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Which cylinder kit to buy ?


raptor 350

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Hi,

 

I'm Jelle and I live in the small country Belgium ( in Europe )

Just 21 years old and I love racing my banshee.

 

My banshee only has Goldspeed exhausts , so after  2 years of riding it, I'm searching for some real hp gain !!

I don't want to modifie my case.

 

So I'm searching for the best cylinder kit without case boring.

I'm thinking of 421cc + 35 pwk carbs + 4mm cranck ?

I don't know what are the good brands of aftermarket cylinders and cranckshafts , so that's why I searching for some professional advice from you guys !!

 

The setup is just for having some fun on the streets , It's legal to ride here in Belgium on the streets ( I have my driver license )

Some times I also go on the track, mx but just for fun.

Looking for +- 80 - 90 real HP

 

post-35202-0-02045700-1358616125.jpg

 

(And sorry for my bad English) ...

 

Thanks in advance !!!

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Have you thought much about what you would do with the suspension? I'm just thinking that my ported 421 with paddles on a +6 swing arm in the sand can be a handful some times. I'm betting even a set of good ported stock cylinders with your current setup on the pavement with those tires would eat your lunch pretty easily. Just a thought. There are a couple different cylinder setups and pipes you could run that would do more than you need. Cub of the Serval would work pretty good. Check out the differerent strokes and bore sizes. Search them there's a ton of stuff on here about them.

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Thanks.

Yeah in the future I will buy some Elka's or Fox shocks.

 

Are 421cc cylinders with powervalves better/faster than those without powervalves ?

I wasn't really talking about the shocks as much as the length of the swing arm. With that much horsepower on a stock swinger on the pavement chances are you could spend a lot of time on your ass.

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I would go with longer swingarm to hold the extra power. I would also go with the serval cylinders since the cub is more for a drag setup. The serval have the bottom and mid power for playing on the streets or track. 

 

If you stay with stock cylinders, just get them ported for your riding style and throw in a +4mm crank.

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I agree.  I stock cylinder set up well should give you what you are looking for.  My 4 mil stock cylinder dynoes just a shade under 80 hp with shearer inframes fueled by 35 pwks, 185 compression running 6* timing.  Anything less than a 6 over swinger is just about un ridable.  Also, suspension is key to getting your power to the ground and handling well.  Elkas are nice (I've got a set of dune additions on the above bike) but they are spendy.  You can get good shocks for less.  Don't forget about your clutch either.  Once you start making power in this hp range a stock clutch is gonna have a hard time harnessing the power. 

 

SP

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oow I always thought that you can only gain a few hp with the stock cylinders...

yeah 80 hp out stock cylinders, that's very nice !!! :P Never thought that was possible , that changes indeed alot.

 

So would this setup perform wel ?

-Stock cylinders with porting

-V force 3 reeds

-crank + 4mm ?? Or keeping the stock one ? ( big difference between a stock one and +4mm ? )

-35mm pwk carbs ?

-K&N Powerflow kit.

 

For the timing , I just need to buy a timing degree plate or ?

 

Thank you guys ! ;-)

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After you port the cylinders you should also match the case to the cylinders.

 

My banshee only has Goldspeed exhausts , so after  2 years of riding it, I'm searching for some real hp gain !!

I don't want to modifie my case.

 

Example:

Look at the photo. Here is what is going on...

  • The BLACK gasket matches the cylinder and the transfer on the cylinder.
  • The Case is the Gray FLAT gasket mating surface.

Dremel it to open up the transfer even more so the case can flow.

 

couldportmatch.jpg

 

Thats all thats necessary as far as I know for case mods. Even after doing that your gasket area has pleanty of sealing power. No base leaks

 

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oow I always thought that you can only gain a few hp with the stock cylinders...

yeah 80 hp out stock cylinders, that's very nice !!! :P Never thought that was possible , that changes indeed alot.

 

So would this setup perform wel ?

-Stock cylinders with porting

-V force 3 reeds

-crank + 4mm ?? Or keeping the stock one ? ( big difference between a stock one and +4mm ? )

-35mm pwk carbs ?

-K&N Powerflow kit.

 

For the timing , I just need to buy a timing degree plate or ?

 

Thank you guys ! ;-)

Absolutely you can get 80+ hp out of stock cylinders.  I just figured you had a hard time getting good port work over there.  I pretty well covered my set up.  35PWKs, I like the V2s over 3s (haven't tried out the 4s yet and 2s are harder to come by these days, 3s would be fine) pod filters., HJR aggressive dune port with a 4mil crank and weisco pisotns, cool head with cut domes at 185 static compression on 110 octane, shearer inframe drag pipes with a lock out clutch, billet basket and pancake bearing, stock flywheel with adjustable timing plate stock stator, with a dunable override.  My drag bike is also stock cylinder 4mil with 40mm alky carbs running out of frame drag pipes.  Prolly at about 100 hp.  

 

It is all in the porting, tuning and matching the set up with components that compliment each other. 

 

Good luck!

 

SP

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for that power on the streets, id build a bigger motor.  something you dont have to thrash the guts out of to keep up with traffic or have fun on.

 

bigger motor will pull through gears better and you wont have to down shift all the time.

 

What do you mean with "bigger motor"  , bigger cylinders or ?

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Cub would be great on open roads! You could definitely do an 80hp stock cyl with some sort of dune type port and have a great all around motor. But in my opinion you would have to be on race gas to make it worth it and you will be on regular roads that have regular gas stations that sell regular fuel. If it were me I'd do a pump fuel cub. No bigger then a 4 mil though because you will be opened up for a lot of long periods on open roads. The motor would be a totally different beast then some trail, dune or drag set up. The lower compression for pump fuel would put you at a high 80's motor and let you get away with the sustained high rpm's of the street. Gear it out to. Maybe get your self an RZ350 tranny and have it cut to handle the shifting under power. Get your self a virgin cylinder, have it ported, and plated here in the states. Get your builder to set up a complete package before you start assembly so you only wait one time.

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What do you mean with "bigger motor"  , bigger cylinders or ?

yeh bigger bore and stroke, with aftermarket cylinders and stroker cranks. cub cylinders go from 64mm-68mm and super cub are 72mm.  and there is 2 different cub cylinders you can get, cheetah cub (strong mid and top end better for racing) or serval cub that has strong low and okay mid (tame, but can be ported for good gains.nice and torquey tho) biggest stroke you can go without case work is +4mm.

 

as tricked said, bigger motor doesnt have to try as hard  so you can run pump fuel. and if you ever want more power, there is alot waiting to be extracted from this setup.

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