watercooled radiator photos, Subaru, Maxda, V6, V8 etc, Please post radiator setups, need some design ideas Options

[dmenche914]

nice set up PJhaun, so the floor is theoutlet on yours? how is the inlet set up? or is it the other way around??? is this the "blue Thunder" car? i have seen photos of it, very nice! it is still a 3.8 V6 right? You have a usable front trunk as i recall.

If the floor opening is at a high pressure area, would a say rubber 'air dam" under teh floor, in front of the outlet hole work to produce a vacuum to help scavange air out of the trunk, assuming the inlet is at the bumper area? or is that not needed? On my car the floor is cut out, the fender inners are open, adn the bumper area is open, all told too much stuff removed!

ENGINE BAY RADIATORS: (the holy grail, no front trunk cutting)
the Del Sol radiator at 14x14 inch could fit maybe on either side of the engine bay right under the engine lid grill (maybe go to a full grill lid?) the air flow would naturally be up from under and out the grill I assume. (opposite teh stock 914 direction, but the 914 is fighting to push the air from the grill, down and out the bottom by using a sealed engine "tin" and the air blowing impeller.

The only issue we might have with the air flow from the bottom up, past the engine and out the enigne lid grill is that the air will go past teh hot engine, and headers prior to going thru the radiator(s). What might be cool (no pun intended) is too get a radiator(s) that would span the entire engine lid grill (assuming the issue of preheated cooling air from the engine/headers). The large area would make it possibel to run a thin (single core) radiator. this would then leave room thickness wise for fans under the radiators The radiatorscould be monted ont eh lid, and with rubber hoses, allow to move with the lid when opening it for engine access. If thickness is still an issue, i suppose a custom engine lid could be made that stand offs higher than the stock one. might block the bottom of the rear window, but heck, you could use two side view mirros for rear vision.

This would be a nice set up (if it cools ok) for flat motors like the subaru, or boxster. however with a taller motor like a V6 / V8 with a tall intake manifold there may not be much room. On my Buick V6, the air cleaner all but touches the engine lid, so maybe two radiators could be used, one on either side of the intake manifold, and aircleaner. Battery / relay board could be relocated to give more room on the sides.
However i am still concerened that the cooling air, coming up from under the car might be too much prehated by the headers. Likely less an issue on a subaru, with headers under the engine, but maybe a problem with V6 / V8 engien with the exhaust ports up high on either side of the engine. They is right up near the top . i suppose heat wrap on teh headers might help.

I guess it is time for air flow tests with little strings tapped on the grill, and some thermo-couples on the engine lid, to see the effects of the header heat on the lid area.

Any thoughts on this???

[sean_v8_914]

that giant hole in teh floor will accumulate positive presure into the trunk above 45 MPH unless you use a very low splitter up front and a spoiler under the leading edge of the hole.

[pjhaun]

Here is the front bumper this is where the air comes in to the radiator.

[pjhaun]

nice set up PJhaun, so the floor is theoutlet on yours? how is the inlet set up? or is it the other way around??? is this the "blue Thunder" car? i have seen photos of it, very nice! it is still a 3.8 V6 right? You have a usable front trunk as i recall.

The inlet is through the front bumper across the radiator and out the floor. There is also room in the front trunk for a spare tire and tools. Right now I am preparing
my car for a rebuilt Buick V6 252 engine. It will have 9.8 compression, aluminum heads with roller rockers and ported fuel injection. I am putting in 4 piston Boxster brakes with 23mm master cylinder. I am also going to put in a hydraulic clutch.

[jsteele22]

Any thoughts on this???

You asked .....

If the floor opening is at a high pressure area, would a say rubber 'air dam" under teh floor, in front of the outlet hole work to produce a vacuum to help scavange air out of the trunk, assuming the inlet is at the bumper area? or is that not needed? On my car the floor is cut out, the fender inners are open, adn the bumper area is open, all told too much stuff removed!

Yeah, this would a perfect situation for a front air dam. It would have the effect of raising pressure at the intake (some of the air can't pass under car, so it gets forced upwards) and lowering the pressure under the car.

The only issue we might have with the air flow from the bottom up, past the engine and out the enigne lid grill is that the air will go past teh hot engine, and headers prior to going thru the radiator(s).

That's an issue, but a very small one, IMO. Any heat that gets transferred from the engine (except the headers) is good - that's the whole point of a cooling system - remove heat. Some cars (ahem) even depend on this effect for cooling. So it's only the heat from the headers that is of concern; that heat shouldn't enter the cooling system, and really should be kept in the exhaust system for better performance. So ceramic coat, header wrap, or whatever would be a double-bonus in this case.

But still, think about the heat that does get transferred from the headers to the flow of cooling air. Imagine the fan is blowing cool air over the headers only and you put your hand in that air flow - it will feel a little warm. Now put your hand on the block - it will hurt like hell. So there's still a huge temperature difference between the stream of pre-warmed air and the coolant entering the radiator. And that's what makes the radiator work. So I think the high-mounted radiator will have a small decrease in efficiency due to header heat loss (on cars with headers in the air flow), but this effect will be very small. All the other heat coming from the engine is just heat that the radiator won't have to remove from the coolant.

What might be cool (no pun intended) is too get a radiator(s) that would span the entire engine lid grill (assuming the issue of preheated cooling air from the engine/headers). The large area would make it possibel to run a thin (single core) radiator. this would then leave room thickness wise for fans under the radiators The radiatorscould be monted ont eh lid, and with rubber hoses, allow to move with the lid when opening it for engine access. If thickness is still an issue, i suppose a custom engine lid could be made that stand offs higher than the stock one. might block the bottom of the rear window, but heck, you could use two side view mirros for rear vision.

I like the idea of the engine lid radiator, 'cause it makes the ducting simple - any air passing through the rad leaves the engine bay. There would be some issue of weight (need some way to hold lid open). And the hoses would take some real thought : the hose would have to be flexible enough to bend frequently, yet somehow avaoid getting pinched/kinked shut. Has anybody ever seen/heard of a lid-mounted radiator on any car ?


Well, it's Saturday, and I'm off to do some (IMG:style_emoticons/default/mrs.K.gif) , Oops, I mean (IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/welder.gif)

[roadster fan]

I remember seeing an oil cooler mounted to the engine lid on a 3.2. IIRC, it was a tight fit but the owner said it worked good. Cannot find the photos right now.

[rick 918-S]

Here's mine.

[dmenche914]

For a lid mounted radiator, flexable corregated hoses would bend better than the stiffer smooth ones. For a flat subaru engine, you'll have more room for fans and such, for a V6/V8 the engine is pretty tall.

anyone have got a good source for thin, wide and short radiators?

if I coould fine some (cheap used0 i would testbed them on my V6 Buick 914, it is kind of a hack car now anyway, ready for experiments, it runs good, but i could test the engine bay radiator design, without too much trouble (me thinks), if it fails, I'll just re-hook upt he front radiator.

the V8 cars with big engine seem to use rather large radiators up front, might be a bit of a stretch to get that much cooling (if truely needed) out of the engine bay.

I want ot consider this, i'd love to try a water cooled conversion without cutting up the trunk. I thinkt he best bet is the flat Subaru for this, thickest radiator and full width to boot.

how ever since i have V6, that is what i'd like to try, space is an issue.

How about for engine access a quick connect hose for coolant, it will have to be large diameter, and seal when disconnected, some one must make something like that for industry (Air Force surplus in flight refueling nozzels!)

[jsteele22]

anyone have got a good source for thin, wide and short radiators?

Someone on this board mentioned Jeep Cherokee (not Grand Cherokee), but I don't know if anyone has used it. Size, IIRC, was about 11 x 31". Years were like 1990-2000 or so, so there should be some to scrounge from

How about for engine access a quick connect hose for coolant, it will have to be large diameter, and seal when disconnected, some one must make something like that for industry (Air Force surplus in flight refueling nozzels!)

Just thinking out loud here about a compromise that might be workable. Kinda hokey, but bear with me. Leave the engine lid as is. Then fab a frame mount for the rad that holds it horizontally just below the lid. (So it's in the same position as before, just not attached to the lid.) When the lid is opened, the frame/radiator/fans can be unclipped and lifted out of the way. This would allow more freedom in laying out the hoses, and experimenting with different amounts of flex/twist demanded of them. I'm kind of picturing two hoses, say, coming from the left side of the engine crossing diagonally to the right side of the radiator with a reasonable amount of slack. With the lid open the radiator could be lifted out and hung vertcally over the left side of the car. When installed, the hoses could be clipped in place to keep them from flopping around.

Oh, and I imagine you might want to keep a pair of gloves handy ! If only there was a convenient place to keep that sort of thing. Sort of a box dedicated to things like gloves. Hmm. Have to think about that one for a while.

[dmenche914]

That would work too, but with the V6 / V8 cars there is a limited space above 9the Subaru should give much more space, plus the headers are down low, not up near the top like the V engines.

one option that still kind of stays in my plan of not cutting up the body would be to make a raised up engine lid, maybe raise it a few inches to gain room for a thicker radiator / fan. the raised section would be screened for heat outless, maybe full screened like the 916 cars. The body need not be cut up for this, just a customized engine lid. I think the corregated radiator lines will work bending the 70-90 degrees when you open the lid. They seem very flexible verses the smooth lines.n Just leave a big enough service loop.

[Andyrew]

I got mine in there somewhere.. (click on my build thread)

If you want to copy a setup. The first link is the best. Its rennegades setup and works better than anything i've seen.

[dmenche914]

Measurements of the buick V6 car show only about ten inches betweent eh headers (HOT!!!) and the engine lid, figure the radiator is stood off one inch, thickness is two inches, and fans are three inches, give a meger four inches betweent he fans and thetops of the headers. Also since the carb / aircleaner is so high (near touching engine lid screen), figure the middle one foot of the engine lid is unusable in the V6 application.

For me, if I were to try it, a raised engine lid would be required, just how much,a nd much rear window i want to block is the question. I see that the engine lid is only about ten inches wide (after allowing for the hinges) so maybe I have space for two ten inch by ten inch radiators. That is small combined, than the one radiator I have in front. Of course my front radiator maybe over sized. I almost never need to turn on the fan, even in stop and go traffic, perhaps i could get by with less radiator, if fans are used, but I am still passing the air over the hot headers. Will need temp measurement s next.

[dmenche914]

Looks like we might be doing a radiator set up like Philip Hains. I don't like the idea of cutting into the front fenders all that much. There is too little room in the engine bay with a V6 for radiators back there I think (the chance of pulling it off I think is too low, even with lots of work) I don't like the idea of cutting up the front trunk too much, but unless I can shoe horn radiators inthe engine bay, that is my only option.

any more ideas on this beofre i commit to a plan?

The lack of space int eh engine bay freaks me out, but i stillthinkit would work with a subaru. (hell anyone got a cheap subaru enigne , and mounting kit?????, maybe ditch the V6 for it? Ahh there i go plotting again.

[neo914-6]

if you can lose the headlights, Boxster/996 dual rads...

BTW, Roger had a long thread about alternative cooling systems...

[dmenche914]

what are the boxster radiator dimensions? width, hieght and thickness? if there are thin enough, maybe just maybe I can have them sqreezed into the engine bay????

thanks

[neo914-6]

what are the boxster radiator dimensions? width, hieght and thickness? if there are thin enough, maybe just maybe I can have them sqreezed into the engine bay????

thanks

They are just small enough to consume half the front trunk ahead of the wheel wells, so they won't fit in the engine bay. I've been told by the Jaide guys they experimented rabbit radiators in the engine bay but ended up with a front mounted radiator.

[dmenche914]

i got a new chassis, hate to cut it up for radiator however. I am stillthikng if i replaced the engine lid with a taller one, full creen, i can fit some radiator(s) with fans, may partially block my rear window, but heack, thats waht the sideview mirrors are for.

Do you know if they tried to fit the rabbit radiaotr(s) with a stock engine lid inplace? and what motor were they tring to cool, a V8? or smaller?

[TonyAKAVW]

I have come to the belief that to properly cool an engine you need ram-air from either a scoop above or below the car, (or to the sides for that matter) or from mounting on the front. I had no ram-air on my car for some time and it worked for around town on cool days. When I tried to take it on the freeway it was pure thermal runaway as the radiator could not keep up with the 100% (albeit little throttle) duty cycling of the engine.

So wherever you mount the radiator try to make provisions to get forced air into it. Also make sure you have GOOD electric fans. There can be as much as 50% difference in CFM ratings for fans of the same diameter.

My results with the engine-bay radiator are mixed. While I haven't finished off the ducting completely (there are some gaps in the ducting still) for the most part it cools okay. The situations where it doesn't cool are when I'm not getting enough ram air. That is primarily in traffic (stop and go is okay, the fans do fine with that) about 30-40 mph. Above 40 or so, the ram air seems to do the job fine. Below that I think I'm just not getting enough pressure at the input of my scoop. One more thing I want to try is putting a rubber flap extending down further towards the ground from my scoop. This will help build pressure and because its rubber shouldn't be damaged by speed bumps.

Eventually though I am going to go with a front mounted radiator. I want to be able to take my car to the track, autocross, etc. in hot weather and not have to worry about heat. To get the same ram-air effect anywhere else on the car is really difficult. I'm planning on running the coolant lines through the cabin of my car above the stock tunnel and use a Scirocco double-pass style radiator.

-Tony

[TonyAKAVW]

Here are some pictures (from my thread) of my cooling system.

By the way, there is not much room to put in a radiator on the engine lid. A pair of thin fans, yes, but a radiator, and fans, not really. And this is about the lowest you can get for an engine. I have cut the oil pan and moved the engine down 2 inches from where it would be otherwise.

[TonyAKAVW]

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