Yamaha rd350 Road Racer Liquid Cooled!!

Re: Yamaha rd350 road racer

der_nanno said:
Oh I remember the article, even though I must have read it ages ago!
I've read it through several times, now to put it into practice
 
Re: Yamaha rd350 road racer

Redbird said:
Levi, the spare RD400 tank I have weighs in at 9lbs on the digital bathroom scale.
And that's minus fuel tap and cap.
Mine weighs in at 3.4 with the caps and taps in place. Thanks again for the numbers
 
Re: Yamaha rd350 road racer

How will you seal that tank against modern ethanol based fuels? I sealed an old tank recently with Caswell but it was a PIA to scour the inside surface to get a good key for the coating.

Just sell if to me and I'll cut the bottom out and use it as a shell for our drag race bike. See how I saved you there.... ;-)

I'm kidding about the last bit, but it will need to be sealed somehow.
 
Re: Yamaha rd350 road racer

teazer said:
How will you seal that tank against modern ethanol based fuels? I sealed an old tank recently with Caswell but it was a PIA to scour the inside surface to get a good key for the coating.

Just sell if to me and I'll cut the bottom out and use it as a shell for our drag race bike. See how I saved you there.... ;-)

I'm kidding about the last bit, but it will need to be sealed somehow.
Haha I see what you did there. I haven't thought about sealer yet, but, for the short term the plan against ethanol will be to run aircraft fuel, as for the compression values I will likely be running (need to pick your brain on that one too) will require high test gas, and the local airport is a stone's throw from my house. I generally get fuel there for winter storage anyhow. I wish there were some of those ethanol free gas stations around here like there are in the south....
 
Re: Yamaha rd350 road racer

No need for avgas, you have non-ethanol options. Avgas is usually 100 octane. Too bad you don't have options like I have options, but you have options.
 

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Re: Yamaha rd350 road racer

irk miller said:
No need for avgas, you have non-ethanol options. Avgas is usually 100 octane. Too bad you don't have options like I have options, but you have options.
I,ve sen that site before, but I'm in Marion, and that Delaware marina (the closest one) is about 40 minutes of pain in the butt highway to get to. For now, being as I pass the airport twice a day, I'll use that for the time being. Maybe make a run to the marina with a few "stock up" cans when the time comes. Thanks man!
 
Re: Yamaha rd350 road racer

If you're worried about roughing up the interior of the tank for Caswell, then put a handful of drywall screws in the tank and tumble it for an hour.
 
Re: Yamaha rd350 road racer

You should be able to find some VP U4 in 5 gallon cans close by.

Avgas is 100LL (low lead) dry gas.
 
Re: Yamaha rd350 road racer

Tune-A-Fish© said:
You should be able to find some VP U4 in 5 gallon cans close by.

Avgas is 100LL (low lead) dry gas.
I'm not on the up and up on leaded vs. Unleaded. Your saying I'd want to run leaded?
 
Re: Yamaha rd350 road racer

hurco550 said:
I'm not on the up and up on leaded vs. Unleaded. Your saying I'd want to run leaded?

I'm not sure if unleaded would hurt it but it ran on regular in the day which was 90-92 octane leaded fuel. Dry gas has less lubricity.
 
Re: Yamaha rd350 road racer

VP U4.4 has alcohol and whole lot of other chemical soup and it's 90 bucks a 5 gallon pail. Stay away from slow burning avgas designed for engines that peak at around 5,000.

CR 17:1, and a load of VP C12 and you should be golden. OK, so not so high. I got 20mm domes for one RD and plan on using 18mm domes in the drag race motor. Compression is related to exhaust port height and exhaust efficiency. With high port and poor exhaust, the effective compression is very low. If the pipe is working well and creating a perfectly timed stuffing wave, the effective compression is much higher.

The other variable ( there's more than one, but let's keep this simple) is squish band or more specifically Mean Squish Velocity which is a function of squish width and depth and angle and RPM. For low revs, we use a tight squish band and/or a wide one. For a top end motor we need a narrower band to keep MSV down at higher engine speeds.

For a slightly warmed over bike with mild porting, compression can be raised a little but not too much.
 
Re: Yamaha rd350 road racer

Or just make it simple and throw a handful of drywall screws in the tank, tumble it for an hour, line it with Caswell, and go to your nearest gas station for a fill up.
 
Re: Yamaha rd350 road racer

It's a race machine and race machines need race gas ⛽️LOL get some oxygenated VP gol dang it


Sent from my iPhone using DO THE TON
 
Re: Yamaha rd350 road racer

irk miller said:
Or just make it simple and throw a handful of drywall screws in the tank, tumble it for an hour, line it with Caswell, and go to your nearest gas station for a fill up.

dangit, I think the artist may be right again haha.

will all the old sealer need be removed before, or just roughed up to accept the new caswell?
 
Re: Yamaha rd350 road racer

hurco550 said:
Haha I see what you did there. I haven't thought about sealer yet, but, for the short term the plan against ethanol will be to run aircraft fuel, as for the compression values I will likely be running (need to pick your brain on that one too) will require high test gas, and the local airport is a stone's throw from my house. I generally get fuel there for winter storage anyhow. I wish there were some of those ethanol free gas stations around here like there are in the south....

I don't know if there are any Sunnoco dealers in your area but I'm using their 110 leaded fuel in all of my bikes now. I'm done with that ethanol crap.
 
Re: Yamaha rd350 road racer

teazer said:
VP U4.4 has alcohol and whole lot of other chemical soup and it's 90 bucks a 5 gallon pail. Stay away from slow burning avgas designed for engines that peak at around 5,000.

CR 17:1, and a load of VP C12 and you should be golden. OK, so not so high. I got 20mm domes for one RD and plan on using 18mm domes in the drag race motor. Compression is related to exhaust port height and exhaust efficiency. With high port and poor exhaust, the effective compression is very low. If the pipe is working well and creating a perfectly timed stuffing wave, the effective compression is much higher.

The other variable ( there's more than one, but let's keep this simple) is squish band or more specifically Mean Squish Velocity which is a function of squish width and depth and angle and RPM. For low revs, we use a tight squish band and/or a wide one. For a top end motor we need a narrower band to keep MSV down at higher engine speeds.

For a slightly warmed over bike with mild porting, compression can be raised a little but not too much.
Im having a hard time finding info on what exactly the rd350 head cc should be. Should I make it the same as stock after I do the head/squish machining work? It makes sense with raising the ex. Port having less effective compression.

I also just printed this off today. I'm about 10 pages in at this point already learning alot, but I think my brain may be bleeding a bit as well from the volume of info ha
c38cbced7ced37f688dd17a096a695d3.jpg
 
Re: Yamaha rd350 road racer

Great book. That man was ahead of his time in many ways. Of course, things have moved on since then and there is more knoweldge in teh pool to dip your toe.

A.G. Bell is a good read - probably easier to read.

Q: do you plan to race it, do track daze or just ride it hard and put it away wet? If it's for teh race track, race gas is a good solution but you don't need super high octane levels. C12 is fine for most things. My race GT750 will run happily on 93 octane street gas but I have run it on U4.4 (wow) and set a new personal best with a drum of old C11 pre-mix.

For a high comp race type motor C12 is fine.
 
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