since registering my car on Tuesday i have been doing a bit of cruising to get everything sorted (and because its fun). as many of you already know my bus is a '76 with an EA81 engine and a radiator mounted at the rear running twin thermo fans and a nice big hole in the back hatch to let all the hot air out. i was a little concerned about this system after being told by many that it wouldnt work, but i am glad to say that it has been going beautifully. i have been doing a 40km return trip to work each day without any problems.
today i headed out from my home in Chirnside Park to Frankston to pick up an annex, and beside a driveshaft parting ways with the gearbox (must have seated it badly when refitting a couple of weeks ago) the car cruised beautifully. once i realised the temp guage was inaccurate (hit 90oC within a minute and sat at 100 - 140 most of the time, obviously not matched to the sensor on the engine) the temp seemed beautiful all the way, no boiling, no sense of exessive heat from the engine or anything, so it should seem that the rear rad setup works just fine.

got any photos of where you've put the radiator?

rad position

Yeah my rear radiator works fine as well. Even on a 40deg day it never went above half way on the gauge and the thermo fans don't run continuosly. I was thinking of putting it in the front, but glad i didn't as it'd be clogged with sand by now, its more protected in the back.

looks so much worse at the front too.

BBCK,
No offence, but,
i'd get ya temp guage working properly before singing the the praises of your setup. 140deg sounds like very hot to me. Find out the factory specs for temps.
What temp does the thermostat open at? Your fans should come on about 15deg higher than that at the most.

My Subie takes a while to warm up but then sits between 80 and 85 on the freeway at 110km/h. Gets to 90max after a bootful and then cools down straight away thanx to the fans and some airflow. And it only gets that hot cause the guage reads off the top of the motor and the fanswitch is in the top rad hose over a foot higher.

my dad tried the rear radiator when he had the holden 202 in the back of his kombi with twin thermo's on it sucking air into the engine bay and found that it work up to speeds of 90 km/h but if you pushed any faster the temperature would climb above 100 degrees.

Hi

Are you sucking air down the stock vents in the side of the Kombi and blowing it out the back of the car?

urban_myth if your dad was sucking air into the engine bay through the radiator and into the engine bay, where did the hot air go?

Steve

I'd imagine melbourne would not be the hottest place this time of year either. For the time & effort putting the radiator up the front away from the engine heat & into some decent airflow, I would do it. Do it right the first time & then never touch it again.
Hope it all goes well.
regards
Jak

you misread, guage isnt working properly, car was definitelyt not actually anywhere near 140 as water was not boiling etc. fans are setup to suck air out of the back of the engine bay, not back into it.

So have you fixed the gauge yet?

coz dude, my temp gauge is my best friend. I keep an eye on it all the time. Nothing kills motors faster than too much heat. I belive you when you say that ya motor is not overheating. But I wouldn't drive with out one on my car.

Now hook it up properly and tell where you are up to with it. What temp does it run at on the freeway?
How often are the fans coming on?
How many reves does it do at 100kays?
And what temp is your thermostat set to open at?

at the moment fans are runnign constantly (wired to do so) but will probably be hooking them up to thermo soon. thermostat is standard so opens at standard temp (not sure what this is). not sure of revvs at 100ks (also need to fix tacho) but will be same as VW as is standard 2l box.

Depending on your tyres. If they are 185/75/14 then they are exactly the same rolling diameter as our 205/55/16 and that gives us 2900 rpm at 100kmh. This is with the 2L box. If that helps at all

seems like it would be a bit tough to do work on the engine with the radiator right there.

good job,

i'm putting mine in the roof section in the rear of my bus with vents to direct air into the radiator, cool air from the top of the bus. it will be boxed in on the inside of the bus with the piping going through the air vents on the side of the bus which aids in cooling the pipes aswell. also weldind in a early bay petrol cap door to fill the rad from the top

here is the panel thats getting welded in next week







and here is the alloy radiator from a vz commodere v8 with twin thermos






and possibly the motor going in it
rammed 350 chev

Ron that is just crazy....! Good stuff.

Sounds a bit low to me. 2L is more like ~3300rpm at 100kph.
1.8L box is ~3600rpm at a guess.
Kombi speedo's have a tendancy to read low.

BBCK,
right on you for getting it going.

The rest is the tweaking. You didnt think it was going to go right first go? Well it goes well but a few teething issues.

I reckon you could be running hot and that could explain the water loss if heaps leaking into the inlet/chamber, can vapourise and blow the vapour through-ergo oil looks ok. Pull the plugs, could tell you if one is brown. Water cooled engines have a great big window that they will run in temp wise. Particularly worn engines. Early corolla engines are nuts, We drove one for bloody ages to get home one noight when it was dying from a burst rad hose. Water level dropped past the temp sender so it looked like it was running ok. You get a consistant range of warmup, then consistant for the trip? Does it run better cool or warm?

I agree, get a temp guage sorted so you know what its doing. The numbers dont have to mean much, just get a known point on the guage you have.

Get the cooling pressure tested, could be a pinhole in a weld, anything, I so hope its not the engine but if it is, once its fixed, you know that bit is ok.

Luck dude, hows the bikes going?

kkk

well now that i have tightened a few things up the car is taking about 2-3min to warm upto a constant temp when on the road (approx 90 - 100oC if the guage is right) then sitting happily at that temp all the way to work (approx 1/2 hour trip up some nasty hills and corners, several start stop sections, 60 - 80kph). sometomes runs a little rough for the fisrt few minutes (have to warm it up a little before headign off as my choke is hard to operate), but generally seems to run at a pretty constant standard. have been thinking about ducting, wondered whether rather then directing air to the radiator, i should be directing it out the rear hatch/stopping air slipping around it?

baybuscamperkid ....I see no problem with your set-up. It has been a tried and tested method. I hope your running coolant, not water due to its higher boiling point and correct thermostat and radiator cap.

I would agree with andy on rpm's. I would consider larger rims and tires.

Good work:thumb


ps: Ron, your a nutter:P

[Edited on 17/5/2005 by phat rat]

will see how rpm's go (i think i have found the wire for the tacho), once i know exactly what it's doing rev wise and talk to the subi guys see what sort of revvs they're using in the wagons i will have a think about things. (i am running 195/75 14s)

urban myth, a simple scoop down the bottom should deal with that shouldnt it? so long as it doesnt pickup anything solid :duh

damnit, since my defensive driving course every time i drive the car it seems to be gettign a little hotter then the last trip, doesnt feel or sound any hotter, but guage indicates that it is heating up. time for some tinkering

My buggy works like this. In traffic, the fans come on a lot. However, once on the freeway, as far as I can figure out, the scoop puts more than enough air in front of the rad for there not to be a problem and the fans don't come on much at all.

My temp guage reads a few degrees higher on the freeway, but the rad works so well that by the time the water gets to the thermo switch for the fan (at the top rad inlet, the water has cooled enough to keep it down to about 85 degrees.

I prefer this setup. I don't mind the fans working a bit in traffic, as long as the car cools well on the freeway.

cool, my fans seem to be workign real well when stationary (knock the temp down pretty quick), still not sure about the rest though, as last week on the way to work i wqas getting to about 100deg, this week 115 on the way there and 130 on the way back if the guage is right, something's going on.