rear mounted rad

[sjoe]

i plan on fitting a rear mounted rad to my surf, will the standard 1kzte water pump be powerful enough to pump the coolant all the way to a rear mounted rad?
if not does anybody have any recommendations for electric coolant pumps i could use?
thanks

[muddle]

Yes it would be powerful enough. Onece the engine is running the flow rate would be the same regardless of distance. Providing the pipes are the same diameter as the standard ones.

[POPEYE]

I think you may be wrong there mate, distance does affect the ability of the stock water pump, dont forget there are "take off's" for the rear heater, front heater and turbo cooler, so water/coolant will find the easiest route to circulate, of cource it all depends how you pipe the rear rad,
when i fitted a rear rad i removed the flow pipe to the front heater, ran it to the back, fitted a electric pump (albeit a 24v one, but it still manages to pump at a reasonable rate), from the pump i ran it to the rear rad (which also has a fan on it) and then back to the heater, and the heater return back to the engine,
this works quite well as i found out when i pulled the fuse on the leccy pump thinking it was the cause of the battery drain (turned out to be a duff batt),
temps went up to just over a 100 and all fans kicked in much quicker, with the pump back working it now stays around 90, with fans taking a lot longer to cut in,
these pumps we used on buses to help pump coolant to the front dimister, (buses being rear engined!)

[red barron]

Water Pump

As popeye has pointed out the stock pump is designed to circulate the water (coolant) around the engine. In what position and where are you mounting the "rear radiator"? To move the coolant in adequate quantity over such a distance you will need one of these. http://www.merlinmotorsport.co.uk/p1...duct_info.html

[sjoe]

the plan is to tray back the surf so the rad will probably end up positioned above the rear wheels.
popeye what pump did you use? are they regularly available? what kind of control system have you used or is the pump running all the time the ignition is on?
thanks for the advice guys

[POPEYE]

Hi mate, the pump i used (am still useing) is a Bosh 24v i managed to "aquire" from the coach builders, i tested it on 12v in a bucket of water and it shot a jet out fairly well for what i assume is half speed, idealy i'd go for a Bosh 12v, evpensive but they are made for long running duty (buses are running all day)

the pump is wired in a circuit that include's the large leccy fan i replaced the viscious one with and controlled via a thermo switch from CPC Farnells (very cheap and works well,) this is strapped on the top rad hose so when the stat opens the fan and pump come on, (the three stock surf back-up fans, two in front of the rad and one on the rear rad are controlled via the temp sender on the filler neck, the back up fan one, also i replaced this stock sender with one from a Corolla that cuts in slightly earlier than the stock surf one,

to get full controll over these fans and pump took a little complicated wiring but it aint too bad and i'll add a diag of what i did and some pics of the rad/pump etc, parts needed are a 5 pin cross over relay, a 40 amp relay for the pump (anither 40 amp relay if your fitting a fan on the rear rad), a double throw/double pole toggle switch, indicator light to show when the things are running, and some 3mm cable for the high power side and stock wiire for the pow side, connectors and what have you and that about it,
basicly your useing a five pin relay to controll the fans/pump relays, it's the only way i could find (with help from MattF to make these temp switches work the way i wanted, so i can wither switch the fans/pump off, switch them on all the time or switch them on to auto (via the temp switches) also useing a batt direct feed to power the low current circuit you get fan over run when the ign's switched off (like normal cars)
i'll need to look through some pics and diags before posting them as i may have altered summat and didn't alter the drawing, so i'll add these asap,

BTW that Craig pump linked there would be great, beyond my affordability tho, but if you can go for it! i only used the bosh as i had it already,

alrighty, first pic is the fan and pump diag (i hope) second is the back up fans (in case it's of interest)

[BUSHWHACKER]

Something else to think about is how fast the coolant is being circulated.
Too fast and the radiator won't be doing it's job..

[POPEYE]

Something else to think about is how fast the coolant is being circulated.
Too fast and the radiator won't be doing it's job..

I take your point Vince, all i can say is what i've done only lowers the running temp slightly, on a longish run the temp sits at around 90-95, with the pump off it runs at around the 100 mark, at a guess if i took the flow to the back from the lower rad return instead of from the heater pipes that could cool it even more and perhaps too much,
anyway i've had this set up on for several years and no problems, also when the weathers freezing i can switch off the fans and pump so it heats up quicker, (that dont take long on a 2.4

[Sylux]

OT...but...Popeye, I may have asked this before (so apologies) but what paint did you use on your underside and is there any prep/primer underneath?

Looks immaculate.

Currently mine looks awful and it needs doing. Including grinding/wire brushing the life out of it

[andyverran]

OT...but...Popeye, I may have asked this before (so apologies) but what paint did you use on your underside and is there any prep/primer underneath?

Looks immaculate.

Currently mine looks awful and it needs doing. Including grinding/wire brushing the life out of it

Save the wire brushing Sy:
http://www.dinitrol.co.uk/classic_cars.aspx

Popeye, fab looking truck, pity you couldn't bring it to that car show, would have liked to see it in the flesh. Maybe next summer?

On the water cooling front, not sure you can have to much pressure (within reason), what matters is the total energy exchange and average/even engine temp achieved, with high pressure the water temp to air temp ratio will be at it's highest all the time, exchanging the greatest amount of energy. If pumping at a lower pressure then the rad water exit temp will be lower, but the engine coolant temp higher (as it's in there for slightly longer)......particularly in the cylinder head.
Hence cars no longer use Thermosyphon cooling.

[POPEYE]

OT...but...Popeye, I may have asked this before (so apologies) but what paint did you use on your underside and is there any prep/primer underneath?

Looks immaculate.

Currently mine looks awful and it needs doing. Including grinding/wire brushing the life out of it

The red is hammerite, yeah it's a bit OTT but sod it, figured if i was going to the trouble i'd make a statment
prior to paint i just spent a lot of effort scrubbing, wire brushing, jet washing etc, then a load of red oxide, followed bt a mix of verious underseal paints a also got from work, i'd collect unsued leftovers and just mixed the whole lot, it just happened to be mostly the color you see, the other was an alloy based paint supposidly banned here and in the us,

[POPEYE]

Save the wire brushing Sy:
http://www.dinitrol.co.uk/classic_cars.aspx

Popeye, fab looking truck, pity you couldn't bring it to that car show, would have liked to see it in the flesh. Maybe next summer?

On the water cooling front, not sure you can have to much pressure (within reason), what matters is the total energy exchange and average/even engine temp achieved, with high pressure the water temp to air temp ratio will be at it's highest all the time, exchanging the greatest amount of energy. If pumping at a lower pressure then the rad water exit temp will be lower, but the engine coolant temp higher (as it's in there for slightly longer)......particularly in the cylinder head.
Hence cars no longer use Thermosyphon cooling.

Cheer's Andy, and i would like to take it to that show if possible, judgeing by a few landys i saw there i might even enter it

not sure i understand about the rest of what you said there all i intended was being able to push some coolant to the back (and back again)

[andyverran]

Judging by those pics it would be a hit there...

It's The Deers Hut Car Show if you want to drop them an email, I used to work with the guy that runs it and he will begin organising it soon...

[Sylux]

The red is hammerite, yeah it's a bit OTT but sod it, figured if i was going to the trouble i'd make a statment
prior to paint i just spent a lot of effort scrubbing, wire brushing, jet washing etc, then a load of red oxide, followed bt a mix of verious underseal paints a also got from work, i'd collect unsued leftovers and just mixed the whole lot, it just happened to be mostly the color you see, the other was an alloy based paint supposidly banned here and in the us,

By "OT" I meant "Off Topic". It's certainly not OTT to me

So red oxide and hammerite is your choice.

Thanks for letting me know

[POPEYE]

Judging by those pics it would be a hit there...

It's The Deers Hut Car Show if you want to drop them an email, I used to work with the guy that runs it and he will begin organising it soon...

I might just do that Andy, long as it dosen't cost too much to enter your car, might be able to talk my son into entering as well, he has a classic Merc 380 SL, we saw one there at the last show, (or his defender!!, )