GT 380 with RG 250 cylinders

Getting your blazingly fast Suzuki powerplant to perform even better!

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tz375
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Re: GT 380 with RG 250 cylinders

Post by tz375 »

Unfortunately, I don't have an RG port map. The longer rod is not a problem. The OP fitted a thick spacer. Or look for shorter rods with correct big end and small ends.

You could also just port the 390 motor and add decent pipes to get 60-70hp, but I like the idea of watercooled top end.
v.f.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

If to do the engine that with water cooling.The water pump small electric also it apparently is enough. Though probably the rg250 engine is not really forced and is not really strongly heated. It is possible to take pipe drain from rg250, they not expensive and in my opinion quite not bad for turns up to 10000. I cannot find Porting map on rg anywhere.... (((
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tz375
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Re: GT 380 with RG 250 cylinders

Post by tz375 »

Agreed. A small electric pump and moderate sized radiator should be sufficient.

For the pump, Davis Craig sell one and there's also a Bosch electric pump used on may VW cars that is small enough but it's a bit ugly. You can probably get one like these locally https://www.ebay.com/bhp/vw-electric-water-pump" onclick="window.open(this.href);return false;
v.f.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

Means we will think...))) you do not know, clutch of gt380 will sustain power 60-70 HPs.Yes, the water pump such, even is possible less, this consumes 5-7 amperes.
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tz375
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Re: GT 380 with RG 250 cylinders

Post by tz375 »

The clutch may need different plates and springs. Just as a point of comparison, an RD400 clutch can hold 70hp and a Banshee clutch (the same as an RD400) has been known to deal with more than that.

RD400/RZ350 have 7 friction plates and a GT380 has only 6 I believe, so if teh clutch slips, it may be necessary to find thinner plates or a basket that can hold 7 plates
v.f.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

And there are not original clutch plates on gt380? On my gpz1400 there is APE clutch, is one more frictional and on one steel disk... Does not slip, but so far oil will not get warm, the gear shift is complicated.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

Rg250 ports....
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v.f.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

People who has street porting map rg250???
Indy650
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Re: GT 380 with RG 250 cylinders

Post by Indy650 »

This is pretty damn awesome not only because of liquid cooling but because those cylinders can make much more power than the stock GT 380 cylinders. I'd love to build one of those someday.

I've done this type of thing before on snowmobiles. One being 3 Polaris XC 600, 700 or 800 cylinders on a Polaris triple jetski bottom end with a taper mod on the crank to fit a snowmobile clutch.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

I changed wheels, brakes front fork, clips. It remains to make the engine gt380 and shove it into the frame rg )))
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Re: GT 380 with RG 250 cylinders

Post by Indy650 »

Man, that is a beautiful bike. I caught my self drooling :P :P :twisted:
sportston
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Re: GT 380 with RG 250 cylinders

Post by sportston »

Seems such a nice bike in standard trim. Is the standard RG250 motor too slow for you? It sure would be an interesting bike if you had 3 liquid cooled pots to play with, but it definitely would be a much heavier engine than the standard gamma unit and wider. I'd love to see the end result if you go ahead and do it. I was thinking of something similar myself using RD125LC pots instead of RG ones. I know they make about 21-22 horses each with decent pipes on. Multiply by 3 and you could have 60 odd bhp (in armchair guestimate theory) before you even think about tuning or big-boring. Start tuning for higher performance and you've got a bike that would be at least capable of giving a Kettle a run for its money.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

Thank you guys for your interest in my bike.
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Re: GT 380 with RG 250 cylinders

Post by v.f. »

I will explain why, I want three cylinders. I often drive around the city, and my weight in equipment is about 88 kg. I do not have enough torque at low and medium speeds. If I would use this motorcycle only on races, then probably, I would increase the power of this engine. The weight of the gt380 engine in my opinion is not much more. I think the handling will not deteriorate. But there are problems with the layout of the engine and frame.
sportston
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Re: GT 380 with RG 250 cylinders

Post by sportston »

The Gammas were known to handle very well so, if you can squeeze the motor in, I am sure the frame could handle it. I had a Gamma 125 when I was 18. Loved the handling of that bike. Rode a 250 Gamma and it felt very similar but I was a little underwhelmed by the performance. Perhaps it was not a good example. Good luck with the conversion. I can hardly wait to see what it looks like with both sexy bike and sexy triple motor.
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