Stroker opinions please

[jaxdwg]

You used the words "at least 250#" when speaking of the weight difference between the two bikes. I was hoping when you said 250# it was really more like 175#. Now using the word "at least",, this is worse than I thought. If that is a true fact and not just an wild estimate, your going to need more than a little extra fuel to offset that much weight with horsepower. Your talking about 25% of the total weight. I think your going to need a bunch of HP to offset that and I just can't see you extracting that much muscle by just adding more fuel.

How does your bike inject spark advance. Would you know what the curve is. Is it triggered from a crank sensor or is it a self contained module with window trigger/reluctance etc.?

He has the ultra with everything he can get on/in it, stereo gps, backrest, a full dressed out bagger. I have the 02 wideglide with just bags and a windshield, he weighs 190 , i weigh 220. He is the one that is about 250 heavier than me. I have done nothing to the ignition system of my 02 wideglide, the crank sensor does it's thing as it has since new. I was referring to what people use as a basic setup when doing engine upgrades, you know, these piston and these cams and this jetting , for a basic setup and break-in then go get it dynoed to get it right on. If I build a 350 chevy and put in a 275 horse cam and such, I know I can take a 600cfm holley and drop it on there and get decent performance with the stock jetting that comes in the carb. I was wondering if the 195 with what i've described above is a decent ballpark figure to work with?

 

[Hoople]

Wish i could help but Carb answers I can not help with. Never owned one. Holley & Q-jet yes, but not these things.

But I am sure your answer is not far away.

 

[glider]

Jack

The 195 is a tad big, better off with a 190 but try this...

Quick and easy way of testing the main jet size.

Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.

If it surges ahead, your jetting is lean
If it stumbles and recovers , your jetting is rich
If it makes no difference, you're pretty close.


This will give you an idea of the adjustable jet needles and how to richen up the mixture.
Using the stock jet needle, you shim it up with 2 - #4 washers under the head to raise it up in the slide. The stock needle does not have the grooves for adjustment.

 

[jaxdwg]

Glider; I went for a putt yesterday, filled it up and went about 120 miles. I did play with the throttle to see how everything felt. the roll on was good and the backing off then back on a little made no difference except that the engine felt "quieter" as if it was not working at all to maintain whatever throttle position I was at. When I got back and refilled the tank it worked out to 41.6 mpg. I will say that the roll ons on a short stretch of freeway where I took it to 90 came very easily and felt as if it wanted to do it. I did have the little surge before putting in the jet. On a roll on at 30 in 2nd it would pull hard at first and then at mid to low upper rpms it would surge a little then continue to wind but at a lesser strength. now it pulls hard all the way to the limiter. I guess I'm pretty close. I'm just a bit above sea level here in Louisiana. My next test will be the run to my VA meeting wed. where I will run freeway speeds for 60+ miles, then I'll redo the fuel mileage and see how much gas it sucked up at sustained speed---80. I doubt that I'll be getting 41+mpg. Thanks to all you guys, I've tucked all the info into my head to be used as needed when trying to help someone else in the future. When I race my buddy again I'll let you guys know the results, and I'll see if I can get him to come clean on his ACTUAL build---- something still seems fishy to me about his claimed engine build---jack

 

[Breeze3at]

Just throwing this out. IMO the Keihn 40mm cv is a good carb., but it was first used on 80 inch motors. You are @95", maybe you have exceeded the flow capability of the carb. It will show good jetting characteristics, but won't allow max fuel/air that your pump could use?

 

[jaxdwg]

Just throwing this out. IMO the Keihn 40mm cv is a good carb., but it was first used on 80 inch motors. You are @95", maybe you have exceeded the flow capability of the carb. It will show good jetting characteristics, but won't allow max fuel/air that your pump could use?

You know, I thought about that but the fact that I ride way more for pleasure than just to see how hard it runs, I think I'll leave the stock cv on as it does work well. Perhaps I'll see about picking up an insurance auction bike to be my guinne pig for the future, mine is my daily rider and I want to keep it VERY depenable for the long haul. btw I hit the 100k mile mark yesterday on old Ruby, she's my baby and I'm shooting for 200k before I do a major overhaul on her.

 

[Terry Jackson]

When I race my buddy again I'll let you guys know the results, and I'll see if I can get him to come clean on his ACTUAL build---- something still seems fishy to me about his claimed engine build---jack

While I can't speak for Harley motors, I used to build Hipo and race motors myself. I knew enough little tricks that my stock rebuild would be a full second quicker in the 1/4th mile than 99% of the other stock builds. Little things add up.
Tuning is also a huge key, as is induction.
Holley makes a 750 carb. The rochester Q=jet is also 750. The stock Holley kicks the Q-jets butt. But, a Q-jet done right will run off & leave the Holley.

It's all in knowing what you are doing. If the guy still insist his is what he says it is, maybe you need his mechanic.

 

[Hoople]

So Terry, what do you think of this 250# weight difference. Would it take some H.P. to overcome that much weight when racing a "similar" bike.?

Jaxdwg, Do you think this is a legitimate test?

To gain a better understanding as to what is going on, you need to see exactly how much effect weight has on the overall performance of the bike. That is the answer you really want to know.

This is what I would do.. Have a friend time you doing a "roll on pull" in 2nd gear. Pick a stretch of road that is flat for say 1/4 mile. Point "A" will be your roll past starting point. Have a friend at the end of the 1/4 mile with a stopwatch (this will be point "B").

When you roll past point "A", blink your Hi beam. Your friend starts his watch and clicks your elapse time as you pass Point "B" where he is standing.

Now do the same test with a 250# 2up passenger. See what the difference in times are.
If you know the exact distance, time in seconds along with MPH when passing point "B" of each run, you can calculate the difference in H.P. that was required in % of total. Once you know that number you will be able to judge if just stroke would/could develop that much of an increase.

 

[Terry Jackson]

From a purely parametric point of view. stroke only would add torque but no HP. However, torque = acceleration (given the same gearing) and HP = top speed. If the % torque increase is greater than the % weight difference, it would accelerate faster.

If the initial throttle response gave him 1 mph speed gain in the 1st second or two, and everything else was the same afterward, he would still be gaining 1.5 ft/sec until the end of the run.

IF both have a limiter, and both run to the limiter, the stroke alone might do it. But I suspect the motor is either tuned much better, built better, or has some other mods/changes.

 

[Hoople]

If the % torque increase is greater than the % weight difference, it would accelerate faster.

Great point and that is what I was thinking. So based on that statement, would you agree that:

Since the faster bike weighs 25% more, he would need 25% more torque to offset the weight he is pulling. And if so, then can the extra 25% of required torque be developed purely by 7 cu/in of more stroke.?

I admit I am no engine builder nor have I ever raced another bike but that does seem like an awful lot to me. Does it to you?

Your right about a "lot of little pieces" all adding up to 1 big difference.
I have this feeling the heavier bike is hiding a Nox bottle.