Cam degreeing

[HWB]

Im curious to know, ive set my cams at 105°/105° the bike is very torquy, real nice but i feel its a very race oriented setup. What other setups are they? What are you guys running as for degrees. Also is going down in degree number torquier at the bottom end and vise versa or how does it go ?

Any magic number ?

[Oilyspanner]

I'm on 104 on each, this gives a very good spread of torque on my engine - have tried a couple of settings. Mine gives nice torque to 3k and very strong from 4k. Lower numbers should loose low down power, but add a bit to the top-end and vice versa. The inlet cam has a much greater effect when moved. Standard cams seem best in a small window, 103 to 105 degrees on the inlet....that's just what feels best and is very close to factory settings....they definitely knew what they were doing !

[clivegto]

Local bike tuner told me to set the Kent Street Cams I have to 110° goes well with a 1216 kit.

[Blubber]

I had the Yoshimura st2 cams on my gsx1400 EFE on 105/ 105 as per instructions. 

On my 1135 EFE i had the stock cams on 110 / 110 with rs36. 

 

I think that is a normal range.

 

[HWB]

Any same cam comparisons ? Lets say stock 1100 cams at 105 vs at 110 and so on.

What changes would happen if i go say from 105 to 107 or to 103

[Lachie04]

Interesting question been meaning to ask something similar there is info around on what it does when changing up and down but real world experience would be good 

It takes a bit of mucking round to change so any difference would probably only show up on a Dyno and that would be more painful than carb tuning lol

There's also duration and opening closing times to consider and different cams et Al 

Just for interest an engine I had built up by the only fella I would trust around these parts slotted the inlet to 104 but left the ex at 105 motor goes fine.

My current motor came out at 106.2 In and I had to slot the ex to get down to 106 and feels good and has a good spread of power on the Dyno 

As @Oilyspanner said not far off OEM settings is usually the bump stop 

I think finding the duration cams open and close and the cross over is the more critical thing and effects flow and scavenging etc more complex than I know though

Apart from slight up and down of both together finding the correct cross over duration and timing would be critical to get that 10th degree with In and Ex tuned separately, the straight combined 103 -106 change I don't think would be felt much. 

Any adults???

 

 

 

 

 

Edited January 26, 2023 by Lachie04

[Gixer1460]

As said, only real way of comparison is use an engine dyno - a chassis dyno is just too much faff, and you'd have to be prepared to write off a couple of days to get meaningful results. Personally i've always had good results with 110 / 110 so never felt the need to chase other numbers.

[HWB]

Understood. So just to be clear the lower the number the more power up top and vise versa ?

[Gixer1460]

4 hours ago, HWB said:

Understood. So just to be clear the lower the number the more power up top and vise versa ?

That seems to be true, probably less overlap helps the torque - I think shorter numbers are recommended for forced induction also for much the same reason?

[HWB]

Ok now im confused..

[Gixer1460]

Bear in mind Summit's advice is generally based on single cam engines where any + move on one lobe has a corresponding - move on its corresponding partner. Its maybe why so many cams are produced just to obtain different LCA's?