@Rains2much

Yeah, The formulas are straight out of Denish's tuning handbook. So did you see much difference going from a 4 5/8 to 5 5/8 increase in length... I do think that the stock intake tract one HDs is way too short. You typically see more power with the forward facing air cleaners that extend the intake tract. I've seen it..

The exhaust tuning is pretty standard for racing.. Years ago the service manager managed to get the same HP as a stock CB750K1 with a XL250.. Last 20% was done in the pipe. Heck I got a 10hp increase by a simple baffle change on this 113.


I'll admit that I've never been in the need for a couple hp.. It was always much more.. Now I happy with 100 even tho I've got bikes with a bunch over that.

 

A little tough to answer it that way. If you hit the pulse.. your on and you can feel it all the way around the rpm band you aimed for. The earlier pulses are defiantly stronger but not many want a 16-18 inch long intake. I never messed with one that bent upward, only the 45 and just kept adding 1 and .5 inch spaces. Once I was at the 5th pulse it was pretty impractical to get to the 4th with a street bike. I made a bracket outta 1/4 inch steel that went from my engine case to the bottom of the carb. Once your too far out there the vibrations and simple leverage of weight start causing leaks too.

There is this voodoo sorcery spot where things just work.. magic synergy of parts. The bike just flat feels better. Your confidence and belief in it.. trust in it holding together you start to understand. Somebody smarter will come along with formulas and math to explain it.. but man it’s no joke when its on and you know it. Tuning the little things by them selves maybe don’t show much.. but when you do everything you can with every thing in the chain sometimes it just comes alive. I never had money or anyone to ask to go get flashy made parts. I raced with stock parts and what aftermarket I could afford and things like pipe tuning and intake.. heck indexing plugs were the only advantages I could buy, build message and believe in. Hot street started to suck because guys with multiple bikes and crews started bring toys to run in that class too. You’d be there with your hand built harbor freight tooled $2500 motor built from stock pieces and swap meets and they show up with 10k billit motors with a team behind them. It wasn’t worth their time to make 25 passes to figure out their intake track length lol. Those hard way methods were for us poor guys.

Gotta remember this was my “only” bike. I really did ride it a lot. 20k a years was not uncommon miles. Heck every winter I’d tare down. Sometimes, hone, oversize rings.. call it good. You’d bore the next winter with new pistons.. followed by re hone over size rings.. then new jugs. I actually have ran 13:1 mechanical compression with $100 3 5/8 Dixie Jugs lol. Just don’t shave the base.. only the top or you could break the flange.

 

Here is my attempts at messing with manifold length.. As far as I could tell it did make a slight difference.

The runs on 4/12 were with the G manifold and one inch carb spacer. Runs on 8/31 were with the G manifold and 2 1 inch spacers.. The intake length with one spacer and stock ac backing plate was 12 inches even.. If using 4th the effect will be 5692 for 13 inches and 6167 for 12. I don't have a time slipp for afterwards. Carlsbad closed down before I could get back out.. My bike on the left..

 

Been a little delay.. Some of it with carb parts and getting the cases and crank back.

I'm going to modify the throttle blade so it won't crack.

 

The timken outer races were slipping a little. It may have been once when the motor got real hot or it may have simply been under hard use.. The fit is typically 0.002 for case in and like 3-4 in aluminum. They measure about 0.001 with a about a 0.0003 out of round. Will be using Loctite 620 to help secure.. The outer timken bearing spacer walked a little. My install an new one or simply move the spacer back and add a little Loctite.

 

For me the SnS breather setup sucked.
You had to get everthing sealled right or it leaked. SnS banjos suck.

The top 2 rows show the my gen1 with new bajos.

Next to use the newer SnS breather bolts and better O ringed banjos.




The bike uses this breather system. Motor was a bleeder partly because of the rocker cover breathers suck and probably also due to the worn cylinders.

 

I have found that the top breathers really don't work that well with the bigger inch motors.. I use the S&S banjo bolt kit without issue but also use the bottom breather.. here's the spacers I had made..


,

 

I forgot to mention that I took a file to both sides of the breather tube mounts.. They were cheaply made and the mating surfaces sucked so I had to true them up but thought the Banjo bolt itself was good quality..

 

Have had no problems out of top breathers, believe I got a good bore job on the big cube, a local old dude had a shop only bored cylinders for a living, was into old British stuff, Nikasil dirt bikes for bigger bores. Have cheap banjo fittings, pulled the hoses off 8 years ago due to 1 started to melt and never put them back on, past summer just seen a slight bit of oil misting on the cam chest area. Will bend up some fancy stainless tubes being smaller to run by the exhaust, since not having to work on it, forgetting about the detail of building a big engine in this thread.

 

Sachs opened up my R1(G clone) throat getting small engine street manors out of a big cube, you know what your doing but thought I would mention it.. Actually street paraded this engine in a tribute for a local Vietnam Veteran with little time left, ride with Shovel guys who are all Vietnam Vets and it's what they do.