done the hard work with the Gearlinkages ect.

Had many a daydream bout a Metro 6R4 replica running that set up.

Seen a Ford KA with a turbo CVH & still FWD. Think that was making bout 250BHP, before the Nitrous.
Dint see it myself but told it cracked an 11 1/4 on street tyres.
Quite feasable as saw it run low 14's @ 120Mph no gas at North Weald.
Best thing was it looked pretty standard too.

I'll have to post a pic of me engine/bay so you can see how limited the space is (maybe in the show us your heart thread).

Quite where i think im gona get the time to do anything i dont know!!
7am/11pm today, are working days sposed to be that long?!?!

[Snake the Sniper]

Any FWD engine can be used in a RWD appliaction, just as Lotus did with the K series. Just pick it out the front, 'box and all, and slap it back in the boot. Job done! The K series used to lunch head gaskets due to someone deciding it was a good idea to put the thermostat in the return line from the rad! Engine starts to lose a little coolant (often from the inlet gasket), the rad starts to get a bit dry, leaving the thermostat high and dry, and shut, the engine then overheats and needs a new gasket set. move the thermostat and most of the problem goes away. As long as the coolant is kept topped up most won't have an issue.

[350zwelgje]

Does formula 1 count? Shouldn't be too bad and last longer then one dyno run... Based on the information that in theory they should only run 'standard' petrol ;-)
Have no knowledge about those engines, but haven't seen them being mentioned.

And spitfire merlin stuff, probably to heavy?

Once read about something like 800cc V8, developing quite some power. Was a motorcycle engine from a long time a go if I recall correctly.

All to add to the debat, and to be 'corrected'(=enlightened) of course.

Rob

[annodomini2]

350zwelgje said:

And spitfire merlin stuff, probably to heavy?

According to Wiki, Merlin 61

1565Bhp @ 12000ft

Weight 745kg

therefore 2.1hp/kg

[XTR2Turbo]

the outright power to weight / cc was for a long time held by the engines that used to be fitted to WWII torpedoes. They were basically a rotary wankel type design. Of course they didn't need to last very long !! One of those useless facts I was told on a museum trip once but don't have the stats to hand to prove or disprove.

Edited by XTR2Turbo on Thursday 19th July 11:50

[chuntington101]

XTR2Turbo said:

the outright power to weight / cc was for a long time held by the engines that used to be fitted to WWII torpedoes. They were basically a rotary wankel type design. Of course they didn't need to last very long !! One of those useless facts I was told on a museum trip once but don't have the stats to hand to prove or disprove.

Edited by XTR2Turbo on Thursday 19th July 11:50

wankel engines are pretty cool! heard somewhere that mazda tested on to destruction and it reved to over 36krpm!

Chris.

[annodomini2]

chuntington101 said:

XTR2Turbo said:

the outright power to weight / cc was for a long time held by the engines that used to be fitted to WWII torpedoes. They were basically a rotary wankel type design. Of course they didn't need to last very long !! One of those useless facts I was told on a museum trip once but don't have the stats to hand to prove or disprove.

Edited by XTR2Turbo on Thursday 19th July 11:50

wankel engines are pretty cool! heard somewhere that mazda tested on to destruction and it reved to over 36krpm!

Chris.

The initial wankel prototypes worked more like early rotary Aero engines where the crank case spun round the crank (don't ask how it worked I don't know!) they could rev to 35krpm.