I would like to have a radiator made with both outlets on the bottem at each corner,..??? Thanks FM

914s are air-cooled.

Most are! My first three were!

Because....

Nobody makes a radiator "for a 914", but lots of companies can make a radiator to your specs for 3 bills.

Look into the Toyota Celica 2000-05 many are using, for 1 bill.

Trunk space...

How are you going to get the air out of the top of the radiator?

I saw a cool radiator and inter cooler setup for an rx7 on the tv show wheeler dealer
It forms a triangle with the two units and exits out the hood. It might work with some mods

There is a tool called "air lift" which applies vacuum to the cooling system and then fills it back up in about 2 minutes. = no air. Works great without having to purge air bubbles. Or... you could use the funnel at the radiator cap and wait a long time for the bubbles.

Howe racing can build you one to your liking . I purchased several from them and
have been happy with their service and product.


https://www.howeracing.com/c-450-racing-cus...-radiators.aspx


Bob

My custom Celica GTS radiator...

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Chris 914 ,..Yep trunk space,want to run line thru the longes on either side,..and Mueller,..well if they can build it,.. Iam thinking pet-cock on top of one side,to bleed and 1 at bottom to drain,..???

I second Howe. I have a petcock at the top. Get a double pass. It will slow the coolant at high RPM's allowing it to stay in range.

Thanks Rick,..I will,..if double pass is the same thing as a double row,..???

You vent it out the nearest high spot. You'll always have at least one high spot on these water cooled conversions.

No, there is a divider in the center of one of the side tanks. Forces the coolant across and back. Not sure how that will work with both Inlet and outlet on the bottom.

If you run thru the longs why not turn up and go out the hole that the large flex tube goes out. You wont be using that old heat tube or it's opening once you convert. Now your in the front with established "high spots" on both side from which to bleed air for both the radiator and plumbing "to and from" the engine. Then drop down to the radiator. Upper or lower locations.

No brainer.. I have trunk space

Run rubber hoses under the car, it helps with cooling.

Most filler neck less radiators have a high mounted petcock for bleeding. If you know what side the fill neck will be on have it put on the same side, otherwise ask for one on each side so you only need to jack up one side of the car for filling & bleeding.

Don't listen to old folks with old info single row single pass is the prefered design for the modern aluminum radiators and use high flow fans, or in the case of the Celica- stock fans. Don't trust the specs of chinese made fans.
The performance rad Bellis uses is a good choice for I'd say up to 300hp.

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There should always be an outlet at the top.
Because gas rises in a liquid,because it is lighter,because the automatic venting of gas in a rad requires an overflow at the high points(plural) in the piping.
Air lock can occur in long coolant lines,disrupting flow.

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Let the vapor out at either end of the system,the low point should be at the center of the wheelbase.
The coolant flow is a known quantity,at the rad.The tubes have to be large enough that the flow is delivered to the rad,the longer pipes presenting greater restriction by friction.
There has to be an air pressure differential on the two sides of the rad without fan assist.
That will keep the coolant at the the inlet temp needed.

Hey! I resemble that remark... Maybe a good thing.

I have seen it happen. fast moving coolant at highway speed or high RPM driving at a slower speed can cause fast cycling of coolant ending up in temp spikes. Ask Kent what he did to fix his cooling on his Suby 6.

Maybe small capacity water jackets can get by with single pass systems like your little motors but larger capacity engines with big pistons and large heads require additional cooling capacity and some consideration in the amount of time the coolant has to pass through the radiator. I'm cooling an engine the size of a big block Chevy. I have even had a few rare issues on days above 90 deg. and high humidity but most of the time I run with the fans off. Never on the freeway and many time not in town.

Actually single pass will flow half as fast as a double pass, given the same size radiator. Think same volume of water going thru half the area twice.
The double thick "performance" radiators half the water speed allowing for more heat removal per trip. Roughly 25%. Modern radiators have gotten thinner because testing has shown that the first inch accomplishes the majority of heat transfer, the next inch is attempting to cool with hot air and so on.

There is no fixed figure, but around 15-25 mph the airflow from speed should be higher than the airflow from the fans. If you have heat creep then airflow is the problem.