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Looking at relocating the rad in the geo ice racer from the engine box inside the car to the front of the car,looking to reduce the engine box temps by not preheating the air with the rad.

The distance would be about 4',will the stock R1 pump do it or am I asking for trouble?.If an electric pump is required any affordable suggestions?.

If the pipe id is close to the same as the pump inlet and outlet, flow will be about the same with the original pump. It isn't critical. The extra coolant in the pipes slows warm up and delays overheating if there is a problem. The pipes also radiate some of the heat and aid cooling.

Have a look at my build. My car is rear engine with the radiator at the front. The cooling system holds just on 5litre of water compared with 2 1/2litre for a ZX10r. My radiator is the same size as the bike. My water temp sits under 70deg while driving.
Works great.

Ok thanks guys I'll give it a try.

The longer the pipe run to the rad the higher the probability of pump caviation. When you have to move a long column of water quickly with the extra water mass and a quick rev'ing motor, you can run into problems. It makes it even more difficult when you have a bike engine that quickly changes RPM. Place a coolant fill canister that Tees in close to the water pump inlet side and a by-pass water line from the out let side of the engine back to the canister. That way when you quickly rev the motor the water pump can draw water from the canister Vs moving the all the water in the system. Once the water flow caughts up, the by-pass will refill the canister. Search F-1 cooling systems for build ideas. They had a lot of problems when the rad used to be at the very front of the nose.
Been there done that with a Mid-engie Hi-rev'ing motor Dave W

Now see, that's why I like this site. I'd have never thought of that. My thought was that it wouldn't matter.

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I drive therefore I am

I can explain it to you,
but I can't understand it for you.

Dave makes a great point. Production vehicles including water cooled bikes normally have a coolant bypass already. This should be retained at the original distance to the pump.

The heater is another bypass, but a few vehicles still use a shut off valve to stop flow when the heater is off. Most have no valve so it is bypassing all the time.

The bypass flow should be no greater flow than necessary, since it bypasses the radiator.

Suction side hoses usually have a coil spring to prevent their collapse, but the pressure differential is not enough to cause cavitation.

Meizure(spelling?)makes a universal electric with 1" ports to match the R1 hose size and with a 20gpm rating.That sounds like lots of flow,they get bigger from there.

I just reread my previous post and I wasn't clear. It was good that Dave brought up cavitation, but it isn't a problem if you do not eliminate the original bypass.

If cavitation were a problem, a higher flow pump would make it worse.

I need to have a close look at the R1 cooling system as I'm not clear what section is a bypass.The electric pump would have a consistant flow regardless of engine rpm.Removing the water on the R1 means removing the oil pan which isn't possible without pulling the engine which I'm not planning on doing anytime soon.

4' won't be a big deal but avoid sharp 90 degree bends if you can and of course figure your air bleed points carefully.

I see your point. I was thinking peak gpm in general. Don't know what peak gpm is on an R1.
If the oem pump already puts out more than 20 gpm at least 1,000 rpm below peak rpm, then there would probably be enough performance gain to offset the inefficiency (heat at the alternator stator and pump motor).

The problem with electric water pumps is they are a constant load on the engine through the alternator. An alternator driving an electric motor driving a pump producing 20 gpm is a greater load on the engine than an engine driven pump producing 20 gpm.

Unlike a cruiser or tourer that has extra equipment and will likely receive some accessories, a bike like the R1 minimizes weight for performance, so they balanced required alternator capacity, necessary size, cooling, and weight.

The alternator stator can be overheated and fail prematurely from the extra load. A stator is usually about $150 and due to case size, are not easily upgraded to have greater capacity. Peak load would be driving after a jumpstart with a low battery charge.

Alternators in general are rated for peak output, not continuous load, which this would be.

Along the lines of what Cheap said, a bad bend in the pipe or stepped reducer to match the radiator or engine pipe id are worse than running a smaller pipe.

Also consider that flow with the thermostat is closed is only using the oem bypass and heater.