Water cooled 500

[greasemonkey]

I know dave, but you know that's not possible for the most of us. And plug and play parts are so boring
And IMHO 2 rotax cylinders would whoop an tr's ass (badly)

[tz375]

That was the point of my original post until someone reminded me about those twisted ports and the lack of space between the barrels.

You could always take a Rotax motor and glue a decent trans on the back of it. Not vintage legal anywhere on this planet, but could be a fun project - not T500 parts in it though.

[Suzukidave]

It sure looks to me that Suzuki designed the cylinders too close together for any design that has the transfers inline

[Suzukidave]

A thought .. maybe down size the cc's of the engine to maybe a 250cc twin but with new tech cylinders could still get a good 80 hp and the smaller bore maybe would allow for the inline transfers ?

[diamondj]

Here's a link to the post on the later MK III TR500 water cooled cylinders:

viewtopic.php?f=2&t=263&hilit=tr500

As you can see the transfers are in the traditional 9 and 3 o'clock positions but are damned near siamesed to do it. You would have to weld up and rework a standard T500 crankcase to use these. So whatever cylinder you want to adapt would have to be pretty compact outside the bore.

For a Suzuki related challenge, get an Arctic Cat water cooled Spirit engine (built by Suzuki) and figure out how to add a gearbox to it. Kinda like Dr. Rob did with the Tularis.

The later 6 port air cooled Arctic Cat/Suzuki 500cc engines are supposed to be good for a reliable 75hp with minor porting. But the cylinders just won't fit on a T500 crankcase. I have started to wonder if you could slice the cooling fins down and bolt three 6 port A/C jugs to a GT550 though.....

Jim

[greasemonkey]

i wass thinking turning the 2 cylinders a bit to the same side, you have to replace te studs anyhow so you can turn and
place them like you want.
the aprillia rs250 got an narrow engine to and i don't know with solution (gt500<-> rs250) is better.

[tz375]

RS250 is a V twin and the cylinders are almost in line.

[greasemonkey]

calling it a V-twin wouldn't do the design justice,
the crank is very similar to a 500's
instead of turning the cylinders they moved them apart.

[tz375]

calling it a V-twin wouldn't do the design justice, the crank is very similar to a 500's
instead of turning the cylinders they moved them apart.

????
Of course it does. That's what it is. What you talkin' 'bout Willis?

Which V twins have you looked at recently? TZ250 with a similar crank or maybe an RS250 Honda that has a similar crank design or a Hoggly Doggly with two rods on the same pin? That Suzuki motor in the Aprilia is a V twin. That's how they make them........ Not all V twins are designed to run both rods on teh same pin. 2 stroke V twins have two pots on different pins as a rule - boat motors are the exception.

Now in the interests of full disclosure, I have been inside all the above mentioned 2 stroke motors, but no hogglies so far.

[greasemonkey]

ok ok ok it's a v-twin. but i will never call them that reminds me of a harley.

my first line of thougt was about what they did to make the engine narrower.

and no tz I also didn't look into any of the engines you named, I'm more of a single cylinder guy
these 500's are my first multi cylinder 2-strokes.

maybe my post count isn't high enough for this part of the forum

[tz375]

Everyone is welcome here. besides, it was me that started this thread with a similar question, so don't feel bad.

There's always a fine line as to how far something should be modified before it is too far. For some people stock is fine, for me I'll redesign and change it up to the point that it has become an example of spending money I don't have to make something that really has no purpose. Just because it can be done doesn't mean it should be done.

[Suzukidave]

I know i would never fall into that type situation

[greasemonkey]

thx man
I always catch me modifieïng stuff, and ik wouldn't be the first time I crossed that fine line you talk about tz.
but in case of this 500 I know it's possible, and BAM there's your ~150 hp tr500
just find the right ones.

on topic: the rotax cylinders are huge got more than an inch overlap, almost 1.5 when you hold them straight.
I collected a bunch of 125, 140, 200 and 250 gaskets from my local turd dealer.

[ja-moo]

I guess I'm just "old-school". I like to see what I can do with what the factory gave us. It takes a lot more dedication than adapting on new tech............. To me it's like bolting on a turbo or supercharger on a car. I like the good old days of hand porting the heads, high compression pistons, big cams and carbs........

[tz375]

Dave Maskell in the UK took a set of GT cases and welded them up to rotate the transfers back to a more normal alignment so that he could fit a late model TR500 water cooled top end. Mk11 was twisted and Mk111 was "normal" according to some of the pics I have and certainly teh MK111 I rebuilt many years ago had "normal" transfer ports.

If I were serious about a water cooled GT500or shall we call it a TR500/XR05 replica, I'd look at a set of Cheetah barrels to see if they could be adapted and then weld up the top case to match. I think that the only way is with a single barrel with a thin wall between the inner transfer ports.

We know that isn't the best set up and really needs the cranks further apart, we also know that a Banshee/RZ motor can make over 100hp with the right parts inside. The big GT flywheels give some scope for a longer stroke custom crank too.

Maybe when I finish the 100 or so projects I have in the shop I might add this one to the list...