cams for GS 1000

[48woody]

Any suggestion for cams for 78 GS1000. Will have 1085/1100 kit, 1980 GS1000G head (reworked). Want to improve LOW and MID range power, not so much high end. Cams from any other bike work? Most cams I've seen improve Mid and High end. Thanks for any info

[TeamDar]

Degree the stock cams to 105 lobe centers. Instant low and midrange power.

[49er]

Any suggestion for cams for 78 GS1000. Will have 1085/1100 kit, 1980 GS1000G head (reworked). Want to improve LOW and MID range power, not so much high end. Cams from any other bike work? Most cams I've seen improve Mid and High end. Thanks for any info

GS850 '82 -'84 are supposed to have good bottom end and mid range response because they open the inlets 10 degs earlier.
I have the stock '79 cams in my 850 which are great from 3000 - 10,000 rpm, even with stock VM carbs. They are degreed at 110. The higher CR helps too.

[srsupertrap]

48woody,

I went with a Andrews s1 set of cams and have never regretted it for my GS1000/1085. The s1 is only a couple of increments over stock and enhances the bottom end and mid range for better roll on performance. IMO a great street cam with over 40K miles on em to date

[Guest]

I have heard that the 1100GK cams are a good upgrade. Anyone know what the numbers are on them?

[TheCafeKid]

I have heard that the 1100GK cams are a good upgrade. Anyone know what the numbers are on them?

No idea on that, but ive also read the GK HEAD is highly prized by the 1000E tuners, because of the "D" shaped ports...

[Tarbash 27]

doesnt' the GS1100G head have a bigger combustion chamber? So wouldnt that be lower compression? or am I mistaken.

[48woody]

thanks all for the info, putting all the info I can into a file for when I do an engine rebuild this winter. There are a lot of things one can do to these motors it seems, just time and money.

[Rudeman]

Take a look at Web Cams. They have several cam profiles for the GS1000. Here's the link:

http://www.webcamshafts.com/index_blank.html?pages/vehicle_search.html

[Nessism]

This is from the 850 manual and shows changes in the valve timing when the GT came out. Which is better for torque?

[Dan Ruddock]

What you want for your needs is cams with very little or no increase in duration but as much extra lift as possible. For My GS1k I had Webcam grind me up a special grind # 151i.

They have only 5 degrees more duration but .050" more lift. My riding impression is more power ever where in the rev range. Set your cam timing at 106 lob centers. Dan

[srsupertrap]

This is from the 850 manual and shows changes in the valve timing when the GT came out. Which is better for torque?

My answer is it's the G model . It's a good question but it does not account for the other factors which might affect torque like the carb model change (Full factorial DOE would be conclusive while varying one factor (cam timing) while holding the others constant is inconclusive). The 79 GN model was VM carb equipped while the 80 GT came with CV carb and wasn't the cylinder port head opened up as well?

So Formula for Cam C/L numbers: Take timing figures, subtract smaller from larger, divide by 2 and add 90.

----------Intake--------- Exhaust

GN---------110------------ 110

GT-------- 100------------ 110

On the surface it appears the GT would be torquier than the GN but I would guess the Suzuki Engineers merely tweaked the cam timing so the 1980 CV version matched the 1979 VM model's performance. I Believe there was no significant performance change between the 79's & 80's version. Anyone have the period tests?

[Nessism]

I have heard that the 1100GK cams are a good upgrade. Anyone know what the numbers are on them?

Camshaft part numbers suggest the cam between the 850/1000/1100 are the same other than a change to a larger sprocket bolt.

[49er]

What you want for your needs is cams with very little or no increase in duration but as much extra lift as possible. For My GS1k I had Webcam grind me up a special grind # 151i.

They have only 5 degrees more duration but .050" more lift. My riding impression is more power ever where in the rev range. Set your cam timing at 106 lob centers. Dan

Increasing lift doesn't help a lot of street engines, it depends on many variables such as port shape/size/tract length, carb type and size, exhaust systems and ignition advance curve. The trick for tractability is to increase the rate of opening and flow rates at that point of induction. This is how good torque is produced. The shape in and around the valve pockets and the lead in tract shape is crucial to achieving this.

[Colin Green]

Increasing lift doesn't help a lot of street engines, it depends on many variables such as port shape/size/tract length, carb type and size, exhaust systems and ignition advance curve. The trick for tractability is to increase the rate of opening and flow rates at that point of induction. This is how good torque is produced. The shape in and around the valve pockets and the lead in tract shape is crucial to achieving this.

Remind me to show you my spare head when you come up