[aaron]

Don't loose too much weight. Jeremy did and we had to support his head with popsicle sticks.

I did not find any play in my bearings. I found a lot of dirty oil and had a bitch of a time getting 39 inchs of exhaust in before the end of the bike. I had a couple of pattern options but went with the Superman S for final product, but no bearing play.

Yah, thats they way I would like the meg, but only you don't see any major threats. I believe Petes 350 has his mounted like that and I couldn't imagine my 175 putting out more pounding exhaust gas pulses then his Ducati. I do indeed like the fact that I used pounding, gas, and pulses in a sentence that wasn't supposed to be funny.

Aaron

 

[jbranson]

Hmmmm... both my engines have developed axial play in the crankshaft due to the bearing shell on the output end of the crankshaft loosening up in the crankcases. Not sure what's causing this yet. Could be the hylomar I used to seal the crankcase halves.

Probably about 10-15 thou. play in and out of the crankcases. I'm going to check the grade of the OEM bolts and see if I can go up a grade and torque them down a bit more.


Aaron, don't sweat it if you have to go a couple inches shorter on the mid pipe...probably better that than doing a fancy S curve. Course you've probably already made the thing. Mine definately ends right at the back of the rear wheel with no room to spare, and the mid pipe ends just under the foot peg.
JohnnyB

 

[aaron]

Ummm... yeah i already made it. I'm real anxious to see the differemce in my hp curve. Its drastically different then what I had. I still need to obviuosly put the meg on, but I think I will dyno it before making changes to the ignition or to the valves.

Aaron

 

[UngaWunga]

quote:
Ummm... yeah i already made it. I'm real anxious to see the differemce in my hp curve. Its drastically different then what I had. I still need to obviuosly put the meg on, but I think I will dyno it before making changes to the ignition or to the valves.

I must admit that it's pretty impressive what y'all are doing to these 175s.

How are you building the header pipes? Do you buy curved sections of the correct diameter pipes and cut/weld to get them to fit? What are you using to weld them (MIG/TIG/Gas)?

 

[jbranson]

I bend the primaries on a hossfeld bender...one piece if possible. Sometimes have to cut and rotate the sections. I TIG weld with silicon bronze rod.

They start out looking kind of like this:

Aaron, remember to keep the ID of the mid pipe as smooth as you can, quite a bit of flow through there. Get inside with a grinder and take off any big buggers. Email me a pic of the pipe if you can.
JohnnyB



Edited by - jbranson on Nov 29 2004 7:00:02 PM

 

[aaron]

Your picture didn't show.

I tried to clean up what I could but based on the Superman patern I was not able to get in too far. One nice thing is when I switch heads I will need to have a professional make me the exhaust minus the meg. Do you know anybody? I will try to get a pic. It might be faster if I draw picture though.

Aaron

 

[jbranson]

I don't know anyone like that.... I can't be a professional because I know they make a lot of money...and I don't make shit.

I tell you what... perhaps we can work something out if you pay for the 1.125" tube die I need to do the head pipes properly... about $200. Seriously...let me know when you want to use the new head and will come up with something. I could certainly bend you up a couple of sections that you can then cut and rotate to make head pipes. In the picture above the left pipe is one piece down to the collector, the right pipe has one "cut and rotate" in about the middle.

On another subject. I did some checking on the crankshaft today. Retorqing the bottom center crankcase bolts snugged up the crankshaft and got rid of the endplay. I'll have to agree with Pete T. it appears I'm stretching the bolts. I'm going to order some new grade 8.8 bolts to replace the stock bolts, then find out just how deep a hole I have to work with, I'll cut the new bolts so they engage as much thread as possible and then go with a few extra pounds of torque on assembly.
Did you use an torque wrench during assembly? I wondering why you haven't encountered a similar issue when I have on both our engines this year. Are you riding like a pussy? Actually I think it could have been the perpetually liquid Hylomar working it's way out of the cases with time.
JohnnyB

 

[aaron]

I wont have a new head for a while yet. I haven't even sent one out. I was just being a wise guy. Your exhaust length before the meg looks like around 35-36 inches. What's up with that?

Is the cases loosening from riding or from stress caused by power? My bike obviously doesn't have the power but I did put it through its tolls this summer. I did torque them but after run in, I just snug things as I see fit meaning I probably didn't do much to them.

Aaron

 

[joe c]

crazy hoyt claimed that by going up 1 size in case bolts, it would stiffen everything. i dont know about that though. aaron, youve been riding a honda too long now. (or hanging out with the likes of me and jeremy too much). id like to see a pic of your bike when you get the pipe on it.

jc

 

[jbranson]

Aaron,
Yeah they probably are a little short. 24-25" head pipes and probably 12-13" mid pipe (from start of collector)...so 37-38".

You've probably already gone bezerk trying to make 15" mid pipe fit huh.

Here's something to cheer you up.

Go Here:
http://www.jrbranson.com/176-Loudon-2004-1.jpg

I was getting lots of requests for poster size images of me....

JohnnyB

 

[aaron]

Just from eyeing it, unless that bend sticks further forward that I can see, theres no way its more then 37. Will measure it just to appease me (Don't know spelling)? Cause when you see mine your going to laugh, and when you see pipe too. Well I followed my specific directions and now I have a weirdo pipe. I actually like it and think that it looks strangley very cool.

Aaron

 

[jbranson]

Here's another view.

JB


Just measured this system (Mary's bike) 24-25" head pipes (measured along the outside of the bend). Mid pipe is about 12 inches. The system on my bike uses the same head pipes, mid pipe about 14 inches.

+/- 2" on head pipes and mid pipe shouldn't make a huge difference either way as far as power. Same with megaphone 22-24" is not going to make or break the power. I'd say you could have a head/mid pipe system as short as 35" or as long as 39" with no appreciable difference in power ( at our state of tune). A megaphone from 21-24" would be fine... the longer being better.


Edited by - jbranson on Nov 29 2004 11:04:02 PM

 

[jbranson]

Does yours look something like this?

This what I had to do to get the length I wanted on when I used pre bent tube. This system worked ok. Bend was very rough though, made before I had my bending dies.

JohnnyB

 

[aaron]

Its supermans brother. Yes Mine looks like that minus the kinked, squarish looking down tubes. If longer is better than I'm all set, the only thing I don't have is a wing on the back. I have to shoot my exhaust upward. I think I'm going to need to get a one of caps that Mac trucks use to keep rain out of there exhaust.

I have questions on exhaust stuff.If I run 39 inches of 1.25 tubing or 24 inch length meg with a 3 od. Why I can't I run something like 30 inches of 1 inch tubing and a 20 inch meg with a 2.5 inch od? If I can adjust power with the a trapp then why can't I shorten the meg making a smaller od but add more disks?

Aaron

 

[jbranson]

I won't pretend to know how to adjust the exact numbers but exhaust is a bit different than intake. It's all about pulse timing and gas velocity in a pressurized system whereas the intake is a negative pressure system.

I think you could adjust things the way you suggest but not to the extent you suggest. The disks adjust back pressure only. The pipe length is tuned to function properly at certain rpm ranges and frequency of exhaust pulses.

In general I think the smaller OD you use, the shorter pipe you can use but I'm sure there are limits to this. The sizes I shoot for 24-25" head, 15" mid, 24" meg (1.25" to 2.75") are based on 1.125" head pipes... and I use 1.25" so I'm off a bit there, that's why I've tried to keep things at the upper end of the length if possible.

Off hand the shorter system you describe doesn't sound like it would hurt power that you or I would notice. Low end you lose with a shorter meg you'd probably make up with the smaller OD head pipes. Not a bad idea. The disks adjust back pressure, which affects power band, but length does the same thing for totally different reasons.

You are thinking in the ball park now, I'm betting the system you describe and the system I use wouldn't show a 1/4 hp difference on the dyno... might move things around a bit, but no real gains or loses. And nothing personal...but anything close has got to be better than some of the things I've seen bolted to your bike in the past

The measurements I've given you in the past are just that..ball park. Not bad enough to hurt you, but probably not optimal either. I've dyno'ed 4 different systems now, and none of them made a substantial difference in peak hp, decent gains were made in mid range with the system I use now though. I don't have the dyno evidence to prove it but on track experience tells me the best change I've ever made to the exhaust was to go from 12 disks to 7....and I did it just because I was pissed about failing the sound check.

The meg is what I would screw with the least, it's a functioning, balanced kind of thing. Besides...the one I'm making you is about 23.5" and 2.75" OD at the big end. I KNOW these work well on Mary's bike and mine. Shorten the mid pipe if you have to, or knock some off the small end of the meg and slip it over the exit of the mid pipe. I know you've already made that mid pipe...but I can't tell you how many times I've cut mine apart and redone them. I'll send more tube. And yes my meg points more to the sky every time I build a system. Hell, look at Roper's...it's almost vertical. I think I have 20" megs in stock, already made if you'd rather I send something a bit shorter.
They are 1.25" x 2.75" x 20".
JohnnyB

 

[imslow]

Hey Aaron: Did BigDaddy ever get back to you about the 175? He seemed hesitant. He seemed hesitant to sell anything he put up on the board, actaully. And, of course, the bike I sold to him for $400.00 he now wants a lot more money for.

Scott

PS. My pipe is not kinked, but the meg does go up to the sky.at about 40 degrees. JB doesn't remember that I ordered a meg from him.

 

[UngaWunga]

quote:
I think you could adjust things the way you suggest but not to the extent you suggest. The disks adjust back pressure only. The pipe length is tuned to function properly at certain rpm ranges and frequency of exhaust pulses.

The length of the headers to where the pipes join also has a big effect on the rpm range of the pipe. At least according to Bell. And it makes sense. If you get a pressure wave down one header that can send a negative wave back up the other header that reaches there just before the exhaust valve closes, you can get a little supercharging like a 2stroke expansion chamber.

 

[jbranson]

Yeah, that's true. Mid pipe length is supposed to be pretty important.

If I had to modify a pipe my priorities in order of importance (what I didn't want to mess with) would be:

Meg
Mid-pipe
Head pipe.

2-1 pipes are a bit trickier than single pipes. So far I've been pretty amazed at a 175's lack of response in peak hp to just about any pipe you bolt to it. However the bikes are VERY responsive to alterations of the intake tract.
I cringe when I think about the developement that still needs to be done. A whole day at the dyno with with a truck load of different exhaust components. And they really need a programmable ignition...or at least one with a curve...running them at 45+ degree straight has got to be hurting low end power. Plus a whole slew of velocity stacks need to be tested. Another three years and we should be close.
JohnnyB

 

[aaron]

IMSLOW - I spoke with him about the bike, but I haven't called him back yet. I was suppose to call him a while ago, but between the holidays and trying to make room I've put it on the down low for now. If I sell more stuff to make room it will be a Giro bike.

Is this the post I was suppose to respond to?

Aaron

 

[jbranson]

So how many people want cylinderhead side intake manifold flanges for their 175's. Or carb side flanges for SL350 Keihin carbs?

About $8 each, laser cut from 5mm carbon steel. I need to sell about ten of them ( 5 sets) to make it economically feasible. Lead time is about 3-4 weeks from the date I place the order.

Here's what they are...take an intake gasket and make it out of steel 5mm thick and there you have it. Nothing more, nothing less. One will bolt right up to a head, the other type will fit an SL350 carb (with the small spigot milled off).

Order yourself a loop of mandrel bent 1.125 - 1.25" OD tube from "headers by Ed", cut it up, weld to flanges, make your own intakes.

I am in no particular need of these flanges at the moment, so don't feel like you have to order them to help me out or anything. It's just a few clicks of the mouse for me as I've already done the drawings and ordered them made before.
JohnnyB

PS. Actually the hole in the flange is larger than the OEM gaskets since I sized them for use with 24mm and larger carbs.

They are the same as the flange used on these intakes.




Edited by - jbranson on Dec 01 2004 04:59:55 AM

Edited by - jbranson on Dec 01 2004 05:04:51 AM