Cool head on Athena Banshee Cylinders

[chippy]

I'm building up a Yamma Gamma (Rz350 motor in RG250 frame 85 model) with Athena Banshee, cylinders. I know there's better cylinders out there but at 580 AUD. Per set they were cheaper than Rz350 cylinders and fitted within my mongrel build budget. I'm not racing it's just a weekend rider for fun rides through the mountains/Hills.
     Is it worth it to buy a cool head, Pro design, Noss Machine or Chariot Performance to run on it. Should I stick with the Athena head. I'm not up on interchangeability of aftermarket domes with the Athena head. And don't know how hot these things run in a rg250.

[bitzz]

I'll tell you the Athena is probably the best choice for a street bike... and the worst choice for a racer.
I think you would be better off with a bigger rad than a head. There is nothing WRONG with the Athena head as long as you can keep it cool, which shouldn't be a problem on a street bike
Pipes are going to be a problem

[85RZwade]

Larger capacity radiators are available and electric fan additions are a proven benefit. As stated above, any RZ pipes will need different flanges to fit the banshee cylinders. It can be done.

[chippy]

Yeak thanks didn't want a race ported motor that drinks like a fish. I'll stick with them for time being. Can get a slightly larger radiator off eBay for not much $$. I'll run that and see how it goes. Just got to find some old rz pipes that haven't been  bashed about too much, 350 stuff isn't easy to get. Was gonna start with some 28mm vms from one of my rds to start with.

[Vintagetz]

We used the Early R6 radiator on a race bike I helped build.  It is a cross-flow radiator so the tanks are vertical on the sides, and the outlet is on the right side bottom like an RZ.  you can get them new cheap and used even cheaper.  Not sure how it would pair up with the RG gamma frame.

[chippy]

Thanks I'll take a look at that

[bitzz]

When I said pipes are a problem, it is because you're putting a Yamaha motor in a Suzuki frame. RZ pipes aren't gonna fit AND you're going to a 68mm bore, increasing the displacement by 10%, with 25% more port area... so RZ pipes are gonna be too small in the head pipe.

... but then you say you're put 28mm carbs on it... if you're gonna choke it down so much on the intake side, RZ pipes might work.

If you're looking for suggestions: 32 or 34mm carbs (I run 38 and 40mm TMXs on my 421, but I spend most of my time at redline), preferably PWK and Swarbrick TZ350 pipes (Swarbrick pipes come in "kit" form and you get to weld them up in any shape you want and Swarbricks have the nicest silencers on the market. The TZ pipe has spigots like a Banshee and IIRC a 42mm down pipe compared to 36 or 37mm on a RZ).

[rodneya]

Do you have the Athena cylinders only?
I have only ever seen them sold as a kit with a head included that has removable domes.

[chippy]

rodneya - Got the whole kit, cylinders heads pistons, rings , domes and gaskets.

bitzz - was gonna try Mikuni VM32SS semi-flat carburetors off an 89 RGV250 (rejetted)

[teazer]

I suspect that the improvement in cooling from Athena to Cool Head will be small compared to a cool head change from a stock head.

And Y E S to Swarbrick pipes.  I had a set for an RD400 project and bought some for a TZ we ran and then found two more TZ sets to use on various projects. The only issue is making sure that the stinger is well supported and welded properly.  We had one pair crack off repeatedly from vibration but we think the welding had made the pipe brittle and fracture prone.

[chippy]

It's kinda of a budget build at the moment. Fixing my ute at the moment so I'm keeping my eyes out for second hand rz350 pipes, not a lot of 400 pipes floating around in Aus. I'm thinking that adapting standard rg250 pipes isn't the way to go either. So I'm just starting with the 392 Athena on a rebuilt rz250 bottom end. Got a set of banshee straight cuts and a Hinson billet basket from another canned project that I'll put to good use.