Slotting cam sprockets, degreeing cams, TDC time line questions

[Guest]

Hi All,

Heading out the door to work so I won't be able to respond to replies for a while but have a question. I am in the final stages of the engine rebuild I'm doing, which is the infamous 650 top end on a 550 bottom. My main question is this,

What is the exact order of finalizing setting up the cam timing? I've seen several threads on doing this but I haven't seen the exact order. I believe it's this:

1) Slot the cam sprockets. 2) reinstall the sprockets, torque down the cams and set the cams in the proper alignment for timing. By this I mean align all the arrows and count the cam chain pins 3) install the cam chain tensioner 4) find TDC 5) degree the cams and tighten down the sprockets to the correct torque 5) check the shims and replace any out of specs 6) move on to installing my Dynatek ignition and coils

Does this sound like it's the correct order of things?

Like I said, I'm off to work right now so I wont be able to reply to anyone until late this afternoon.

Thanks for the help

[storm 64]

I think you need to find Top Dead Center before installing the Camshaft. Also set your valve clearances before dialing in the cam timing...

[rapidray]

Yes, that looks to be about the correct order. Make sure after you degree the cams & have all of the sprocket bolts tight that you remove them ONE at a time, red Loctite them, re-install & torque.
Ray.

[Guest]

Ok, great. Seems as if I'm ready to move along with this then. Thanks rapidray for the help. You've provided a TON of help on this site and it's greatly appreciated. I had forgotten the "remove sprocket bolts one at a time and Loctite them before torqueing" part of it.

One more thing to clarify. Like storm 64 stated... do I need to find TDC before installing the cam shafts? And do I need to get the proper shims and set my valve clearances before dialing in the cams? I thought I read on a thread here that even if the valve clearances are good before degreeing the cams that they'll have to be checked and changed after getting them dialed in.

Any help is appreciated.

[GregT]

I'd put a degree wheel on the crank - and set TDC - before doing anything else...

Valve clearances on a bucket and shim motor won't need changing once set. Lobe centers are independent of clearances.

[rapidray]

Whet Greg just said.
Ray.

[Guest]

Ok, that's the kind of information I was looking for. Thanks again to all of you for helping.

[Guest]

One more quick question, and it may sound stupid, but: Find TDC... then put in the cams and go from there. But since there is TDC for pistons 1+4, and TDC for pistons 2+3 (?), do I find TDC for pistons 1+4 and then install the cams?

Thanks.... still wrapping my brain around this process. Feel like I'm missing something after reading so many articles on degreeing the cams. There's 2 cams and yet when I hear find TDC I get confused since it sounds as if there could be 2 TDC points.

Please forgive me my ignorance.

[hannibal]

It's TDC for 1-4.

I checked valve clearance then got caught in the rain with the valve cover off. When I came back to finish checking clearances and swapping shims, I found rust on the cams and pulled them off to clean them. When I reinstalled the cams, my clearances had change. So I don't think you can check clearances til the cams are set. Aorry if this was irrelevant but I'm not sure what you mean by dialing in cams.

[Guest]

Ok, Hannibal. Thanks.

Dialing in the cams entails slotting the cam sprockets and using a degree wheel to get everything timed up. If you do a search on the web, there's a lot of info out there.

[GregT]

It's TDC for 1-4.

I checked valve clearance then got caught in the rain with the valve cover off. When I came back to finish checking clearances and swapping shims, I found rust on the cams and pulled them off to clean them. When I reinstalled the cams, my clearances had change. So I don't think you can check clearances til the cams are set. Aorry if this was irrelevant but I'm not sure what you mean by dialing in cams.

If I'm building a motor I do the valve clearances with the head on the bench - and no camchain at all. Just set the cam you're working on so the lobe you're checking has it's pointy end away from the valve......
Once you've found TDC on 1&4 - and set the degree wheel - install the cams (with slotted sprockets) with the notches roughly level with the top face of the head. This is just your starting point prior to degreeing them to whatever timing you have decided on.

[Guest]

Thanks GregT for the help. I think I've finally figured it out.... that once you get 1+4 TDC, the cams, with the lobes being offset, will do the rest of the work as they go through the full cycle.

I think I read too many articles and started to confuse myself. But it's all making sense right now.

[60ratrod]

question, are there any advantages to degreeing a stock motor?

[GregT]

question, are there any advantages to degreeing a stock motor?

Most definitely - some motors more so than others.
The 16V 1100's have what i'd describe as odd cam timing std - presumably to help emissions. Dialling them to a more suitable timing shows big results. The 8V motors can show worthwhile differences too.
Depends on the application - and on your laws. Perfectly legal here in NZ.....