Watercooled conversion?

[m in sc]

ive used studs from elsewhere as well.   

LC pistons aren't as available here in the US, but i've used both. ive been running mine in various forms since 2004, i've never noticed one piston style wearing more than others so in the end, i dont think it really matters that much. 

Robs bike was a complete lc motor swap, probably the smarter way to do it as the pump is already in the motor, but you have to make new motor mounts. 

yes, they run stronger for sure, they take to porting and head work quite well, and the temperature control help a LOT. But, its a project for sure.  also note: the exhaust studs are the same spacing as an rd400.(for reference).

[stresa]

Mark,
it was not a wearing problem we ran into. On not proper heated up race bikes we had some cold seizures. I am with you. Don't think that it is much of an issue on a road bike. But we have LC pistons easily available here so I think its better to use pistons that are designed for use in these LC cylinders.
Regards Uwe

[IR8D8R]

There was an RD350 side cover already milled to accept a water pump for sale on Ebay for a long time. At least I think that's what's going on.

https://www.ebay.com/itm/113714936583?hash=item1a79f03b07. Looks grubbier than I remember so maybe not the same one.

Says "Kick Stater" at the plugged kicker mount hole. ..."R" is missing. Which is weird. Definitely altered.

IR8D8R

[m in sc]

i can see that. yup looks to be modded to accept a tz pump.

[elliottles1]

another old hack for these heads in the uk where they were REALLY common, was to scrap the head gasket, lap the surfaces together and then assemble with heat resistant silicon, it gets the squish just right. i tried it on mine and it worked.

les.

[pdxjim]

Yes, these appear to be intended as replacement cylinders for the 1980-83 RD350 LC (RZ350 in Japan).

They have the same stud pattern and transfer layout as the aircooled 1973-75 RD350 and will bolt on to those cases without modification.

Our RZ350 was known as RZ350R in the JDM.  When shopping Webike or other JP websites, RZ=LC, RZR=RZ.

... and as Les mentioned above they can be run without a head gasket.  I had Chuck Q cut mine for o-rings and use RTV or Threebond at the water jacket.. I believe he said it was too tight without relieving the squish a bit, but that was a few years ago, so I may be remembering wrong.

Looks like UK tuner Dave "Mutts Nuts" Wattam is awaiting delivery on a set of these cyls and will be able to comment on their quality soon.

... and modern Banshee/RZ pistons work great as long as you trim the tang.

[m in sc]

i cut the head on mine myself, 1st w the mill, then the squish.. which wasn't easy on a lathe as i had to make a counterweight, and a crazy looking rig, to get it right to use readily available pattern gaskets.  but its been good for a long time. 

[teazer]

...If you want to do water cooled on a RD, use TZ parts, they're cheaper... and probably better quality

4 transfers? What's the point? If you were making new barrels for a RD why not 6 port? and a boost port?
... and why no removable domes (it would make them cheaper to produce... and better)? or at least some sort of description of the head dimensions.
Seems to me these are strong on bling, weak on upgrade

All good questions but 6 port TZ350G aka 3G3 barrels are piston port and only the works OW31 and replicas had reeds plus 6 transfer ports and they still had small RZ350 sized reed valves. 

RD350LC barrels were being ported back the day to make as much (more or less) power as a comparable TZ350 and they or the RZ or any model of TZ is very old school cool. If the objective is mega amounts of power start with a banshee or RZ and add a stroker crank and big bore CPI barrels and you are looking at over 100-150 hp.

For a reliable street RD making more power than stock in the old configuration, a set of plated LC barrels would be a good place to start. And won't make so much power to overwhelm the chassis.