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[Admin]

Here’s my report from the first round of my AHRMA Vintage Road racing season from Willow Springs. Friday practice went well, got the jetting sorted out early, dropped one main jet size to 250 to accommodate the track’s 2500 ft elevation.

The weekend was sunny and hot, it got to about 103deg F on Saturday, but it’s DRY heat. I had a great time seeing old friends; Tim Gilchrist and his immaculately restored ’72 T500, Dave Ray and his vast knowledge, the Albuquerque boys Tracy Riffe, Glenn Maxwell, Hurley Wilvert & Dennis Parrish; Dave Crussel and many others. Just being at the track hearing the sound of vintage racing engines is oh so cool!

Saturday came and I did two morning practice sessions, waiting for Formula 500 race #8. For the F-500 race I did the warm up lap, took my place on the grid, got to the 2 board and then I heard a funny clunk, and then the exhaust note started sounding different. I looked down at my left chamber, only to see the where the silencer used to be and the silencer lying on the ground. 1 board comes…sideways…green flag and I let the whole field go ahead, kick the silencer off the track, and then motor up to the pit out entrance and back to my paddock spot.

It should be noted that Saturday’s F-500 race was won by Ralph Hudson riding his Suzuki TR500, followed by Hurley Wilvert and Dave Crussel on their H1R’s. Ralph’s TR500 is wickedly fast and can he ride, go Suzuki!!

After $10 donation to the Benevolent Fund and I get the silencer back, then take it to Andrew Cowell to weld the flange back on to the chamber. Furious wrenching ensues and I get the whole mess back together for third call for race #11, Formula Vintage. I didn’t have time for a warm up lap so I take my place on the grid, starting with a cold engine and cold tires. After a horrid start with a balky engine, half lap I figure the tires are warm so I start riding after the back pack, battling with a Super-Mono2 bike that started in the second wave. I’m having fun trading places with this guy; I can pull him on the straights. After the crossed green and white flag I’m pulling up on this bike coming thru turn 8 when I hear another funny exhaust sound and the bike starts running real badly. I throw up my hand to exit the track at pit in, look down to see the left silencer missing again, ARGGHH!!! As I rider thru the pits I wonder why people are looking kind of funny at the bike; when I dismount I can see why, the complete left hand expansion chamber is missing.

Apparently when I reattached the pipe earlier in the day I tightened the rear rubber mount too much, creating undo stress on the pipe hanger which broke off.

Another $10 donation to the Benevolent Fund and I get the entire chamber back, again Andrew Cowell welds the pipe hanger back on and I’m back in business come Sunday Morning. I make the last practice and everything seems to be holding together, so with fingers crossed I’m hopeful for Sunday’s racing.

Again I’m in race 8 (F-500) and 11 (F-Vintage). For F-500 I finish fourth out of fourth behind faster riders on faster bikes…heck I’m just contented to finish without a mechanical DNF.

For F-Vintage I have another epic battle for last place with Tracy Riffe on his GS1000; Tracy kindly slows down on the straights so we can duke it out in the corners. Sunday’s F-Vintage race is the most fun I have all weekend.

So that’s the report for Willow Springs, some broken parts, no broken bones, lot’s of sunshine and heat, and lots of smiles.

[Admin]

Hey Ralph!

Thanks for the update! Sounds like fun aside from the mechanical issues. Does Ralph Hudson post here? I'd love to hear more details about his TR500....

Jim

[Admin]

Here's another dumb question on the RC Barker Dunlops - are they "speed rated" at all? I was looking at the Avon tires I suspect Krash uses and they are all H rated (good to 130mph). Not that I expect to get to 130mph while wobbling around Grattan or Mid-Ohio but still I'd like to know if the Dunlops carry any sort of speed rating?

Thanks,

Jim

[Admin]

Hey Ralph!

Does Ralph Hudson post here? I'd love to hear more details about his TR500....

I don't think Ralph ever signed up for this board. He's extremely busy in his business of set and float production for the entertainment industry.

I did have a fun weekend, even with the mechanical issues. But hey, even the problems are part of racing!

[Admin]

Here's another dumb question on the RC Barker Dunlops - are they "speed rated" at all?

I don't believe the Dunlops carry a speed rating since they're labled "not for highway useage," plus they're not typically sold in the US. The Dunlops are basically vintage size/tread pattern tires molded in modern road racing compounds.

When I had my Dunlops mounted by the Dunlop trackside rep he commented that the compounds are the same as those used on modern slicks.

Many of the "fast guys" use the Dunlops...Dave Crussel, Ralph Hudson, Hurley Wilvert.

[Admin]

Zook-e let me know last week that he and Otis would probably not make it to Grattan in June (16 & 17). Instead they may shoot for hitting the Nelson Ledges WERA event on July 7 & 8.

I'm still a loooooonng way from getting my racer done so I'm wondering if anyone else here was going to Grattan? Otherwise I may take the extra time and hit Nelson Ledges instead.

Jim

[Admin]

I was planning on attending, but....finances say that Mid-Ohio is all I can do.

See you all at Mid-Ohio!

[Admin]

All,

I had a set of Swarbricks welded up by a local guy that does a lot of stuff with racing two strokes and Yamahas (TZ750s) in particular. He did a beautiful job but we were concerned that there weren't flanges/spigots included in the kit. I had a different set of flanges from another pair of pipes that he used to line everything up. The new pipes fit into the old flanges by about 5mm or so which leaves a dead space between the edge of the exhaust port and the edge of the chamber of about 20mm. I think I can cobble together a mounting set-up using the flanges, the first 20mm of the stock exhaust header, and a bunch of high temp exhaust gasket sealer but this seems like a less than ideal way of doing this.

I emailed Dave Swarbrick regarding the missing spigots and was told they are not included with the T500 kits but I can spend another $150 with him to get the "barrel stubs with alloy inserts". Or I can put together a slip-fit arrangement to hold the pipes in place. A follow up email to ask what I get with this kit and how it works has gone unanswered.

I had asked Zook-e about this and he said the flanges used to come with the Swarbrick kits so. For those of you that have racing chambers (and specifically Swarbricks) how do that attach to the cylinders?

Thanks,

Jim

[Admin]

I spent today wrenching on three bikes, my '71 T500 cafe racer, '75 T500 road racer, and '74 TS250.

I got the T500 road racer ready to go for Mid-Ohio, re-jetted to 260 mains, converted chain to 520, re-mounted my chambers yet once again, and mounted new race tires.

For tires this time I went with Dunlop KR124A front and KR164 rear. I'll have to see how these tire affect handling, but I wanted higher profile tires that what I ran last year (KR825 front, KR124A rear).

So who else is ready to go???

See pics.

[Admin]

Hey Ralph,

Isn't the KR164 a 135 width tire? Isn't that more than the T500 needs? Or did you find the 124 rear not enough last year?

As for ready to go... I have a rolling chassis although it's not on the wheels I intend to race on. I'm ready to assemble the engine although I don't have cylinders yet. I've still got to track down carb parts for the 34mm Mikunis (care to reveal your carb set-up so I can copy it?). and I'm not sure I have all I need to mount the Swarbricks correctly at the cylinder. How are you chambers mounted?

I'll definitely be at Mid-Ohio. If I'm racing or not remains to be seen.....

Jim

[Admin]

GREAT opportunity for those racers not racing, to become tuners/helpers for others who are, no matter which coast they come from.

[Admin]

Isn't the KR164 a 135 width tire? Isn't that more than the T500 needs? Or did you find the 124 rear not enough last year?

Yes the KR164 is 135 width tire, it's what Dave Crussel and Ralph Hudson user on their H1R and TR500's. Main reason I went with the KR124A front/KR164 rear combination was to get back some ground clearance, the KR825 front /KR124A rear combination were too low profile, I was always dragging my chambers in the corners.

Who knows if this tire combination will work for me on the T500, but that's what test and experimentation is about!!

I've still got to track down carb parts for the 34mm Mikunis (care to reveal your carb set-up so I can copy it?).

I bought new VM-34's from Pro-Flo. My jetting for Mid-Ohio is 260 mains, 159Q2 needle Jets, and 6DH4 needles in the lowest position. Think I'm going to try a 6DH2 needle next.

and I'm not sure I have all I need to mount the Swarbricks correctly at the cylinder. How are you chambers mounted?

Obviously not very well if you read my race report from Willow Springs!! I've just completed remounting them so their not over constrained. I use two rubber straps from a muffler hanger kit with a hole in each end. The top hole I run a screw with a bushing (to determine clamping force) attaching to my rearset mounts. The bottom hole I sandwich the mounting tap on the chamber. This design provides side-to-side motion as well as front to rear swing.

This was the setup I used for my Jemcos' and ran for three years with nary a problem. I got in a hurry mounting the Swarbricks and bolted them directly to the rearset mounts, over constraining the mounting tabs and inducing too much vibration hence stress on the chambers.

See pics:
Right Side



Left Side

[Admin]

Getting the old race bike back. Had sold it three years ago and now it is coming home. Will have it this weekend as Frank Tarpley is bringing it half way to me and I am delivering a T500 motor to him.

Going to put a different seat and front end on it is all.

[Admin]

Eric,

Great news, what an easy way to get a race bike...buy your old one!!! What kind of front end are you going to put on it?

What are specs for bike? I gots to know what my competition has in store for me!

[Admin]

All,

How loose or tight should the chamber fit into the spigot/outlet stubs? The ones I have are a tight fit and I thought they should be a loose fit instead?

Jim