Radiator question.. Core thickness/air flow

[3t-RA40]

Joel,
What temp is your thermostat? I just changed mine to a 71 deg, haven't had it on the road yet as it's still strapped to the dyno but I'll let you know how in gos, should have the car back tonight. Also sounds silly but have you checked the thermo fan to make sure it's flowing the air the right direction?
Cheers,
Neil.

[TurboRA28]

Hey all, should have updated this thread.. But my cooling problems were all sorted out.

I placed some thick foam and metal around the radiator so it is all boxed in and air cannot get around it.

At the wakefield day I last attended (hot day, over 30 deg), temps never got above 92 degrees! That was pushing the car hard too.

Also the last dyno tune it had the operator mentioned no problems with temps getting up high.

So I think it was just a matter of sealing up the radiator well.

Also I did purchase a new hyundai radiator.

Cheers
Joel

[Toy77]

G'day Joel (and Co.)

just thought i d throw in that i am running a SINGLE core aluminium radiator out of (i think) a r33 skyline.

it has no dramas keeping the single turbo 1g in my celica cool on 40 degree days.
have not tested on the track. (well i have on the strip.... at dubbo 2 years ago it had no dramas running back to back all day (had 2 drivers, lucky dad huh, getting to flog your sons car on the drags strip)

it is fitted flush to front panel and has twin thermos on the back.

Cheers
Stew

[BrianRA23]

Good to hear the cooling problems are sorted out and that getting the air flowing through the radiator fixed the problem.

My brother (who prefers to drive his old F150 around) has been investigating overheating problems for a while. This is mainly due to its increased likelihood on LPG cars and it seems that while in most cases people fit a bigger radiator to fix the problem it is only part of the equation. Getting the engine temp constant is the idea but there are other things to consider.

One of big things is due to the design of cars these days that slope down at the front the highest part in the cooling system is generally inside the head. Localised boiling inside the head and block can cause steam buildup, which unless it can be reabsorbed back into the water gives you an area where the heat can't be removed. For long runs this may not happen until the car is parked and may result in warpage of the alloy. A steam bleed would be required and in the case of the 3SGTE I had planned to unscrew the allen keyed plugs from between the spark plugs and, if it appeared to be a high point, putting a series of coolant outlets to a header tank. On my Landcruiser 1HDTE we will most likely drill the head into the water jacket.

Another thing is whether or not modern pressed metal impellers on the water pumps actually pump enough water at all speeds. I have seen how some just caviate when the revs get up. The last pump I fitted I had the impellor removed and a hand made impellor with tapered and curved fins welded to a solid face and closer tolerance to the wiping face. This works inconjunction with a bypass where the water is able to circulate around the engine when the thermostat is closed (common on most Toyota engines).

I also rounded off any poorly cast edges and filled in crevaces to removed cavitation points. This was on a 2H in a 60 series cruiser which had no thermostat due to it getting hot. After with the thermostat fitted on a 2000km trip through the Canning Stock Route heavily loaded it never even looked like getting hot and no hint ever since.

If the water is moving faster and consantly then your engine temp is consistent front to back. Old Holden V8s used to always do the head gasket near the glovebox. The cold water came in at the other end and was much hotter when it left. The engine cylinders were the same, and therefore the engine could never be tuned the same for all cylinders. The other reason was getting the same mixture to all cylinders with different length runners (air velocities were diferent and so were the mixtures)

I have seen many samples of coolants, which when placed in a coke bottle and shaken they take a good half minute and longer before the bubbles disappear (water is almost instant). When heated and sent through the channels around the engine and agitated by a rapidly spinning paddle pump the scenario gets even worse.

A few cars I know that have been done to fit this criteria can have the radiator cap lifted at any time since there is no pressure build up (steam).

With the various changes the F150 has two temp gauges, with one sender on the engine (normal position) and another on the radiator. After a cold start the one on the engine comes up to operating temp before the other moves. From then on the engine one stays steady and the other moves up and down with load - quite a lot.

Fitting a bigger radiator, removing the thermostat or fitting a colder one just increases the temperature difference of the total amount of water going in an out the engine. My challlenge will be to have the temperature across the whole engine the same and at constant operating temperature under load. Maybe after that I might still need a bigger radiator but from what I have seen so far a normal radiator will be fine.