Watercooled conversion?

[pdxjim]

Anyone wanting to do a watercooled cylinder conversion on their DS7, R5 or RD350, here's your chance to work with new parts!



https://japan.webike.net/products/25625108.html

[rodneya]

Nicasil bores. Nice

[bitzz]

It says it's for a RZ... but won't fit a RZ
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

[pdxjim]

These are reproduction first gen RD350 LC 4L01 cylinders and heads.  Known as RZ350 in the Japanese market.

They appear to be true to the design of the originals with the nikasil bores as the only upgrade.

Look like a great option for those wanting to keep a stock appearing engine.

[m in sc]

wow! didn't see that coming. that's awesome!

[Striker1423]

ooo. looks good

[gargantua350]

Hello,

Would I need RZ pistons?  Does this bolt on to an RD350 bottom end no problems?

How does the water cooled compare to aircooled power wise?  Is there better porting on the water cooled?

Can the VM28s be utilized without any issues?  I assume I would need a water pump would that be mechanically or electrically driven?  would spec 2 classics be compatible with this set-up?

thanks...I figured i'd ask the experts here.

[sav0r]

I will preface this by saying I don't know what I am looking at. I have researched it precisely none.

But it seems these are replacement cylinders for water cooled RD350's which are denoted by the "LC" moniker. Or as Jim points out, for the Japanese RZ350 which is the same as the RD350LC.

These are not for aircooled RD's as far as I can tell.

Somebody feel free to correct me if I am wrong. But some clarity to the entire situation would be good.

[Hawaii-Mike]

The water cooling plumbing and radiator would need to be configured.

[elliottles1]

Hi,
done this conversion before, they do indeed fit straight on any earlier model, however the stud lengths will need to be longer, and the liner tangs on the 350cc barrels i believe touch the flywheels so they need to be taken down a bit. i used a bosch 12v coolant pump from a volkswagon golf, about 50 euros. never had a problem.
cheers
les.

[m in sc]

I too have done it, a few times.

you use the same pistons as an aircooled, rz pistons will work but you still need to detab the piston as its not a bridged intake.

aftermarket radiator for an lc and n electric water-pump makes it pretty easy.  you DO need 12mm longer studs to bolt the cyls/heads down but it absolutely bolts onto an aircooled 250/350 case.

ive never had a liner issue on the flywheels in my experience.

[Hawaii-Mike]

Interesting! How is the performance with the stock cylinders, that is if the water cooled cylinders aren't ported, compared to an a/c RD?

[gargantua350]

I remember several members bolting these cylinders on an earlier bottom end with success.  On the old forum I believe Rob bolted it on his R5 bottom end with success as well.  He had stock pipes I believe.

So yeah, it can be made to work with the "aircooled bottom end".

thanks

Hawaii Mike, Elliots1 and Marc.

[stresa]

As Mark said. I have 2 aircooled engines to watercooled at the moment and never ran into flywheel troubles also.
Mark, you can use RD/LC pistons if you use LC cylinders or TZ pistons if you use TZ cylinders. It is definately the better choice as aircooled piston as the taper and material of the LC pistons are matching the cylinders.
On both of my current engines(one with 250LC top end and the other with TZ250 top end) I have a TZ waterpump. But I had converted engines in the past with a electric waterpump solution. Both works.




Regards Uwe

[elliottles1]

hi,
one "cheat" that i used, that people will probably hate me for, was to buy a metre (yard and a bit) of high tensile threaded bar from the local hardware shop and cut studs of appropriate length for the cost of about 5 euro. they never failed once.
les.