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Guest Message by DevFuse

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Newbie with some questions ;)

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3 replies to this topic

#1 Ausbert



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Posted 19 February 2018 - 03:45 AM

G'day Fellas. Just brand new here today. Have built and maintained a small fleet of L Series over the last 5 years and have just put together my first '86 turbo (from various doner cars). Trouble is its running hotter than Im comfortable with in this summer weather we're having down here..

Have done all the usual checks: HG's (no coolant loss, no CO2), flushed, new rad, w/pump, timing ok but suspect the turbo is cooking its water as it idles forever at good temp but heats up quickly when the turbo's in use and recovers when you back off..


So I've become interested in trying to increase the cooling capacity of this and have some questions if anyone would be kind enough to share:


1. Has anybody successfully shoe-horned a Brumby (Brat) radiator into an L series?

2. Which way does the water flow thru the turbo? (Out the top back to the thermostat housing?).

3.  Which way does the oil flow thru the turbo?

4. I saw some photos here of a vortex (XT) which seemed to have its bonnet scoop plumbed to a funnel focused on the turbo. Would this be right and did the factory do it for more cooling do you think?


Thinking of putting some extra coolers in line with these but open to any suggestions.


With thanks, (only 1500 pages of topics left to read) Bert.


#2 wagons


    USMB is life!

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Posted 19 February 2018 - 11:35 AM

First advice check catalytic converter for obstruction. Next if you really want to make it run cooler I got two words for you, custom parts. I got quoted only $350 for a custom radiator much thicker and more surface area than my stock gl. Adding a small extra cooler on the turbo water lines might help, but a high cost is still involved

#3 hush777


    More Subarus than Kids!

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Posted 19 February 2018 - 02:53 PM

If you search a bit on here you should find some more info about the engine and cooling system.

Several problems with the engine have been listed and I'll try to fill you in on that a bit.

1. Engine wasn't designed to allow maximum cooing between the halves so the pass side always ran a bit hotter than the driver side.

Not much you can do about that.

2. Turbo on this engine is fed coolant from the passengers head, so the coolant is already hotter that the rest of the engine when it goes into the turbo.

A couple things you can do about this. I found that you can take the coolant feed pipe off the pass. head and install it onto the drivers head with a little bending of the pipe to get around everything in that area (egr, steering etc....).

So then the coolant is going into the turbo a little cooler, or about the same as the temp of the engine. But the water flow is reversed..... Never tried to get it set up for the normal direction of cooling.

Mine did run a bit cooler but still ran hot when pushed.

I also tried adding in a reservoir after the coolant left the head to allow the water to cool down a bit more before it got to the turbo. Also adds some capacity to the whole system. That helps also but still not enough for my tastes.

Wire the cooling fans to always run. Jump across the connector for the temp sensor on the Radiator.


Make sure the O2 sensor and cat are working and you aren't running lean.


I ran one of these in the interstate up here in Idaho during the summer and the turbo so so hot that it ignited the vapors from the vapor canister and caused all of the threads for the bolts that connect the 2 halves of the block together to pull out and had to be heli-coiled.


Water flows out the bottom of the head threw the turbo and then to the thermostat housing.

Oil flows out the head through the pipe then drains threw rubber hose back into the head threw gravity.



#4 Ausbert



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Posted 20 February 2018 - 06:52 PM

Thanks fellas.

I'll post back when Ive got some experiment results..


Still interested to know if anyone has managed to fit a brumby (brat) radiator into an L series tho..anyone?


Cheers, Bert.

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