For some reason, I've been looking into liquid cooling. I'm not sure that it's a good idea for me, since I like 90cc+ mild street stuff for my use. I'll post the stuff I've looked at and my thoughts though, and see if any of you have suggestions or opinions on either the stuff I've looked at and alternatives or the whole idea of liquid cooling for me.
Be warned; I'll probably ask a few stupid questions or make silly remarks as I have exactly 0 experience with small liquid cooled engines.
Radiators : It wouldn't have to be from this seller, as many sell them for about the same price, but these are the ones that looked decent to me after some searching for various 85-125cc dirt bike radiators (2005-2014 Yamaha YZ125). They have brackets that look like mounting would be as easy as any of the rads I looked at and most of the hoses would be in OK locations. The outlet is at the top, which seems like a good idea other than not being as clean as the setups with 2 bottom inlets/outlets. Not sure about the hose sizes, but they should be able to work as long as they're in the ballpark. I'd imagine cooling should be more than I'd ever really need, since the combination of 2 rads are at least as big as the radiator for my TMAX 500 (it does have a fan, which this wont, but it doesn't come on much).
The setup from scootertuning.ca (also linked below) looks to be as simple as you can get to setup, but I'm not paying that.
www.ebay.com/itm/FOR-Yamaha-YZ125-YZ-125-2005-2014-06-07-aluminum-alloy-radiator/352112064562scootertuning.ca/en/cylinders-replacement-parts/17092-bolt-on-radiator-set-yamaha-bws-zuma-2002-2011.htmlIf I went with the YZ125 radiators, I could get the anti-vibration mount setup from Yamaha parts dealers. I could probably also make something on the lathe and then use universal rubber grommets. The Yamaha parts that I'd use would be 90387-06065-00 (collar) and 90480-15528-00 (grommet). I wouldn't pay Yamaha for their bolts or washers. I guess I'd need 4 of each of those, with shipping that's around $30. If made at home, probably less than half that cost but much more time.
www.partzilla.com/catalog/yamaha/motorcycle/2005/yz125-yz125t1/radiator-hoseOverflow/Expansion : The YZ125 looks like it just has an overflow to the ground, but I'd probably want an overflow tank. Not exactly sure what yet. Something small. Suggestions appreciated. I'm assuming $20-30 should do it for a new part or less if I can get a good condition used part. I did notice Polini makes one for $25.
scootertuning.ca/en/cylinders-replacement-parts/17112-expension-tank-polini-with-cap.html
Water Pump : Electric pumps look great for lowering parasitic drag, and they can be ran even with the engine off to help cool if needed. I don't think the latter is of much use to me, as I know it mostly as something drag racers do and hopefully whatever setup I have would not have major cooling issues. Reducing drag is nice, but I think a mechanical pump may be right for me. I don't wish to have to worry about my electrical system (already running 100W worth of headlights) and the mechanical pumps sound like they're pretty reliable. I was checking out the HOCA pump for $70 and the TPR for $80.
scootertuning.ca/en/cylinders-replacement-parts/17064-water-pump-top-performances.htmlwww.partsforscooters.com/169-136_Water_Pump_HousingI'd also need the studs to drive the pump, which are about $15 for a set.
www.partsforscooters.com/169-352-Hoca-Minarelli-Water-Pump-Stud-KitI'd still need hoses and clamps. I could stick with CHT, but I'd kinda like to monitor water temp so I'd either need to switch or add a new gauge. My CHT doesn't work now anyway. Could be $50-100 in accessories, depending how that goes. So at this point, the cooling system parts are totaling up to somewhere around $250-300, but could be more. Also, a link to the clear hoses you guys use would be appreciated if someone has it handy. I know it's in one of the build threads, but it didn't come up in a search and I haven't looked through them all.
Thermostat : Does anyone even use one on these? Looks like it fits under the head, but quick searches made it seem like most just let it flow full time. Could suck if I ride in cold weather I'd think.
Cylinder Kit : This is where it goes a bit pear-shaped for me. There aren't many options (that I've found) for mild 90cc stuff in liquid cooled kits. Basically the Hoca 53mm bore kit and a 54mm kit from Autotech355. Both are basically $300, double or more compared to what I typically pay for air cooled 54mm kits.
www.partsforscooters.com/169-153-90cc-Big-Bore-Head-Kit_3www.ebay.com/itm/Top-End-water-cooled-8-ports-54mm-big-bore-kit-Apex-Pro-MXR-90-ATV-/232497004981?vxp=mtr&hash=item3621e6c1b5The Hoca kit is listed as 77.9mm tall and the kit from Autotech says 77mm tall. Both would be considered short or maybe regular cylinders for the 90s and would be intended for shorter strokes like 42mm. I have 2 new and one used 45mm cranks around, so I'd rather not buy a 42mm... plus losing some displacement. I have used short cylinders many times with 45mm strokes on my air cooled setups, and sometimes it actually works out better than the tall cylinders do. My issue here is, it seems like it would be more of a pain to modify the LC setup if needed. Base gaskets or spacers shouldn't be any different on LC than AC, so that part is fine. Head gasket thickness or milling (actually just sanding on glass in my case) are often used to get the squish right. I guess with a modular head, it may be just about as simple, but I'd think it's more difficult to work with the LC heads as far as thickness. Maybe it's not terrible if all surfaces are level with each other?
Another thought with those cylinders is; how long will they be around? PFS has 2 Hoca cylinders. There aren't many listings for them on eBay. There are certainly enough around right now, but how about in a few years? The AC stuff is more common, so I'd guess that will be a safer bet down the road. There are also stock cylinders for the DRR and Apex ATVs, but they want a small fortune for stock top ends.
There is stuff like the TPR 86cc kit that is a decent price ($480) for a crank and cylinder kit claiming up to 24HP, but even that would need an exhaust and a better ignition so you can still expect over $1000 into the engine combo. Lots of high end stuff is out there, but my impression has always been that it's not a great idea to try to ride 200-300 miles in 8-12 hours straight on such a setup and even if they make it through that stuff, the single ring race oriented kits will always require more maintenance and wear any driveline parts more quickly as the tradeoff to all of that wonderful power and RPM. Also more "fun" to tune. Plus, I'm not sure if the aftermarket ignitions will deal with 100W of lights well, and they are essential for me at night since I ride mostly areas with no lights at all (corn fields, forests, swamps).
scootertuning.ca/en/cylinders-high-end-77-100cc/17107-cylinder-package-tpr-86cc.htmlWhat it all comes down to are these questions/concerns :
- Is it worth ~$600 for me to tool around at 7500-9000RPM on a ~100cc? The steady temps of the LC setup should help, and maybe a little extra power could be made, but I wouldn't expect a whole lot of difference. Even if I set it up for the Peace Pipe and it revs to about 10,500RPM, I'm not sure that it's worth it. That setup is more likely to run hot, but then I don't generally ride around using all of it's potential when it's AC anyway. For racing or even for a 70cc where tons of kits are available, it would make more sense to me.
Perhaps I could just stick with a 70cc midrace with a C16 and be happy and have something that holds up and isn't quite as expensive. I don't know that I'm ready for that yet with 2 brand new 45mm stroked bottom ends sitting here and the one in the scoot.
- Is it worth if for the complications? 2 large radiators, hoses, overflow, and way more potential for leaks.
- So much for anywhere near a stock appearance. I do enjoy that T2 looks pretty stock. I mean it's odd looking, but the engine doesn't raise any red flags, especially with a PG pipe on it. It is fun to try to fool other scooterists, though most that know much comment about how it sounds anyway and realize they're about to get smoked... but my main concern is the popo. Will hanging two obvious radiators off of my little scoot cause an officer that wouldn't have raised an eyebrow to bug me about what I'm riding? Some of them already have pulled me over thinking I'm riding a dirtbike instead of a scooter.
So yeah, there's a bunch of the stuff I've thought about regarding going to liquid cooling. I think I mostly like the idea of it because I've never done it. Once I get beyond that and look at the details though, I'm not sure that it makes much sense for me. I've been told numerous times over the years that I should consider LC, but I have a feeling most of the people saying this have not looked into it too deeply considering what I do.
If I just want to haul ass, I could put the $1500-2000 that I'd probably have into the LC and a race kit into a sportbike (not that I have this cash around ATM anyway). Granted, that would only be 1/3 of something decent used, but I'd be looking at 100-200HP vs 20-25HP and something that goes anywhere and outruns damn near everything else on the road (of course I meant to say race track, wouldn't want to speed or race on a public road). The main thing that would lean me toward the race kit then would be the hilarity of playing with cars at lights with such a scoot, but then we go back to can it hold up to those all day rides to get to the beach where I do that? I can't say I'm a fan of trailer queens that get toted around in pickup trucks, although I would have a blast once it was unloaded. I could ramble on and on, but I'll shutup now and see what you guys have to say.
Even if nothing else ever comes of this and I continue to ride my AC junk around, at least anyone that has ever told me I need an LC setup should be able to see that I have been seriously looking into it.
Looked fun! Looked like you even spun a little on one of those "launches"? GiTTyHaaah! 
