What about the best pre75 engine by weight and HP

[Slakewell]

Not a Black Shadow but 1 of 25 works bikes made by Vincent

[Tim754]

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

[shelpi]

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

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) (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 

[shelpi]

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  ) 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

[shelpi]

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?

[EML]

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.

[VMX60]

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  

Cheers

[EML]

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.

[Davey Crocket]

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.

[huskibul]

    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 

[Tim754]

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..

[Purple Dave]

TM400 and SC500.....you got lots of patience or a death wish..

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 !!

[EML]

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

[shelpi]

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  but for me I will eventualy build the Dog Terd replica 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!

[EML]

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.