Hey guys. Sorry I've been a bit slack lately. I haven't updated for a while and a fair bit has happened.
Here she is in her current "iteration"
So my quest for my desired power delivery with cams didn't stop there.
I was never happy with the noise that the Price "R" cams created. I found that something is going on with the bushes. They are made from the Electra X cams reground with steel bushes. When the lash is adjusted and tappets set one of cams tightens up on the base circle and then go slack again. Which tells me one of the cam wheels has a bit of run out. It creates a fair bit of racket when the engine is running clacking away. Louder than usual. Later down the track I'll replace the bushes with phosphor bronze jobs.
The Price "R" cams are very good in power delivery. But were still tapering off by 3500rpm. In my engine configuration they are similar to stock Iron Barrel cams, just they pull further through the midrange and gentle taper off after 3500rpm. Which was close, but not quite what I wanted. Along with the noise they created did concern me.
So my last stab was the Hitchcocks 200180 Performance cams.
Finally! These were it!
They have the same lift to the Price "R" cams, just a little more duration and later inlet valve closing event.
Their characteristics would describe similar to the old Redditch Bullet power delivery.
It lost its off idle thumping bottom end but these cams come on around 2000rpm and don't quit pulling till 4500-5000rpm. It allowed the engine to rev easier and once you get going from a stand still. You don't notice the bottom end loss.
Only its noticeable from a dead standstill.
The HMC 200180 Cams are the 2nd row from the bottom.
Working from the top down.
Standard Indian Cams.
Price "R" Cams.
HMC 200180 Performance Cams.
HMC 90023 Race Cams.
For jetting, I turned it up a notch.
This time around I used the heated 02 sensor my GT535, wired up a simple circuit to turn the heater on and off. I found that with the heater on compared to the un-heated 02 supplied with the AFR kit I'd get better consistent readings at idle and lower throttle openings.
Packed a bag and headed out to my favorite stretch of road. Ironically in front of my old Motocross track I used to race at and ride religiously 20 years ago!
I resorted to a older method I would use tuning main jets on my race bikes. It's more of a "seat of pants" method but with some recorded metrics.
1. Set a point A and Point B (start and finish line)
2. Stop watch in my left hand, in 3rd gear, rolling along at 55km/h which was the speed/rpm the motor would accelerate away from when the throttle is cracked wide open.
3. Hit the timer as I went over Point A, simultaneously pinning the throttle wide open.
4. Finishing at point B, stop the timer and shut the throttle.
I tested each main jet with 3 runs and recorded the average.
With the new Digital Daytona Speedo. It's go some handy features. Such as maximum speed and maximum rpm reached.
So that was 3 metrics I could record.
Elapsed time with the handheld sports stopwatch. Max Speed (Km/h), Max Rpm.
With also the AFR gauge showing me what was going on per main jet change.
All this can be done, just via stopwatch. Or even using a mobile phone app with a GPS signal speedometer. But depending where you are in the world. Aren't entirely accurate.
20 years ago, all I used was a stopwatch and plug chops.
As my friend the Mikuni guru would say. There's only one right main jet. The rest are wrong.
Here's the results as follows. The table implies the above statement.
AFR readings were 12.5 in the higher RPM/Road speeds. Richer 12.3-12.4 lower rpm speeds. Which is good thing at lower travel speeds to keep the air cooled engine cooler.
My experience is with Mikuni and Keihin Carburetors.
Keihin were more "set and forget" where as Mikuni were a little more sensitive but performed that little bit better. My Aussie mates who raced these things tell me the poor old Amal was the first thing to be thrown in the bin when it came to performance. On went the Mikuni round slide. Sorry to say to my English friends!
On my bench is a 20 tooth front drive sprocket and a new 38 tooth drum sprocket. just waiting on the X-Ring chain to arrive. Then all that will go on.
The bike will easily pull the 20 tooth, it happily revs to 6000rpm with the 19 tooth in top gear if you let it/punish it.
Next tangent is I have a Pre 55 Redditch frame sitting there waiting for me. Build a new set of wheels with stainless rims. Get all this running gear into the Redditch frame with a complete re-spray.
Cheers!
Ben
Topic: "Rocker" Bullet 535 (Read 14051 times)