adjustable camshaft timing how to.

[Racer x]

how to adjust camshaft timing
adjustable cam timing how to
this thread is about how to adjust cam timing. Before I begin doing it with a 250 ninja motor. First lets look at what its all about.

DEGREEING IN YOUR CAMSHAFT

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WHAT IS DEGREEING IN YOUR CAMSHAFT?
Degreeing in your camshaft means synchronizing the camshaft's position with the crankshaft. A few degrees of misalignment can affect the engine's operation dramatically. If there were no manufacturing tolerances, you would only need to line up the marks on the timing chain sprockets and the cam would be degreed, but with a group of components (the camshaft, crankshaft, timing chain, and sprockets) all with their own standards and tolerances that when installed, can stack up against you. You can never be sure that the cam is in its correct position until you degree it in. For best performance, you should degree in all performance camshafts.

The basic tools required are a degree wheel, a stable pointer that can be mounted to the engine, a dial indicator with at least one inch of travel in .001" increments, a stand that mounts it to the engine, and a positive stop device to locate TDC.



FINDING TRUE TOP DEAD CENTER ( TDC )
DISCONNECT THE BATTERY! Do not use the starter to perform any of these steps.

To find Top Dead Center use a piston stop, to stop the piston in the same position on either side of TDC and take readings from the degree wheel. You will then split the difference in these readings and move the pointer this amount, making it the true TDC point.

First mount the degree wheel on the end of the crankshaft, and rotate the engine to approximate TDC

Mount the pointer and line it up at zero on the degree wheel.

Now rotate the engine to move the piston down into the cylinder. Install your positive stop device into the spark plug hole and extend the bolt.

Turn the engine by hand, rotating it until the piston comes up and stops against the piston stop bolt.

Look at the degree wheel and write down the number of degrees shown by the pointer.

Turn the engine by hand in the opposite direction until the piston comes up and stops on the piston stop bolt again.

Go back to the degree wheel and write down the degrees it now reads.

Add these two readings together and divide the answer by two.

Now either move your pointer by this many degrees, or carefully loosen the degree wheel (without disturbing the position of the crankshaft) and move the wheel this required amount.

Retighten the bolts, and rotate the engine again making sure that the readings on each side of TDC are equal degrees away from zero. If they are, the zero on the degree wheel will now be the true TDC point.

Remove the positive stop device from the spark plug hole.

You're now done finding true TDC

we will start with finding top dead center.this is a video for that,
I will now go out and get things set up on the ninja engine.

http://youtu.be/bcMuttJ9RFc
__________________

[Racer x]

You're now done finding true TDC.

FINDING INTAKE LOBE CENTER LINE
Remove all valve lash (clearance). Place your dial indicator on the valve spring retainer, or tappet. If you are degreeing in a pushrod engine we recommend placing the indicator on the valve retainer. Please be sure the angle of your indicator travels at the same angle that your valve travels. Zero the dial indicator, then turn the engine until you reach full lift and record how far the valve traveled off its fully seated position. This will be the actual valve lift of your desired cam profile. Note: Rocker arm engines can vary. At this point make sure there is additional clearance with your dial indicator to verify plenty of travel for our next step.

Rotate the engine until you are back to Top Dead Center (TDC). Zero your dial indicator. Next you will start turning the engine until you are .050 off the seated position of the valve (It is very important to turn the engine it’s normal way of rotation). Look at the degree wheel and determine how many degrees the valve opened. If we are working on the intake valve this will normally occur Before Top Dead Center (BTDC). Record that number in degrees. NOTE: Some low overlap engines may open After Top Dead Center (ATDC). Record that number in degrees for further calculations.

Look at your inner dial on the dial indicator and record that number to help achieve our next step, however some dial indicators do not have this feature and is not needed to proceed. See WEB CAM camshaft degree kit part #95-144. Proceed to rotate the engine until your inner dial is back on the number it left from. You will notice your big dial is almost back to .050. Slightly move it until it is exactly reads at .050. If you pass it back way up and come at it again. You are now .050 from closing on the opposite side to achieve your next number on the degree wheel, which is normally After Bottom Dead center (ABDC). Now you will use the following steps to properly calculate what actual lobe centers are on the opening valve timing events.

If the valve opened Before Top Dead Center (BTDC) do the following calculation:

Take the open number plus the closing number plus 180°, which will be the duration at .050. Next divide the duration into 2. Subtract the open from that number, which will equals the centerline of the intake cam.

[Alex]

[Racer x]

I an having trouble posting the article from web cams.
I am making a tool to check TDC. Its a hollowed out spark plug with a 1/4 inch extension welded in one end . And a wood tip glued onto the other. This will act as a piston stop with the head on.

[mgentz]

waiting to see the rest of the story/directions/video(?)!!!

[Racer x]

The setup I am using to measure cam timing on a 2098-12 250 ninja engine is a motion pro degree wheel. I welded a thread to the end of the tool that pulls the fly wheel. I have to remove the side cover for this .
I also fashioned a pointer from a piece of aluminum. The pointer lines up with the mark on the flywheel. But that is just for reference. Measurements are taken at the wheel.

[Racer x]

For the top I bolt a flat piece of steel to the cam cap . I have to remove the corner of each can cap to allow the dial indicator to reach the cam bucket.

[Racer x]

I cannot get the article from web camshafts ( do not search web cams)
I am not sure what is going on. If someone can post it here that would be great. But we are going to go one step at a time anyhow.

So first step is put the measuring stuff on the engine
You will need...
deg wheel
Flywheel puller to mount deg wheel.
A way to attach the deg wheel to flywheel puller
Dial indicator
Some sort of pointer for the deg wheel
And a piston stop.

Second step is to remove the valve lash. It goes over this like its no big deal. What I did was adjust all the valves after assembling the engine. Then removed the shims closest to the chain and replaced them with very thick shims so there is no clearance .>.05mm anyow.

Once everything is set up I will need to find TDC . So after I finish the piston stop that is next.

[Racer x]

I will wright the rest of the article by hand as we go since I can't cut and paste it.

These are examples of the math for finding the intake lobe center line.

Example
+10* Opening before Top dead center(BTDC)

+39* Closing After Bottom Dead Center (ATDC)

+180* Distance from Top Dead Center(TDC)to Bottom Dead Center (BDC)

= 229* Total Duration@.050 inches of lift

229*/2=114.5*

114.5*- 10*=104.5* lobe center.



If the value opened After Top Dead Center.(ATDC) subtract the open from the close plus 180*, which will be your duration at .050.
Next divide the duration into 2. Add back the open number which will equal the centerline of the intake side.

Example
-10* Open After Top Dead Center (ATDC)

+39* Closing After Bottom Dead Center (ABDC)

+180* Distance from Top Dead Center(TDC) to Bottom Dead Center (BDC)

+209*Total Duration.@.050 inches of lift

209*/2=104.5*

104.5* +10*=114.5* lobe center.

Now is the time to adjust the gears.

I am going to make all the measurements on the ninja engine now. First I will put in what I have , I am using a stock intake and exhaust cam. I have the adjustable sprockets set up to the center of there travel.
So first I will figure out what the intake cam centerline is . Then move on to finding the exhaust cam centerline.

[mgentz]

Please see the attached PDF

[Racer x]

Thanks Mike. Now everyone can follow along. I am going to type out the directions from web cams one step at a time. And inject my findings as I go.

[Racer x]

OK looks like we are getting two feet of snow. Time to work on this might come early.
First I have to redo the mounting for the dial indicator. The piece of metal I used is to flexible. So the pointed has to much slop. It really needs to be very ridged. That will be first thing. Then find intake centerline. At this stage I just want to see what I have and learn how to measure it. Not trying to set or change anything yet.

[Racer x]

This is great. I took a piece of flat steel. 3/16 I think. Bolted it straight across the cam caps. Now the dial indicator is rock solid. Tomorrow we measure!!

I would not recommend the dial indicator mount that has a black flexible shaft with vice grips. Harbor freight sells one for under forty dollars. It is far to flexible for this job.

[mgentz]

Eric,

Do you have your numbers from claying the motor as is? You will want to know this so that you can measure your clearances at 10 degrees BTDC and 10 degrees ATDC and have a very accurate point of comparison for how you are measuring now.

[Racer x]

I did not clay the motor. When I assembled it without a head gasket I could see the mark that on the piston ware it hit the head. Kinda a lump between the valve reliefs. Its totally gone now.

[mgentz]

I mean for piston to valve clearance. Once you start moving around the timing you will need to check your clearances 10 ATDC and 10 BTDC to avoid issues. This is where the valves come the closest to the piston. Changing the timing changes these clearances. The dome point of contact is not my point of concern.

[mgentz]

Couple links for info

Http://www.starracing.com/Cam%20Lobe...0Explained.htm

Http://www.tildentechnologies.com/Cams/CamBasics.html

[bruce71198]

Originally Posted by Racer x

I would not recommend the dial indicator mount that has a black flexible shaft with vice grips. Harbor freight sells one for under forty dollars. It is far to flexible for this job.

I think the key words are "Harbor Freight". Remember you get what you pay for. I have been using mine for decades with no issues.

[Racer x]

I used the HF as an example. I tried a snap on one. Needed to sand the ball and socket to keep it still. But the over all length is the problem even if it was welded. This job involves moving the cams just a hair. What ever you use .The pointer must be ROCK SOLID or you will get different readings every time.

[mgentz]

MUST BE ROCK SOLID

agreed.

[Racer x]

This is the number I got for the intake can centerline.

+10° Opening Before Top Dead Center(BTDC)

+34°Closing After Bottom Dead Center(ABDC)

+180°Distance from (TDC)to(BDC)

=224° Total Duration@.050 inch of lift

224°/2=112°

112°-10°=102° lobe center

I will recheck this a couple more times but I think it is good. Now we move to the Exhaust center line

[Racer x]

The above math is incorrect. The first number should be 9 not 10. And this makes the centerline 102.5 not 102. I did not change it in the past post to point out how important it is to check a couple times.

Now I am moveing on to the exhaust side.
First thing to do is measure total lift. WOW. I could not believe it. The intake is 378 thousands and the exhaust is only 270! I need to get another intake cam. It is a full revolution of the dial more lift. No wounded the nitrous loved it.

[Racer x]

The numbers for the exhaust centerline are
+39° Opening Before Bottom Dead Center ( BBDC)

+4° closing After Top Dead Center (ATDC).

+180° Distance from Bottom Dead Center. (BDC) To Top Dead Center. (TDC)

= 223° Total Dutation@ .050 inches of lift.

223°/2. =111.5°

111.5 - 4 = 107.5 Lobe Center.

Now this is just a starting point. And I am going to get another intake cam. But in the meantime. HELP!!!
Brandon or anyone what do I change the cams to? I have no clue what numbers I should look for. At this point it has been an exersize in finding the numbers. Now I want to tune the engine for top RPM with 100. % power adder with nitrous.
Looking for 70 HP.

[Racer x]

For better top end power I need to widen the camshaft centerline.
When I talked to Brandon he gave me numbers intake 108°-110°
And 110°-120° Before with the exhaust. It has taken a while to get my head around the numbers . But I think I get it.

I made a Quick adjustment and set the intake to 106° and the exhaust is at 109° I am tempted to run it like this. But I will wait and get a second intake cam.

[bruce71198]

Originally Posted by Racer x

For better top end power I need to widen the camshaft centerline.
When I talked to Brandon he gave me numbers intake 108°-110°
And 110°-120° Before with the exhaust. It has taken a while to get my head around the numbers . But I think I get it.

I made a Quick adjustment and set the intake to 106° and the exhaust is at 109° I am tempted to run it like this. But I will wait and get a second intake cam.

I have never heard of making the center line "wider". You can advance it or retard it or use it as a reference for increasing or decreasing overlap. It appears the specs he gave you are pretty vague. Overlap is something to consider between NA engines and supercharged engines.

[Racer x]

I guess a more accurate turn would be lobe center separation. By adjusting the cams from the stock position. To numbers closer to Brandons suggested number I increased the desperation. The is supposed to good for top end power. We will see.

[Racer x]

I have not run the engine yet.
But will be doing that soon. This is a list and photo of all the tools you need to adjust cams using adjustable cam sprockets or grinding the bolt holes out some.
Piston stop made from spark plug with wood tip.
Degree wheel
Flywheel puller with nut welded to tip. ( to mount deg wheel)
Dial indicator.
Valve shims to remove valve lash.
Pointer for the degree wheel
I 1/8 inch steel plate to rest dial indicator on.
The instructions from Web Cams
Normal hand tools to remove the engine.

[mgentz]

I forget...did you do this mod by itself or with others? I am wondering how much hp you can gain from just this.

[mgentz]

Awesome stuff btw

[Racer x]

The motor is stock with 66mm Wiesco pistons ported head and Barnett clutch. That and the BRT-Rtis ignition and 31mm CR Special carbs. If it goes above 35 HP its the cam timing.

[fast1075]

Actually, you don't need to remove valve lash to find, or adjust lobe center. The opening and closing numbers are different, but the formula arrives at the same data point since the lash is equal on both side of the ramp. You do need to remove valve lash to find the true duration data, which may or may not impact how the cam performs.

One of the most common ways around camshaft rules in which "stock cams" are required is to build a cam with stock base circle and stock gross lift, but change the ramp profile to get fast opening, or more duration, or even a slower closing profile to help with valve control.

The generally recognized model is "duration at .050 lift" since it is very difficult to determine when the action of going from base circle to ramp occurs. Also, it is widely believed that little in the way of air flow begins until .050 lift. Personally, I buy into that for the intake side where the pressure differential in a NA motor is very low during valve overlap.

[Racer x]

I'm back at it with adjusting camshaft timing.
I have Web Camshafts and will need to dial them in. I have some specs to work with both from Web Camshafts themselves as a starting point. And the specs from this thread. Any input or suggestion are welcome because I am basicly clueless as to what to do and why and even how for the most part.
I have all the parts except a woodruff key for the crank( don't ask). But I will have that soon enough.

[Mohawk]

I'd suggetst a set of EX250-H1/H2 Cams, known here in the UK as GPZ250 or GPX250, they have the longest duration I'm aware of, short of buying custom ones. Increase the overlap for max RPM power, reduce for more torque/mid-range power.

Oh and most engines make max power around 105 degrees on the cams, start there & then test adjustments. Make a mark on the adjustable cam sprockets to suit 108 either way in 1degree amounts (3 marks each side of 105) on the bench. Saves having to strip & re do once testing with a running engine, will allow you to set by eye in 1/2degree amounts either way.

[mgentz]

Mine have 280 degrees of duration each. What do those have?

[mgentz]

Originally Posted by Racer x

I'm back at it with adjusting camshaft timing.
I have Web Camshafts and will need to dial them in. I have some specs to work with both from Web Camshafts themselves as a starting point. And the specs from this thread. Any input or suggestion are welcome because I am basicly clueless as to what to do and why and even how for the most part.
I have all the parts except a woodruff key for the crank( don't ask). But I will have that soon enough.

What did Web give for numbers?

Also, I have a spare Web cam if you want it.

[Mohawk]

Early H1-H2 models had 277degree duration (I assume at 1mm lift) according to the manual. My H12 has 272degrees, but I've not verified that. I will once I get round to the big bore fit with head porting etc.

[Racer x]

Web said tk start with 106 intake open 12 deg close 44 deg
104 exhaust open 44 close 14 . But she was reading from a book. I don't think they had pure top end power in mind.

[mgentz]

Originally Posted by Racer x

Web said tk start with 106 intake open 12 deg close 44 deg
104 exhaust open 44 close 14 . But she was reading from a book. I don't think they had pure top end power in mind.

ok. what were your centers without adjustment (i.e. stock sprockets)?

there were a few people on here that had done some testing and playing with the numbers, but honestly I cannot recall seeing them on here anymore. Also, like Brandon, they were kinda vague on the numbers. I think its because it takes so much time and work in order to find the best numbers, that people dont want to just give the information away. How much would it be near you for a tuner to find the best numbers?

[Racer x]

There are no tuners I know of. And this sort of work is all trial and error. That is why I started this thread. It is valuable information. When I first bought the sprockets I just put them in and tried riding the bike around. All I GT was detonation or the engine would not start.
I then played around measuring compression. Just cold cranking. I could get the compression to go from 90 psi to almost 300 psi.
Now that I have the tools I can be more specific about it. Last week on the dyno of the first time I ran the 282 that I started this thread with. I have a stock engine I will use the tools and find out what is stock. That will give me a base line and help me get comfortable measuring

[Racer x]

I think I have the lobe center figures for a stock 2010 ninja 250 engine. The engine has 31000 miles on it . But ran very well and was very well taken care of.
I used this method to figure things out.

http://www.enginelogics.com/degree-d...ead-camshafts/

It was just easyer to deal with than the Web Camshafts page.

So this is what I got after a second edit
Intake from 0 TDC
Rotate to .040
10deg BTDC
Then rotate till the dial reads.040
Stop at 27deg BBDC

27
+180
=207
-10
=197
Devided by 2
98.5

Exhaust from 0* TDC
Then rotating the engine until .040 lift stopping at 36 deg BBDC
Continue rotating to max lift. Then keep going until the dial reads.040
Stopping st 69 BTDC

69
+180
= 249
-36
=214
devided by2
106.5

So intake lobe center is 98.5
Exhaust lobe center is 106.5
Does this sound right? I have checked it about six times and get the same readings.
Now I am going to adjust the valves and install the adjustable sprockets. And set everything back up and get it to the stock position.
Once that is done I will do a compression test..