Author Topic: Racer Resurrection  (Read 91675 times)

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Offline al_pritchard

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Re: Racer Resurrection
« Reply #120 on: June 01, 2017, 09:51:45 AM »
Did a dry engine build over the weekend, and took some measurements. Not sure I’m doing it exactly right, but here's to trying.

Cylinder Base to Deck: Left - 81.71mm and Right - 81.99mm
Cylinder Base Shim: 0.94 mm
Piston to Deck Height:   1.91 mm

Transfer port opens at 108° ATDC
Transfer port is fully open at 148° ATDC

Rear transfer port opens at 103° ATDC
Rear transfer ports is fully open at 178° ATDC

Exhaust port opens at 87° ATDC
Exhaust port is fully open at 154° ATDC

Rotary valve opens at 137° BTDC
Rotary valve is fully open at 100° BTDC
      
Rotary valve closes at a° ATDC
Rotary Valve is fully closed at 75° ATDC
* NOTE: Rotary timing is using the stock wiper. I’v not modified it yet.

Visual Timing


I’m going to go back any do the measurements again to double check.

Vinny’s idea of stepping the head into the cylinder is interesting. Letting me run without a head gasket. But I don’t get the feeling that 1mm is enough.

I’d love to hear some thought on deck hight, squish and head cutting.
Al Pritchard
Highlands, NJ

BS175 Racer

Offline bsracer

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Re: Racer Resurrection
« Reply #121 on: June 03, 2017, 11:07:40 AM »
Hey Al,

I just sent some heads off on Thurs to a guy who does a bunch of Kawasaki H2 stuff. I still need to get him the piston crown angle and the deck height. He wanted to see how they might weld up. I'm interested if he can do something like I've seen done on Suzuki GT500. An insert like they do for water cooled bikes. You use a heat transfer paste between the machined parts.

paul

Offline al_pritchard

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Re: Racer Resurrection
« Reply #122 on: July 05, 2017, 01:48:42 PM »
Hey Paul,

Very interested to see how that effort comes out. I’m having a hard time working out what direction to go with the heads.

On another note, who are you getting your tires from? I’m wondering if I’ll get lucky and be able to pick them up at NJMP weekend after next.

* Anyone else, feel free to chime in with a recommended tire dealer.

I’m thinking:
Heidenau K40R 2.50-18 Front
Heidenau K45R 2.75-18 Rear

Al
Al Pritchard
Highlands, NJ

BS175 Racer

Offline OldSwartout

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Re: Racer Resurrection
« Reply #123 on: July 05, 2017, 06:19:07 PM »
One of the AHRMA racers is a Heidenau dealer, so he'd probably be at NJMP, but unfortunately, I don't remember the name and he's not advertising on the AHRMA website.  He's probably in the AHRMA magazine, so you can probably check the ads there. 
Karl Swartout
Mooresville, IN
BS175 Roadracer. BS200RS, BS350 GTR

Offline bsracer

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Re: Racer Resurrection
« Reply #124 on: July 07, 2017, 12:08:27 PM »
Hey Al,

I just had some heads done. Not like the ones pictured. I'll post some pics when I can. I have been running the Heidenau's and they're ok. They change the gearing quite a bit from the Bridgestone BT39's.

paul
« Last Edit: July 09, 2017, 01:42:30 AM by bsracer »

Offline al_pritchard

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Re: Racer Resurrection
« Reply #125 on: August 21, 2017, 10:53:16 AM »

Keep me motivated Paul - Lets see some info on the heads.



Haven’t moved forward much, but I thought I’d check in and explain why.

If you’ve been following along, you may have noticed that the build had moved into my living room. Now I may have the worlds most understanding wife - but I will admit building a race bike in the living room is a bit of a challenge. So we began looking for a more “appropriate” location for my workshop. And we happened to stumble across a 1890’s farmhouse not far from where we live. With the best basement you could ask for. Fully dug out to 7' with a fresh painted slab floor. And did I mention someone built a bar down there. Long story short, we bought the house and moved last weekend. Still a lot to do to get the workshop us to speed. But it shouldn’t take to long.

At least she got to get out and see the sun


And arrived safe to her new home
[url=https://flic.kr/p/XSa1wj]

More updates as they happen.
Al Pritchard
Highlands, NJ

BS175 Racer

Offline bsracer

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Re: Racer Resurrection
« Reply #126 on: August 22, 2017, 11:25:52 AM »
Very Cool Al.

Congrats on the new house. I like both the idea of bar and workshop down below. I have a friend who once lived in a house (in San Diego) that had a trap door in the living room floor that went down to a bar with pool table in the basement.

I've slowed up on things a bit too. The guy I was building the motor(s) for pulled the plug. I was still in mid production on a bunch of parts. One set of heads was for me one for him. The rotary valve covers aren't done yet and I still need to move forward of the ignition. This sets me back a bunch of $$$ so I'll just try and regroup next year. I will try out one set of the new heads at Barber in October. I hope to get them on in the next week or two and replace the ignition gear that failed.

The pics are of the two new sets of heads. First is 12:1 with a 10cc trap volume (I think?) and the second 14:1 with a 8.8cc volume. Both are set up for a zero deck height.

paul

Offline al_pritchard

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Re: Racer Resurrection
« Reply #127 on: September 25, 2017, 11:17:13 AM »

The workshop is taking shape. New workbench built and moved the bike bench in. Also started putting in some new lighting. Cant recommend this lighting enough. 6 LED strips 4ft each. They put out a fare amount of light that is very white. It tends to feel brighter than it really is. I’m going to install  6 more in the back of the shop over the bike on a separate switch. Giving me one level of lighting for hanging out, and a second stage for working. Lights from Amazon



Bartenders View


And View of the Bar




Paul. I’m interested in how you have the heads cut. It looks like you are setting them up for o-ring gaskets. I still weighing my options with how to cut the heads. And I’m not sure if ~1.5mm is deep enough to take the approach of cutting them to fit into the cylinder.

Did you cut the dreads to take an off the shelf o-ring? And if so, do you ming sharing the specifications?
Al Pritchard
Highlands, NJ

BS175 Racer

Offline bsracer

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Re: Racer Resurrection
« Reply #128 on: September 26, 2017, 01:12:43 AM »
Hey Al,

Workshop is looking good!

I sent them off to someone in the LA area. I don't have any of the specs. I guess I can get them if he'll give them to me. I think he uses some software because I had to provide him with a bunch of different measurements. He had to build up both sets of heads with weld. The 10.0 heads have quite a bit more compared to the 8.8cc heads.

The orings are off the shelf. YZ125/85. I can send you the part number when I get a chance.

I just put the motor together Saturday and into the bike yesterday. Sounds/feels pretty good. Gotta get my stuff together and up to LA on Friday to get everything to Barber!

paul
« Last Edit: September 26, 2017, 01:14:20 AM by bsracer »

Offline SR-175

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Re: Racer Resurrection
« Reply #129 on: October 23, 2017, 11:05:11 AM »
Hi Karl,

Would you mind sending me this file in the three formats you can ? Not sure yet what the printer wants just yet.

Thanks .. ray - ray@bsrestoration.com

From Karl :
Here's a similar size logo in .jpg.  I also have it as a vector file in .wmf, .dxf and .dwg line formats that can be easily scaled and/or used to cut decals or stencils.

Offline OldSwartout

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Re: Racer Resurrection
« Reply #130 on: October 24, 2017, 08:53:29 AM »
Files sent to your email.  They can't be attached to post due to the file formats.
Karl Swartout
Mooresville, IN
BS175 Roadracer. BS200RS, BS350 GTR

Offline SR-175

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Re: Racer Resurrection
« Reply #131 on: October 24, 2017, 10:54:02 AM »
Hi Karl,

Got them and thanks !!... A bit of tweaking to do but getting there.

Offline SR-175

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Re: Racer Resurrection
« Reply #132 on: October 24, 2017, 10:56:05 AM »
Oops ...

Offline al_pritchard

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Re: Racer Resurrection
« Reply #133 on: October 24, 2017, 12:18:50 PM »
Hey Paul, how'd you do at Barber? It looked like the 200Gp grid was rather large this year.


Been sniffing around the Yamaha 2-Stroke forums looking at how they are doing o-ring head conversions. And I'm gaining confidence that I can pull this off. The groove does not not to hard to machine. And since I'll have the head on a lathe anyway, might as well cut a groove.

It looks like lot of the Yamaha guys are using off the shelf high silicon o-rings from McMasterCarr. $7.00 for a packet of 10. And that may be an alternative to the Yamaha o-ring.

I think my measurements are close - I'm beginning to questions the accuracy of my tools and technique. But this is what I came up with:

There are 3 potential o-rings that would work with the material space we have available on the head.

Dash Number 037, 036 & 035 o-rings. The 036 o-ring would sit almost dead center between the bore and the stud hole. With 0.417 / 0.402 on each side (actually a little less as the groove needs to be slightly wider that the o-ring)

(Edited, because I suck at math)
The Dash 035 o-ring is probably the best bet. Re did the measurements last night and realized I didn't account for two things. One, the cylinder head surface is narrower at the side, than it is at the stud holes. And I was effectively doubling my measurements.


Curious abou the Yamaha part number Paul, and the groove dimensions from your heads. I suspect Yamaha uses a standard dash number o-ring. Looking at the head images above, I suspect it's the 035 size. As the groove looks to be centered between the bore and the stud holes.
« Last Edit: October 25, 2017, 09:20:42 AM by al_pritchard »
Al Pritchard
Highlands, NJ

BS175 Racer

Offline bsracer

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Re: Racer Resurrection
« Reply #134 on: October 26, 2017, 11:19:41 AM »
Hey Al.

My bike ran well at Barber, I didn't. I seem to have fallen into a habit of backing off when I shouldn't. I'd turned a 2:04/2:05 at Barber in the past. The best I could pull off was a 2:08. The fast guys in GP200 were in the 1:57's. The group of people I think I can hang with were in the 2:01 range.  I'm gonna switch back to the Bridgestone tires for next year. Maybe it's a mental thing but I can't seem to go faster than I use to. I've had the Heidenau's on for a few seasons. I can't ever seem to gear it right. They are quite a bit taller than the Bridgestone BT39SS.

paul

I can give you the guys ph# who did the heads. I don't have any info on what he did only the trap cc volume. I ran the 8.8cc heads at Barber. I want to dyno the bike before I take it apart to look at everything.

Offline hardy

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Re: Racer Resurrection
« Reply #135 on: October 27, 2017, 05:15:52 AM »
YOu Should be able to download the boring groove specs from any good manufacturer ie Parker or ludiwinci

Hardy.

Offline al_pritchard

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Re: Racer Resurrection
« Reply #136 on: October 27, 2017, 09:23:42 AM »

Marko has a relatively easy to read chart that I'v been referencing. (https://www.marcorubber.com/o-ring-groove-design-face-seal.htm).

I'v been looking for a Parker chart, but I think you need to buy the book. I'm going to risk it, and use the Marko measurements. I suspect I won't be as exact as a real machinist ... so the accuracy to the 100th may be lost on me.  :o

Al Pritchard
Highlands, NJ

BS175 Racer

Offline al_pritchard

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Re: Racer Resurrection
« Reply #137 on: November 26, 2017, 06:56:48 PM »
Happy Thanks Giving Everyone!

So finlay, forward progress. Spent some time Saturday on the lathe - I'm still learning but I'm getting better.

I took 0.059in (1.5mm) off the head, and cut the o-ring grove. Making the tool to cut the grove took the most time, but I think I managed to do a fairly good job. The new measurements are:

O-ring Gland
Width: 0.084in
Height: 0.052in
Outer Diameter: 2.379in

Deck Hight: 0.060in (1.54mm) *With medium base shim
Base Shim: 0.0315in (0.79mm)
Spark Plug: B-8HN
Head Volume 8.3cc

Still need to cc the cylinder to work out total volume. At some point this winter when I don't want to go out in the snow, I'll tackle that. Until then, I tink I might be okay with - the removal of the head gasket, and going with the o-ring should help off set the lower hight of the RM piston. And swapping between the the thick, medium, and thin base shim should allow me a little flexibility between compression ratio and port height.





I do wonder if the o-rings I have are the same dimension as the ones Paul is running. They look similar form the photos.
Al Pritchard
Highlands, NJ

BS175 Racer

Offline al_pritchard

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Re: Racer Resurrection
« Reply #138 on: January 01, 2018, 09:09:01 AM »
Happy New Year Everyone!

Finished up 2017 with an arts and crafts project, and final preparations for the engine build. First, arts and crafts!

Over on the North American Two-Stroke forum (natsforum.net) there is a thread about someone rebuilding/freshening his '97 TZ250 for 2018 vintage racing. One of the tasks was the creation of an "air dam". It go me thinking. I had a large area un-covered by the fairing, just under the tachometer. The fairing has a plate that normally covers this area, but it's designed to be use with the stock steering yoke. The upgraded yokes that I'm using are thicker and stick down lower that stock. I couldn't work out a way to get the fairing mounted low enough to use that plate.

The air dam might just do the trick: lowering the debris entering the cockpit, and funneling more air to the engine. Started with a simple cardboard mockup. Transferred to "marine board" available at West Marine, it's the same as HDPE plastic sheeting. Cool stuff, cuts just like wood, but you can't glue it.

You can see the space between the forks, that would normally be covered


Cardboard!




Plastic!





Engine Build
All the parts have been striped down, cleaned, oiled, and prepared for assembly. Only one thing missing, gaskets. :o I was originally planning on not using a gasket, and relying on Yamabond. But when I did a final test assembly, and tightened down the case bolts. The crank felt like it was binding, and I had a very hard time getting the transmission to shift. Everything is very smooth before tightening everything up. So I guess gaskets are a necessity.

Paul, Karl what are you doing for gaskets? Cutting your own or buying?

All prepared for assembly


[url=https://flic.kr/p/21ZyNmG]

[url=https://flic.kr/p/21ZyNBb]
Al Pritchard
Highlands, NJ

BS175 Racer

Offline OldSwartout

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Re: Racer Resurrection
« Reply #139 on: January 01, 2018, 10:43:28 AM »
I cut my own cylinder base and clutch cover gaskets, both to save money and to use better gasket material. From my job, I knew about gasket materials with release agent on the surface, so there weren't worries about stuck gasket material when trying to change parts in the pits. I scanned originals and then printed patterns as needed, stuck the printed pattern to the gasket material with a glue stick, cut with an Exacto knife; a bit tedious. That way I always had plenty of spares.

There isn't a gasket between the crankcase halves, only sealer.  If things don't spin freely when the two halves are tightened, there is an issue that needs to be addressed. Transmissions are somewhat difficult to shift unless pretty well oiled, but the individual shafts and the shift drum shouldn't have any noticeable drag when spun.

The air deflector you designed for the fork/lower triple is a really good idea.
Karl Swartout
Mooresville, IN
BS175 Roadracer. BS200RS, BS350 GTR

 


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