adjustable camshaft timing how to.

[Racer x]

Looks like my exhaust reading are wrong. Don't know what happen. I suspect te dial indicator was doing some binding I just don't know.

But after installing the adjustable sprockets I could not get any sensible readings. After a lot of fiddling around this is what I have now.

I'm just looking for min and max readings. Moving the cam gear from one direction to the other.

Intake range is 94.5 - 98
The exhaust range is 105-109.
I am still totally clueless as to what to do. I want to get back to stock setting. So I think I will reinstall the stock cam gears and start all over.
I will edit the above post after I get that done.

This is giving me a headache. But I am getting better at it.

[HoneyBadgerRy]

It seems as if you are making this more difficult than necessary. You should be able to lay the stock gears over top of the aftermarket gears and make an indication of stock timing, then using a protractor, score lines for every degree of retardation. The difficult part would come in tuning it, but an hour with a dyno and some adjusting and you should be able to get it adjusted fairly well.

[RacinNinja]

Originally Posted by HoneyBadgerRy

It seems as if you are making this more difficult than necessary. You should be able to lay the stock gears over top of the aftermarket gears and make an indication of stock timing, then using a protractor, score lines for every degree of retardation. The difficult part would come in tuning it, but an hour with a dyno and some adjusting and you should be able to get it adjusted fairly well.

That will tell you how many degrees the cams are advanced or retarded, yes.

It will not tell you at what position the crank/piston are at when the valves are opening or closing. That's why you need the degree wheel on the crank, a piston stop and the dial indicator on the valves.

Lot more to degreeing cams than just the cams themselves. You should read the link that he posted. It explains a lot. There are no shortcuts in doing this.

[HoneyBadgerRy]

Originally Posted by RacinNinja

That will tell you how many degrees the cams are advanced or retarded, yes.

It will not tell you at what position the crank/piston are at when the valves are opening or closing. That's why you need the degree wheel on the crank, a piston stop and the dial indicator on the valves.

Lot more to degreeing cams than just the cams themselves. You should read the link that he posted. It explains a lot. There are no shortcuts in doing this.

Isn't the end goal just more power at a certain RPM? You shouldn't need to truly degree camshafts to achieve this goal, just have them adjusted to the best position, which you should be able to do with time and a dyno.

[RacinNinja]

Originally Posted by HoneyBadgerRy

Isn't the end goal just more power at a certain RPM? You shouldn't need to truly degree camshafts to achieve this goal, just have them adjusted to the best position, which you should be able to do with time and a dyno.

Sure, that's it!

We all just waste our time doing it the "old" way.

Carry on.

[Racer x]

That is a great idea marking the cams. I am glad you mentioned that. I will definitely do that. It will be very helpful to see how much I change the cam position. And I will be able to return to that position later.

My goal here is to not only figure out the best position for the gears. Yes that is when the dyno comes in. But also the process of learning how to measure the lobe centerline.

At this point I can't even get accurate readings. I have the tools and they are good. But the amount of movement is very very slight. It is frustration level doing a twin cam engine. My only experience is with car engines. They put the intake and exhaust on the same cam. So it is easy. And two stroke port timing is also fairly streight forward.
I am trying to make it as uncomplicated as I can. But I am really having a struggle.

Thanks for all the input. I need to get this clear in my head. And a really need to get this right. Other people have invested time and money in my project. I feel a strong obligation to make it right.

[HoneyBadgerRy]

Originally Posted by RacinNinja

Sure, that's it!

We all just waste our time doing it the "old" way.

Carry on.

I certianlly wasn't trying to be a dick, I guess I just see things from a different perspective. If knowing the actual timing is important to you then by all means figure it out, but personally I don't care about what it is, I just want it to be the best possible.

[mgentz]

Originally Posted by HoneyBadgerRy

I certianlly wasn't trying to be a dick, I guess I just see things from a different perspective. If knowing the actual timing is important to you then by all means figure it out, but personally I don't care about what it is, I just want it to be the best possible.

For reference, BEET details that their cams are best at lobe centers of 100 both on EX and IN. It's in their specs.

[Racer x]

I marked the cams. The gears are hard. My center punch just bounced off. First push tossed a spark. I'm guessing that was the point. Now it just leaves a smudge. O well

I used a dremmel and made five marks.
The long center Mark is the stock position. The two ends are the max position. And the ones between are , well in between. So now I am going to go back and find the stock lobe center.

Valves are adjusted now also.

[Racer x]

Do I read this as 95 or 85?

[RacinNinja]

Ok, what cam is this for (intake or exhaust) and is it opening or closing? That will give you your answer as to how you read it.

[RacinNinja]

According to an FSM I found for stock cams:

Intake Open 36 BTDC, Close 56 ABDC
Exhaust Open 61 BBDC, Close 31 ATDC

If you are degreeing a stock cam, your wheel is way off.

Stock intake lobe center should be 100 degrees.

Stock exhaust lobe center should be 105.

If I don't have the right stock cam numbers, please correct me and I'll re-do my math.

[Racer x]

Originally Posted by RacinNinja

Ok, what cam is this for (intake or exhaust) and is it opening or closing? That will give you your answer as to how you read it.

I can't remember now.

[Racer x]

Originally Posted by RacinNinja

According to an FSM I found for stock cams:

Intake Open 36 BTDC, Close 56 ABDC
Exhaust Open 61 BBDC, Close 31 ATDC

If you are degreeing a stock cam, your wheel is way off.

Stock intake lobe center should be 100 degrees.

Stock exhaust lobe center should be 105.

If I don't have the right stock cam numbers, please correct me and I'll re-do my math.

I am getting intake 98.5
Exhaust 106.5.
That is pretty close. The next step will be to figure out what to do now.
I did the exhaust side. It will adjust from 101.5 to 111.5 . Give or take 1 or 2.

I think if I remove just a little bit of the cam cap I can get a better aim at the valve shim bucket.

[RacinNinja]

Originally Posted by Racer x

I am getting intake 98.5
Exhaust 106.5.
That is pretty close. The next step will be to figure out what to do now.
I did the exhaust side. It will adjust from 101.5 to 111.5 . Give or take 1 or 2.

I think if I remove just a little bit of the cam cap I can get a better aim at the valve shim bucket.

If you're using the cams with 31,000 miles on them, this is probably why your numbers are off a degree and a half either way.

Question is, what do you want to do with your power? This will dictate which way you adjust the cams. More up top? More down low?

Perform the same process with the Web Cams using their numbers for a proper install, now that you understand the process.

[RacinNinja]

Retarding the cams should give you more top end.

Since you're land speed record setting, I'd start with 2-4 degrees of retard on each cam and see where that gets you.

Might run a little rough down low...but you won't be there long.

Also, retarding means you want the higher end of the scale, opening and closing later. IE, 106.5 is the center, you want 110-111 degrees.

[HoneyBadgerRy]

Originally Posted by RacinNinja

Retarding the cams should give you more top end.

Since you're land speed record setting, I'd start with 2-4 degrees of retard on each cam and see where that gets you.

For top end you also want a little more overlap, so you might want to retard the exhaust farther than the intake.

[RacinNinja]

Originally Posted by Racer x

I am getting intake 98.5
Exhaust 106.5.
That is pretty close. The next step will be to figure out what to do now.
I did the exhaust side. It will adjust from 101.5 to 111.5 . Give or take 1 or 2.

I think if I remove just a little bit of the cam cap I can get a better aim at the valve shim bucket.

What you actually need is the proper attachment/lever for your dial indicator so you can reach into those spaces. They are roughly $30. I would recommend you get one before you go further...it will ease your headaches somewhat.

CDI30 might work well...

http://www.dialindicator.com/accessory_attachments.php

[Racer x]

Thank you so much for the help. I think it is more the cam chain the the cams themselves. They look pretty good. But the valve seats also change things. I'll post up a photo of what I'm using to get in the small space. It seems to matter that I always use the same setup and get the motion of te indicator in the same line with the valve.

Yes for land speed I only want top end power. Even a couple hundred RPM on top end makes a difference.

My plan is to set up this stock engine. Next month April 27- May 1 I will be in Ohio. I will run the 282cc engine with nitrous . If it goes well I will then swap in the Stock 250 engine and run it. See how that goes. Then hit that with a light shot of nitrous. The clutch and valve springs can't handle a 30 shot. But I want to see how that all goes. Then use what I learn to set up my 250cc engine on the Project X engine.

[choneofakind]

Originally Posted by HoneyBadgerRy

You should be able to lay the stock gears over top of the aftermarket gears and make an indication of stock timing, then using a protractor, score lines for every degree of retardation.

Ppfffffttt!!! A protractor!?!?

I've never done this. This is beyond my experience. But a protractor? Good grief man.

Carry on.

[RacinNinja]

Originally Posted by Racer x

Thank you so much for the help. I think it is more the cam chain the the cams themselves. They look pretty good. But the valve seats also change things. I'll post up a photo of what I'm using to get in the small space. It seems to matter that I always use the same setup and get the motion of te indicator in the same line with the valve.

Yes for land speed I only want top end power. Even a couple hundred RPM on top end makes a difference.

My plan is to set up this stock engine. Next month April 27- May 1 I will be in Ohio. I will run the 282cc engine with nitrous . If it goes well I will then swap in the Stock 250 engine and run it. See how that goes. Then hit that with a light shot of nitrous. The clutch and valve springs can't handle a 30 shot. But I want to see how that all goes. Then use what I learn to set up my 250cc engine on the Project X engine.

You're welcome, FWIW.

I have a hard time with text...much easier to do hands on and explain as I go.

[Mohawk]

Why waste so much time on the timing ? just use a hard set for maximum early opening.
Do the following with NO cam chain & NO cams. You can combine this with a plug piston stop.

Measure the maximum lift availabe if you think tyhe cams may be reaching close to maximum lift, by lifting a valve as far as it will go with the piston at BDC.

Then decide how much clearance you want as a minimum when the valve starts to open BTDC on the intake valve. To find this, set an intake valve to 2mm lift (1mm for Japanese manufacturers Vavle timing & 1mm piston clearance, you can adjust this number) turn engine by hand very slowly until contact is made with the piston. From your degree gauge note this as the MAXIMUM intake valve opening point BTDC. For maximum high rpm power you want this.

The cam lobe will determine the closing point & as you have the numbers from the cam maker, just adjust based on your opening point determined above.

So you only really need to work on the exhaust cam timing & again valve closing ATDC is determined by clearance at or BTDC, so the max lift & 2mm lift rule above will let you work that out. This sets the MAXIMUM ATDC closing of the exhaust valve, again the lobe numbers deterime the opening point. This in effect determines the maximum overlap you can achieve.

You can now work on adjusting the overlap safely & the advance/retard of the cams on the dyno to get the best power numbers.

YMMV

[HoneyBadgerRy]

Originally Posted by choneofakind

Ppfffffttt!!! A protractor!?!?

I've never done this. This is beyond my experience. But a protractor? Good grief man.

Carry on.

Protractor- a tool to measure angles. How else are you going to measure angles.

[Racer x]

Originally Posted by Mohawk

Why waste so much time on the timing ? just use a hard set for maximum early opening.
Do the following with NO cam chain & NO cams. You can combine this with a plug piston stop.

Measure the maximum lift availabe if you think tyhe cams may be reaching close to maximum lift, by lifting a valve as far as it will go with the piston at BDC.

Then decide how much clearance you want as a minimum when the valve starts to open BTDC on the intake valve. To find this, set an intake valve to 2mm lift (1mm for Japanese manufacturers Vavle timing & 1mm piston clearance, you can adjust this number) turn engine by hand very slowly until contact is made with the piston. From your degree gauge note this as the MAXIMUM intake valve opening point BTDC. For maximum high rpm power you want this.

The cam lobe will determine the closing point & as you have the numbers from the cam maker, just adjust based on your opening point determined above.

So you only really need to work on the exhaust cam timing & again valve closing ATDC is determined by clearance at or BTDC, so the max lift & 2mm lift rule above will let you work that out. This sets the MAXIMUM ATDC closing of the exhaust valve, again the lobe numbers deterime the opening point. This in effect determines the maximum overlap you can achieve.

You can now work on adjusting the overlap safely & the advance/retard of the cams on the dyno to get the best power numbers.

YMMV

I'm sorry but you lost me with this.
I am only trying to adjust the cams to make max power at high RPM. I have done a lot of engine modification with the 250 ninja. Most of what I have done gives me more torque or a broad midrange increase. I have been told to widen the lobe separation. This is what I am trying to do. And not just for this engine.

I am confused enough, but slowly making progress using the adjustable sprockets. My dyno availability is very limited. And very expensive at this point.

I have to do everything at home. Make an appointment . Go the the dyno. I get a couple pulls . They measure the horsepower and torque . And give me the Air fuel ratio. That cost 122 dollars and takes about an hour. Then I can go home and make adjustments.
I wish I could pull the valve cover and adjust things then go again. But there insurance won't allow me to work on the bike in the shop. They will let me pull plugs or carb jets. But pulling the bike apart is pushing it. It's a big dealership. Plus they are very busy.

[Racer x]

Originally Posted by RacinNinja

Ok, what cam is this for (intake or exhaust) and is it opening or closing? That will give you your answer as to how you read it.

I get the near 90 deg reading on the exhaust cam closing. I went back to the web cam method of measuring.

[Somchai]

Eric for one word.
More important than AFR is the measurement of the CO coming out of the exhaust.
And to do this right you should (must) measure each cylinder separate - then you really know what's going on.
Then get this and do your own dyno http://atom007.heimat.eu/tmt/gsf_dyno.html
Or as an alternative this: http://virtualdyno.net/
or this: http://www.ddisoftware.com/ttdyno/

Become more independent of others, you're doing so many things so why don't do all easy possible steps by yourself?

[choneofakind]

Originally Posted by HoneyBadgerRy

Protractor- a tool to measure angles. How else are you going to measure angles.

That's the equivalent of using a ruler to measure if your pistons are 0.010" out of round... Use precision tools for precision work. I'm not being critical of Eric, because he's the man and knows his stuff. I'm being critical of your suggestion at how easy this is, Ryan. If it were as easy as you make it sound, he'd have been doing this for years already.

I'd try to get it set up on the 4th axis of our plasma cutter (stepper motor for rotating pipe to cut tube profiles) and use machinist bars as a guide to score lines in the outer face at even intervals.

The other option I've been thinking about: you know how many teeth are on the sprocket (40? 38? just guessing from only seeing 1/4 of the gear)

Therefore you know an easy interval of degrees you can mark around the gear. That's a place to start for intervals, he's got the equipment to set up the "0".

I've been trying to think of ways to set up a jam bolt temporarily to make very fine changes in between the cam and shaft, but nothing simple is coming to mind that won't get in the way upon assembly.

[HoneyBadgerRy]

Originally Posted by choneofakind

That's the equivalent of using a ruler to measure if your pistons are 0.010" out of round... Use precision tools for precision work. I'm not being critical of Eric, because he's the man and knows his stuff. I'm being critical of your suggestion at how easy this is, Ryan. If it were as easy as you make it sound, he'd have been doing this for years already.

I would argue otherwise. In engineering classes the only tools to measure we used were a compass, a protractor, a calculator, and some formulas. They make really nice accurate protractors.

Everything I know might not be right, but I know common practice for changing cam timing it to find out how much one tooth of a cam gear changes, lope the bolts .5 degrees less than that, and mark every degree of the lope. You then slide the bolts on the lope until you hit the other side, then you skip a tooth and start on the other side of the lope.

Does that accomplish Eric's goal? I guess not, I don't know what Eric's goal is, but if he said that it will not accomplish it, then I'm sure it won't. I just wanted to respectfully offer my but I don't know everything, and I fully support him to do whatever route he wants to accomplish anything he wants to do. To me what he was doing seemed like using calipers to measure chain slack, but he probbably knows more about four stroke motors that I do (most my knowledge is either passed down from my grandfather, or based off of the studies I did on two strokes and my schooling on fluid dynamics), so it makes sense that some of you see how I was in the wrong.

[Racer x]

Originally Posted by Somchai

Eric for one word.
More important than AFR is the measurement of the CO coming out of the exhaust.
And to do this right you should (must) measure each cylinder separate - then you really know what's going on.
Then get this and do your own dyno http://atom007.heimat.eu/tmt/gsf_dyno.html
Or as an alternative this: http://virtualdyno.net/
or this: http://www.ddisoftware.com/ttdyno/

Become more independent of others, you're doing so many things so why don't do all easy possible steps by yourself?

Thanks for the suggestion.
First off my computer skills are sorely lacking. Second I don't have any type of data logging. I use the go pro and record the dash at the track.
I can only run the bike at the track. I cant get 0-60 times.
There is no OBD2 connector on my bike.

The dyno uses a single pick up. I had a dual exhaust set up. But now I am using a 2-1 exhaust. I do have independent exhaust gas temp. But that is all I have to work with. Also my money situation is very bad. I retired and moved. So I am dead broke and only work part time for minimum wage while I remodel my new house. But I do appreciate all the suggestions.

[choneofakind]

@HoneyBadgerRy, we're OT. I'll PM you later when I get the chance.

Sorry, Eric.

[Racer x]

I went back and set the adjustable sprocket from one extream to the other . I measured each side and measured each individual mark between. I got 115 on one side and 112 or 113 everyplace else?? Not only are these not the numbers I am looking for they don't seem to change. I must be doing somthing wrong. I used both methods described in the text. Addin and subtracting and all that.

I discovered in my reading an dial indicator that makes more sense to me.

[Racer x]

I went back and moved the cam pull from one extream to the other again. Marking with tape the position of maximum open. This is what I got. It seems to me all I need to do is set the max open position to the number I am looking for.
I.E. 105 for stock

[Racer x]

I set the exhaust cam to the stock position. With the valve at max lift. The dial reads 105. Is that the lobe center I am looking for?

[RacinNinja]

Originally Posted by Racer x

I set the exhaust cam to the stock position. With the valve at max lift. The dial reads 105. Is that the lobe center I am looking for?

Lobe center of a stock cam is 105, yes.

Looks like you're figuring it out.

[RacinNinja]

Originally Posted by Racer x

Thanks for the suggestion.
First off my computer skills are sorely lacking. Second I don't have any type of data logging. I use the go pro and record the dash at the track.
I can only run the bike at the track. I cant get 0-60 times.
There is no OBD2 connector on my bike.

The dyno uses a single pick up. I had a dual exhaust set up. But now I am using a 2-1 exhaust. I do have independent exhaust gas temp. But that is all I have to work with. Also my money situation is very bad. I retired and moved. So I am dead broke and only work part time for minimum wage while I remodel my new house. But I do appreciate all the suggestions.

EGT's can tell you a lot. If your dyno guy is worth his salt, he can tune your bike with a sniffer in the pipe while it's on the dyno, combined with EGT monitoring.

.

[Racer x]

He is not. I have to do the tuning. That is not a problem. The problem has been adding and subtracting numbers to get what I found the easy way.

[RacinNinja]

Originally Posted by Racer x

He is not. I have to do the tuning. That is not a problem. The problem has been adding and subtracting numbers to get what I found the easy way.

Ick. Dyno guy here is 175 for a PowerCommander or Carburetor tune. Guy is magic. He looks at the AFR map and says....drop main X sizes, raise needle X notches, pilot screw out another turn.

Bam. Done. He doesn't quit until it's perfect. Doesn't matter if it takes 15 minutes or two hours. If he can't get it right, he won't charge you full price.

Sounds like we're spoiled out here on the Wet Coast.

I think part of your problem is your indicator set up. I think the right angle adapter will really help....remember also that 1.5 crank degrees is 0.75 cam degrees. That's small!!

Lastly, were your measurements done with the valves checked and adjusted properly? I would assume so but it doesn't hurt to ask. That should be done first since it will affect measurements.

[Racer x]

It's a Harly Dealer.
I have years of tuning experience. I can change jets really quick. And adjust the ignition system with a custom map. I use the EGT to tune and monitor the nitrous
I have no problem doing that. I was doing it befor the dyno guy was born. But pulling the tank and valve cover to adjust cams is more than I can do in the dyno room.

I am getting consistent readings with my set up. I will get a better one. I had no problem setting the dial indicator up and finding max lift and the open and close events. It was just the adding and subtracting using the formulas in the links. Why do they want to add the number then subtract it?

[RacinNinja]

Originally Posted by Racer x

It's a Harly Dealer.
I have years of tuning experience. I can change jets really quick. And adjust the ignition system with a custom map. I use the EGT to tune and monitor the nitrous
I have no problem doing that. I was doing it befor the dyno guy was born. But pulling the tank and valve cover to adjust cams is more than I can do in the dyno room.

I am getting consistent readings with my set up. I will get a better one. I had no problem setting the dial indicator up and finding max lift and the open and close events. It was just the adding and subtracting using the formulas in the links. Why do they want to add the number then subtract it?

Sometimes I do not ask why. The why is not always important. Things that ARE is important.

Web cams paper does things....hinky. Use the PDF you linked to. Much simpler.

Also, if the pointer of your indicator is not exactly in line with the valve, this will throw off your measurements.

[Racer x]

Ok I'll go back and try again and see if I can make improvements thanks.