Topic: Cam chain tensioner ajustment with electronic ignition

[enwri]

Can you take a photo of the exhaust rocker at full open/down as far down as it can go?

Are the rockers for inlet and exhaust identical? Could they be swapped or be on the wrong sides? There's only 3 things it could be. Long valves, they don't look too long, wrong rockers/hard facing way too thick, cam massively oversized. You're running out of options. 

[AlekStooge]

Right. I will check when home. The rocker faces all look the same thickness. As mentioned yesterday the intakes look longer from the photo. Will verify. They are 1mm OS but that isn't a length measurement. I will try to find the invoice for the head work.

[AlekStooge]

If that’s a razor blade, hold it perpendicular with a light behind it. Itll be like in Missouri. It’ll show me. (You) 😁

Here you go. There is a step up to the exhaust.

[enwri]

The gaps are because you're holding the blade at an angle to the axis and not on the centreline.

I haven't seen a picture of a rocker holding a valve down yet.

Have you seen a valve actually being pushed down compressing the spring?

[AlekStooge]

I haven't put the valve cover on yet. I will work on that in a bit. Here are the rockers again fully compressed before I put the cover back on... just in case.

[enwri]

Full lift will not be at tdc either, just spin it until any exhaust valve is fully down, we need to see how far the rocker travel is off away from normal.

Slight difference at the base shouldn't matter  that's what adjustment is for.

That base doesn't look like big enough difference to cause what you see. It'll be comparing standard rockers to what you have next after that.

[enwri]

That is NOT the rockers fully compressed. It is exactly the opposite.

[enwri]

Just checking, you know that the valves need to be pushed down to open them, that's what the lumps on the cam do. Push the valves open by compressing the springs holding them closed.

[AlekStooge]

That is NOT the rockers fully compressed. It is exactly the opposite.

My bad I was rushed.

Right I do know. I don't know of a way of pushing these down by hand without the cam. I didn't remove them or install them.

I need to put the cover on.

[enwri]

"I need to put the cover on."

Yes. To rule out any problems in a systematic manner,

1. Turn crank and cam until both cam lobes on number 1 cylinder are facing DOWN. Away from rockers. (TDC 1-4)

2. Number 1 is important. Do not turn crank.

3. Fit cover.

4. Fit both number 1 cylinders adjusters and adjust to .003 or the clearance recommended by cam people. It's a tiny gap.

5. Turn crank about 270 degrees (3/4 of a turn)

6. Take picture of cylinder 1 exhaust rocker, it will be down about as far as is will ever be.(Full lift)..  Intake tappet gap should still exist or may have started to get smaller.

7. Turn crank another 180 degrees (half a turn). Intake rocker should be down about as far as it will ever be (Full lift intake.) Exhaust rocker should have come back up, Tiny clearance may begin to be felt.

8. Turn crank another 270 degrees, It should now be back at TDC 1-4. Compression on cylinder 1 and both tappets should have your set clearance again.

* If the adjusters are still over extended (sticking up) either the valves are too long, rocker pads too thick or cam base circle too big. That is a problem for a machine shop.

9. Turn crank another 360 degrees (full turn) to TDC it will now be on cylinder 4 compression.

10. Fit cylinder 4 adjusters and set both intake and exhaust to clearance.

11. Cylinder 1 rockers should be tight and have NO clearance, both valves being partially open on overlap.

12. Turn crank 180 degrees (half turn) cylinder 2 or 3 will now be on compression and overlap. (TDC 2-3)

13.  I don't know which one is on compression,  pull rockers up and down, the pair (intake and exhaust) with the LARGEST travel is ready to for the adjusters to be fitted and clearances set.

14. Turn crank 360 degrees (full turn) fit the last cylinder adjusters and set clearances.

**   If any SOLID resistance (not springy smooth resistance, it does take energy to compress the valve springs) to turning is met near tdc on any cylinder, do not force it, You will know, and feel a sudden hard stop. Like a piston touching valve. Not likely if the cam people haven't warned you about it.

Sorry if this sounds a bit preachy, I have no idea what anyone reading this might know to start with. 

I'm assuming no previous knowledge.

[AlekStooge]

Hey not at all. I appreciate people breaking things down. It makes communication more concise. I am having a good time doing this by the way.

Well I think figured it out. Some of you might be disapointed since it is kind of anticlimactic; but I supposed that is a good thing.

I followed the instructions in the post above me and got to step 9 before calling it quits for tonight.

I did start out by finding TDC again with the piston stop before the cover went on.

1. Cams lobes were both down on cylinder one before installing the cover.

2.Crank was left at TDC.

3. Cover fit.

4. I used the cam card specs for lash .005 in and .006 in (this is another delima, see posts from before on the cam cards. I don't want to distract from the topic at hand).

*The exhaust adjuster looks significantely better. It looks normal.

Steps 5-9: everything here checks out as in the post above. See pictures. (Pictures are in order of instructions: cam without cover, next two are cylinder 1 exhaust valve and last is cylinder 1 intake).

I haven't done the other adjusters but since all four were previously high, I think we're good.

This is the result of adjusting valves way to loose. I know some of you might want to kill me right now. My mechanical knowledge is at a strange point where I was able to do something like degree a cam in it but improperly adjust valves.

I have a paranoia of adjusting valves too tight. I had valves adjusted on my /2 and my friend checked them and said way too tight!

I think my perception of the valve lash feeler was off. Yes I know I know, light drag like pulling a piece of paper from in between two glossy magazines or just enough to not the next size up feeler. But there is a somewhat perceptive feel to the anount of drag you should feel and I haven't quite got it yet. I need someome to verify my perception is correct and gain experience that way.

Well I think I will finish off the remaining steps and since I have the modded cover on check the cam degree again. What do you think?

I am hope this is a resolved problem. Thank you guys I would be buying you all beers right now.

[jgger]

Much better.

[enwri]

It is the result of setting tappets on the overlap instead of compression. That's it, nothing else. Mentioned by several people, several times by myself alone.

You're not the first, I think the notch thing in the manual assumes some knowledge, and valve/piston clash is a real thing to watch for on modified cams.

No.6. Now you can get your dial gauge and measure actual lift. I've never bothered to degree a cam but I thought you did it from the rocker and that was why they give a lash dimension with the degrees, to determine the beginning and end of duration.

[AlekStooge]

You're not the first, I think the notch thing in the manual assumes some knowledge, and valve/piston clash is a real thing to watch for on modified cams.

No.6. Now you can get your dial gauge and measure actual lift. I've never bothered to degree a cam but I thought you did it from the rocker and that was why they give a lash dimension with the degrees, to determine the beginning and end of duration.

With the notch thing apparently it doesn't matter if it's at 3 or 9 when installing. I just copied the photo in the manual.

I did the whole lift measurement when finding cam centerlines. I am going to do it again. You put the dial on the retainer and make sure it does not touch the rocler or cover. The reason for this is because apparently the rocker or stem (don't remember) doesn't travel in a straight line.

I did forget one thing yesterday. It was to tighten the tensioner. You do that after adjusting the valves or before?

[enwri]

If you did it before already, and as long as it's tight enough for the cam not to visibly flop over-centre and the chain not slapping while turning it over the crest of a lobe, it's tight enough. Do it again after if you want.

You should the check the timing with the dial gauge, and match the numbers for opening/closing on the cam card if you have an adjustable timing sprocket and degree wheel.

you will have to remove the cover again if you do have to change it.

Measure timing with no.1 cylinder before setting all of the tappets, otherwise you'll have to go through the whole procedure of removing all the adjusters again and resetting clearances.

I probably could have mentioned that before you set them all.

[flatlander]

to measure lift, set the feeler of the dial indicator on the valve spring retainer. the feeler should be pushed in some way before you zero it, so that it can travel down with the movement of the valve without ever losing contact to the retainer. the feeler should run parallel to the valve stem, and make sure it can move freely without binding anywhere.
max valve lift is the highest amount of "drop" in mm or inches that you can measure as the retainer travels. not the amount of valve lash you have set before measuring as it will affect the reading.

as you have that "funny" ignition: did you mark TDC so that you don't need to install the degree wheel every time?

[enwri]

to measure lift, set the feeler of the dial indicator on the valve spring retainer. the feeler should be pushed in some way before you zero it, so that it can travel down with the movement of the valve without ever losing contact to the retainer. the feeler should run parallel to the valve stem, and make sure it can move freely without binding anywhere.
max valve lift is the highest amount of "drop" in mm or inches that you can measure as the retainer travels. not the amount of valve lash you have set before measuring as it will affect the reading.

as you have that "funny" ignition: did you mark TDC so that you don't need to install the degree wheel every time?

Do you know if he should check the timing with the dial as well, and how to set and read it?

It took 4 pages to get to here, let him set that stop and wheel every time as punishment as well as set all the tappets again if he has to remove the cover to change timing..

[flatlander]

i assume you mean cam timing - not ignition timing as the dial indicator won't be needed there.

this is not the first thread where we try to explain to him how to install a cam etc.
i wrote this all down before, let my try and find it again.

[flatlander]

here's the whole cam degreeing process incl. finding TDC:
http://forums.sohc4.net/index.php/topic,140833.msg1890649.html#msg1890649

[flatlander]

here's the whole cam degreeing process incl. finding TDC:
http://forums.sohc4.net/index.php/topic,140833.msg1890649.html#msg1890649

measuring max lift is not essential for degreeing, it's just additional data that in this case, if in doubt about the grind, can be checked against the cam card.

[enwri]

Yes for checking timing and duration. Must have had about an 1/8 of an inch lift like it was..

Wonder if it would have run. Probably sound a bit "tappety".

[AlekStooge]

here's the whole cam degreeing process incl. finding TDC:
http://forums.sohc4.net/index.php/topic,140833.msg1890649.html#msg1890649

Right these are instructions I have been using and believe I did correctly. Lobe centers both ended up being 105, we'll see. I did that back then. I do have an adjustable sprocket on and modded cover on, which hopefully I won't have to adjust the cam position.

I measure max lift just to check the grind of the cam. I have never checked it before as I had no doubts in the past.

Yes I should just have to take everything off just to find TDC as a reminder of my foolishness. Seriously what's the best way to mark TDC with my ignition module setup?

One more thing when tightening the cam tensioner you don't have to be at TDC; as I kick it through a few times per BryanJ's recommendation?

I am so glad I checked all this. It was a nice refresher and piece of mind. Appreciate the input.

[Tracksnblades1]

Google “Go No Go” feeler gauges… It’ll help you devise you lash technique.
The same can be done with a .004 .005 .006 gauge on you intake lash now. If the .005 will fit and you can’t  get the .006 under it your done on that intake valve. If you remove the .005 and can’t get it back under the rocker but the .004 will slip under. It’s to tight. Once you develop your technique you’ll be able to split the 1/2 thousands too.

Dial indicators should always be in the same plane, centerline, or perpendicular to what you’re measuring.
If you’re indicating for valve lift, make sure your indicator’s shaft is the same angle as the valve stem is. (In the same plane)
Preload your indicator.500 (1/2 inch) for your Cam.
Measure the retainer’s maximum downward travel…
.that’s why you preload.500 so the indicator can travel .300+ for actual valve lift traveling away from the indicator.
You can add your .005 lash to the maximum retainer travel for max lobe lift. If your rocker arm ratio is not exactly 1:1 it won’t add up perfectly to your cam card..the rocker arm ration would only be 1:1 at half valve lift anyway, depending on how well your rocker arm geometry is to begin with..

With an indicator just remember an 8 foot 2x4 is only 8 foot tall when installed plum. At an angle it’ll never be as tall as the plumb one..

Was your cam shaft out of time ?  Everyone has done it…

  A .400 lash is a lot different  than a .004 lash. Something pretty big would have had to happen to use up all the exhaust rocker arms lash adjusters travel. Subjective (how tight you lash compare to how tight I lash) lash adjusting differences are never more than a thousandth or so. Your exhaust adjuster looks like it has a  .250 difference than they did…..🤔🤔🤔

[scottly]

Seriously what's the best way to mark TDC with my ignition module setup?

There is no way to index the PowerArc/C5 ignition rotor to the crankshaft, unlike the stock advancer base which has a pin that fits into a hole in the end of the crankshaft. It was one of the design faults that required reinstalling the stock unit to set the motor to TDC, or finding TDC through the spark plug hole with an indicator and degree wheel, and since there are no timing marks, you can't verify the timing with a strobe. The main problem with them was that they didn't function as touted, and they weren't reliable, especially in high temps.   

[AlekStooge]

I did the measurement for intake lobe centerline. Start at zero on the degree wheel and preload the indicator to .500 and zero it out. Lift value is .040-.005 (following the instructions), I check the degree at .035. I get 2.5 from TDC.  I spin the crank around till the indicator starts moving back and I stop at .035 again and check the degree after BDC, 27.5. My numbers for centerline were around 102.5. My original was 105. So I'm thinking most likely valve lash difference.

However I did then realize the total travel was coming up short at .221 I reset the dial indicator and my centerline results were similar.

I need an extension for the indicator. The instructions did say to use a long spindle. I always thought this will suffice. Let me see if I could borrow one.