Topic: Cam chain tensioner ajustment with electronic ignition

[enwri]

Here is the notch photo.

And it is on tdc compression on no. 4

[AlekStooge]

So, does your Ignition TDC “T” advancer match your degree wheel TDC paint brush mark..?

I’ll look at all your pictures to make sure I didn’t miss anything..

Well yes I found TDC using the piston stop method and just verified it by puting the handle of a paint brush into the spark plug hold on cylinder 1.

Not to distract from the topic and don't take this the wrong way, since it's most likely me not understanding something. I know ignition is not important at this moment. The TDC mark light on my ignition turned on 1° advance. I haven't touched this nor the cam position.

When you say advancer I am automatically think of the mechanical advance, which is not on. Is it necessary for me to take off the module and put the advancer on?

Here is the notch photo.

And it is on tdc compression on no. 4

Yes it is a TDC . Hang on I have to read through the posts because I don't know which stroke this is for cylinder 4. I think this may be what I was missing. (Ignition is not on in photo)

[Tracksnblades1]

That’s what the “T” mark will tell you.

Compression stroke TDC. What everyone is encouraging you to verify…

There are “2” crankshaft TDC’s per cam shaft revolution.
You may be setting your lash during exhaust/intake TDC. Also known as overlap, opening and closing “ramps” not the base circle..

Your ignition is crank driven so it  will fire on every TDC compression or exhaust.

[bryanj]

Having seen the pic of the ignition(one i have NEVER seen before) i can understand part of your problem.
On ALL other units you can see the marks on the advancer backplate line up with static mark on crankcase

[AlekStooge]

These are the cam lobes on 1. Looks like the intake is about to open and exhaust about to close; if I were to turn the engine ccw (alternator side)

So this would tell me 4 is on compression?

Okay looks like I just need to take off the ignition and put on the advance like everyone is telling me. This is really testing my mechanical knowledge but that's good because I'm learning. Thanks for your patience.

[AlekStooge]

Cam lobes on 4. Okay Okay I'll look for that advance unit.

The module came from a C5. I'm using Dyna coils since the previous ones tested bad.

[enwri]

Lobes up = overlap.

Lobes down  = compression

You can find TDC 1 - 4 any way you want.

[AlekStooge]

Lobes up = overlap.

Lobes down  = compression

You can find TDC 1 - 4 any way you want.

As I suspected. Thank you for verifing.

[Tracksnblades1]

This little pin should bring Igntion, compression TDC, and camshaft timing into the light.
Crank turn 2 times for 1 turn of camshaft. Timing is everything…

[AlekStooge]

Ok I am following instruction of how to degree a cam.

http://forums.sohc4.net/index.php/topic,140833.1550.html

 On step 6. After verifing the above. We are at cylinder 1 compression. I adjusted the exhaust valve. Sits high.

I am going to do everything by the cam card numbers and use Mike Reick's reccomendation to use running lash opposed to 0.

Note for clarity (From my engine build some of the members here recomended I use the old cam card numbers before Megacycle revised them. My lobe centers ended up matching with the old numbers last I degree. The details fog my memory but here we are revisiting it again.)

[grcamna2]

subscribed

[Tracksnblades1]

🤔 Did you figure out why your original lash adjuster were backed all the way out to get the correct lash..? 🤔

[enwri]

If you put the cover on with the cam how it was in the picture, notch forward, and have not turned the crank, no. 4 is on compression and no. 4 has to be set. Then turn the crank 360 degrees, the cam will turn 180 degrees to do no. 1.

[AlekStooge]

🤔 Did you figure out why your original lash adjuster were backed all the way out to get the correct lash..? 🤔

I am about to. Read through that. I remember calling Megacycle to resolve this. I will update once. I found out.

I just adjusted the approriate valves on cylinder 1 compression and then cylinder 4 compression. .005 in intake and .006 in exhaust. Exhaust is screwed in about a quater turn. I am not kidding! I would start the thread about 1/2 turn then back out as I was checking with .006 in feeler. I then pulled up on the tappet just to make sure it is holding the threads. Next feeler guage up forget it.

I verified the punched stamping on the cam 126-00.

[AlekStooge]

If you put the cover on with the cam how it was in the picture, notch forward, and have not turned the crank, no. 4 is on compression and no. 4 has to be set. Then turn the crank 360 degrees, the cam will turn 180 degrees to do no. 1.

I put the cover on with bands on the rockers. At that time cylinder 4 was at compression. Cam notch facing forward. Then I kicked the engine through a couple times. I adjusted the cam chain tensioner as Bryanj recommended with pressure on the kickstarter. I got the cylinder 1 to TDC compression (both rockers were loose) adjusted the correct valves. Turned it over by hand 360 crank degrees to cyclinder 4 compression (both rockers were loose).

This is where I am at now as far as I could tell I am doing everything correct.

[bryanj]

My guess is the cam is not ground correctly

[enwri]

Just get it to TDC 1-4 again and adjust the loosest pair of either 1 or 4.

one or the other should have pressure on the valves.

The T mark will only have a 50/50 chance of cylinder 1 being on compression, and if 1 isn't 4 will be.

[AlekStooge]

Just get it to TDC 1-4 again and adjust the loosest pair of either 1 or 4

I think I am past that point. Repeating the same thing won't give me different results. All the exhaust valve tappets end up barely threaded on.

I got the dial indicator on. I don't know what the travel angle the valves travel at on the 1978 CB 550K but this look pretty lined up. I'm on cylinder 4 compression. The instructions say one compression but I don't think it makes a difference where the centerline is found.

I am afraid Bryanj may be right. I may have to post to the high performance section before I come to such conclusion. Anyway I am going to take a break and then find lobe centerline.

[AlekStooge]

Ok read this post (The first intial post) from a long while back about why I decided to use different numbers.

http://forums.sohc4.net/index.php?topic=166819.0#lastPost

Basically the 126-00 cam was remeasured digitally in 2000. The grind stayed the same but a new card was issued with different numbers. Okay following me so far?

The cam card I received has centerline numbers are 1° apart. My results of multiple cam degrees and adjustments, always ended up even at 105°. That matches the old cam cards before the remeasurement! So I was advised to follow the old cam card numbers for centerline (which I got) and use old valve lash. It was not stock but .001 in wider on both intake and exhaust. I was advised that I did this correctly and let it be.

This however does not solve the problem at hand of the exhaust tappets being back almost all the way out.

[Tracksnblades1]

Tell us about your exhaust valves……OEM..?
Are the intake adjusters backed all the way out too…?

[AlekStooge]

The intakes look normal. I belive l had all Kimblewhite components.

[Tracksnblades1]

The intakes look normal. I belive l had all Kimblewhite components.

Do you know the stem lengths of the exhaust valves.?
Installed heights…?

[AlekStooge]

No Mike Reick installed those when he did the head work.

[Tracksnblades1]

No Mike Reick installed those when he did the head work.

Can you compare the intake base circle od with the troublesome exhaust valve base circle od…?

I would have thought the cam grinder would have caught a base circle error…

I saw a dial indicator mounted, does your exhaust valve have the cam card max lift values within a few thousands..?

Did you install hard welded rockers on the exhaust..?  If so does the pad thickness look similar to the intakes.?

[AlekStooge]

My bolts for the degree wheel came loose when I tried to move the crank. I adjusted the timing plate a little and torque it back down perhaps that caused the bolt to loosen. I have to figure out how put the wheel back on. Do people normally leave the alternator rotor on when they degree?

I'm exhausted. I will find TDC tomorrow and continue the process and hopefully answer some of those questions.

Yes hardwelded rockers. As far as my eye could tell they looked the same never measured them.or payed much attention to them.