I finally got a copy of my old dyno run, and downloaded the Dynojet runviewer. This is from November 1996.

http://www.chrishajer.com/bike/XLF/11-1996.jpg

Here are the motor specs:

883 to 1200 Conversion
Branch #5 heads
J&E 10.2:1 pistons
SE High Performance cams (.536" lift?)
Bartel's 2 into 1 megaphone
HSR42 carb
HD SE 8000 RPM module
HD stock 6R12 plugs
Stock coil
22/47 chain drive gearing

I haven't looked through all the other runs in this forum to know if this is good or bad, but I'm throwing it out there. There are more recent runs too, all with streetable mufflers on there (the Bartel's megaphone is NOT streetable) and less horsepower. This was back in 1996 when we were racing the 883R series (hence the Bartel's pipe), before I had heard of NRHS. Things were a lot different back then...

Sorry if I posted too large a pic. I just added a thumbnail.

Also, if there are standards for CF and smoothing, let me know and I will conform.

--Chris

oh for 3 more hp , so close to the 100. I ownder if a good ingition would get you there. Nice fiqures

That is a really good run. Not many can boast those kinds of numbers.

Pretty close to the numbers I was making in 96 when I had a couple quarter miles in the 10.80s @ 120. Nice dyno run.Looks about right for that setup.
Ted

Pretty close to the numbers I was making in 96 when I had a couple quarter miles in the 10.80s @ 120. Nice dyno run.Looks about right for that setup.
Ted
That would be nice at the drag strip, if I knew what the h:censor!! I was doing there!

--Chris

oh for 3 more hp , so close to the 100. I ownder if a good ingition would get you there. Nice fiqures
I ran a Thunderheart programmable module and some other crap when it came out, special plugs, different coils, all that. Nothing made any more power. It got me to thinking about a theory I had, where whatever the restriction was maybe wouldn't let the benefits of another component show up. (this theory was hatched on one surreal evening in the dyno room, where we were using a timing light in the dark to watch the ball of fuel walk in and out of the carburetor due to reversion with varying RPMs)

Like, if your air cleaner was holding back your power potential, but you didn't know it, and you were making changes to ignition and fuel and whatever else, but nothing made any difference. Is that a valid test, because with the air cleaner being the restriction, hypothetically, even better components would not increase your HP at all?

Then I realized, the bike is tuned, it makes good power, it's a blast to ride, and I don't feel like dyno testing it any more. I have about 200 dyno runs on the bike, most of them after this one (this was #041 I think.) So, just ride it. I never was shooting for 100. Nowadays, it's just so much easier to get to 100 HP.

--Chris

(when I say 'realized' I mean 'after much money and work I wasn't able to make any more power than this setup right here.' I changed to V9 cams, several different head/piston combinations, all the ignition stuff was tried, many different pipes, different fuels, etc. This was the best combination. BTW, the exhaust changes had more effect than anything else, and I find that true to this day. A certain combination has a certain power potential, and if it's not living up to its potential, it's probably the exhaust. 95% of the time, it holds true.)

I finally got a copy of my old dyno run, and downloaded the Dynojet runviewer. This is from November 1996.

http://www.chrishajer.com/bike/XLF/11-1996.jpg

Here are the motor specs:

883 to 1200 Conversion
Branch #5 heads
J&E 10.2:1 pistons
SE High Performance cams (.536" lift?)
Bartel's 2 into 1 megaphone
HSR42 carb
HD SE 8000 RPM module
HD stock 6R12 plugs
Stock coil
22/47 chain drive gearing


--Chris

This is a great chart!!! I'm in the process of building a very similar motor right now. The main differences are that I'll be 10.5: 1, Red Shift V531 cams and a Super E. Also I'm running Hooker Step Tune 2 into 2. I'll be happy if I even crack 90 HP.

Chris, I have a question for you. What head gaskets were you using, and did you set up the squish? I'm going to use Cometic .030 head gasket and either a .020 or .010 base, whichever is the least I can get away with.

While you are answering if you set up squish please explain how it is done.

Chris did you see my question to you? I'm very interested in you answer.

This is a great chart!!! I'm in the process of building a very similar motor right now. The main differences are that I'll be 10.5: 1, Red Shift V531 cams and a Super E. Also I'm running Hooker Step Tune 2 into 2. I'll be happy if I even crack 90 HP.

Chris, I have a question for you. What head gaskets were you using, and did you set up the squish? I'm going to use Cometic .030 head gasket and either a .020 or .010 base, whichever is the least I can get away with.
I am using stock HD head gaskets. To set up the squish, I cut the base of the cylinder down on the lathe. :yikes Then I used a standard base gasket (I think it was from James.)

Then I changed pistons (more power, more power!) Now the squish was too tight, and the piston was hitting the head. There was ~.025" clearance when cold, but I tore it down to fix a leak and saw contact between the piston and the head (maybe it was carbon, maybe it was a bad measurement, not sure, but it ran a long time with whatever minor contact there was.) So, I used these really thick base gaskets, I think they were an experiment by James, sent as a sample. They are around .030" thick, I think. This was all over 10 years ago, so the details are fuzzy. Stock base gaskets are around .018".

So, I cut my cylinders shorter to tighten up the squish, then I had to use a thicker base gasket to put some clearance back in there. It's been together like this for 10 years or so.

I would not do it like this today. This was a long time ago. I would run a thin aluminum cometic base gasket and maybe a sandwiched or copper head gasket to bring the squish closer. I know NRHS likes to use Yamabond or TB1104 for a base gasket, but my 'nads are not that big. I like a gasket in there :)

I can't recall what the squish clearance is right now. I think it was probably around .035" when I assembled it. It has J&E pistons with Branch #5 heads, and they have 20 or 30 degree domed pistons. Can't recall that either, and can't find the paperwork from when I built the motor.

NRHS has a good article about squish:
http://www.nrhsperformance.com/tech_squish.shtml

--Chris

So, I cut my cylinders shorter to tighten up the squish, then I had to use a thicker base gasket to put some clearance back in there.--Chris

Thanks for the reply. Very informative to hear about your experience. Thank you for sharing. I always though this would be better than running without a base gasket. Used 883 cylinders can be bought on ebay for cheap now days.

I have Branch #5 with 15 degree pistons. I probably won't go to the trouble to cut down the cylinders, but it seems like I might be alright with .030 head and .010 base gaskets. I think my first attempt at checking the squish will be with the .020 bases. I guess I'll try not to go below .030

I guess I'll try not to go below .030
I think that's a good plan. With angle top pistons, .030" clearance seems to work pretty well.

--Chris