z1 - HP question & cam advancing question

I have a 2 part question -

1974 z1 painted 75 colors



Question #1

My set-up is below. Assuming everything is in dialed running condition, how much horsepower would you guys loosely estimate this set-up makes? It rips pretty freaking hard. It definitely wants to rip past the redline. If stock HP is 83, I was thinking this set-up would be around mid 90's right? Maybe just under 100?

- weisco 10.25 - 1015 kit
- webcam 118 grind
- new: valves / KPMI (.425” capable) valve springs / new guides
- 3 angle valve job
- no porting or polishing
- keihin cr special 29mm carbs - 122 main / 62 slow - individual uni pod filters
- kerker 4-1 with 2” comp baffle
- dyna s ignition
- lockhart oil cooler
- I run 93 octane in it

Question #2

I’ve posted on this forum before regarding this issue, but now I think I understand the issue a little bit more...

I bought this bike for $580 as a barely running jalopy. The list of stuff above is what I did a year ago to get the bike running solid.

Look at the below picture. This is 100% directly on 1/4 TDC (T mark).



With stock cam gears (which I have) and from this angle, the cams should be pointing directly at each other right? Like… 100% pointing straight at each other, centers dead on. This would be 110 lobe center, right?, which is stock? So, based on this picture, both my cams are advanced maybe 2 degrees it seems? I know we’re just eye-balling it, but what do you cam-degreeing guru’s think. How many degrees advanced does this seem to be?

With stock cam gears it’s not a possibility that the intake is advanced 3 degrees and exhaust is 1 degrees. Meaning, they would have to be advanced the exact same number of degrees. Correct?

And to back up a step on how this all came about… I think my cam chain was stretched like a mother fucker when I got the bike. I never did a new cam chain when I did all the engine stuff (insert foot in mouth) so, with a stretched cam chain, both cams were retarded almost a full tooth, so I advanced each cam 1 tooth, which is where it is now, as in pic… which seems to be way closer to spot on, but advanced a couple degrees. A couple degrees advanced is better than 1 full tooth retarded in my opinion. I know I need a new cam chain and adjustable cam gears. I just havent done it yet.

And just to throw this in the mix, my dyna s is set to fire spot on. The dyna is not advanced or retarded.

So, my question is, at 1/4 TDC, how many degrees advanced do you think my cams are. I know we're just eye-balling it... but what do you think.

That was well thought out post

Your cams look to me just about what you think they are for lobe centers.

HP wise, a stock 900 made about 72 -74 RWHP. With the carbs and cams you have it's within the realm of possibility for yours to be pushing 80 - 85. But it's not just Peak HP that you've gained. You should notice a nice increase in torque throughout.

You're at least now lift the valve to the convergence lift so it can take full advantage of the available flow of the stock port. The combo you have is a good bolt on combo. You did well in your choice of components.

Thanks! I chose my upgrades based on things I heard on this forum. This is my street / distance / trip bike so I wanted to stay conservative... but wake the motor up just a tad.

So, my next question: With stock cam gears, let's say both cams are advanced exactly 2 degrees, that means the intake cam is 108 and exhaust is 108?

The Webcam 118 degree card says lobe center should be 105... so in theory does this mean if each of my cams are advanced 5 degrees, i'm spot on to what webcam wants? Am I figuring that correctly?

Based on a chart I saw... "advancing cam timing builds more low end torque". I suppose that is good right? Should I be hurrying to put in a new cam chain and get the cams back to be spot on, not advanced?

In theory... moving the cams 1 sprocket tooth... how many cam degrees is that equal to?

And last - Is it safe to say that the "poor mans" quick way to degree stock cams or low lift cams like the 118's, is to just make sure the lobes are pointing identically at each other at 1/4 TDC and that's 110 lobe center?

I appreciate the response, thanks.