Dry Lakes Racers Australia

We are a team from WA entering a 1972 Suzuki T500. Its been tweaked in all the right and possibly wrong places just to go that little bit faster.

There are 2 of us coming across next year. We did not make last year purely because we did not get the motorcycle set-up in time. My delightful aunt made a tin (possibly a drum) full of ANZAC biscuits for the intended journey. (The Lake from Perth is a long drive, so there was a lot of baking going on) Fortunately they were not wasted and provided adequate nourishment over the winter to get the bike ready.

We are ready!

We dyno’d the T500 last week and are happy with the initial set-up to bring across in late Feb. Its making power and running reliably. Its now gong to be a lazy summer.

A bit about us - Muzza (or Dr Von Cobra) has been racing T500’s since they were new (that's a awhile ago) and in that time collected a few spare parts. He is known in the T500 world for knowing a lot about T500’s. Rather than seeing good parts rust I persuaded him to instead bring them to the salt. My role has been to put the bits together, port some ports, glue some pipes, weld up some tanks and pilot the motorcycle. No massive budget or big expectations, more about using what we have got on hand to go fast.

Here is the first dyno run
https://youtu.be/wur24VPQQUY

Here are some pics of the build

"Welcome",, Sweet lookin piece ,, What did she go on the dyno ,,

Velcom team Von
A long , long time ago I had a "patch laying" competition with a mate on his Titan, and me on my Norton 650 ss, he laid 40 yards, I ripped 30 teeth from my rear sprocket,,,,,
They are torquey lil phukka's eh !
Good luck with your new addiction blokes,,the bike looks GREAT!
Tiny

Nice work. It will sound great on the salt.

Dave

Welcome to the House of Fun Team Von

Great build ..... see you in Feb .....

Pete

Thanks guys for the welcome. I have enjoyed reading your posts and development too.

Stayt`ie : the rear wheel made 55hp at 7000. There is some room to move up with ignition, revs, squish and pipe. It could pack a bit more heat however we want to get a few runs in first. Making more power is achievable but at the expense of reliability. Also I am not sure how 1min of sustain WOT on the salt is going increase CHT... someone might be able to chirp in here?

Not sure about Air Cooled temps but my advice is LOTS OF FUEL.

Have you got CHT gauges as well as EGT?

Dave

Yes, both EGT and CHT for each cylinder. Sustained temps have been safe so far and A/F has been around the 13.4/1 ratio at WOT. All feels ideal but have not experienced pulling in 40+ heat on the salt so far. I would expect to go down a whisker on the main jet in salt conditions but then again "run 'er rich" so they say. We have pulled back 2 degrees on the ignition from peak power as a safety which has lowered temps but only very slightly.

Do you find that at the end of the timed section (on a run) that your temps are at the edge?

13.4:1 might be a bit lean for the Salt ....

What Fuel/Gas/Petrol are you running?

I run a RGV 250 smoker and use Sunoco Supreme ..... it's a fast burning fuel suited to 2 Strokes ....

it has excellent anti detonation properties and is Gas Class Legal ....

Pete

Yep, what Pete said. I would be aiming for 12.1 or richer to start with. You can always lean it out after a run. Lot easier and cheaper to replace a fouled plug than a piston or two.

And lots of the best quality oil you can get as well.

Ive seen 1245 F on my EGT after a successful run. But all motors are different.

Dave

Thanks Pete & Dave,

Gas. I am running ERC 110k and had previously been running Supreme with Bel-Ray H1R. Piston wash has always been beautiful, it burns so clean.To be honest i have not noticed any difference between the fuels except $6.(ERC is cheaper) Both are fast burning. I used to use Mobil1 Racing 2T oil, another great oil except that it is clear. I missed seeing fluids come down the tube, it was doing my head in so i decided to drop it. I do expect to run richer than the current set-up, controlling cylinder head heat will be more of problem than high EGT. Being "air cooled", the head/barrels retains a lot of heat which builds up and up. i expect it to do so on the salt. My only experience is on the track racing in Period 3 historics which you are up and down on the throttle so heat is not so much an issue. I decided to run cast pistons instead of forged. Forged tend to nip up or i should say "lock up" when too hot.

Separate from the overthinking the heat thing, Clutch slippage was our first hurdle to overcome. If you saw the dyno chart at the end of the video you can see the earlier run where we were losing approx.10hp due to slippage. We changed springs and plates and various combinations. They are not the greatest clutch set-up, a hydraulic conversion would be nice but maybe too fancy for the period. Again one can improve or overcome inefficiencies by converting to water cooled barrels, but i might as well get later bike as a platform. I am *rooted in the vintage world (rooted can be interrupted both ways) You guys must be getting 80+hp out of your RGV's ?

Von Titan

What you said confirms what I understood to be the performance limiting factor with Air Cooled engines ...

I had clutch slip issues on the first Dyno runs ..... There was some info about that this can happen to RGVs using a full synthetic gearbox oil (Motul in my case) if the clutch had a few Kms on it ......
am lucky enough that the Clutch design is good and can run an over the counter heavier springs by EBC ... I also change to a mineral gearbox oil the original Castrol MTX .... but I am pretty sure if your clutch is in good condition any Brand name Oil works fine .....

RGV 80hp, no they won't make that sort power on gas/petrol, 75hp tops as they really are a Production Bike, not like the Yam TZ or Honda RS engines ...

Pete

Lookin good,
There is some debate on this forum which is the fastest colour , red or green, you guys will add weight to the debate, cant wait to see the fastest colour proven once and for all. At this stage my mellow yellow proves yellow is the most unreliable, although that bloody triumph has taken all my colour luck.
just remember to enjoy the experience you need to be like father xmas and bring enough biscuits for everybody.
cheers johno

Great work guys on the build.

As the guys all say run it rich (a couple of jets more then you think) you can always come back. A mile pull flat out on the salt in the high temps sure does increase the heat and stress.
Our bike started with a 4 plate clutch and now has seven and shims and better springs.
Remember to finish first you you have to finish.

Look forward to catching up on the salt.

Kind regards,
JP

Good looking build there, will be great to see and hear another two stroke on the salt.

The T500 is not that old. I can clearly remember when the 305 Yamaha ( and Hondas ) were the largest available. And the Anzac biscuits, what memories they bring. A few years back I rode a full suspension Mountain Bike from Brisbane to Longreach. Mum supplied plenty of Anzacs as they are my favourites. ( bit of a problem carrying them on a pushie) Yum. She also supplied them for my MTB ride to Birdsville. double yum.

Hope all goes well on yr first visit to LG and you get the speeds without any probs.

See you there ... Ian R. #1215 ( Aprilia 125)