Early Sportster XLCH 900 Dyno Runs

[chevelle]

Results on my Stock 1965 XLCH, with stock bore/stroke, P cams, Fixed Magneto, SU Carb, 2" pipes & -62 mufflers w/ 3/4" hole reamed in them.

This is a VERY good running bike, so I believe this is a good example of a stock 900.

You wiil see a couple blank areas in the curves, I believe this is due to the RF issues I am having w/ the electronics and the magneto ignition.

Im sure I could get rid of the slight torque dip around 3200 w/ some tweaking.



Here is another run w/ a different exhaust.
This exhaust is a unknown brand 1.750" pipes w/ combined mufflers.
The angled baffle plate has been reamed w/ a 1" thru hole.

Notice the max TQ and HP are about the same but this exhaust has a much more noticeable dip in the 3200 range.




Here are some results of Harley PB cams in my stock 900.

First let me say these cams were nearly impossible to get tuned, and this run shown still did not have a optimal ARF curve.
I had been doing all my runs for comparison w/ the same parts.
Well the SU w/ only a main circuit and a needle was not up to the tuning challenge.
I installed the trusty CV w/ much more tuning capabilities and although I did get better results, tuning the AFR w/ these cams was still a bitch.
It is richer than necessary from 2500 until about 4000, then starts going lean up to 5500. I even had to shim .200” under a NOKH needle to get the midrange decent.

I have no idea how anyone back in the day ran these PB cams on a stock 900 w/o issue, especially w/o a AFR monitor and dyno.
Im sure they do work well if setup correctly and w/ the right combination.
If I intended on running these PB’s I would spend more time adjusting and possibly try some other pipes, I think a 2:1 would definitely help w/ these cams.
Im sure this combo could make more power if you really wanted to spend time w/ setup.
There is a gain and a loss as you will see.
I will be sticking w/ the original bolt in no fuss P cams, that give awesome results for a stock cam IMO.

Stock 1965 XLCH, with stock bore/stroke, P cams, Fixed Magneto, SU Carb, 2" pipes & -62 mufflers w/ 3/4" hole reamed in them.
The only differences in this run 407 (orange) is the PB cams and the CV carb .200" shim under NOKH needle 46 pilot / 185 main, stock spring.

[gasketscraper]

Thanks, for sharing the info. You've definetly put a lot of time and effort into dialing this engine in. I've got a 900 that I'm putting andrews Q cams in and a "baby" SU on. Its a '70 engine with a stock circuit breaker. Its a ways off though, got too many projects in front of it.

[chevelle]

Originally Posted by gasketscraper

Thanks, for sharing the info. You've definetly put a lot of time and effort into dialing this engine in. I've got a 900 that I'm putting andrews Q cams in and a "baby" SU on. Its a '70 engine with a stock circuit breaker. Its a ways off though, got too many projects in front of it.

Q cams are Harley, they were not offered in a xlch (magneto style)
Possibly you have your letters confused? Andrews Y or X ?

[FlameThrower]

Interesting as hell... thanks for sharing that information and data.

[chevelle]

Originally Posted by FlameThrower

Interesting as hell... thanks for sharing that information and data.

This thread has some runs on my stroker:
http://jockeyjournal.com/forum/showthread.php?t=91571

[Dragstews]

Very good info on what it takes for dialing in. (Peaking the motor)

I run an early HD6 1-3/4 SU...
Sure was a chore to dial in the jetting.
Picking the right needle and piston spring was a job..



Being this carb was from the era of the bike...(Came off a 59 Jag)... I wanted to keep it...Many times the thought was there to shit-can and bolt on a Harley CV or an S&S carb...
But with the HELP of JOE CURTO "The SU King"....Got it dial in...

He has in stock parts for any model SU,. He also makes alot of upgrades for them....

[chevelle]

Originally Posted by Dragstews

Very good info on what it take for dialing in. (Peaking the motor)

I run an early HD6 1-3/4 SU...
Sure was a chore to dial in the jetting.
Picking the right needle and piston spring was a job..

Being this carb was from the era of the bike...(Came off a 59 Jag)... I wanted to keep it...Many times the thought was there to shit-can and bolt on a Harley CV or an S&S carb...
But with the HELP of JOE CURTO INC. 22-09 126th ST. COLLEGE POINT,NY. 11356..(718-762-7878) The SU King....Got it dial in...

He has in stock parts for any model SU,. He also makes alot of upgrades for them....

Very cool, IMO the SU is the coolest looking vintage carb.
What needle are you running?
The BBT needle works well in my stock 900 and my stroker as long as the
"Hotrod" cam induced reversion is not hurting my afr.
Haven't had any of these tuning issues w/ stock p cams, and so far they have put out a better power curve than any other cam I have run.

[Dragstews]

I'm running a RH needle...And a .100 viton fuel jet diaphragm.
The OEM Air Filter doesn't help at all...Kinda a trade off in that area.

Joe has over 1,000 diff. needle's in stock. He is mostly into the Automotive end of these carbs. Does the Stromberg's too.



If you are in need of parts for these Carb's....This guy is the source.

[shupe]

Thanks for posting. Very interesting.
I have a 1962 Cycle World magazine test of a 62 XLCH.
It says H-D claimed 55 hp but CW thought it was about 50.
Glad to see that was about right.
CW clocked a top speed of 122mph.
I'm surprised the peak is only 5,500rpm. I would have guessed
about 6,200-6,400.

[gasketscraper]

[QUOTE=chevelle;786771]Q cams are Harley, they were not offered in a xlch (magneto style)
Possibly you have your letters confused? Andrews Y or X ?[/QUOTE

Thanks, for the clarification. Dusted the box off. They are Andrews R(5?) cams. Geared for a mag. Don't know why I was thinking Q.

[chevelle]

There is an update, I did a few changes on the 900.
Click the link for the info.

http://xlforum.net/vbportal/forums/s....php?t=1222275

[kickstarts]

That 2 into 1 looks like a solid low end winner.

[Monte03]

I want to know how the Bike runs on a Back Road Ride - Seat of the Pants with those H cams..

[chevelle]

Originally Posted by Monte03

I want to know how the Bike runs on a Back Road Ride - Seat of the Pants with those H cams..

The bike now feels more powerful than my stroker.
It is really strong after 4000, but down low is a huge improvement as well.
Very fun on twisty back roads 3000-5000.
The CV helped get the most out of the H's.

[Jtw79]

Okay so I have to ask your opinion Chevelle. I have stock CR Keith Black pistons with my own polishing job on the heads. A 2-1 exhaust of my own design, it uses SuperTrapp discs. Using a CV carb and electronic ignition. It is a '71 900. Do you think I would really benefit from those H cams? Would I make more HP? Thanks for posting your findings, I enjoy all the tech stuff.

[Monte03]

Originally Posted by Jtw79

Okay so I have to ask your opinion Chevelle. I have stock CR Keith Black pistons with my own polishing job on the heads. A 2-1 exhaust of my own design, it uses SuperTrapp discs. Using a CV carb and electronic ignition. It is a '71 900. Do you think I would really benefit from those H cams? Would I make more HP? Thanks for posting your findings, I enjoy all the tech stuff.

Not to Hi Jack but you'd have to bring Tom Sifton Back as these H Cams were late Sixties early 70's.. Bravo Chevelle to the awesome Tuning..

[Jtw79]

Monte03 I hear you, those cams will be like finding a needle in a haystack. Just thought I would toss the question out to see what the resident experts thought. Thanks!

[Monte03]

Originally Posted by Jtw79

Monte03 I hear you, those cams will be like finding a needle in a haystack. Just thought I would toss the question out to see what the resident experts thought. Thanks!

Keep your Eyes peeled on a set of HH .475 Cams, I had them in my 66CH 900 years back with R Valves, awesome Street- Occasional Drag Basting Cams, smooth at all rpm levels..

[chevelle]

New update, R5 cams:

http://xlforum.net/vbportal/forums/s...1222275&page=7

[skinthead]

I have read this thread, followed the changes on this motor over at XL, and looked through your stroker thread too. I just don't get why the stroker isn't making a goodly percentage more power than the stock motor. unless something is amiss in the compression dept I would have thought the stroker would have made at least 15% more power over the stock motor.

What am I missing here?