Hot Cam in a GS850?

[RustyTank]

Just for grins, giggles, and hotrodding purposes: would a shaft drive 1000G or 1100G engine fit in the 850 frame? Seems like that would be more bang for the buck than putting a hotter cam in the original 850 engine.

This has been brought up earlier in this post. Comment #6 and #9 in this thread I believe, if you wanna look back at them. The subject is definitely worth exploring. But again I ask, if I've got the top end open, why not drop a set of hotter cams in?

 

[RustyTank]

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

Steve, the 79 GS850 also has electronic ignition, so I'm not sure what your getting at.

 

[Rob S.]

The weight, and the shaft. It wasn't built for that. But there will always be guys who drag race their lawn mowers and Harley Davidsons.

 

[Nessism]

Steve, the 79 GS850 also has electronic ignition, so I'm not sure what your getting at.

Suzuki adopted electronic ignition for the 1980 model year bikes. 1979 bikes have points.

 

[Steve]

Suzuki adopted electronic ignition for the 1980 model year bikes. 1979 bikes have points.

Keep in mind that the 1980 production did start in late '79, so some of the 1980 bikes (WITH electronic ignition) will have 1979 assembly dates. Some people have mistakenly identified those as '79 bikes.

.

 

[GS1150Pilot]

The weight, and the shaft. It wasn't built for that. But there will always be guys who drag race their lawn mowers and Harley Davidsons.

You mean like Korry Hogan? Yeah.

 

[RustyTank]

Suzuki adopted electronic ignition for the 1980 model year bikes. 1979 bikes have points.

Oh right. Thanks for the reminder Nessism. I totally forgot that the 79 850 had points
I've upgraded my 850 with electronic ignition.

 

[RustyTank]

The weight, and the shaft. It wasn't built for that. But there will always be guys who drag race their lawn mowers and Harley Davidsons.

Rob, can you expounding on this a bit. I don't want to do anything that will ruin the engine.

 

[GS1150Pilot]

Rob's just being Rob, which means silly. Nothing you are thinking about, if properly done, will ruin that motor. That cam set may make it less fun to ride, however.

 

[Rob S.]

Rob, can you expounding on this a bit. I don't want to do anything that will ruin the engine.

It won't ruin your engine, but it won't win you many races.

One of the few times I've been to a drag strip was in the early '80's in New Jersey (Atco?)
About five of us piled into my parent's car for the trip and left our rice burners at home.

The few times Harleys raced, if they weren't up against another Harley, they were given a few seconds handicap at the start. They never won regardless.

My friends and I were on one side of the strip. There were some vocal Harley fans on the other side. We were laughing at them and their bikes. They didn't belong at a drag strip. That's all I'm saying.

In the late '70's, I had some money from a lucrative summer job. I bored my CB 350 from 325cc's to 435 (the largest available). I put a "type two, off road" cam in it (the most extreme available). The dealer advised against the cam, saying it would cause un-street personality. I dug my heals in. They had to grind out the inside of the cam cover. It was nice, but within a year the bearings were shot, and I didn't have another $800 to put into it.

Is your 850 doing what it was designed to do? It may very well tolerate the hotter cam. It may deliver noticeable power increases that are worth the money and effort. This is for you to decide. Just realize that when stock GS 750s are smoking your souped-up 850, you were told that may happen.

 

[Rob S.]

That cam set may make it less fun to ride, however.

That's what the dealer was telling me. "You'll get more power up top, but you'll pay for it down low. The bore increase may somewhat offset that."

Nudge the throttle, nothing. Nudge it some more, nothing. Nudge it again...hold on! I rather enjoyed it.

 

[GregT]

That's what the dealer was telling me. "You'll get more power up top, but you'll pay for it down low. The bore increase may somewhat offset that."

Nudge the throttle, nothing. Nudge it some more, nothing. Nudge it again...hold on! I rather enjoyed it.

Yes, I like a bike with a big response on the cams.....but that isn't a nice tourer. Which the 850 is designed for.

I've found it interesting reading this thread as in my memory most of the queries around the 850 on here have been related to changing the gearing.
The common complaint has been too high revs at highway speeds.

You can hop up anything. As Rob has said, people race lawnmowers and HD's. Doesn't mean it's worthwhile. Can be fun though.

 

[RustyTank]

Rob's just being Rob, which means silly. Nothing you are thinking about, if properly done, will ruin that motor. That cam set may make it less fun to ride, however.

GS1150Pilot, less fun to ride do to reasons already explained, or do you have something to add?

 

[Steve]

A rough recap of "all those reasons":
- Yes, it's possible to install a hotter cam.
- Because the 850 has one of the lowest power-to-weight ratios of all the GSes, it might be enough to notice.
- The 850 has a wonderfully-wide power band which suits its intended purpose.
- Installing hotter cams will change that power curve.
- The shaft drive will likely handle the additional power, as long as you don't just dump the clutch.
- The same basic driveshaft is used in the 1000 and 1100.
- To really take advantage of the hotter cams, you might want to also change the carbs and exhaust, but that will further change the power curve.
- If you just want more power, swapping in a 1000 or 1100 engine might cost less, but you would probably want to 'freshen it up' with new gaskets, etc.
- Dropping new cams in your 850 will only require a valve cover gasket and some valve shims.

Yeah, it's possible. Whether it's practical is something you will have to decide.

.

 

[GS1150Pilot]

GS1150Pilot, less fun to ride do to reasons already explained, or do you have something to add?

Dropping hot cams in a motor without building the rest of it to suit (higher compression, possibly porting the head, not to mention the headache of rejetting to suit) will rob the bike of the powerband that has made it endure as one of the great all round Suzuki classics. It will do little to improve what makes that bike great, and the shift of the powerband is likely to make it less enjoyable, since it is not a race bike.

 

[TeamDar]

Most cam manufacturers have a wide variety of profiles to choose from. Of course if you choose one of the more aggressive grinds then you will see a difference in the rpm range that the engine makes its power. There are “drop in cams” that are made to work well without having to change valve springs, increase compression, or modify the pistons for valve clearance. These cams usually have a modest increase in lift and duration. They are ground at mid range lobe centers like 105 if you install them without slotting the cam chain sprockets to degree the cams to your liking. The Web 118 grind description is as follows:
[TABLE="width: 813"]
[TR]
[TD]“High performance street profile for stock engines. Very broad power range. Stock base circle.”

This is not some pro stock race cam that idles at 3000 rpm’s and doesn’t make power until 8000 rpm’s. Just changing the cam timing with stock cams makes a difference that you can feel. 104-106 lobe centers gives you more midrange power with a slight loss of high rpm maximum power. Dar[/TD]
[/TR]
[/TABLE]

 

[Brendan W]

UJM Jenga......... I wonder?

 

[GS1150Pilot]

ujm jenga......... I wonder?

bingo .....

 

[wymple]

Unless you spend a lot of time wringing it out, torque is far more fun than HP.

 

[RustyTank]

I appreciate everyone's two cents. This was a fun discussion, great to get everyone's take on it. For what it's worth, I've decided not to do it