Author Topic: 1350cc Pushrod bike (Read 52139 times)

wobblywalrus · « **Reply #30 on:** February 15, 2010, 02:00:21 AM »

Jim, in reference to DSCO7417. The transition between a strong built up section and a tube can be problematic. The abrupt change in section concentrates the flexural stresses at the joint weld. Possible fatigue problems. Sometimes a simple set of gusset plates can be used to dissipate these stresses through strong lap welds to nearby frame members. This takes a big load off of the critical joint weld.

The front is definitely looking stronger. This is one bruiser of a bike. The sound from the four meggas will be great.

JimL · « **Reply #31 on:** February 15, 2010, 12:05:17 PM »

Thanks for the note.... actually the top tubes are just tacked and will come back off for more prep to that area. The bike is still held together by the table and braces. What looks like weld is just the grind marks on the end of the heavy tube (it took a lot of hand shaping to get a tight fit).

I'll use gussets similar to last years bike, and there will also be tubing at the bottom (front end) of the upper tubes, angling down parallel to the cut off box section seen below the joint. That lower tube has to sweep forward, then turn down and back, before passing under the bike. All because of the front carb and exhaust positions....and I'm still hoping to be able to get the engines in and out as a unit. It looks like the lower tubes will have to be 1" .120 wall (same as last years) in order to get smaller radius bends.

JimL

isiahstites · « **Reply #32 on:** February 19, 2010, 09:33:28 PM »

Nice to see you again today Jim, I enjoyed your stories and information. Looking forward to your progress.

Scott

JimL · « **Reply #33 on:** February 20, 2010, 08:13:44 PM »

Lower tubes on the frame, with the "unusual" forward shape required to clear some of the important bits on the forward engine. We were able to ALMOST get the engines out as a unit...but not quite. And they are really heavy.

I'm mounting the motor plate to the frame, which will allow installation of one engine at a time. I tried taking it apart that way, and I can do it single handed.

More to come....

thanks for the note, Scott...hope your project is going well.

JimL

JimL · « **Reply #34 on:** February 22, 2010, 01:04:22 AM »

More work today. Gussets on some of the main tubes (1/8" steel plate), and many mounts for the engines. I have thick wall tubes welded to the "horizontal" tube, and 10mm studs in the engine blocks. These allow me to "present" the engines (one at a time) into the frame, secure them with nuts, and then run in the many 6mm bolts that hold the blocks to the motor plate. Now I have to start cutting the 1/4" plate overlays, that will be the mount spacing for bearing carriers (for the cog belt drive between engines).

I also built a large mount for the left front of the forward engine (not shown), and will have another one for the left rear of the rear engine, as I get closer. I can get all 4 heads off, with the engines in the bike.....but hoping to get the engines sealed before I go to Speedweek (IF it gets done in time....not sure yet).

So far, the FZR1000 forks are handling the weight well. I have about 2-2 1/2" I can push the front end up, and (of course) the 2 1/2" tire sidewall height. I'm hoping for 4-5" of ground clearance, but may have to shim the fork springs..... anybody ever done that on these upside down forks (first set I've eve had....know NOTHING about them).

Thanks for any knowledge you could pass along.

JimL

oz · « **Reply #35 on:** February 24, 2010, 12:57:04 PM »

What kind of static sag have you got or what i mean is how much of the travel is taken up by the weight of the engines against the total travel.

You may be able to get heavier or progressive springs for that model rather than trying to shim them,I have had upside downers extended with slugs in the top retaining all the adjustment facilitys albeit only 1.5"-2" and the top being held in 1" billet yolks.

https://www.harris-performance.com/website/acatalog/Online_Catalog_Yamaha_front_fork_springs_107.html

just a thought.

Love the build Jim.

cheersOz

fredvance · « **Reply #36 on:** February 24, 2010, 02:45:08 PM »

Jim, why so much ground clearance?? Generally speaking, on bikes the lower the better.

JimL · « **Reply #37 on:** February 25, 2010, 02:21:40 AM »

Oz....so far the engines aren't at full weight and the forks are only moving about an 1/8th of an inch. Maybe I can get some weight on it this weekend and see where I'm at.

Fred....leaving enough room for the bellypan, and I'll have to make space for 4 megaphones, staggered down the right side of the bike. Also....I had a lot of trouble with trailering last years bike...my crew actually got hurt right after tech, what with the bike hanging up during loading (LONG wheelbase). We were responsible for all that blood on the salt, just past the motorcycle shade. I'll have to do something about my trailer setup this year, with both of my rides running 70 inch wheelbase.

Here's a couple of pics of head work....larger valves and seats (the fuzzy pic shows new valves in the middle, and old intake and exhaust on each side of them). Also a pic of the 40mm intake ports and shape mods. My 500 heads will actually have slightly larger valves than my 650 heads, because the 500s are a much higher RPM engine (extreme oversquare design). We are changing to very small stems on the 500 heads, to improve flow and try to keep the intake Mach number down at 11,000 RPM......that was part of the problem last year, when I was even more ignorant than I am now!

Regards, JimL

oz · « **Reply #38 on:** February 25, 2010, 01:20:29 PM »

You may find that the forks dont need altering if they are only dropping that much i reckon the best bet is load it up with a bit of weight and see how it is.
If it aint broke dont fix it.
And I would hardly say ignorant was an apt discription of your talent I still feel like I am staggering around in the dark with my projects its read a book buy a bit modify this try that and i aint really sure if any of it will get the desired results.
You seem to know exactly what you are at Cool!!

JimL · « **Reply #39 on:** February 25, 2010, 08:51:54 PM »

oz, it truly is a case of knowing exactly where you're at, after you've walked past it about a dozen times!

That's why my hip feels better, these days.....sitting on an empty wallet is easier on the sacroiliac!

JimL

1212FBGS · « **Reply #40 on:** February 25, 2010, 09:26:42 PM »

Jim
those custom sprockets we had made for ya showed up today.....
Kent

JimL · « **Reply #41 on:** February 25, 2010, 10:33:25 PM »

Thanks, Kent.....gotta' go be a port rat for a few more days. I'll come bye (buy) at first chance.

JimL

JimL · « **Reply #42 on:** March 08, 2010, 12:24:22 AM »

Have you ever noticed how these projects get hung up on the speed bumps?! Seems like nothing happening fast, but many items are "in the works". Kent got some sprockets sourced....here's a quick pic....I just HAD to try it on the rear wheel to see what it looks like.

Looks like trouble....that's what it looks like.

Regards, JimL

Rex Schimmer · « **Reply #43 on:** March 08, 2010, 01:02:36 PM »

Jim,
Don't worry about the chain sawing thru the swing arm, when it gets enough aluminum sawed away it will be perfect! Amazing how everything turns into a "challenge"!!

Love your build it will be fun to watch at the salt.

Rex

JimL · « **Reply #44 on:** March 09, 2010, 01:50:32 AM »

Thanks....I was thinking about your comment, and realized I could sharpen the bottom of the side plates with my chain saw tool. That'd speed up the "run-in to fit" process!

Tonight I got my rear drive gear, inner bearing race, positioned. The 1/4" steel plate will get additional bracket out to the motor plate, and side supports into the crankcase. It's currently mounted on three studs, set dead level, to provide the end spacing for my coupler shaft. The gear is resting loose in the photo, but fits correctly when held square to the crank (the bolt and spacer is just temporary...I'll be using 1 3/8" shaft). The outer bearing will be a sealed unit, carried on a support mounted to the motor plate.

This was a big step for me.....getting the rear coupling shaft properly located.....I didn't even mind the cold shop, tonight.

JimL

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