Hot Cam in a GS850?

[RustyTank]

I'm curious if anyone on here has installed a hot cam in a GS850, and what the results were?
Webcam has a set for sale. http://www.webcamshafts.com/pages_ve...zuki/1940.html

[greg78gs750]

I have nothing constructive to add, but i will say that everyone always seems to want to soup up the 850's, always seems like an unconventional choice to me, maybe that's the point?

[Buffalo Bill]

Why not? Only because it's for the 7,000 to 10,000 RPM range of performance.
You'll have to upgrade the intake, exhaust, engine and transmission to use that RPM range.
Almost forgot; tires & suspension too.
Most of all you'll need a race track to enjoy using that performance range, and track riding is awesome.
After looking at the whole of it, maybe you wanna do some vintage racing?
If so, you'll wanna look and learn a lot more about where you wanna go, and what are the best choices for you.

[RustyTank]

I have nothing constructive to add, but i will say that everyone always seems to want to soup up the 850's, always seems like an unconventional choice to me, maybe that's the point?

Just to be clear, I'm coming at this with zero expectations other than learning from people who probably know better than me...which to be honest is most people on this forum . In other words, I'd love to know more about why you think it's an unconventional choice Greg.

[RustyTank]

Why not? Only because it's for the 7,000 to 10,000 RPM range of performance.

Where are you reading that it's only for that range Bill? But to your point, how often am I in the 7000 to 10,000 RPM range for it to make much of a difference.

You'll have to upgrade the intake, exhaust, engine and transmission to use that RPM range.
Almost forgot; tires & suspension too.
Most of all you'll need a race track to enjoy using that performance range, and track riding is awesome.
After looking at the whole of it, maybe you wanna do some vintage racing?
If so, you'll wanna look and learn a lot more about where you wanna go, and what are the best choices for you.

I have no plans to do any vintage racing. And quite frankly, I'd be willing to change up the exhaust and the intake, but that's about it.
Several years ago I owned a 78 Honda CB550. One of the common upgrade hacks for that engine is to swap the stock cam for a CB650 cam, was a direct drop in. If you're rebuilding the top end you might as well do it. I did so and noticed a bit of power increase in the higher RPM's, nothing extreme, but you could feel it for sure. Well, I'm planning a top end rebuild on my 79 GS850G and I figured I'd explore the realities of putting in a hot cam. I guess from my perspective I was simply thinking, "nothin wrong with a bit more power!" But it sounds like your point is, but what's the point if your not using it? I'll also note, my GS850 is plenty powerful enough for me. Took her on the freeway recently after months of not riding her and was pleasantly reminded at how much she likes to pull once she's above 45 mph!

[Nessism]

High duration cams are designed to be used in high compression engines. The long overlap timing will bleed off compression and the 850 only has 8.8:1 compression so it's not well suited for that sort of thing. If you want more power I think upgrading to a 1000G would be a nice option. Can't remember off the top of my head if a 1000 engine will fit into the 850 frame but if so, that would be a fun project

[RustyTank]

If you want more power I think upgrading to a 1000G would be a nice option. Can't remember off the top of my head if a 1000 engine will fit into the 850 frame but if so, that would be a fun project

That WOULD be a fun project
May be worth exploring in the future.

[Buffalo Bill]

I'm sharing some of, but not all my thoughts and experience with sport bikes including my GS1100G.
I rebuilt and slightly ported my GS1100head, and spent this summer exploring it's limits.
Risky fun but you wanna keep out of court.

[Steve]

Can't remember off the top of my head if a 1000 engine will fit into the 850 frame but if so, that would be a fun project

The two frames have the same part number, so yes, it will fit. I don't remember whether you will need the mounting tabs for the 1000. There is also a possibility that you will also need the driveshaft from the 1000. Not sure if it was the 1000 or the 1100 that had a different size flange at the back of the engine, but the rest of the system would be a bolt on.

Oh, second thought: since the 1000G debuted in 1980, it will have electronic ignition, so you will need to change all THOSE parts, too.

.

[RustyTank]

The two frames have the same part number, so yes, it will fit. I don't remember whether you will need the mounting tabs for the 1000. There is also a possibility that you will also need the driveshaft from the 1000. Not sure if it was the 1000 or the 1100 that had a different size flange at the back of the engine, but the rest of the system would be a bolt on.

Oh, second thought: since the 1000G debuted in 1980, it will have electronic ignition, so you will need to change all THOSE parts, too.

.

Great info Steve. Thank you sir

[greg78gs750]

Sorry, didn't mean to crap in your thread. Been a bit grumpy lately...... Just seems like there are better platforms to spend the kinda money a cam would cost on. I mean the 850 is a great bike, but not exactly svelte, ya know? And by the time you sink the money and the time into it.... would performance gains from a cam be worth it? Just thinking practically. Probably I'm just jealous cause I am parting mine and have no replacement on the horizon...heh.

[RustyTank]

Sorry, didn't mean to crap in your thread. Been a bit grumpy lately...... Just seems like there are better platforms to spend the kinda money a cam would cost on. I mean the 850 is a great bike, but not exactly svelte, ya know? And by the time you sink the money and the time into it.... would performance gains from a cam be worth it? Just thinking practically. Probably I'm just jealous cause I am parting mine and have no replacement on the horizon...heh.

I took no offense man. Sounds like you're right, the 850 just isn't really a good bike for that application. No sweat though. And again, I'm really sorry about your recent accident. I hope things on the insurance side of things end up in your favor. You'll be back on a horse before you know it

[wymple]

I have no qualms about hopping up any engine if that's what you want. Guys still build 302 Chevies and Fords when the outwardly identical bigger engine drops right in for far less time & money. Shoot, I've got an old 250 inline 6 in my Chevy truck we are getting parts gathered up for.....just because. I could drop in a smallblock & double the horsepower for the same money, but, no.....just no.

[RustyTank]

I have no qualms about hopping up any engine if that's what you want. Guys still build 302 Chevies and Fords when the outwardly identical bigger engine drops right in for far less time & money. Shoot, I've got an old 250 inline 6 in my Chevy truck we are getting parts gathered up for.....just because. I could drop in a smallblock & double the horsepower for the same money, but, no.....just no.

Thanks for your two cents wymple. I suppose it just comes down to cost/benefit, right?

[Brendan W]

Thanks for your two cents wymple. I suppose it just comes down to cost/benefit, right?

Sometimes the benefit being just having done it and learned something by doing. It's hard to put a price tag on experience.