| Author | Message | ||
     Lakes |
Hi all , well I have posted about this in the past. now i'm really confused! well I thought my M2 00 was stock with sportster cams, but some wise men in the Forum told me it would have the Bolt in SE cams as international M2. but I already bought bolt in SE cams. well I had my barrels decked to get the swish band clearance @ 40 though there was no way the swish band as it came stock could work as was not close. but works now. well I had the bolt in SE cams from stock as you predicted & I put SE 1.72 ratio Rockers & it had lots of mid range throttle response & lot of grunt just not as strong in top end power but fine for street. but 215 pound cranking was on high side so I wished to lower it. got SE bolt in thinking this will lower the cranking, but then we took cam cover off it had the SE bolt in cams there. so we got out the cam timing looked at the SE 556 but it would not change cranking pressure so looked @ Andrews & S & S , Andrews N6 or S&S 500 looked like what would work as 8 degree more duration than SE bolt in & intake valve closes latter & it worked with stock valve springs. phoned up & got a set next day. put them in got everything right start up ok runs fine probably even better than the SE bolt in. I forgot to mention we could not use the 1.72 ratio rockers as @ TDC not enough clearance so used stock ratio rockers. we warm motor up then do a cranking pressure check & it show's 230 pound so I can't explain this can anyone else? I road the bike it feels good and 4,000 up its a lot stronger & it has a lot more power up high to 7,000 I have a shift light & it comes on real quick, b4 took longer to rev not now. does not ping but if you are below 3,000 and put a load on it it pings. i'm going to look at changing ignition not a nose cone module but an outside module so it's away from heat but I think the Buell has too much timing @ 20 degree @ idle & 40 degree up high so i'll be retarding that as I never run HD's with that much advance & I've seen HP gain retarding b4. but this still does not explane how the N6 cams get 230 pound cranking & the SE bolt in get 215 pound? | ||
| Pash |
And... breathe... | ||
| Harleyelf |
Because there is a different amount of total gases in the combustion chamber when the intake valve closes on each set of cams. This volume of fluid is compressed as the piston moves up. N6 must close the intake valve a few milliseconds before the SE does. More gas to compress, more PSI on the gauge. | ||
| Lakes |
Harleyelf that's why i'm puzzled as the SE bolt in & Andrews N4 the intake valve opens @ 30 degree & closes @ 46 this is the cam that I was getting a cranking pressure reading of 215 pound with so took out put the Andrews N6 in it's intake valve opens @ 34 degree & closes @ 50 degree and i'm getting 230 pound cranking pressure so how do you explain that? the N4 has an intake dration of 256 & the N6 has a duration of 264 so 8 degree longer duration & intake valve closes 4 degree latter with the N6 the bike really wants to rev & is a lot stronger at higher rev I like it but the cranking pressure too high i'll change ignition as it has the Buell lightning module too much advance | ||
| Harleyelf |
Why do you say it is too high? Does the starter have trouble turning over? More duration, later closing... sounds like it's taking a bigger breath to me; that means bigger compression reading with the same amount of swept area. What's to explain? More stuff in the same area means higher readings. If starting is the only thing you don't like, consider adding compression release buttons to the heads. They let the motor turn over once without compression so it can get a running start at turning over with compression. All big-twin shops can do them. It's like drilling & tapping for a second plug, but instead of a plug they install a push-button device that relieves compression once and then seals. | ||
| Lakes |
No it's only a little 74cid starts easy I have a twin cam 95cid with 230 plunk cranking too that needs decomp valves have them in but could get 98 octane easy,but now moving & will only get 95 octane & I'm deaf worried about the bottom end Roller bearings | ||
| Lakes |
Thanks Harleyelf, I think you are right about improved cylinder fill, I've ordered a dyna 2000 p ignition module mounts same as stock but adjustable | ||
| Harleyelf |
95 octane should be plenty to avoid damaging the motor's bottom end. Set your timing correctly and you will have no detonation. | ||
| Lakes |
thanks harleyelf will do that and get my friend who is a lot heavier than me to test ride to listen see if it pings | ||
| Lakes |
Well got the Dyna 2000p ignition module & fitted it yesterday it has different pre programed advance curves you can select & it fits same as stock module, the motor realy goes hard now love it. might put on dyno again & if I get time go to track, but right now i'm busy moving to new house | ||
| Lakes |
now i've got to ride it a lot more. i'm loving the n6 cams & got some VP fuel that is good for 17:1 comp i just add a small amount to the 98 pump gas & motor runs sweet these n6 have more go @ the rev i normally ride at & smooth motor out over 4k. have not been to the track yet or had on dyno but its got more i can feel it. | ||
| Stev0 |
Interesting with the N6's. Lakes. Never been a big fan of them myself, the numbers were a bit different to how I like to build. I can't recall exactly why now but if I looked at the numbers closely I'd probably remember why.. it may be the cylinder pressure numbers you're getting.. I had good success with the N4's and SE 0.536's and even N2's in the right application... I have some Red Shift 585's and N9's in the box to feed the 88" when I build it. | ||
| Lakes |
Stevo, i like the N6 but only put them in as longest duration i could find that was bolt in. but has a lot more go mid range & top end than the n4 but i have 2" collector. | ||
| Lakes |
Well few month's on, & loving the N6 cams & the dyna ignition, & the VP C16 gas i put a quart of that too a tank. i went for a good ride with a friend that has a 09 Ulyses XB , up high i had more speed & excelleration love it also been doing a lot of miles on it but not one issue with the bike, it's sweet, spring is here too | ||
| Lakes |
Done 15,000k with the N6 cam's now & love the way it performs, were i live now its open back twisty mountain roads no traffic. love it. also the M2L new shock i put on about 4 or 5 months back? works great no problem yet. |
