Cams question

[Anonymous]

I was looking at an extra head dad had put up. The cams in it are marked like this.
Exhaust cam: "EX", a raised "M", a raised "3", and "R2"
Intake cam: "IN", a raised "B", "455", a raised "9", and "R1"

The head they are in is a ported GS1100E head with VHR stamped into it.

Are these stock or aftermarket cams?

Can post pics later.


Jim

[Anonymous]

Re: Cams question

I was looking at an extra head dad had put up. The cams in it are marked like this.
Exhaust cam: "EX", a raised "M", a raised "3", and "R2"
Intake cam: "IN", a raised "B", "455", a raised "9", and "R1"

The head they are in is a ported GS1100E head with VHR stamped into it.

Are these stock or aftermarket cams?

Can post pics later.


Jim

verry dangerous--send them to me and ill dispose of them properly. Dont forget the head

[Anonymous]

OK...
Am I to assume this is a GOOD thing? 8O


Jim

[Anonymous]

OK...
Am I to assume this is a GOOD thing? 8O


Jim

Well you have a ported head and i dont know what the cams mean. If you dont get one of the guys to tell you about the cams then call star or shnitz--cope--murdoch- one of the race part suppliers. I only replied because my dream is to have a head with some work in it--mine is not good enough as most folks already know

[Anonymous]

Cool, I will see about posting some pics when I get them downloaded.


Jim

[focus frenzy]

could VHR stand for Vance& Hines Racing??

[Anonymous]

Here are some quicky pics of the head.
the VHR stamping.

A J 18 stamping

and a couple of pics of the intake runners



Let me know what yall think.


Jim

[focus frenzy]

I dont know about the cams but the head may have been done by Vance & Hines racing, E-mail them and see if they ever did 1100 heads and if they marked them with the VHR stamping.
looks like a good smoothing out of the ports, could breath good.

[Anonymous]

I emailed V&H to see if they could point me to someone to talk too. Took a couple of better detailed pictures too.


Jim

[Anonymous]

Figured I would bump this back up... and see if any members who missed this last time may have a clue as to what I have...
Here are some pics. www.planetboost.com/images/suzuki


Jim

[Anonymous]

Jim,

My long post just got deleted! Frustrating. I'll try to do this again.

First, I don't think those are stock cams. The stock ones I have do not have those markings. I do have what I think are some Yoshi stage1 that have the R1 makings on both cams. However, I don't think makings are going to tell us all we need to know to make a positive ID.

Cams are usually specified with 'lift' and 'duration' - we all know that. However, 'lift' is specified at the valve. It will be pretty hard to determine lift with the head off the motor, unless you had some valve springs that were made for this task (very weak so you can turn the cam easy). 'Duration' would be impossible to do without the head being mounted and using a degree wheel and dial indicator.

So lets forget 'duration' for now and concentrate on the 'lift' specification to get a little better idea what those are.

Instead of 'lift' we can easilly measure 'lobe height' with the cams out of the head. "Lobe height' is basically largest diameter on the cam lobe. It is related to 'lift' by the ratio of the rocker arms. So if we know the rocker ratio and the lobe height, we basically know lift.

Another measurement is the 'base circle' measurement. This is the diameter of the cam lobe without the lobe in the picture. You would think that all of the 'base circle' diameters would be the same, even for different cams, for the same engine. That would be an incorrect assumption.

For the stock cams, the base circle on intake and exhaust should be ~1.18"

Stock - intake lobe height = 1.363" exhaust = 1.353"

My Yoshi stage 1 (I think thats what they are!)

Intake and exhaust base circle = 1.18"

Intake lobe height = 1.385, exhaust = 1.385

Here is a spec sheet that you may find useful. If you need any help with it, let me know.

http://www.bertaut.com/gscamspecs.html

Please post the measurements on those cams. I am very interested in helping you determine what they are. It will help me too!

[Anonymous]

I will see about getting my hands on a set of calipers.
I will also see if I can get a measuement at the valve.

I dont have an engine to put this head on... so I want as much info as possible to give to the buyer when I get ready to sell.


Jim

[Anonymous]

Jim,

You don't need a measurment at the valve for now. Just get the lobe height. Calfiphers will get you that. It's just a measurement on the cam itself.

[Anonymous]

I guess I should have gone into this in a bit more detail so you can see what I'm trying to do.

The lift at the valve is basically the ('lobe height' - 'valve lash' - 'base circle') x rocker ratio. So if we know the 3 of those we can ge the 4th.

From the spec sheet url I gave you - an '83 stock GS 1100 exhaust cam has a 'lift' at the valve of 0.282". My '80 GS 1100 exhaust has a base circle of 1.18 and a lobe height of 1.353. This gives a rocker ratio of ~1.6886. (I'm using valve lash of 0.006" as the sheet specifies - I subtract that from the lobe height). I say approximately because that is for an '83 cam not an '80 and 0.006" valve lash is a bit much for a stock cam. So I'm off a bit, but probably not by much.

Now, using that ratio of 1.6886 and plugging it into my measurements for the cam I think is a Yoshi, I get -> ((1.385 - 0.006) - 1.18)) x 1.6886 = 0.336". The spec says for that cam it should be 0.330".

There is also a VH cam on that sheet that has a lift of 0.343". What I'm trying to determine precisely is what the rocker ratio is. I have 2 cams now and a third will help a lot with that.

I little bit of error on the rocker ratio can make enough of a difference so that it is ahrd to determine the cams. I'm trying to determine that by measurements. If anyone knows it - then please tell me.

[Anonymous]

That cool face was supposed to be an 8). It was interpreted as something I didn't expect.