cam timing numbers

[Guest]

whats the reason why most are reccomending higher numbers on the exhaust cam 106-108 ex etc

[gearhead13]

Advancing the intake cam 2 degrees over the exhaust gives you more torque.

[4cyl h2]

Advancing the intake cam 2 degrees over the exhaust gives you more torque.

im installing some grind number 190 370 lift 242 @ .050 webs in a 10.5 -1 1325 plan on playing with it

[rapidray]

Street or drag race? For the street, 105/107. Drag race 109/111 or 110/112. Call me if you need help or questions answered.
Ray.

[blowerbike]

guides/springs/and rocker bumps ground off?

[4cyl h2]

guides/springs/and rocker bumps ground off?

its what id call a street play motor has a star racing ported stock valve 1150 head, looks real nice prob what youd call a street port fron radius valve job all the way back to ported boots CM g3 cams i started out at 110-110 now at 102.5-104 the lower i go the better i like it not as good from 9500to 11000 but like ray has mentioned a lot more fun on the street hoping the extra lift and shorter duration will make it much more agressive 38RS carbs vance and hines old style pro pipe

[4cyl h2]

short bronze guides vs1100 s 400 lift springs titanium retainers dont remember about the bumps but will if i havent

[4cyl h2]

im wondering how these 370 242 dur webs would compare in the real world to CM g21 380 lift about same duration

[4cyl h2]

ray can you tell why always a couple more degrees higher on the ex???

[trippivot]

its what id call a street play motor has a star racing ported stock valve 1150 head, looks real nice prob what youd call a street port fron radius valve job all the way back to ported boots CM g3 cams i started out at 110-110 now at 102.5-104 the lower i go the better i like it not as good from 9500to 11000 but like ray has mentioned a lot more fun on the street hoping the extra lift and shorter duration will make it much more agressive 38RS carbs vance and hines old style pro pipe

I know you are asking ray for help but it is so funny to me what you observed about your experiments with lobe centers.

I tune exactly opposite of what ray suggests, his street numbers are my track numbers and his track numbers are my street tuning.

SO just like you said , the lower numbers the more you like it? -sure the idle lopes if you try to get it under 1100 but she PULLS like a freight train without that torque dip in the middle, am I right? bell curve smooth until power shuts off. just shift before 9 or 10K and change your sprocket ratio -great for the drag strip or a power hungry hooligan wheelie addict. so the engine has more overlap - pollutes with more CO and HC's at idle uses more gas and has a unsettled steady cruise . but it is ready to whip the tach needle without fore notice.

compared to your starting point?

110/110 or 112/112 is perfect for street riding/cruising - less overlap, will pass emissions, idles super smooth -cruises at 2000 and is great up to 4700 then you DO have a distinct torque dip just above normal cruising RPM- ok wait for it and the power comes back over 6500K - To me that is great for the street because of the economy it offers from idle to 5K - who really rides like they want to go to jail all the time?

Now before I wear out my welcome and since I have everything backwards- I'd like to hear some more about the expanded lobe centers instead of equal .

[GregT]

ray can you tell why always a couple more degrees higher on the ex???

Don't know Ray's take on it, but i've always thought it was biasing the overlap period to take advantage of the negative pressure created by a good pipe and hence get better cylinder filling. Bear in mind that for decades, 2 valve singles were using inlet lobe centers from 96deg to 100 deg but the exhausts were stuck at 110 deg...But that was with megaphone exhausts and they simply had no midrange....

I looked at Trippivot's post and have to say, outside the US where we don't have to pass emissions tests, on old bikes anyway...I find that a setting which will give good response right through the range suits both track and street. By track, I'm specifically saying roadrace which of course on tight modern tracks will favour midrange anyway...

[4cyl h2]

Don't know Ray's take on it, but i've always thought it was biasing the overlap period to take advantage of the negative pressure created by a good pipe and hence get better cylinder filling. Bear in mind that for decades, 2 valve singles were using inlet lobe centers from 96deg to 100 deg but the exhausts were stuck at 110 deg...But that was with megaphone exhausts and they simply had no midrange....

I looked at Trippivot's post and have to say, outside the US where we don't have to pass emissions tests, on old bikes anyway...I find that a setting which will give good response right through the range suits both track and street. By track, I'm specifically saying roadrace which of course on tight modern tracks will favour midrange anyway...

funny thing im having- degreeing in these 370s only getting 340 ontwo different dial indicators and compression is lower than with my longer duration g3s