been looking on the site and cleaning up the floor in my 75 914 that will some day
be water cooled and a question poped into my head. why run the water lines in the center tunnel? Couldnt I use the space currently occupied by the air tubes? Has this been done? I searched and everyone with a radiator up front runs them down the center. There would be no use for the air tubes. Just a thought.

We don't suggest running the water lines in the center tunnel, because the shift linkages and rod occupy the space. There have been a few that have gone the longs (heater tubes) route, but the easiest route would be to run underneath the car in the provided groves. I think it was Ahmenson that ran the water lines in the longs. Search for his name it should be in his project thread.

And...

thanks, its a long way off but just a thought

well did the search for his name and nothing but this thread.

Rod Simpson popularized the V8 swap what, twenty-five, thirty years ago? His conversions all use copper tubing and go up through the outer longs.

Yes, I know using the word "popularized" means I'll be forever excluded from CW'edness. Damn.

Here is Scott's (Amenson) PorSti Thread

PorSti Thread

Enjoy@!

If you are going to use the suby tranny you will probably be using a cable shifter so there won't be a shifter shaft in the tunnel. Also I would not put the fuel lines alongside the coolant lines in the tunnel. I think I will use the tunnel as it seems to be the cleanest routing I can come up with and I've been studying it quite awhile. I'll still have to look at the rack area and into the front trunk approach to make my final decision. If I use the tunnel it will have a open bottom to help release the heat. Or put a louvered cover on it to be really fancy. It seems a galvanized c shaped cavity would be the cats meyow. Like a galvanized 2x6 metal building perling except with the lips turned out instead of in. I will just get a sheetmetal shop to make it and weld it in. It should be even stronger than the original.

FYI, a ton of the ideas that are for V8's apply to subaru swaps also. Turbo subaru swaps require large amounts of fuel and cooling... maybe not quite as much as a V8, but you get the point.

Aluminum will cool faster than iron but horsepower is what makes the heat. Also the turbo motor only makes the big hp numbers while it's on boost which is not even 30% on the street. On the track it's different. Also the torque applied to the chassis is less because the suby doesn't make v8 torque down low when you are taking off so the stress is way different. A electric motor with it's immediate torque is the most destructive power to a driveline in normal use.

Well put! What I was trying to say is that some of the V8 stuff could be overkill, but like you said, horsepower makes heat and the suby definately has potential to make horsepower. The suby may not break trannys like the V8 does, but building a tranny the same way you would for a V8 could be done. The gear ratios that might be used for a V8 make sense for a suby too. Running 1800RPM on the highway sounds nice for any motor.

I like the idea of running the cooling lines through the longs sounds like the way to go. But initially, under the car might make more sense. Don't get me wrong, I'm not the type to take shortcuts. But, in my mind there is a line between doing it right with the lines in the tunnels and the car on jack stands for an extra 6 months or longer. Versus running the lines under the car until you get around to doing a restore or installing an Engman kit.

The only thing I don't particularly like about the longs is the inside the passenger compartment behind the speakers. Behind the front wheels is more appealing to me if the longs are used and then the rocks protection needs to be attended to.

Hi,
I have a V8 conversion and ran the lines thru the center tunnel. Right side, no interference with the shifter or the fuel line, which I moved to the left side. I don't get any problem with heat in the cabin, but I only have a 283 (prob 275hp). The good part is at no point do the lines pass thru the cabin and it is a pretty straight shot under the gas tank. 2 - 45 deg elbows and the lines are in the front trunk.

Running thru the longs would be nice, but is more difficult in terms of going from the longs to the front trunk. You will have more bends/elbows, and you probably need to run thru the passenger interior at some point. Maybe you can build a box around it.

At the time, I didn't want to add months to my project, so I chose the easier.

Once again alot of good ideas and thoughts to consinder. So from what I gathered going through the longs means cutting them open right? If I was to do this with the car on the ground how much bracing/jacks/stands would I have to use? Mine seam to be in good shape so would cutting a couple small opening be enough to get the work done? thanks for all the coments. Makes a newbie feel at home

What diameter lines did you use through the tunnel? I wouldn't mind insulating the fuel lines if I need to.

1 inch lines - same as if rubber hose was used.



If I remember, it looked very tight to run anything into the wheel well. If you have a 16in wheel, turning, it's just very close. Thats why I think you would have to run the line behind the wheel well, near the speaker (and into the interior, or below the car.)

As far as insulating the fuel line, if I did it over again, I don't know if I would worry about insulating the fuel line, but I would run a return line. I think more heat is coming from the pump - not enough flow.

I see alot of guys running a piece of wood between where they put the jackstands, but it seems terribly unstable. I'm sure they have figured out a stable way to do it, you'd have to ask around. There are threads detailing peoples thru the long coolant projects. I would also do some reading on long repair projects to see what to do with the supports and were you can safely cut into.

yeah, ive seen that but most of it was when on a rotisary. Just kinda wondering if it would be the same if the car was on it tires or jack stands. also I think the radiator in the engine compartment is really cool but seems like alot more work and thought put into it and wordering if it works as well.

no flames please , but I still keep looking at the "extra room infront from the short ej20 layout and have the radiator in the engine compartment.. I found an AL three fan cherokee radiator.. 36 in across and and 13in high...Sit it low and use the natural air flow from bottom to top...


Click to view attachment


and I know a friend of mine keeps saying "radiators belong in front of the car"

I wouldn't recommend running the hoses through the longs, I have lost count of how many mangled lines I have pulled from the longs of overheating converted 914s. With so many bends it is almost impossible to bleed the hoses completely and this will cause overheating issues. If you must run them through the body check out Tom's (carreraguy) subie 914, he had someone run his inside the center tunnel and it looks pretty good, and from what I understand there is no interference, there pics somewhere on the site.

I thought the PorSTi thread was on to something, but he has some 90 degree bends in there. I'm anxious to see how it runs.

I would have to believe that Dana would know what works and what wouldn't though.

He is also using 1.750 and 1.50 id lines I think. The stock suby id is 1.25 or a little less.

If your going to change the car that much, why not put the cooling behind the engine. Pull the air into the engine cover, tear out the trunk and let it excape under the car. Less plumbing and its closer to the engine.

The most pressure on the car is in the front. It would be a terrible deal to butcher the complete rear end and find you need to babysit it at 100 degree temps. I would much rather use just one trunk and keep the other complete but I don't think it can be as good as the front.