ESE's works engine tuner

[F5 Dave]

Very nice.

And a pertinent question, but probably awaiting track test to see it is doing the business, is how much capacity is that Rad? Doesn't have much frontal area but is very thick. My 496 one would be a similar size, maybe a bit smaller, but is only 35mm thick, that looks like 50.

[wax]

Looks good, Keen to see how it goes on the track.
Handing it to the 4 jokes.

[husaberg]

Tech qestion here Wob
I realise most of the stuff was based on the US banshee hence the us driven aftermarket stuff but how close is the RD400 bottom end stuff i understand a lot of the early TZ stuff was very similar to the RD250-350 as well as the DS7 stuff and i understand it was not that hard to mount early TZ top ends on RD's. So other than the obvious stroke being 62mm on the RD400 how does the rest of it vary in the crankcase is it not possible to build a squarer engine or is it a case of using what is commonly available.
I definitely are out of my comfort zone with Yams so if if i have over simplified.

I guess the 400 has wider centers and larger crankcases?

[wobbly]

No - the RD400 is based directly on the early RD cases, in fact a TZ side cover will bolt on - just bigger crank diameter.
The bore centres are 102mm and are common to RD/RZ and is the big Achilles heel of the engines,no room for good transfer duct shape.
The RD400 shares the good gear ratios of the RZ, but the RZ has VERY strong gears, as does the Banshee, but with crap ratio splits.

[husaberg]

No - the RD400 is based directly on the early RD cases, in fact a TZ side cover will bolt on - just bigger crank diameter.
The bore centres are 102mm and are common to RD/RZ and is the big Achilles heel of the engines,no room for good transfer duct shape.
The RD400 shares the good gear ratios of the RZ, but the RZ has VERY strong gears, as does the Banshee, but with crap ratio splits.

Ok then. why is no one build more square big bore engines based on the 400's longer stroke?

[Yow Ling]

Ok then. why is no one build more square big bore engines based on the 400's longer stroke?

You can get banshee cranks up to +10mm (maybe more) no need to use old rd400 cranks

[husaberg]

You can get banshee cranks up to +10mm (maybe more) no need to use old rd400 cranks

Maybe i am Dutch
ok Scottish
12-16mm billet $1200-1300 US.
I would assume a lot of the others are based on re-welds

[skism]

oh fuk, this stupid boring thread is still going, its fukn over 500 pages.

[Moooools]

oh fuk, this stupid boring thread is still going, its fukn over 500 pages.

[Brian d marge]

oh fuk, this stupid boring thread is still going, its fukn over 500 pages.

whee heee 9 posts .....

Stephen

[wobbly]

I suppose its what to expect on a public forum, you get a few public brain dead fuckwits.
The problem with the RD series is the close cylinder stud dimensions.
Means that there is no room for tripple Ex ports nor round the back, room for Boyesen ducts into the case.
The RZ studs are alot wider, and can be made external rather than up thru the cylinder.

[F5 Dave]

Don't worry about that Turkey, he can't even spell Schism.

Just been thinking about air correction jet sizes vs mainjets. I thought you took your chances a bit with what you were provided depending on the carb, but could fill & drill if it were a real mismatch, but that would likely affect the curve on the way up, but I didn't expect it to have a pronounced affect on over rev, or at least hadn't even considered it.

So with a PWK with typically fixed air jet, would one expect some gains here fitting & trialling another size jet?

[2T Institute]

You can get banshee cranks up to +10mm (maybe more) no need to use old rd400 cranks

There is NO comparison between the old air cooled RD cranks and water cooled cranks, the air cooled cranks are works of art, the water cooled cranks are built to a price. RD 400 is the best of the air cooled cranks.

[wobbly]

I have done a heap of machined RZ cranks to fit into RD/LC and then add a special offset locator circlip.
The 58mm stroker will go straight in, any longer stroke needs case trenching that I dont like - the cases are weak enough as it is.
I agree the 400 crank is a good one - with balance holes or lead inserts for balance, its done to 55%, I measured one to check.
But as I said, the stud holes are a real handbrake.

[husaberg]

There is NO comparison between the old air cooled RD cranks and water cooled cranks, the air cooled cranks are works of art, the water cooled cranks are built to a price. RD 400 is the best of the air cooled cranks.

I have done a heap of machined RZ cranks to fit into RD/LC and then add a special offset locator circlip.
The 58mm stroker will go straight in, any longer stroke needs case trenching that I dont like - the cases are weak enough as it is.
I agree the 400 crank is a good one - with balance holes or lead inserts for balance, its done to 55%, I measured one to check.
But as I said, the stud holes are a real handbrake.

So the crankshaft on the LC went to the crankpin as part of the Crankwheel on one side. Yamaha then i guess then back to a more conventional set up on the RZs?
I see as wob alluded that the stud setups are a lot different on the RD400 vs the RZ350/Banshee with the rear center 2 studs offset to the rear.