cams SE 255 Vs S&S 551 Easy start
#1
02-18-2011, 12:44 PM
cams SE 255 Vs S&S 551 Easy start
these are the specs:
SE-255:
Lift @ Valve Intake/Exhaust.556"/.556"
Duration @ .053 Intake/Exhaust 211˚/235˚
Timing @0.53 lift open/close:
intake : 6˚ BTDC/25˚ ABDC exhaust: 48˚ BBDC/7˚ ATDC
TDC lift @ value intake/exhaust 0.130"/.116"
S&S 251:
Valve Timing Open/Close Intake17º/19º exhaust 41º/17º
Duration intake/exhaust 216º / 238º
Valve Lift .550”
Centerline Intake/exhaust 91º 102º
TDC lift @ value intake/exhaust.178”/.170”
ok , I have no idea of what does all of this mean LOL numbers look very similar IMO but S&S has this chart on their website:
http://www.sscycle.com/userfiles/Dyn...mvsS4B3971.jpg
83.7hp @5500 rpm
100 ft/lbs torque at 3100 rpm and torque keeps over 90 until 4500rpm...
not bad for a stock 96 stage 1
my question is, I dont want a drag racer, just want the torque at low and med rpm lost with duals to come back. I would also like to have a nice iddle sound with some lope. I usually drive between 2500 and 4500 rpm and most of the time I ride alone so... cams gurus... wich one do you think will work better for me?
SE-255:
Lift @ Valve Intake/Exhaust.556"/.556"
Duration @ .053 Intake/Exhaust 211˚/235˚
Timing @0.53 lift open/close:
intake : 6˚ BTDC/25˚ ABDC exhaust: 48˚ BBDC/7˚ ATDC
TDC lift @ value intake/exhaust 0.130"/.116"
S&S 251:
Valve Timing Open/Close Intake17º/19º exhaust 41º/17º
Duration intake/exhaust 216º / 238º
Valve Lift .550”
Centerline Intake/exhaust 91º 102º
TDC lift @ value intake/exhaust.178”/.170”
ok , I have no idea of what does all of this mean LOL numbers look very similar IMO but S&S has this chart on their website:
http://www.sscycle.com/userfiles/Dyn...mvsS4B3971.jpg
83.7hp @5500 rpm
100 ft/lbs torque at 3100 rpm and torque keeps over 90 until 4500rpm...
not bad for a stock 96 stage 1
my question is, I dont want a drag racer, just want the torque at low and med rpm lost with duals to come back. I would also like to have a nice iddle sound with some lope. I usually drive between 2500 and 4500 rpm and most of the time I ride alone so... cams gurus... wich one do you think will work better for me?
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LMCI-Enforcer (12-07-2018)
#3
02-19-2011, 07:35 AM
#4
02-19-2011, 10:00 AM
SE 255's VS S&S 551's
Both cams will do the trick. I have a 2011 Road King Classic. It now has 1800 miles on it. I'll try to save you a lot of trouble and a big headach. You ask 3 guys about cams...and you will get 3 different answers. It's l like beer. Which one is the best.
I HEAVILY researched cams for my bike. It has a Big Sucker and Reinhart True Duals. I ride two up 98% of the time. I looked at Andrews 48H's, Andrews 26's, S&S 551's, Wood TW 555's (the triple nickel) and finally SE 255's and SE 204's.
I wanted to keep the bike in warranty. I was going to go with the SE255's and decided to go with the SE 204's. The SE 255's were just too mild for me.
I can't convey to you how much better the performance is. It's like a different motorcycle. The key here, is in a good tune/dyno. I bought a EFI Super Tuner, S.E. Pro #32109-08B. Expensive...yes at $459.95. But my friend. you will know where that extra money went when you stand on that sucker. Make room for a BIG SMILE on your face.
My final dyno numbers are:
Max Power = 91.98
Max Torque = 106.46
If you don't care about warranty issues, I would go with the Wood TW 555's or the S&S 551's.
However, for a Stage II bolt on cam.....those numbers ain't BAD. The motorscycle rips. This is solid advise from an avid Harley rider that just went through the entire cam deal. Do it!!!.....GOOD LUCK
I HEAVILY researched cams for my bike. It has a Big Sucker and Reinhart True Duals. I ride two up 98% of the time. I looked at Andrews 48H's, Andrews 26's, S&S 551's, Wood TW 555's (the triple nickel) and finally SE 255's and SE 204's.
I wanted to keep the bike in warranty. I was going to go with the SE255's and decided to go with the SE 204's. The SE 255's were just too mild for me.
I can't convey to you how much better the performance is. It's like a different motorcycle. The key here, is in a good tune/dyno. I bought a EFI Super Tuner, S.E. Pro #32109-08B. Expensive...yes at $459.95. But my friend. you will know where that extra money went when you stand on that sucker. Make room for a BIG SMILE on your face.
My final dyno numbers are:
Max Power = 91.98
Max Torque = 106.46
If you don't care about warranty issues, I would go with the Wood TW 555's or the S&S 551's.
However, for a Stage II bolt on cam.....those numbers ain't BAD. The motorscycle rips. This is solid advise from an avid Harley rider that just went through the entire cam deal. Do it!!!.....GOOD LUCK
Last edited by R 103; 02-19-2011 at 10:11 AM.
#5
02-20-2011, 11:16 AM
One big virtue of the 255's is that you can find low-mileage CVO pulls on Ebay for about $150, while the S&S cams will cost considerably more. The TQ curve you provide looks very good, with with a very smooth shape and low-end TQ holding well. I'm leary of the mechanical complexity of the S&S "Easy Start" series, perhaps without good reason, but I can't argue about the engineering result of that design. Some small utiliity engines (e.g., mowers) come with this type of cam that eases starting, so I doubt if there are reliability issues with them. OTOH the 255's are conventional in design and there should be no starting issues with stock compression (9.2-9.6).
If low-end TQ is a priority I would consider these two as well as the Andrews 48H. Anything else with 9.2 compression will likely manifest a loss in the low-end, but for those with factory 103's with 9.6:1 compression the field opens a bit more. The SE204, Wood 555, and several others would be good in those bikes, I believe.
If low-end TQ is a priority I would consider these two as well as the Andrews 48H. Anything else with 9.2 compression will likely manifest a loss in the low-end, but for those with factory 103's with 9.6:1 compression the field opens a bit more. The SE204, Wood 555, and several others would be good in those bikes, I believe.
#6
02-20-2011, 12:34 PM
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(my question is, I dont want a drag racer, just want the torque at low and med rpm lost with duals to come back. I would also like to have a nice iddle sound with some lope. I usually drive between 2500 and 4500 rpm and most of the time I ride alone so... cams gurus... wich one do you think will work better for me?)
Before you make that big decision, do yourself a favour and take a good look at cycle-ramas 575 cams. I just installed them this week in my softail, had it out for a good run yesterday and am very happy with their performance. great low down torque and power all the way through. just another option but a good one.
Before you make that big decision, do yourself a favour and take a good look at cycle-ramas 575 cams. I just installed them this week in my softail, had it out for a good run yesterday and am very happy with their performance. great low down torque and power all the way through. just another option but a good one.
#7
02-20-2011, 12:46 PM
The majority of virtually any Harley motor's life is spent in the mid-portion of its rpm limits, between 2000 and 4000 rpm. At open-road cruising speeds, that range is more like 2500 to 3500 rpm. With current Big Twin gearing, top gear at 2500 rpm returns a road speed of 55 mph and 3500 delivers 84 mph. Riders sometimes "putt" around at 2000 or less. Even when accelerating to cruising speed, few of us use more than 4000 - 4500 rpm as a shift point. Very seldom, in day-to-day use, do our engines get near 5000 rpm, let alone 6000.
Even the mildest of Harley-Davidson's aftermarket cams (Evo or Twin Cam) do their best work above 3000 rpm. At 2000, the majority of these cams seldom perform significantly better than stock cam(s).
The rpm at which a Big Twin gets "happy" can be predicted by the closing point (angle) of the intake valves. The angle is expressed as the number of degrees After Bottom Dead Center (ABDC) that the valves reach .053" from being fully seated.
The following list predicts the rpm at which the engine gets "on the cam" based on the closing angle of the intake valves. These relationships are approximate but should hold true to within 200 rpm or so. They also assume that all other tuning factors, exhaust, ignition, etc., are operating correctly.
30 degrees = 2400 rpm
35 degrees = 3000 rpm
40 degrees = 3600 rpm
45 degrees = 4000 rpm
50+ degrees = 4500 rpm
Even the mildest of Harley-Davidson's aftermarket cams (Evo or Twin Cam) do their best work above 3000 rpm. At 2000, the majority of these cams seldom perform significantly better than stock cam(s).
The rpm at which a Big Twin gets "happy" can be predicted by the closing point (angle) of the intake valves. The angle is expressed as the number of degrees After Bottom Dead Center (ABDC) that the valves reach .053" from being fully seated.
The following list predicts the rpm at which the engine gets "on the cam" based on the closing angle of the intake valves. These relationships are approximate but should hold true to within 200 rpm or so. They also assume that all other tuning factors, exhaust, ignition, etc., are operating correctly.
30 degrees = 2400 rpm
35 degrees = 3000 rpm
40 degrees = 3600 rpm
45 degrees = 4000 rpm
50+ degrees = 4500 rpm
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#8
02-21-2011, 11:22 AM
Road Warrior
The majority of virtually any Harley motor's life is spent in the mid-portion of its rpm limits, between 2000 and 4000 rpm. At open-road cruising speeds, that range is more like 2500 to 3500 rpm. With current Big Twin gearing, top gear at 2500 rpm returns a road speed of 55 mph and 3500 delivers 84 mph. Riders sometimes "putt" around at 2000 or less. Even when accelerating to cruising speed, few of us use more than 4000 - 4500 rpm as a shift point. Very seldom, in day-to-day use, do our engines get near 5000 rpm, let alone 6000.
Even the mildest of Harley-Davidson's aftermarket cams (Evo or Twin Cam) do their best work above 3000 rpm. At 2000, the majority of these cams seldom perform significantly better than stock cam(s).
The rpm at which a Big Twin gets "happy" can be predicted by the closing point (angle) of the intake valves. The angle is expressed as the number of degrees After Bottom Dead Center (ABDC) that the valves reach .053" from being fully seated.
The following list predicts the rpm at which the engine gets "on the cam" based on the closing angle of the intake valves. These relationships are approximate but should hold true to within 200 rpm or so. They also assume that all other tuning factors, exhaust, ignition, etc., are operating correctly.
30 degrees = 2400 rpm
35 degrees = 3000 rpm
40 degrees = 3600 rpm
45 degrees = 4000 rpm
50+ degrees = 4500 rpm
Even the mildest of Harley-Davidson's aftermarket cams (Evo or Twin Cam) do their best work above 3000 rpm. At 2000, the majority of these cams seldom perform significantly better than stock cam(s).
The rpm at which a Big Twin gets "happy" can be predicted by the closing point (angle) of the intake valves. The angle is expressed as the number of degrees After Bottom Dead Center (ABDC) that the valves reach .053" from being fully seated.
The following list predicts the rpm at which the engine gets "on the cam" based on the closing angle of the intake valves. These relationships are approximate but should hold true to within 200 rpm or so. They also assume that all other tuning factors, exhaust, ignition, etc., are operating correctly.
30 degrees = 2400 rpm
35 degrees = 3000 rpm
40 degrees = 3600 rpm
45 degrees = 4000 rpm
50+ degrees = 4500 rpm
Thanks for the enlightenment in laymens terms
paul
#9
02-25-2011, 12:11 AM
One big virtue of the 255's is that you can find low-mileage CVO pulls on Ebay for about $150, while the S&S cams will cost considerably more. The TQ curve you provide looks very good, with with a very smooth shape and low-end TQ holding well. I'm leary of the mechanical complexity of the S&S "Easy Start" series, perhaps without good reason, but I can't argue about the engineering result of that design. Some small utiliity engines (e.g., mowers) come with this type of cam that eases starting, so I doubt if there are reliability issues with them. OTOH the 255's are conventional in design and there should be no starting issues with stock compression (9.2-9.6).
If low-end TQ is a priority I would consider these two as well as the Andrews 48H. Anything else with 9.2 compression will likely manifest a loss in the low-end, but for those with factory 103's with 9.6:1 compression the field opens a bit more. The SE204, Wood 555, and several others would be good in those bikes, I believe.
If low-end TQ is a priority I would consider these two as well as the Andrews 48H. Anything else with 9.2 compression will likely manifest a loss in the low-end, but for those with factory 103's with 9.6:1 compression the field opens a bit more. The SE204, Wood 555, and several others would be good in those bikes, I believe.
