GS1100 Cam Lobe Centers

[scotgary]

I was messing around with my new dial gauge by checking the timing on the stock cams in a gs1100 engine that is on my bench. I got lobe centers of 117.5 intake and 81 exhaust. I've never seen numbers like this as I have not had reason to check a stock set-up. Is this what they come out of the factory with for timing?

[GregT]

Not usually....I suspect you've got odd cam sprockets. More usual for a 2V 1100 to be around 110/110. I've seen early std 16V 1100's around 110/118.
Not knowing which you have, I'd ask where you're measuring lift - and at what lift are you taking the figures ?

[scotgary]

It is an early 16 valve motor. Stock cams with stock non-adjustable sprockets. I'm measuring lift from the spring retainer. Readings are taken at 1.27mm (0.050") off the seat.

[Nessism]

Did you set valve lash before checking?

[Blower]

Do you have correct TDC?
1100 16V readings should be around 105/105 - 110/110.

[scotgary]

Ok. Got the measurements sorted out. I have intake at 113 and exhaust at 106. There is lots of variations in the factory timing of these motors. I will have to get some slotted sprockets and get them closer to 110/110

[Blower]

You can file the original cam sprocket bolt holes wider. You just need a good quality file and vise.
I have modified several original cam sprockets, some by filing and some with milling machine.

[posplayr]

Ok. Got the measurements sorted out. I have intake at 113 and exhaust at 106. There is lots of variations in the factory timing of these motors. I will have to get some slotted sprockets and get them closer to 110/110

For street more like 105/107 ; 110/110 is like a turbo kick in at 6K RPM (0.340 cams/1166/mid port).

[GregT]

106in 108ex is very good for a midrange street motor. Early unhardened cam sprockets file easily with a good quality chainsaw file.
The late hardened ones, I use a carbide tip in a die grinder.

I'd recommend setting your checking valves to zero clearance. IE, no clearance can be felt, but the follower can still slide sideways.

[mmattockx]

106in 108ex is very good for a midrange street motor.

This is what my 82 1100E is set to. It works fantastic on the street. Much stronger in the midrange and no noticeable loss of top end power in street riding.


Mark

[scotgary]

106/108 is what we are going with. I'm just waiting for my gs1150 efe cams to arrive!

[blowerbike]

you will have no worm gear on the exh. cam=no tach.

[scotgary]

Running an electronic tach off the Dyna ignition

[mmattockx]

Running an electronic tach off the Dyna ignition

In that case do you have the plug that Suzuki make for blocking off the tach drive hole in the valve cover?


Mark

[scotgary]

Yes I do, The part number for anyone interested is: 26442-45000