Look at picture in step 2 for the advance alignment procedure. Align the key into the 4 degree slot.. now align that with the upper mark. IOW.. the key itself MUST be installed into the 4 degree slot.. then aligned with the upper mark. The picture shows just that. If you really want to see the difference between the two slots.. straight up and 4 degrees?.. just look at the sprocket tooths relationship compared to each keyway is all. It only changes slightly but is clearly visable. On the 0 degree slot.. the top of the crank gears tooth is right above the slot. On the 4 degree advance slot.. it's bewteeen the teeths highpoint. Either way.. the cranks key is ALWAYS clocked to line up with the upper mark. If you look closely though.. in the advanced position.. the upper mark is aligned to the RIGHT EDGE of the lower keyway/key. And retarded is to the LEFT EDGE of the keyway/key. See it in the pics?
The teeth and the chain can only mesh at their matching positions, so the keyway in the crank sprocket is cut 4 degrees "off center" from the centerline of the tooth. If you align the key and the cam sprocket, the chain will "make" the crank sprocket rotate the 4 degrees in order for the teeth to mesh with the chain.
yep. I was just trying to paint pictures to better help him understand where things would end up. I tend to talk.. and type too much when doing it, is all.
Apologies for the confusion, sometimes I can be a little dense when applying what little logic skills I possess. I think I finally got it, I missed the whole offset key piece in the in the diagram. I constructed a crude diagram just so I understand it. I think I’m ready to move on. I wanted to make sure I understood the mechanics of what was happening before I took the next step. (First time I used a variable timing chain, again apologies for the confusion).
yep.. you finally got it figured out. :Handshake As Paul mentioned above.. with each selected keyways notch.. the lower gears top of tooth will be pointing straight up towards the upper gears mark to allow the chain to mesh between the two gears properly. So in essence.. the advance/retard notchs just clock the crank gear to the left or right slightly in comparison to the 0 degree setting to achieve the desired timing. Good luck with the rest of the buildup and keep us posted on the progress. PS. pretty healthy "little 200" cam you chose there. Best to have decent gears to get er' moving off the line.
After catching the second half of the Grease Monkey “Bandit Build” I suddenly came to the startling conclusion that I should spend an extra 25 bucks to replace that troublesome cam bearing....... (cheap insurance policy!) That said, I’m going to take a step back and pull the cam. I ordered the bearing on the way home tonight and should have it by Friday.
Don't feel bad. For every person who has the courage to post stuff that they are doing and ask questions about it, there are 100 other people sitting on the sidelines watching because they are in the exact same 'boat'. If everyone was afraid of making mistakes, and not asking questions or sharing stuff, this would be a pretty boring forum. This thread is a perfect example of how great this forum and all it's members are--even YOU for stepping up and sharing your experience with us. You should not feel ashamed or stupid!:Handshake Good Luck with your build!
Yep.. some mistakes are good since they tend to stick in the old memory banks and keep us out of trouble later on down the road. And the bigger the mistakes.. the more they sink in. Unfortunately for me.. the little ones don't sink in too quickly and I have to repeat them a "few more times" till they finally do. This was surely a tiny one and you caught it well ahead of time. Which is why it's best that we blueprint, test fit, and mock things up in the first place, right? And Paul is right on target as usual. Dropping the male pride and inflated ego sure can accelerate the learning curve and keep us out of trouble. Also helps to have a few friends around who actually take the time to give a crap too.
this looks like a mistake you almost made. that's why it's good to check and recheck...in my world they say I...over think...things...most of the time they're right...
Things went exceedingly well today, I feel 1000% better about the cam bearing. I popped out the trouble maker and installed another new bearing. This time, the cam slid in like buadda (butter) LOL! After looking at the bad bearing , I believe I made two mistakes. I think I got a little cockeyed on the way in which I believe led to a slight ovalling of the bearing making the rear “tight” in several spots. I also believe this was due in part to the block surface area that accepts the bearing having a few tiny high spots (tiny nibs sticking up off the surface from the original assembly). I don’t recall seeing them the first time but sure enough I could feel them as I rotated my finger across the bore. I cleaning up the block surface area and smoothed things out, inserted the new new bearing and everything went as smooth as silk. I lined up the cam and crank to “0” degrees and now ready to move on to piston assembly. As a side note, I inspected the other cam bearing and they all looked “brand new”. Figured a second look at those wouldn’t hurt either.
Glad the cam bearing got fixed. I see from the crank sprocket that you have decided not to advance your cam timing?? Looks good!
Ultimately it will be at (+) 4 degrees but at this point it needs to be set at “0”. As soon as I get further in the build I’ll be able to degree the cam. That will verify the manufacturers specifications and I won’t have to remember that I put any artificial variance in and I’ll be able to determine if they (the mfg.) did as well. Once the data comes in, I’ll know what the true numbers are and I’ll be able to set the final (+) 4 degrees. (Thank you!)
