Topic: When Installing a Performance Cam

[Tracksnblades1]

You'll get it after some training.
Understand the cam profile details as served here, a bonus
Get similar numbers as the cam card is the goal.
Or IN differ from card as EX does.

Is there a general number or a range, as in closeness to the cam card numbers, that I would be okay in?

Let’s look at your cam card.

Intake opens @ 25*btdc  Intake closes @ 59*abdc.   Exhaust opens 66*bbdc  Exhaust closes 26*atdc.
and your intakes intake lobe center line is 107* atdc  exhaust lobe centerline is 110* btdc.

If you measure the above readings on your degree wheel after finding true TDC you are done and your the best
engine builder/tuner known..😁

But what do you do, as PeWe was trying to articulate, if your readings indicate:

Intake opens 23*btdc Intake closes @ 61*abdc. Exhaust opens  68*bbdc. Exhaust closes 28* atdc.
Intake lobe center line is 109* atdc.  exhaust lobe center line is 112* …..?

Or they indicate

Intake opens @ 25* btdc closes @ 59*abdc. Perfect.  But you exhaust is reading 2* late @ 68*bbdc and closes 28*atdc.

Or your readings indicate

Intake opens @ 23* btdc closes @ 61*abdc.  Exhaust opens @ 64*bbdc closes @ 28*atdc. Showing +4* duration on both.

Or any other possible combinations..?

Just preparing you. I’ve only seen one engine block and one crane cam ever check “exactly perfect”  on all 8 cylinders. And that’s if I wasn’t in error…😁😜

[Ellz10]

You'll get it after some training.
Understand the cam profile details as served here, a bonus
Get similar numbers as the cam card is the goal.
Or IN differ from card as EX does.

Is there a general number or a range, as in closeness to the cam card numbers, that I would be okay in?

Let’s look at your cam card.

Intake opens @ 25*btdc  Intake closes @ 59*abdc.   Exhaust opens 66*bbdc  Exhaust closes 26*atdc.
and your intakes intake lobe center line is 107* atdc  exhaust lobe centerline is 110* btdc.

If you measure the above readings on your degree wheel after finding true TDC you are done and your the best
engine builder/tuner known..😁

But what do you do, as PeWe was trying to articulate, if your readings indicate:

Intake opens 23*btdc Intake closes @ 61*abdc. Exhaust opens  68*bbdc. Exhaust closes 28* atdc.
Intake lobe center line is 109* atdc.  exhaust lobe center line is 112* …..?

Or they indicate

Intake opens @ 25* btdc closes @ 59*abdc. Perfect.  But you exhaust is reading 2* late @ 68*bbdc and closes 28*atdc.

Or your readings indicate

Intake opens @ 23* btdc closes @ 61*abdc.  Exhaust opens @ 64*bbdc closes @ 28*atdc. Showing +4* duration on both.

Or any other possible combinations..?

Just preparing you. I’ve only seen one engine block and one crane cam ever check “exactly perfect”  on all 8 cylinders. And that’s if I wasn’t in error…😁😜

Well what WOULD I do? Call it acceptable in that range? If I can get them that close I'd be doing alright, is that the general idea?

[Tracksnblades1]

You'll get it after some training.
Understand the cam profile details as served here, a bonus
Get similar numbers as the cam card is the goal.
Or IN differ from card as EX does.

Is there a general number or a range, as in closeness to the cam card numbers, that I would be okay in?

Let’s look at your cam card.

Intake opens @ 25*btdc  Intake closes @ 59*abdc.   Exhaust opens 66*bbdc  Exhaust closes 26*atdc.
and your intakes intake lobe center line is 107* atdc  exhaust lobe centerline is 110* btdc.

If you measure the above readings on your degree wheel after finding true TDC you are done and your the best
engine builder/tuner known..😁

But what do you do, as PeWe was trying to articulate, if your readings indicate:

Intake opens 23*btdc Intake closes @ 61*abdc. Exhaust opens  68*bbdc. Exhaust closes 28* atdc.
Intake lobe center line is 109* atdc.  exhaust lobe center line is 112* …..?

Or they indicate

Intake opens @ 25* btdc closes @ 59*abdc. Perfect.  But you exhaust is reading 2* late @ 68*bbdc and closes 28*atdc.

Or your readings indicate

Intake opens @ 23* btdc closes @ 61*abdc.  Exhaust opens @ 64*bbdc closes @ 28*atdc. Showing +4* duration on both.

Or any other possible combinations..?

Just preparing you. I’ve only seen one engine block and one crane cam ever check “exactly perfect”  on all 8 cylinders. And that’s if I wasn’t in error…😁😜

Well what WOULD I do? Call it acceptable in that range? If I can get them that close I'd be doing alright, is that the general idea?

The goal is the first example the same as the cam card. Then your could experiment advancing or retarding it from this base to see what compliments your build…

The second example shows the cam is retarded 2*. By advancing it 2* you’ll put it back to cam card specs..

The third example could be as simple as you used your old cam chain and it’s worn out. Or as complicated as a problem with the camshaft bore not perfectly centered horizontally between the rocker arm pivot bores. Or the rocker pivot bores themself, etc, etc….

The third example could be a camshaft bore vertical error, rocker arm ratio, pivot, etc,etc,….
Or as in all the examples, humans error..😁

PeWe addresses averaging the errors by adv or retard to achieve his cylinder pressure goal..
Another topic of its own..

Check x 3

[PeWe]

I read another post about advanced or retarded cam. With focus on IN open and EX close only.

(In open degrees) - (Ex closing degrees)/2
If the result will be positive the cam is advanced, or else retarded.

The numbers above:
Intake opens @ 25*btdc  Intake closes @ 59*abdc.  Exhaust opens 66*bbdc  Exhaust closes 26*atdc.
25/59
66/26

---> 25-26= -1
-1/2= -0.5.  Retarded 0.5 degrees.

I guess it will be better to set the cam 2-3 degrees earlier (advance it)
Like this:
IN   27/57
EX 68/24

BUT:
CycleX specify these numbers for the CX-11 cam at 0.050" lift:
 
IN: 19/62.5
EX: 57/22.5

(maybe with lash 0.004"/0.005")

Max lift is usually done at 0 lash.

It is not that easy to get the exact values you need. If advanced 1-2 degree more, no problem.
Who knows, maybe even better?


Most important is that you measure IN and EX open/ close in the exact same way.
The exact numbers does not matter, how they relate to each other is the thing here.

There is only one cam. If you advance in, ex will follow.

Another thing if someone has used this very cam profile and has a good timing experience.

Advance the cam will be better for street anyway. Power will happen earlier.

Lets see your numbers!

EDIT:
I forgot to mention the initial sprocket position.
It must be installed as the stock sprocket to start with.
1:4 at T
Cam markings on right side as a stock cam. Adjustable sprocket in its middle position.  It can sit one tooth wrong.
Easy to adjust chain before mounting the chain tensioner. I have always to adjust by lifting chain on corrrect side of sprocket and let chain roll over the sprocket so it will sit right.

The notch can sit wrong on some cams, the horisontal markings parallel to cam bearings to use then.

[Ellz10]

I will be finally giving it a go tonight and starting my calculations. Will post with an update soon!

[Ellz10]

Okay I'm getting frustrated. I set my dial indicator up on intake #1 with the crank at 0° TDC and I got .040 of valve lift. That didn't seem right so I went to redo it and somehow now it's not reading anything. The valve retainer goes down and then comes up but never past where the tip of the dial is.

[PeWe]

The dial indicator tip must be in its bottom position when starting at 0 lift.
The valve will go down and indicator tip will follow.
The clock has often only 10mm working range and cam can sometimes lift more.

So important it really is close to bottom position, but not completely.

[flatlander]

and make sure the feeler is parallel to the valve stem, and that it can move freely without binding anywhere.

[Ellz10]

The dial indicator tip must be in its bottom position when starting at 0 lift.
The valve will go down and indicator tip will follow.
The clock has often only 10mm working range and cam can sometimes lift more.

So important it really is close to bottom position, but not completely.

How am I supposed to know how much lift there is if it's not lifting UP from TDC?

Valve timing needs to be taken at .050" - so that means I zero my gauge on the spring retainer, turn the crank til the valve lifts the retainer up and stop at .050 then do I zero my gauge from there or what?

[Ellz10]

As you can see, there's 0 valve lash and my dial indicator is sitting just flush with the top of the retainer and is at 0 where it's supposed to be. The motor is at 0°  TDC on the degree wheel after finding true TDC. Now when I go to turn the crank, the dial doesn't move at all, the rocker arm just pushes the tappet down and never goes up. So how the hell am I supposed to record or find the valve LIFT?

[flatlander]

"lift" is down, not up. your dial needs to measure the amount of downward movement.
in your pic the feeler is already fully extended when zeroed so if the valve moves down, it can't show any movement because it can't extend further down. bring it down further, then zero it, and then it will show the "lift"

[Ellz10]

"lift" is down, not up. your dial needs to measure the amount of downward movement.
in your pic the feeler is already fully extended when zeroed so if the valve moves down, it can't show any movement because it can't extend further down. bring it down further, then zero it, and then it will show the "lift"

Oh.

[flatlander]

you're in an upside-down world

[Tracksnblades1]

Ellz 10,

Remember you will have two True TDC’s for #1 now.
Your cam is turning  1/2 the speed your crank is..
1) is TDC compression no valve depression.
And the one you’re interested in is TDC  during valve overlap, the time that both valves are open.
Also start watching for your .050 around 35* btdc - 10* btdc during the overlap TDC intake cycle, depending how much slot you have in your sprocket. Hopefully it be .050 at 25*btdc like your cam card…🤞

[Tracksnblades1]

Not to futher complicate it.
After you find your opening closing points, while you’re still set up on your intake you could see what intake’s 
centerline timing is using the centerline method..?

[Ellz10]

So I'm doing intake #1 and exhaust #1. For some reason I'm .100" off when it comes to valve lift and about 55° off when it comes to duration at .050"  (I'm reading .285 on intake and .230 on exhaust. My cam card states .385 and .330 respectively)  -  however when I do my calculations for determining lobe center, I'm almost right on target. My cam card states 107° Lobe Center for intake and I'm at 108° while my cam card states 110° for exhaust and I'm at 110.5°.

Any ideas why my lift is off? And yes it is a 1" indicator. I've tried using both digital and analog (needle) and both show it off by .100" and yes I've depressed the feeler all the way down on top of the retainer then zeroed it out.

[Tracksnblades1]

At the Honda T mark/ True TDC degree wheel, set up your 1inch dial indicator on the intake’s retainer and carefully preload it to .500. Zero the indicator. With cam chain tension adjusted and locked, turn the crankshaft in normal direction towards cam card 25* btdc intake opening. At the indicator’s first .050 movement stop and record degree wheel pointer number btdc . While observing the indicator’s movements, continue turning crankshaft towards and past the cam card 107* atdc. Recording the maximum indicated value. Should be close to .385 at zero lash..Continue turning crankshaft in normal direction until the indicator falls to .050 indicated. Stop and Record degree wheel pointer number. Hopefully 59* abdc..😁

[Don R]

 If you can't get it figured out and wanted to take the dial indicator off of the lifter, you could check directly on the cam lobe. zero on the back side and rotate to max lift.

[Tracksnblades1]

If you can't get it figured out and wanted to take the dial indicator off of the lifter, you could check directly on the cam lobe. zero on the back side and rotate to max lift.

He may have zeroed indicator at TDC with intake at overlap lift…?
I think he has .385 lift indicated through his rocker arm now…

[Don R]

 Cool.

[Ellz10]

If you can't get it figured out and wanted to take the dial indicator off of the lifter, you could check directly on the cam lobe. zero on the back side and rotate to max lift.

How would I go about doing this? Because no matter what I do or how I do it, I can't get it to read past .285"

Would I take the rocker arm off for that lobe and then measure?

[Ellz10]

Well I took the rocker off and was able to get a higher reading. Still nowhere near the .385" indicated on the cam card.

Just trying to figure out what I'm doing wrong..... very frustrating



EDIT:  I was able to get .360" on both intake #1 and 2 but no more. Still off by .025" and I can't see any way to achieve that number. I've measure many times at different spots on the lobe itself. If anyone has any insight I would love to hear it please.

[Ellz10]

And I've been able to measure .321" on the exhaust lobe, so I'm only .009" off from cam card specs.

[Tracksnblades1]

 It might be time to call your cam manufacturer if your confident your measurements are accurate.

I once ordered a .670 lift intake cam and received a .520 lift cam shaft with the .670 lift’s number on it.
With the same manufacturer received a cam with one bearing journal considerably larger and wouldn’t fit in the sbc block.

Check your .050 intake opening and closing and see if it is any where near your 268* total duration.

Doesn’t matter whether it’s 25*btdc - 59* abdc or earlier or later. Just the total is close to 264*.

[Tracksnblades1]

Here’s what web cam is advertising.
I don’t see one with less exhaust lift than yours.
No others besides your grind, that has as much as you measured on the intake lobe.
Or one that has 55* less duration..?