Thinking of a different way to duct a radiator, to keep front trunk space... Options

[scotty914]

okay as we all know i dont have engine tin, and i have a trashed front seal on the engine lid... so for the wcc i put a peice of electric tape on the seal to hid it a little. well about half way up the east coast on the way home the tape came loose to about the middle of the car. so i got to watch a peice of tape flap on the the engine lid for 400 miles. the tape was secured at the rear window.

so what the tape did was it was plastered to the front part of the engine lid ( solid ) and the rear part flapped in a circlular motion, it was not blown of off the lid nor was it held down.

so i would say it is a pretty good airflow area that really did not blow in or out, but i would say that the turbulance would be slightly pulling air out of the engine bay

[flat_iv]

Roger,

If you are still looking at 2 radiator up front, look at the 95 Dodge Neon (5sp, no air. The radiator is approx 13 x 13 x 1 1/4 thick. I am planning using the 2 radiator set up in my 74 Ghia.

Richard

[roadster fan]

I know I am coming into this discussion a little late, but how about this.....

The Boxster S models came with a third radiator set in the middle of the front bumper between the two front wheel well rads. What if you used 1 or 2 long skinny radiators (jeep cherokee?) mounted inside a fiberglass front bumper (like fiberwerks for example). The rads could be mounted similiar to a turbo intercooler (ie way out front). Air could be ducted to the wheel wells or underneath GT style. This would allow you to maintain all/most of the front trunk.

If you supplemented this approach with finned tubing in the rockers or a small rad in the engine lid it may work. (IMG:style_emoticons/default/idea.gif)

Also, the Boxster rads are plumbed in parallel to maximize efficiency using two aluminum tubes with Y's (W's for S) in the front. I have pics but can't find right now will try to post tomorrow.

[J P Stein]

The job of any radiator (including oil coolers) is to keep an engine within its proper opperational temperature. "Other" considerations lead to the tail wagging the dog.

An excess of cooling capacity is gud.....that can be modulated.

A lack thereof and you are fucked. At best, a redo is in order, at worst, your motor suffers damage then you get to redo that also.

Do it once, do it right.....then consider the peripheral BS. With a 914/SBC, after the cooling capacity is settled, I would more concerned with venting the heat without structuraly weakening the chassis....which is the tail & which is the dog here?

[marks914]

Good luck!
I too thought of doing something like this but abandoned it after talking to some thermodynamic engineers at work when I was doing some work in our wind tunnel a few years ago.
When cooling it comes down to 2 things, air flow and heat transfer.
I ended upgoing with the rad in front.
Mark

[Two914s]

I have been working on an aluminum fuel injected V8 conversion for some time. I have it driveable now, but with no radiators. The car weighs 1878 lbs on the corner scales right now. The inlet and outlet of the engine are just connected together with an in-line radiator cap. I can drive it for about 3 minutes before needing to shut it down. Fun 3 minutes!

I have been working on a duel inside-the-engine-bay radiator setup this spring.

I am committed to not cutting either trunk at all. I am willing to do some major modification to the engine lid, because that can always be changed. Engine lids are cheap. I want the powerplant to be able to change between chassis without more cutting.

My latest idea is to use a Subaru WRX top mount intercooler as a radiator. They are very often for sale on Ebay and are beautiful. They, of course, are made for air-to-air heat transfer, but they look like they would work for water. They are thick, which is just what we want. Lots of fin area without being big in external dimensions. I plan to modify them and have the TIG welding facilities to do so.

They are a good size to mount two of them under the engine lids with PULLER fans. It is much better to pull the air through a heat exchanger because the air is less turbulent that way. Have you even noticed that you can feel a fan blowing on one blown side but not sucking side? The laminar flow across the fins is what you want.

I certainly agree that it is better to plumb them in parallel and not series. You want to slow the water down as it goes through the exchanger. Pumping it through too fast doesnt help. The parallel radiators help with that.

There are several companies that make the finned tubing that was mentioned earlier. I would try to use that if using a small radiator up front..

Basically an engine only converts 1/3 of its gasoline energy into horsepower. So if you have a 300 horsepower engine, the fuel going into the intake manifold has the equivalent of 900 horsepower!! 300 horsepower is converted into heat that must be disipated through the block and radiators and oil coolers. 300 horsepower goes right out the tailpipe in the form of hot exhaust gas, and then 300 goes out through the flywheel and into the transmission. Yikes!

But remember, you dont drive around at 300 horsepower very long, especially in a 914. I would guess that it takes about 25 horsepower to cruise at 60 miles and hour in a 914. So the radiators must only dissapate 25 horsepower under those circumstances.

So, I am going to try two radiators in the engine compartment and then mount an OIL cooler up front in the GT style...maybe with a fiberglass bumper with the GT opening. Any heat that I get rid of with the oil cooler with subtract from the amount of heat that the radiators must transfer to the air. I may modify the engine lid extensively as this part is easy to obtain another.

Good OIL cooling is one major reason that the 911 and 914 air cooled engines work. These engines are both air AND oil cooled.

You can help the situation as well with the coatings mentioned before on the pistons and cylinder heads. That will blow more of the heat out the tailpipe and into flywheel horsepower, and less into the block which must be dissipated through the radiators and oil coolers. Retarding the timing slightly, running the engine a little rich, using water or methanol injection would also help, but those things are against the whole point...

If the radiators are under the engine lid, you can always have your significant other dump some of their bottled water over the rear window if you get caught with some overheating. This is passenger-assisted evaporative cooling.

OK, I have said enough....

[Dr. Roger]

yep,
i'm aware of the Y but wasn't aware of the W setup for the vasser cooled P cars.

Porsche, once again, already does what i'll probably end up doing for mine. =-)

i'd like to see your end product pics with tubing specs, the intercooler functioning, and some performance statistics when your done.

actually many people on this site would be interested in your outcome as i rekkun there's a bunch of fabricators/do-it-yourselfers around these parts....

thanks for you input! (IMG:style_emoticons/default/beerchug.gif)

[drive-ability]

I love to see all the innovation going on. I too like the idea of having a trunk as a practical matter. I am sure there is a way to consolidate a system using available space. I will say it was over 90 degrees today in Ca. and I drove around in stop and go traffic sprinting from stop sign to stop sign and never saw 195 degrees. In fact if I were to just over-ride my thermo switch the car would have run in the 160 range. I would just hate to have a car that runs on the hot side, I am now looking into an oil cooler as my coolant temps are low my oil can get hot.
I think you guys are on to something splitting up the radiators keep us informed. (IMG:style_emoticons/default/beerchug.gif)

[TonyAKAVW]

In my Subaru conversion thread I go into some detail about how I am going to pull air into the engine bay from the top and suck it out the bottom with the assistance of a venturi generator under the car. I'm guessing that this same generator would work well for other engine bay mounted radiator setups. It will be at least a couple months before I get the engine in the car and can start testing, but I'm planning on building up a mold for making fiberglass panels for this purpose. If others are interested in this, it would give me more motivation to spend the time building up the rather large mold.

-Tony

[Rand]

I had posted a question like this in January (in thread V8 radiator outlets, alternative to cutting wheelhouse).

I thought it would be feasible to put ducts between doors and rear fenders (just like most modern mid-engine cars) to pull air in (naca style if not flared much), use a sealed duct/shroud system to force air through radiators positioned next to the v8 block (surprising amount of room there on the conversions) and out through the bottom or rear (again with well-designed ducting I think you could get a lot of good flow through the rad - naturally at speed, or assisted with fans when needed).

Keep pushing on this Roger. I know it can be done. Borrow from what's been done and put some ingenuity into the rest. (IMG:style_emoticons/default/beerchug.gif)

[banksyinoz]

this maybe a brainless idea butr here i go

just thought as i have not done any research as yet ,

would it be possible ( or even wise ) to allow air to flow ( force at speed ) through the sills where the original equiptment once blew hot air for the heater,
this would allow engine compartment radiators greater air flow,

i have removed the heater/ fan box from below the screen and was considering using this opening for this purpose as well as a similar scoop as scott, i have 2x dual pass radiators to mount infront of my ej20t & auto

pplease give a (IMG:style_emoticons/default/alfred.gif) if this is a no go

(IMG:style_emoticons/default/beerchug.gif)