Cam Fitting Trouble -- Which Position

[Suzuki_Don]

I am having second thoughts now after I read this in a Clymer Manual for the 550.

What do you think.

My #1 arrow was a mm or two above the joint surface.

 

[hampshirehog]

Bloody 'ell Don - talk about conflicting messages. I reckon I'm right, but then I would wouldn't I?

Having said that even Clymer wouldn't have written that if they weren't sure; it's probably easier to make a mistake on a diagram than it is with the written word, especially when it appears to have been written so precisely.

In your photos I also noticed that those slots on the end of the cams didn't line up exactly, regardless of which position you engaged. That made me a tad nervous about my earlier thoughts as I've never seen them like that - maybe the 650 (which I've never owned) doesn't follow the Suzuki 'rule book'.

You could start measuring things with a TDC probe / dial wheel etc and digging out your old school maths book - I think I'd be tempted to go down that route as a check of the Clymer setting.

Ref your previous post about your carbs by the way....don't bother with any of that nonsense, just pop 'em on, fill up with fuel, start up and hit the red line as you pop a wheelie out of the garage

 

[Suzuki_Don]

Ref your previous post about your carbs by the way....don't bother with any of that nonsense, just pop 'em on, fill up with fuel, start up and hit the red line as you pop a wheelie out of the garage

But don't I need to run it in.

 

[Suzuki_Don]

Bloody 'ell Don - talk about conflicting messages. I reckon I'm right, but then I would wouldn't I?

Having said that even Clymer wouldn't have written that if they weren't sure; it's probably easier to make a mistake on a diagram than it is with the written word, especially when it appears to have been written so precisely.

In your photos I also noticed that those slots on the end of the cams didn't line up exactly, regardless of which position you engaged. That made me a tad nervous about my earlier thoughts as I've never seen them like that - maybe the 650 (which I've never owned) doesn't follow the Suzuki 'rule book'.

You could start measuring things with a TDC probe / dial wheel etc and digging out your old school maths book - I think I'd be tempted to go down that route as a check of the Clymer setting.

Thanks HOG,

When I had the cams installed with the #1 arrow just above the upper head surface the notch in the end of the camshaft was pretty square to the head surface, but when it was one tooth the other way and the arrow was just below the upper head surface then that notch was on a definite angle, not level.

Just to add some more uncertainty I looked up the 550 and 650 manuals and they give differing link numbers between intake and exhaust cams. The 650E Manual gives it as 19 teeth and the 550 Manual gives it as 20 teeth. So going by this bit of info I could be spot on, 1 tooth or 2 teeth out on the sprockets.

It looks like it is back to "OLD SKOOL" engineering and digging the degree wheel out and trying to fathom via TDC which settings are right.

With my limited knowledge this could be fun. Just as well I've got some spare valves in the cupboard.

Thanks for your comments WALLY, they are all helpful.

 

[Suzuki_Don]

CHECKED The Degree on the Cams Today

CHECKED The Degree on the Cams Today

Today I checked the degrees that each cam was opening and closing at and from that fathoming out the lobe centres for each shaft.

This degree checking was done with the cams in the first position in this post with the #1 arrow above the upper head surface and utilising 19 pins to the intake camshaft.

I could not use a dial gauge on this motor with it being an 8-valve, instead I used the feeler gauge method. I used a 2.25 shim in the bucket being measured and a .003" feeler gauge. I had approx 0.5mm clearance between cam lobe base and shim.

EXHAUST CAM:

Opens: 40 degrees BBDC
Closes: 14 degrees ATDC

40 + 180 + 14 = 234 degrees DURATION

234 / 2 = 117 - 14 = 103 degrees LOBE CENTER

INTAKE CAM:

Opens: 10 degrees BTDC
Closes: 46 degrees ABDC

10 + 180 + 46 = 236 degrees DURATION

236 / 2 = 118 - 10 = 108 degrees LOBE CENTER

________________________________________________________

STANDARD CAM TIMING FOR THE GS650

________________________________________________________

As most people seem to suggest that the lobe centres should be somewhere between 102 and 110 degrees then it would appear that I have the cams and chain pins in the correct positions. As one tooth on the cam sprocket by my reckoning is 12 degrees; 360 degrees divided by 30 teeth = 12 degrees.

The only problem seems to be that the cam Lobe Center numbers seem to be reversed as pointed out by RAPIDRAY in another of my threads. The exhaust cam usually has a higher number than the intake to allow for cylinder scavenging.

Obviously this reversed formation is the way it was designed, so not sure what to do now. Do I leave it this way with the exhaust on 103 and the intake on 108 degrees or slot the cam sprockets and set them at 104 intake and 106 exhaust as suggested by RAPIDRAY for for low down grunt.

Help please from all the knowledgeable guys on timing cams, RAPIDRAY, CHEF, etc.

Sorry about the Magna Carta & hope my calculations are OK. STEVE will soon let me know if they're not. He probably has this info on a SPREADSHEET somewhere.

 

[Nessism]

If it's only off by a degree or two from Ray's suggestion I'd call it done. Good work Don.

 

[waterman]

Do you want to time this for a 650 or for a 550? Is the timing for a 650E the same as for a 650g? I only have a factory service manual for the G models which states the timing as your post shows. Even though the 650's share heads, the timing must be different since the cam gearing is different. Please don't take this as an insult to your approach, just trying to clarify it for my one curiosity:-k

I did a little checking through my 550 shop manual, thanks BassCliff, and the 550 is timed a little differently than the 650 as you state. If you download the 550 manual it is on page 28. Sorry that I can't copy and paste a diagram like your post, but essentially it states that exhaust opens at 54 degrees before BDC and closes at 26 degrees after TDC. Intake opens at 26 BTDC and closes at 54 past ABdc. This gives an even 260 degrees of duration for both intake and exhaust timing.

I am not smart enough to figure these out, just trying to get some information out here so someone who is smart enough can get the answers for you.

 

[trippivot]

after you put them in time you need to "gently" turn the engine 720 degrees and see how they line up after. That is 2 complete crank turns. if you have it wrong you will feel resistance and that will be the indication to stop - and return to the begining. Also after the 2 turns if it is wrong the lines do not line up

You have it right in the first set of pix. The second way would probably just not rev up. 1 tooth off can be caught if you turn the engine over and over.

just think, they slapped these together on an assembly line going pretty fast.

 

[waterman]

EXHAUST CAM:

Opens: 40 degrees BBDC
Closes: 14 degrees ATDC

40 + 180 + 14 = 243 degrees DURATION

234 / 2 = 117 - 14 = 103 degrees LOBE CENTER

Don, shouldn't this be:

243 / 2 = 122 - 14 = 108 degrees Lobe center

 

[Suzuki_Don]

Do you want to time this for a 650 or for a 550? Is the timing for a 650E the same as for a 650g? I only have a factory service manual for the G models which states the timing as your post shows. Even though the 650's share heads, the timing must be different since the cam gearing is different. Please don't take this as an insult to your approach, just trying to clarify it for my one curiosity:-k

I did a little checking through my 550 shop manual, thanks BassCliff, and the 550 is timed a little differently than the 650 as you state. If you download the 550 manual it is on page 28. Sorry that I can't copy and paste a diagram like your post, but essentially it states that exhaust opens at 54 degrees before BDC and closes at 26 degrees after TDC. Intake opens at 26 BTDC and closes at 54 past ABdc. This gives an even 260 degrees of duration for both intake and exhaust timing.

I am not smart enough to figure these out, just trying to get some information out here so someone who is smart enough can get the answers for you.

Ed the "G" and "E" camshafts are exactly the same as far as timing goes, it is only the number of teeth on the sprockets that is different.

 

[Suzuki_Don]

EXHAUST CAM:

Opens: 40 degrees BBDC
Closes: 14 degrees ATDC

40 + 180 + 14 = 243 degrees DURATION

234 / 2 = 117 - 14 = 103 degrees LOBE CENTER

Don, shouldn't this be:

243 / 2 = 122 - 14 = 108 degrees Lobe center

Hi Ed, thanks for your comments.

The final figure for the Lobe Center is correct, it was the Duration number that I got wrong. It has been corrected to 234 degrees now.

Thanks.

 

[BassCliff]

Hey Don, et al,

I just wanted to let you know that I'm keeping up on this thread and learning from all of your experiences. Thanks for sharing. Keep up the good work.


Thank you for your indulgence,

BassCliff

 

[Suzuki_Don]

Hey Don, et al,

I just wanted to let you know that I'm keeping up on this thread and learning from all of your experiences. Thanks for sharing. Keep up the good work.


Thank you for your indulgence,

BassCliff

Thanks Cliff,

I too am learning a lot, particularly about degreeing camshafts. Looks like I will have to pull them again and slot the sprockets to get them right.

When I finally get it finished it should be a good ride. 75+ hp and 6 speed transmission, and plenty of choices with rear sprockets to get the gearing right. It should be a joy to ride.

I should do a full write up on the project one day. I have thousands of photos. It is a complete rebuild from the ground up. Epoxy coated frame, etc. split crankcases (some parts replaced in bottom end), apart from crank assembly all bearings replaced, tapered rollers in head stock, needle bearings in swing arm, etc.

Even if no-one else is interested I will make up a document for my own reference from go to woe.

Thanks again Cliff for your encouragement.

And to everyone else on the GSR that has been able to contribute and offer help so far. Two more months I hope and it will be on the road.

 

[waterman]

Hi Ed, thanks for your comments.

The final figure for the Lobe Center is correct, it was the Duration number that I got wrong. It has been corrected to 234 degrees now.

Thanks.

I should have stopped with my first post, obviously I am not smart enough to even do simple math problems, can you tell it is Monday? Maybe you shouldn't follow any on my advice...

Keep up the good work and remember, GSR Man of the year, BassCliff, is watching you.

 

[Suzuki_Don]

I should have stopped with my first post, obviously I am not smart enough to even do simple math problems, can you tell it is Monday? Maybe you shouldn't follow any on my advice...

Keep up the good work and remember, GSR Man of the year, BassCliff, is watching you.

I thought it was Tuesday.

Ed keep the ideas coming. You made me recheck my maths and do the alterations needed. No comments are worthless, even if they just cause us to go back and rethink an issue over again.

Yes I wonder when Cliff is going to get a REAL job. I think his real job is keeping the rest of us honest and his musical prowess is just to keep him busy at nights.

 

[Steve]

Just to add some more uncertainty I looked up the 550 and 650 manuals and they give differing link numbers between intake and exhaust cams. The 650E Manual gives it as 19 teeth and the 550 Manual gives it as 20 teeth. So going by this bit of info I could be spot on, 1 tooth or 2 teeth out on the sprockets. ...

Don't worry about that little tidbit, the number of teeth between the marks is different between the 650E and 650G engines. Just follow what the book says.

... Sorry about the Magna Carta & hope my calculations are OK. STEVE will soon let me know if they're not. He probably has this info on a SPREADSHEET somewhere.

Sorry, not for valve timing.

Adjusting your clearance with shims, yes. Timing, no.

I thought it was Tuesday. ...

No wonder you're having problems.

You blokes "down under" aren't even in the same day as the rest of us.

.

 

[tkent02]

I should do a full write up on the project one day. I have thousands of photos.

You should do it now. If you wait until it's running, you will never write it up, you will be too busy riding.

I following in your footsteps, I really am. I just need to find a 550 to start on.

 

[Guest]

Back to the future part V

 

[Suzuki_Don]

You should do it now. If you wait until it's running, you will never write it up, you will be too busy riding.

I following in your footsteps, I really am. I just need to find a 550 to start on.

A 550 should be cheap over there and in abundance.

BTW I have a lot of my photos on a Photobucket album.

 

[Suzuki_Don]

I picked up a dial gauge today at a FORD swap meet (Sunday). It was just what I had been after. It came with the magnetic base (V block) and attachments to adjust position of gauge. It is a good brand one as well. It also came with a wire pointer with a thread tapped on the end to screw into the gauge. Should be able to adjust (bend) it to sit on the bucket as I do a final check on my cam timing. Currently it is at Intake 104.5 and Exhaust 105.75. But that was done without a dial gauge. So I can now do a final check and make sure it is all OK.