Radiator placement - need help measuring space

Hi, I have a Rotary engine and am planning to mount two small radiators with a fan each for cooling in the front of the car. I want to keep the spare wheel placement stock so was planning to install them directly behind the front headlamps and infront of the front wheels. A tube (somewhere behind the spare wheel well and front torsion bars) will connect the radiators. I will get some airflow from the front indicator grills and will make a metal air dam to catch some air from underneath the body.

My problem is I live in Belize and all my parts including the body are currently 3,000 miles away, so I don't know how much space there is behind behind the fibreglass headlamp buckets and front wheels. Can anyone help me by measuring the width and height in this area?
Thanks, Otto

Maybe a better place would be above the transaxle, even if you have to raise the rear shelf to fit it in. A partial belly pan to bring air up from underneath the car and a good electric fan. That's just dead air and a debris pocket behind the headlight buckets, not sure that you'd get the movement and cooling air that you'd need (those little engines run SCORCHING hot) but you would collect a lot of dirt.

Just thinking, not sure.

Luck . . .

In the front fenders would make the radiator(s) awfully vulnerable to road debris, especially that close to the wheel.

Of an even higher priority than the radiators is the placement of your oil cooler. Only the outer part is water cooled, the rotor is oil cooled. I've got two cars at the house and can measure them, but I'm not there right now.

Priority 1 - oil cooler. The radiators are secondary.

angela

Oil cooler could go up below the existing engine grille.

Curious question Angela-how is the rotor cooled by oil-is the eccentric shaft drilled w/ oil galleys? ( early 13B's had oil metered to the intake...presumably for lubrication-ie 2-stroke). Thanks, SS

The bearings are oil cooled (as are all) and the e-shaft has a groove that squirts oil into the rotor cavity. The cavity doesn't fill with oil, but the oil is squirted in there for the sole purpose of cooling. Like a piston squirter only different and with more volume.

It is seperate (and in addition) to the early rotary (e.g. 12A and 13B) oil injection which lubed the rotor seals.

angela

Wow. Five posts and NOBODY has even started to address Otto's question!!

OK, Otto. Here you go, measured from my CMC build (should be identical to just about all of the bodies out there):

Tire Diameter = 23 inches

Headlight bucket:
Height = 10 inches
Width = 8-1/2 inches

Spare tire well is about 17 inches wide (FYI)

Useful space behind the headlight bucket:

Height = 17 inches (top of headlight bucket to bottom of body - add 4 inches for the area above the headlight bucket, but the airflow there would be minimal)

Width = 17" from inside of fender forward of the wheel to the spare tire/battery well

Depth = 8 inches from back of headlight bucket to front of tire

You might want to contact Carey Hines at Beck (carey at beckspeedster.com) - he has, on some cars, mounted a radiator in the front, down below the headlight buckets under the nose that might be what you're looking for. Developed a small air scoop as well. If I remember correctly, his radiator was in front of the spare tire well and cuts into the well area to exhaust out right in front of the torsion tubes. It's mounted on an angle (top towards the rear) and is something like 10" high by about 20" wide and is remotely filled at the rear of the car (because it's too low). Water lines ran under the door sills on one side.

Good luck! Last time I was in Belize it was called British Honduras (1967). Absolute paradise - I envy you!

Gordon
The Speedstah Guy from Beaufort

Thanks Angela. SS

Thanks Gordon and everyone else, thats great, really appreciated, now I can start looking for radiators. When you measure the width of 17", was it from the bottom of the fender to the spare wheel well? I was just wondering how much narrower the width is as you go up, given that the fender tapers inwards.

The oil coolers, I was planning to use two 96 plate coolers with 10" fans, one mounted each side of the engine. I was thinking of mounting it below the engine grill, I like the idea of the engine grill being functional, but it will reduce the room I have to access the engine bay.

I'm hoping debris and stones wont be an issue, the radiators will be in front of the front tires so they should be OK.

What were you doing in Belize back then? It's population has more than doubled since then, but it's still very laid back.
Otto

Otto:

That was useable space. There's about 19" from the bottom of the body to the spare tire well, which tapers down to 16.5" up above the headlight bucket but that area wouldn't get a lot of air flow so I discounted it. Still, I would contact Carey Hines for his input as I believe a single, larger frontal radiator would be much more efficient (and easier to mount) than duals up front. You might be able to save the spare tire well if the radiator was horizontal and angled steeply towards the rear from the nose.

In 1967 I was part of a group called "Los Amigos de las Americas", a volunteer group providing health and social improvement in the aldeas of Honduras, Guatemala and El Salvador. They're still around, and just about to head into the area for their annual summer tour of young volunteers. I was in La Esperanza, Honduras, and got over to B.H. a couple of times for "R&R". Toured much of Central America, down as far as Ecuador. Amazing scenery everywhere you looked.

Thanks again Gordon. This will help me do my research online for a custom radiator. When I visit the states again next year I will take a look at a complete speedster and work out what I can do. I dont get much vacation time in the states, so the measurements will help me work out what I can fit in there in advance of going there.

I haven't heard of the organisation. I have lived in Belize City for the last ten years. Since 1967 it hasnt changed all that much, more concrete buildings now where as before there were mostly wooden. I have yet to go to Honduras, have been to Guatemala a few times, El Salvador and Costa Rica once. Usually I head to Mexico every few months, sometimes up to Playa Del Carmen just outside Cancun which is quite different to Belize being more developed. If you ever come to Belize again give me shout. Hopefully I will have the speedster here and built next year.

Otto, none of the dimensions on my car would be useful to you, but ...
In most of them, the channels under the longitudinals (inside the space under the door sills) is also open. Here's a shot of my car on its back, if that helps; I feel like you could probably line up a pair of motorcycle radiators on each side for killer cooling.

Hi Cory, thanks for the photo. I was thinking of running the radiator pipes below the door (in the sill), one either side.

In the photo it looks like you welded the rear torsion bar outer housings? I have an IRS chassis with the long, 26" rear torsion bars. I went to fit my new adjustable rear spring plates only to find that they are shorter, so I will need to buy the shorter, 21 3/4" torsion bars to match the adjustable spring plates. Another thing I was considering was using rear coil-over shocks instead, but I'm think the ride height will then be fixed as per the springs used? I have a Porshe 901 transmission and I want to move everyting forwards as much as possible for better weight distribution (the tranny is about 1" longer than a VW to start with). Another idea I had was to cut the middle of the rear torsion bar housing and move the inner mounting point outwards, so as to leave space in the middle of the chassis to allow mw bring the tranny forwards (in effect using 21 3/4" torsion bars, sticking out the same distance as 26" torsion bars). These are all ideas and I need to research them more.

Contact Henry Reisner at IM as he moves the tranny forward like you are planning. He may be able to provide some insight.

Otto, my rear suspension is pretty significantly modified from stock.
It used to be IRS, and is now shortened a swing axle setup. In order to do that, we kept the longer IRS torsion bars, caps and the inner section of the torsion housing was cut by three inches on each side.
We welded in the swing-axle spring blades, welded the torsion back together and made the shortened axles the dimensional guide to point them straight rearward.
It took a long time to get that exactly right; three or four days of messing with it. Ultimately, since the torsion caps were from the IRS, it wound up being as simple as cannibalizing both setups for the right pieces and welding them as thoroughly as possible. The resulting ride is pretty tight. No problems (knock on wood) since 2006.
I took a picture of the requisite parts before we welded the second assembly together.

Thanks for the advise, I give Henry a call and see whats possible with an IRS set up.

Otto:

Be aware that there are two versions of spring plates used on IRS rear ends.

One version has a single spring plate and a shallow end cover. The other version has a dual spring plate that the rear hub spring plate tabs go between. The end cap has spacers on it to clear the two plates. If possible, with the torque that rotary engine will produce, I would run the dual plate rear.

Just a thought.

gn

Hi Gordon, I didnt know there are single and double spring plates. I have aftermarket adjustable spring plates, there are two pieces each side, but the reason for this is so that they are adjustable so in effect they would probably be considered the same as single spring plates (having one piece of metal for the trailing arms to mount to)

The ones I brought are the wrong size unfortunately, they are the shorter housing type and I had the longer torsion bars on my chassis. I may just buy new shorter torsion bars to fit (I was thinking of the slightly heavier duty 24mm torsion bars, as the car is about 100lbs heavier in the rear with the rotary engine and 901 transmission).

Another option I was thinking about is to buy the longer housing type adjustable spring plates, and use short axles, cut the middle of the torsion bar housing (behind where the VIN is stamped) and leave an empty space there (relocating the torsion bar housing a few inches each side of the middle of the chassis). This would then give me space to move the 901 transmission and engine further forwards for better weight distribution. I'm not sure if this is possible, I will call Henry at IM in the next week to see what they do.

I'm now thinking of adding a third radiator, in the middle, in front of the spare wheel well. Can anyone tell me the distance between the front left and right metal bumper brackets for a Vintage speedster? The plan is to put the radiator between the two brackets. Thanks!

Giday, Otto. Don't know if this is useful info, but I slung a Jeep Cherokee rad underneath my bumper brackets side to side and have a fan mounted to it. The rad measures about 32"x 11" and is sloped slightly up at the front due to the shape of the bumper brackets. It's lowest point is 5 3/4" and is mostly protected by the front bumper. It would have to be a pretty talented rock to hit it. Not much cutting and fitting to put it in either.

Hi David, I was considering the same radiator. Sorry what do you mean by the lowest point being 5 3/4 inches? Just to clarify, your radiator is mounted underneath the body, in front of the wheel well, behind the front nose of the body right?

Did you mount the fan in the middle, infront of the radiator (pusher type)?

I'm re-reading your message. Do you mean 5 3/4" from the ground?

Sorry for any confusion in my hasty post, Otto. The rad as it sits now attached to the bumper brackets has 5 3/4" ground clearance. On
my car....and yours might be different, there is room on top of the rad for two 10" fans, puller style between the bumper brackets. I only have one fan fitted now. Again, the rad is canted slightly up at the front due to the shape of the triangulated bumper brackets. The rad is generally protected by the bumper itself and the little bit of bodywork which projects down lower than the bumper. If you do chose to go with a Cherokee rad, be advised that various years and models have different placement of the inlet and outlet fittings. You can select one which has very convenient fittings easily creating a high spot where you can mount a coolant temp sensor which can be used as a bleeder valve.

Thanks for explaing. Just to clarify, your radiator is mounted vertically (at an angle), as in a normal car? Not horizontally (flat) right.

When you say the fans are mounted at the top of the radiator, do you mean mounted at either end of the radiator, in the area in front of the left and right wheels near the headlight buckets?

Nope...the rad is almost mounted flat ( horizontal to the earth's surface :-). It is slightly raised at the front because it follows the same angle of the lower bumper brackets to which it is attached.

I see, it might be difficult to mount it like that while keeping the spare wheel well. How much HP are you running and does it cool well?

I don't have a spare wheel well that would get in the way. There is a well big enough for a full sized battery and a few tools in my car. The bottom of this well is about even with the top of the bumper brackets whereas the rad is slung underneath those bumper brackets. My engine is a stock EJ22 Subaru but just recently installed and I have no experience with it on the road in hot conditions. I opted for a rad that may be too large rather than too small. Time will tell but I'm pretty confident with my choice. I live in Canada just North of New York State, Otto and it's cool up here. I did take it out for a run recently and it was 32 degrees F outside. I warmed up the car in the garage to about 190, took it up the road and the coolant temp slid rapidly down to about 170 which would give the engine stat fits I guess because it is a 172F. The engine should put out about 137 hp but I cannot ever see me using that much. We cruise and travel with the car.

Ahh that would explain it, no spare wheel. I have just found out bar and plate intercoolers, which are smaller than a radiator so I may go down this path, connecting three of them instead of radiators. Thanks again for your help.

Can anyone help with the measurement between the two front metal bumper brackets on a Vintage Speedster? I think it's around 20"?

I think I have the radiators figured out. Im going to use three in the front. One in each front wheel well, behind the headlight buckets. They measure about 16" wide by ten inches tall, from a Yamaha 450 ATV. The inlet/outlets are too small so I will reweld these to a larger diameter. The radiators are full aluminum, 2-core and get be brought new on Ebay for around $75 each. In the middle, in front of the spare wheel well I will mount another radiator. The space here is about 20" wide by 10" tall. I have searched car, bike, ATV and industrial machinery but cant find a radiator this size. Rather than get a custom built radiator for $400 I will buy a BMW E30 radiator (19"x19") for around $100, cut the top off and reweld it so it is shorter. Its a 2-core all aluminum radiator also. All of this will give me about 300 sq inches of core. The RX7 radiator has a core of about 350 sq inches so I am a bit under. I'm hoping the extra piping to the front of the car, three fans and 2-core design will compensate for the smaller core size. It's quite a bit of work but I hope i can keep the spare wheel unchanged.