fzr600 camshafts

FZR400 Forum

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Mouser
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fzr600 camshafts

Postby Mouser » Sat Oct 15, 2016 1:12 pm

Hi folks,

I read in an older thread here in the forum about using the fzr600 (3he) camshafts in the fzr400.
Apparently the lift is a bit higher (wich seems to be so reading in the worksbook).

Did anyone try this yet?
How about the piston/valve clearance? How does this affect the riding?

thanks
Mouser

Evilchicken0
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Re: fzr600 camshafts

Postby Evilchicken0 » Wed Oct 19, 2016 8:06 am

It's not something I'd do to a road bike.
Don't read everything you believe
FZR400RR 3TJ Bimota SB6

Mouser
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Re: fzr600 camshafts

Postby Mouser » Thu Oct 20, 2016 1:39 pm

because.......

Evilchicken0
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Re: fzr600 camshafts

Postby Evilchicken0 » Fri Oct 21, 2016 7:33 am

The best mods you can do to a road bike is on the suspension. The cheapest is changing the sprockets.

Modding an engine will give you more power or help it to pick up quicker but it's always going to be expensive, even if all you need is to check the carburation on a dyno. Take this camshaft mod ... in theory you take out the cams and replace them, easy innit. Although you'll check the valve tolerances while you're there, but, with the valves moving further or opening longer you have to wonder if the springs are up to the job. If you replace the springs you need the head off. OK that's good for a clean up and regrind the valves but what if the valves are dished a little ??? hmmm well maybe the camchain could be replaced (it does help to get the timing bang on). All that is great if you're tuning a race bike but it's a pain in the tits for something that isn't going to ridden wide open for any more than 2-5% of the time. I know this because I had the cams on my Bimota (GSX-R1100 engine) change to race spec ... it picked up an exhaust valve, punched it through the head and munched on the piston (a JE piston) and scored the cam.

If you still feel that you desperately need the extra power on a road bike then simply thrown the whole 3HE engine in your frame but sort out the important stuff first
Don't read everything you believe
FZR400RR 3TJ Bimota SB6

tabond
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Re: fzr600 camshafts

Postby tabond » Fri Oct 21, 2016 8:21 am

I'm 99% certain cam profiles for the 3HE and 1WG are identical (not sure on the 3TJ's) I do believe the 4JH has a bit more lift, but same duration as its predecessors, but have never confirmed it.

Big cams require quite a bit of work, and honestly unless your headed toward FCR's they're not worth the headache. If you don't want to go through the expense of installing bigger cams, simply slot the stock cam gears of your 3HE and set them at 103/103. She'll wake right up. Using the 1WG springs in place of the 3HE stockers is a good idea as well. They last longer, allow higher resistance to over-rev, and a tad less parasitic loss.
BRS Racing #61
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Mouser
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Re: fzr600 camshafts

Postby Mouser » Sat Oct 22, 2016 7:13 am

Hi,

@evilchicken

it's for a trackday/race bike, not for road,so not 5 but 85% time full throttle.
I've done already a lot of work on the bike, suspension and and and... so I'm looking to get some bhp more out of the little racer.

@tabond
3he and 1wg cams are not identical,
1WG in lift/diam 32.65/25.145
out lift/diam 32.35/25.10
3he in lift/diam 32.85/25.098
out lift/diam 32.65/25.098

As to the springs the 3he seems to be the better choice,not the 1WG
1wg free length 41.94 in/ex
3he free l. 43.15
inst l. 41.2
unless they have a difference in quality...??

what do you mean by setting the cams to 103/103?

Anyone knowing about the valve/piston clearance with the 3he cams in the 1wg....that's still my question....as for the rest of the result I'll see it for myself :).

thanks
Mouser

tabond
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Location: Upstate NY

Re: fzr600 camshafts

Postby tabond » Sat Oct 22, 2016 4:07 pm

Mouser wrote:Hi,

@evilchicken

it's for a trackday/race bike, not for road,so not 5 but 85% time full throttle.
I've done already a lot of work on the bike, suspension and and and... so I'm looking to get some bhp more out of the little racer.

@tabond
3he and 1wg cams are not identical,
1WG in lift/diam 32.65/25.145
out lift/diam 32.35/25.10
3he in lift/diam 32.85/25.098
out lift/diam 32.65/25.098

As to the springs the 3he seems to be the better choice,not the 1WG
1wg free length 41.94 in/ex
3he free l. 43.15
inst l. 41.2
unless they have a difference in quality...??

what do you mean by setting the cams to 103/103?

Anyone knowing about the valve/piston clearance with the 3he cams in the 1wg....that's still my question....as for the rest of the result I'll see it for myself :).

thanks
Mouser


In the world of comparison to the full road race cams I'm used to playing with, their identical... I'm well aware the 1WG springs are a tad shorter it's a portion of why they survive, but if you're certain the 3HE springs are a better choice based solely on their free and installed length, toss em in and you'll soon find out why they aren't. 103/103 refers to your measured lobe center cam timing settings. 103* intake, 103* exhaust. With stock cams (either of them) it's an excellent starting point for increased gas flow through your (assuming) stock ports while maintaining in excess of .007" valve to piston clearance. You'll want to "Google" the cam timing relationship well in advance of making cam installation decisions. Good luck with your build.
BRS Racing #61
VRRA Competition Coordinator

Mouser
Site Newbie
Posts: 11
Joined: Tue Oct 11, 2016 3:52 pm

Re: fzr600 camshafts

Postby Mouser » Tue Oct 25, 2016 6:53 am

Hi tabond,

Thanks for the infos!
Didn't want to say that the 3he springs are "better" just because they are longer, seemed to me more a reference for "faster" closing valves (which needed in high rpm's), but I might be wrong, why exactly you get better results with the bit shorter 1WG springs?
Ports are (still) stock,yes, tended to make some work on them this winter...
about googling the cam timings...for the 1WG....tried it already....but there is hardly anything on the net about this ¨3he switch...

greets
Mouser


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