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Does anyone know of a twin cylinder engine that will fit into a ZXR 400 L frame

I'm considering building a 650 twin for the Manx GP

Kawasaki make a 650 twin don't they?

I don't really understand why you want a 650 twin, or why you want to put it in a ZXR400 frame?

How about converting a ZXR400 to a 'big bang' configuration?

what about the sv650 engine?

Jamz wrote:I don't really understand why you want a 650 twin, or why you want to put it in a ZXR400 frame?

How about converting a ZXR400 to a 'big bang' configuration?

The reason is easy really.
It has just been announced that 650 twins are allowed to race in the Ultra lightweight race of the Manx GP
The combination of a tuned 650 twin in a zxr400 chassis kind of appeals to me.
I've raced against 650 twins with my 400 for sometime now and 650s are better and faster in many ways but to get the best from a SV650 you need to make some very big changes like fitting a GSXR front end. I reckon a 650 twin engine in a zxr400 chassis would be a fun bike to build and also be competitive.

Ive wanted to fit an SV engine into a ZXR400 frame for years, At the end of the day if you can get it to fit in the frame then your only worries will be lining up the spockets and getting everything to fit under the tank and fairing. Width shouldnt be a problem at all, maybe height! But you can get 750cc kits for the SV motor, not that you would probably be able to run that in competition races, but in the quest for more power.....

cargo wrote: Kawasaki make a 650 twin don't they?

the ER-6 engine yes.

probably a better bet than the SV in terms of packaging as it's a parallel twin, so at least remotely the same shape as the original engine.

stock power is the same - but I'd guess there's a bit more tuning experience around for the SV cos it's been around so much longer. There must be a few people racing the ER6 in minitwins series by now though.

the ER6's are used in the mini twins now, how competative they are i dont no.

Surly you'll have all sorts of problems with weight distrobution using a twin insted of a inline engine?

i have a ER-6 and now its derestricted i will confirm its a very smooth engine. but whe you open it it goes i wouldnt worry about that. I would say it would be as good if not better than the SV, due to the SV engine design being a few years old, you though Kawasaki would have had that as teh bench mark. If you would liek and simple dimensions you only have to ask mate.

ive got an firestorm engine sat outside, and when i had the zxr apart the frame fitted over the lump quite easily

defiantely could be done!

muffinman wrote:ive got an firestorm engine sat outside

now there's an interesting idea (even if it's a H*nda ). I think everyone would realise it wasn't a 400 the first time you started it up tho!

It would tear the frame apart tho like the CBR motor did surely?

considering it will make far more tourque as well whats more likly to rip it apart than a smothe CBR engine. Still with some braceing id expect it could take it

RobB wrote:It would tear the frame apart tho like the CBR motor did surely?

Possibly, but with the knowledge of what happened to the blade engined bike, you would make sure you took steps to brace the frame.

And I don't know that 'tear the frame apart' is an accurate description (I haven't read the account for a while). It didn't all fold up as soon as he opened the throttle. It just accelerated a fatigue failure which would probably still happen with a 400 engine if you rode it far enough.

This is getting into some fairly in depth engineering, and I've glossed over a lot of problems, but the long and the short of it is you could, if you wanted to, beef up a ZXR frame to take any amount of power. The question is whether in doing so you'd lost any weight/handling advantage that led you to like the 400 in the first place.

It was simply an exageration in terms

rene wrote:the ER6's are used in the mini twins now, how competative they are i dont no.

Surly you'll have all sorts of problems with weight distrobution using a twin insted of a inline engine?

I race with NEMCRC and there's a fella called Dave Bell beating everyone on an ER6 in the minitwins class, he performed well at Oliver's Mount as well.

Hey Cargo, howz it going mate? I'll be at the Manx 2008, i'm helping Garry Dickinson with his 250.