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.
MikeM ·
got any photos of where you've put the radiator?
baybuscamperkid ·
rad position
ratbug ·
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.
baybuscamperkid ·
looks so much worse at the front too.
pete wood ·
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.
urban_myth ·
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.
1303Steve ·
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
Jak Rizzo ·
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
Craig Torrens ·
TYP-114 wrote:Doesn't oil begin to separate at 125 degrees?????
No.
baybuscamperkid ·
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.
pete wood ·
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?
VWCOOL ·
TYP-114 wrote:Doesn't oil begin to separate at 125 degrees?????
No. That's a 1960s urban myth/fallacy designed to help sell oil coolers and other crap you don't really need!
[Edited on 16/5/2005 by VWCOOL]
baybuscamperkid ·
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.
helbus ·
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
rubyred ·
seems like it would be a bit tough to do work on the engine with the radiator right there.
wacked1 ·
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
squizy ·
Ron that is just crazy....! 😎😎😎 Good stuff.
pete wood ·
baybuscamperkid wrote: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.
go buy a cheap temp guage and tacho.
look for the thermostat temp on the web.
You'll really only know how efficient your rad setup is when the fans are not running all the time. Trust me on this. And i wouldn't be surprised to find that the fans aren't doing a super job either. Until I really ducted air in front of my rad, the fans were struggling to cool the rad enough on the freeway.
BTW, where is the air for the rad coming from, up from around the hot engine, of from the top vents, or from the outside somehow?
Put some strips of paper on the car and then get a mate to drive it along the freeway while you drive behind and watch what direction the air is flowing. That will help you know what to do next about ducting it somehow.
Andy ·
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.
Helbus wrote: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
koolkarmakombi ·
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
baybuscamperkid ·
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?
pete wood ·
baybuscamperkid wrote:(approx 90 - 100oC if the guage is right)
Find out what the standard running temp should be. Or, find out what temp the thermostat opens at. Should be printed on the side of the box.
baybuscamperkid wrote: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?
Figure out where it's going first, then you'll know where to get the air from and where to send it to.
BTW, why not think about putting the rad under the car like Custom offroad does? Will the rad fit between the chassis rails?
phatrat ·
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]
baybuscamperkid ·
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 ·
1303Steve wrote: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
He had the theory that when you were moving along there was a vacuum being created behind the van which would force air through the decklid hole. This worked fine up to a certain speed because the air flow being created by the vacuum + thermo fans was greater than the air flow being sucked from underneath the car into the engine bay so the hot air would be forced out through the bottom of the engine bay.
but when speed went above 80 or 90 km/h the air flow coming from underneath the car became greater than the air flow being sucked through the radiator which resulted in no heat being able to escape so the engine temperature climbed.
baybuscamperkid ·
urban myth, a simple scoop down the bottom should deal with that shouldnt it? so long as it doesnt pickup anything solid :duh
baybuscamperkid ·
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
pete wood ·
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.
baybuscamperkid ·
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.
pete wood ·
mmm, 130 is not happy at all. Do you know the factory temps for it yet?
Brad ·
so how is your rear radiator going these days ?
I see you are having a few cooling issues, do you think it could be related to your rad position ?
baybuscamperkid ·
talked to a couple of people, tink its the guage playing up, as water temp seems fine, everything seems to be flowing well, so think the guage or the sender is faulty, last time i was at these temps (when i was leaking water) it boiled, yet this time it is no-where near doing so.
Brad ·
how are you testing the water temp ?
baybuscamperkid ·
only via checking evaporation/leakage dribbles etc compared to previously, have to run a new wire for the water temp guage to the rad shortly.
baybuscamperkid ·
YAY! old guage was mismatch with sender, got new matching sender and guage and am now cruising at 80deg :thumb
koolkarmakombi ·
no leaks?
pete wood ·
Good to hear. I hope it's all working ok now.
BTW, do you know what the safe operating temps for your EA81 are yet? Are your fans still running all the time? What speed were you doing when it was registering 80 degrees?
Brad ·
mmm 80 degrees is a little cool for an EA 81 / 82 you will find it uses to much petrol at that temp, try and get around 90
baybuscamperkid ·
will see what it is like on the highway, sits close to 90 on the way home form work, no leaks in the water system but one in the oil just near the filter (bodgey gasket, will replace soon), as far as operating temps, i think the thermostat opens around 90?
baybuscamperkid ·
oops, meant to say 90deg, top speed of 80kph, lots of hills on the trip. isnt guzzling too much petrol (has crept up from 10l/100km since i have been driving harder, but still well under 13l)
pete wood ·
are the fans still running all the time?
coz if they are, I reckon that's the next thing to sort. It will allow the motor to warm up quicker and so it won't wear out as fast. Also will take the drag of the fans off the alternator while the engine is under the temp of the thermoswitch.
baybuscamperkid ·
yeah, thats next on my list, rad has a thermo switch in it, so will probably run off that.
Kombicol ·
BBK,
I would wait till you have experienced a wide range of driving conditions before you are confident it will be OK.
I was running the radiator in the back of my kombi for about 18months and about 50 000km on my ej conversion, and i never cooked it. Driving aroung town wasn't a problem, however driving at 110kph up the freeway on a 35+ degree day was an ask. it was running too hot.
I tried the fans pushing, pulling, bigger radiators, etc . the only thing that i think would have really worked is making some ducts down from the snorkles to the radiator and fully sealing the system as suggested in a post here.
in the end i went for an integrated radiator-bullbar setup kindly made for me by brad and co.
some may consider it a ugly, and i agree it would look out of place on a more original bus, however mine is a bush pig, and i had already put one huge dent in the front after hitting a roo, so i needed a bullbay anyway.
before the radiator fans ran almost all the time, since moving the radiator, it has come on only once- when driving slowly at high revs up a steep sandy track at the beach. never on the road.
that has been my experiences.
admittedly though, the ej probably pump out more heat than the ea engines. keep us posted on how you go.
Col
Kombicol ·
gee that pic came out all dodgy and pixellated when i compressed it.
helbus ·
Be good if you could get a front off one of the Air conditioned South American busses like this one.
helbus ·
.
helbus ·
They were pretty cool busses, the roof was a bit ugly, but the microbus had sliding windows and flipper quarter vent windows in the front.
baybuscamperkid ·
maybe that'd be a good place to import cheap front 1/4 flip windows from?
baybuscamperkid ·
went for a long spin today (about 250km), with only a partial shroud in place and still leaking oil (think i have fixed it now, bodgey pan seal), cruised happily at upto 80kph without getting over 90 - 95deg, pushed it upto 100kph and temp slowly crept up, backed off when it hit 110deg held temp (didnt rise, nor fall) at 90kph, warmed up slightly easier on the way back, due to dropping oil. am fitting a scoop down below tomorrow, considering elephant ears as well, water level at least stayed fine, cooled really well at lower speeds, just gotta force some air up into their at speed.
pete wood ·
Do you know where the air is going round the back of the car?
Stick some strips of paper on the get a mate to follow you with a video camera. See where the air is going before you start forcing more air in there willy nilly.
baybuscamperkid ·
the rad is positioned a little low in the rear, meaning that a large portion of air is capable of escaping over the top and around the sides of the radiator. by putting a shroud across the top of the radiator (blocking the air flowing over the top) i managed to slow the warming proces, but also slightly slow the coling process meaning that the extra resistance is partially blockign the natural flow of air that was coming up from under the car. i am planning on fitting a small shroud down over the lower part of the rad mount down to just below the sump, forcing air up and into the radiator, as at the moment the air is flowing up less and less as i accelerate past 80kph (at 80 the engine will cool a fraction, at 90 it will hold temp, and it creeps up at 100kph, meaning that less and less air is getting to the rad). i am also considering rabbit ears but am uncertain as to whether the air from them will simply flow out past the sides of the radiator.
pete wood ·
I ask again,
pete wood wrote:Do you know where the air is going round the back of the car?
I mean know exactly. You might find the air is going back into the engine bay through the back door. Anyway my point is figure it out first. Stick some piece of paper ribbon in various strategic spots and go for a drive. Let a mate drive and then you follow and see what the strips are doing. Then you can decide what you need to do.
helbus ·
There is also the horsepower v's cooling factor. You use more hp to go 90kph than 80kph, so therefore more cooling is required. It may not be just more airflow required, it may need a bigger radiator? A certain size radiator has only so many fins available to transfer heat from the core to the air, no matter how much air.
I had the same problem with my supercharged EH. It cooled fine up to 90kph, but at highway speeds it was just on the brink of boiling. 110o The airflow was heaps at that speed and the second fan I fitted made no difference.
Once I fitted a bigger radiator it dropped down to approx 85o at highway speed. Cooler and therefore more power when I needed it.
baybuscamperkid ·
thanks helbus, will play around a bit more first, but the current rad is quite small (stock subaru item) so will keep that in mind.
baybuscamperkid ·
well, problem seems to be fixed, i took it to an engineer/VW mechanic, he was really impressed with my scoop etc and said if i simply ran a big sucker fan on the back of the rad all my problems would be solved, so i went out, bought a giant but thin bosch fan, fitted it up, and beside a couple of small hickups (such as a dud alternator - refer to other post) the car is now cruising at under 100deg for extended distances at 100kph.
helbus ·
Good to hear it is sorted. I hope to cruise next to you one day 🙂
baybuscamperkid ·
how bout wagga? u and fleur going to that?
denver ·
I run two radiators in my kombi
1. Datsun 120 radiator mounted in the engin bay on the passenger side with thermo fan.
2. Holden 6 radiator mounted between chassie rail with scoup runs of the heater hoses.