OzVMX Forum
Clubroom => General Discussion => Topic started by: EML on June 26, 2013, 04:51:06 pm
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As a follow on to the "best engine ever fitted to a dirt bike" can I have some votes for best engine fitted to a dirt or road bike built before the end of 1974.
It can be 2 or 4 stroke (or anything else) but must be judged by power to weight and, just to add spice, it must be readily available and easy to service/maintain.
I leave it in your hands gentlemen. :)
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For me it HAS to be the 73-75 Yamaha RD350, torquey with plenty of power, TZ bits fitted on no probs and you could get serious power with a bit of tuning and pipe work.
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You can get a 440 stoker crank for them.....Vaughn wouldn't be able to hang on. ;D
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Kawasaki 350 Big Horn, needs a rod/piston swap, good enough to beat a TZ500.
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lightest and most power
jawa 500 or jap 500 speedway motor
no question end of story
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Are talking motocross road racing or speedway?
If we're restricting it to motocross it's be hard to go past the 50+hp of the first series 501 Maico. Offering up the 350 Bighorn with a " rod/piston swap" is a tad out there. If that's the criteria I pick the Kawasaki Z900 fitted with a 1450 stroker kit and 3 stage nitrous oxide kit ::)........lets keep it real kids.
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The homo wants to put it into a pre75 trolley.....Hey Mark, I wonder if anyone has put a TZ700 motor in one?....they came out in74.
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Are talking motocross road racing or speedway?
If we're restricting it to motocross it's be hard to go past the 50+hp of the first series 501 Maico. Offering up the 350 Bighorn with a " rod/piston swap" is a tad out there. If that's the criteria I pick the Kawasaki Z900 fitted with a 1450 stroker kit and 3 stage nitrous oxide kit ::)........lets keep it real kids.
Real enough? Kiwi Big Horn just dyno'd at 43hp with no real work on it.
https://www.youtube.com/watch?v=xHJD0yOXPZ4
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Are talking motocross road racing or speedway?
If we're restricting it to motocross it's be hard to go past the 50+hp of the first series 501 Maico. Offering up the 350 Bighorn with a " rod/piston swap" is a tad out there. If that's the criteria I pick the Kawasaki Z900 fitted with a 1450 stroker kit and 3 stage nitrous oxide kit ::)........lets keep it real kids.
Real enough? Kiwi Big Horn just dyno'd at 43hp with no real work on it.
https://www.youtube.com/watch?v=xHJD0yOXPZ4
Never had a go on a Kawasaki Bighorn. But they had want to be good in a motocross application , to be better than a rotary disc valve Rotax motor from a Can Am TNT or MX1 ;).
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John Elliot put an RG500 in one but it spent all of it's energy spinning it's wheels on one spot.
So lets keep 'em coming....with some real power to weight comparos.
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What you think I am going to suggest :D :D :D
Well lets us see .
Power to weight? stock 67HP show room floor in a unit type dry sump set up, not bad for a 4 cylinder 4 stroke released in 1968.
Only two valves per cylinder, nut type valve adjust not poxy shims, points ignition (or oodles of aftermarket electronic conversions that can be fitted easily by a dyslectic jellyfish) more than a couple sold all round the world, so parts new or used not hard to find. Stock clutch and gearbox that rarely gave trouble.(When was the last time if ever you heard someone whinge about a CB754 box heh! (Yes I know I run back cut polished strengthened cogs and a Barnett full race heavy clutch but if they are sitting on your parts pile !!!) Has four easy to adjust round slide carburetors. (Remember them ;)) Solid kick start mechanism that does not shear off when a hundred and twelve year old gently rests a soon to be amputated foot on it in anger. Does not rip he other leg off with rocket launch kick back either! (Or maybe just press the standard electric start button to fire it up ;) ;)) enough for now Tim754
PS Which bike has won the most "Bike of the 20th century awards" :D ;D
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Never had a go on a Kawasaki Bighorn
I have and they're a ploddy old trail bike, no better or worse than an RT1 or a TS400. Lozza's right though in that they are a sleeping giant that can be made to really hoot with a bit of work. A friend of mine fitted one to a TZ350 roller and it kicked arse. BUT, just about any motor can be made to produce performance they were never designed for. I assumed this discussion was about stock motors, not "the best pre75 engine by weight and HP once it's hotted up" or " the best dog engine that can be transformed into a GP winner". ??? ??? ::)
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So far I'm liking the Jap and the Yam twin....light and fast.
The Jap will need and AMC or similar g/box though and I have no dimensions of the RD350, it should fit ok.
Any other options??
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Bump,
Com'on guys
What about Maico 501 or 440? What do they weigh and what HP?
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I'm with Jimbo on this. A longstroke 2v Jawa 500 or a JAP 500. Standard they are over 50 bhp.
The tricked up ones racing Longtrack on the Continent were more like 70/75 bhp
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Yes, but what do they weigh and more to the point, what would they weigh with a primary cover and gearbox attached???
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Ossa Phantom 250 is pretty light for having such a large cylinder. I'm under a lifting restriction or I would weigh it. ;D
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Surely the only answer is the Yankee twin if one is going to fit an extra wheel
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I agree that the Yankee might be a good choice, except they don'e exactly grow on trees. I do have two Pioneer motors and a welder though :D
Sort of makes the RD350 sound good too as there is a few of them about.
A collegue has a 500 Yam twostroke twin from the sixties, though I don't think he would want it in a Wasp frame :)
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You asked whats best you didnt mention achievable or price ;D
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It can be 2 or 4 stroke (or anything else) but must be judged by power to weight and, just to add spice, it must be readily available and easy to service/maintain.
I leave it in your hands gentlemen. :)
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Suzuki T500 / GT500 easy to get good power with a great power and torque spread, reliable, parts are good, strong after market supply in UK, easy to make very fast, compact and reasonably light. Should be a great MX SC engine. they were used in speedway sidecars from memory.
The early version may even be Pre68 but not sure
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I had one of those early Suzuki 500 twins and they pulled like a tractor funnily enough I always said you could fit a side car to this thing.I think Brad Lewis still has it in his shed.
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Suzuki T500 / GT500 easy to get good power with a great power and torque spread, reliable, parts are good, strong after market supply in UK, easy to make very fast, compact and reasonably light. Should be a great MX SC engine. they were used in speedway sidecars from memory.
The early version may even be Pre68 but not sure
first T500's were manufactured in Japan in 1967 but were not shipped to Australia till early 1968, it could be bought up as a case with MA but I didnt take it any further and went for the T250 wich fitted pre 68 and with alot of flow on stuff ;) and yes Geoff Baran used the T500 with great success(speedway, Rolly Park)
to me the DT360A (400)is up there for best pre75 or TM400 itsa power to weight thing and of course application Mx solo or sidecar etc:D
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In my reading of the context asked here.
Did I hear current availability of pre75 bikes, parts or modification bits??
T500/GT500 Suzukis great powerful two stroke twins (shite standard gearboxes). May as well add the GT750 water cooled triples (same bore size and pistons..) Hard to find Bikes and parts.
Long stroke Jawa's 500's and J.A.Ps with or without gearboxes attached , Ossa Phantoms, Maico 501's and 440's, Yankee twins, crikey Kawasaki 350 Viagra horns. All fabulous machines BUT finding the said machines or parts in any quantity ...................... ::)
Early Yamaha two stoke twins series like YDS, R5 DS7 RD yep the bits are about, getting them off the Post classic Road Racers be sticky.
Early Yamaha four stroke twins series like XS650 now your thinking with sense. TX650/750 a decline in standards, TX500 pus from a warthogs anal sores...
DT400 are not pre75 You have to get the DT360 or earlier RT's ;) they really are about lots of leg snapping fun though!!!
TM400 and SC500.....you got lots of patience or a death wish...
Kawasaki Z900...your wallet has got lots of patience or a death wish.
Back to beloved SOHC Honda CB750 K and F series . The ubiquitous* one sold squillions all over world and still has companies making parts, standard or hot up for them. :)
ubiquitous* means every bloody ware like Indian telemarketers :D
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A collegue has a 500 Yam twostroke twin from the sixties :)
Really ? Tell us more. ???
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Ditto that and a piccy or two would be interesting ;)
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I took this rather bad photo at my mates place the other day of this old works bike. I'm sure this engine could power your third wheel contraption. Be pre 68 as well.
(http://i1357.photobucket.com/albums/q747/Slakewell1/vincant_zpsf7ad8309.jpg)
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Looks more like the cotton-reel spools of a Vincent twin-drum front end. Then there's the pipes....so yes, probably pre-'68... ;D
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more likly pre60
didnt mention black shadows
picture tells all
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Not a Black Shadow but 1 of 25 works bikes made by Vincent
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Apologies I was correcting syntax and spelling in my previous post and arr oops it's gone :-[ looking for an undo button . Cheers from Embarrassed Tim754
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Apologies I was correcting syntax and spelling in my previous post and arr oops it's gone :-[ looking for an undo button . Cheers from Embarrassed Tim754
;) :) :D ;D 8) as we said DT400A meaning DT360A with a 400 piston in it ;) thats legal its still stock appearing on the outside and you are allowed upto 1300cc in a Pre75(sidecar) :o (if ya check Tim I am sure it says DT360a)
admitedly Tim you would have to gear the TM400 so it is All torque so ya would be working the gear stick like it was a 125 and do all ya can to generate low rpm power :D
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EML I would luv to see a RD350 in a sidecar with the 400 pistons in it, as long as the frame was on the light side and so with the pilot and the gunner (gunna stay on :D) it would fly, the power to weight would be right upthere but on saying that would love to put it up against a DT360A (400) jigger :o
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Apologies I was correcting syntax and spelling in my previous post and arr oops it's gone :-[ looking for an undo button . Cheers from Embarrassed Tim754
while you were correcting syntax were you useing semantics and frenetics? ;)
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Soooo, finally got some folks to come out and talk. Still no weights and measures as such though..yet.
I know that the Anthonys have a very quick DT360/400++ hybrid that takes on all comers. Also that the T500 was very good...in it's class back in the day but many tried to spin the crank and run it at 270 degrees. I just haven't seen one lying in a shed for a while ::)
The RD400 sounds like the go but what years does the GT380 cover?
I like the idea of your 250 Shelpi espec the 6 speeds,but not easy to find either.
Maico 501 could be good but they are rare too and similar in reputation as the SC500 and TM Cyclone.
Thinking has changed alot in sidecarcross since the advent of the lightweights in the mid 80's onwards as before that it was all big Nortons and Yam XS based stuff. The Haller Bros did win the Euro champs on a Honda4 Tim but shite they are heavy and wide and as I said, thinking has changed.
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The bike that changed the MX world
Sidepipe CZ 250/360 ZEDS
King of the hill Power wise World wide
4 speed gearbox out of a Russia tank unable to kick to destruction
And a dumb shit like me can fix with a 13mm and 17mm spanner
Plus both models are still racing today with the same parts made 40 years ago Gets my vote ;D
Cheers
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So, what HP and about what do they weigh please.
I have also thought of the 360 Greeves which I know worked OK even back in the 60s. Prob not as reliable as the Cheq. book racer.
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What type of chassis where you going to use....be a waste of time getting a lightweight motor if the rest is a big fat poo cart.....I'm sure it could be done but loosing weight costs money....usually lots of money....ie...exotic materials and lots of custom parts. A single cylinder motor is going to weigh a lot less that a multi and what motor you use will depend on what the parts availability is and then you will have to develop the motor to suit the trolley application. Then there will be the reliability issue's, testing, remaking broken parts stronger...good luck and I hope to have a ride on it when its done.
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Bultaco astro's engine's weigh in at aprox 27kg and on dyno charts come in at 40.90 hp for the 250,and 50.40 for the 350 standard on pump fuel ! for comparison the pursangs are rated at 34.32hp for the 250 and 40.18 the 350 ;)
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From genuine Honda CB750 workshop manual.(book serial No. 632001)
Engine weight with oil a trifling 80kg (176.3lb) Now you have to admit that's basically as light as a fat dinosaurs dick....
67Hp at 8000 rpm , what sort of measuring method they used, no bloody idea..
Maximum torque , a stump pulling 6.1kg-m at 7000rpm (44.12lb-ft) Someone else can convert that to Newton /metres thanks.
Maximum width , arr next.. must be time to quit as the ship be sinking a bit.. :D
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TM400 and SC500.....you got lots of patience or a death wish.. :o :o :o
Tim, I've been resurrecting an SC 500 for the last 6 months.....it will be ready to rumble in July.....LOTS OF PATIENCE.....
I'll get back to you on the DEATH WISH !! ;D
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Joan, the Wasp is in fact very light, granted not as light as a modern, but being all chrome-moly and alloy it's not too porky. Tha fact that they fit fat old twins and multis is the problem.
So, let's fit a nice light 2 stroke and see what becomes of it. It was done in the day by teams that sort to keep up but couldn't get hold of a VMC or similar light-weight, but against the more modern single shock stuff, they lost out.
WIth hindsight and retrospect, we can now go back and make a light-weight to race in pre75 class and this is what I'm aiming at.
That is unless I can source a Norton 850 with Quaife box for $100 and I will make a Robert Grogg replica instead. The fact is that being a '76 model frame, it is poles apart from any of the pre85 stuff it must race against currently and more likely to be converted back to a '75 model to which it has more similarities.
I feel confident that the scary SC500 motor will be tamed by the 3 wheels as modern sidecar crossers have in the rhelms of 70 to 90 HP
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spot on EML it was the Anthony's I was thinking of when stating Dt 360/400 and yes 3 wheels does tame the beast along with gearing and exhuast, contrary to somes belief in the feild of the pipes long and skinny generates lower rpm to hp perameters, Stay away from gt380 they have problems, so instead go the GT550 (came out here in 1972)common as muck and mucho parts at a reasonable price :o but for me I will eventualy build the Dog Terd replica :o a small light power house tamed by gearing, pipe, carburation, compression and porting to generate a modest but a healthy 40+ BHP ;) its not what ya got but how ya use it!
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It's interesting how the nay-sayers think that a passenger wont be able to hang on if it has 50+HP. The wosrt things to ride are the big heavy twins with, no HP.
The Jumbo with it's >120 HP was the easiest sidecar I've ever swung on and the VMC/EML/Wasp light-weights were a doddle, even at GP speeds. I think it's more about inertia, weight moving in the wrong direction, that makes it a task and I tip my hat to the early GP passengers from the late 60s and 70s.
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Bultaco astro's engine's weigh in at aprox 27kg and on dyno charts come in at 40.90 hp for the 250,and 50.40 for the 350 standard on pump fuel ! for comparison the pursangs are rated at 34.32hp for the 250 and 40.18 the 350 ;)
Methanol maybe but not on pump fuel.
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Iam only the messenger ! thats whats claimed in bultaco specs sheets/charts and seems they listed the pursang 250 @34hp and the 350/370 @ 40hp and all we know thats right - so can't see them bullshitting too far off the mark ! dunno :-\
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lozza you seem know a bit about vintage road racers what do Bully TSS's have in claimed horsepower ?