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 Post subject: RX-7 Rotary Cooling
PostPosted: May 19, 2008, 12:50 pm 
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Building dedicated modified autocrosser using a book chassis, standard nosecone size (maybe a TTL from Kinetic) with a 12A rotary engine.

Anyone have leads on what size radiator will fit the nose cone AND keep me cool from grid to course and back?

I have a high flow oil cooler from a V8 stock car, this should be overkill on the oil cooling.

Thanks


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PostPosted: May 20, 2008, 1:07 pm 
Put a large radiator in back with an electric water pump and a high CFM fan. Put the oil cooler front and center in the grill. Run some aluminum or copper piping to and from the front of the car.


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PostPosted: May 20, 2008, 5:23 pm 
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An early 90's Honda Civic radiator seems to be a favorite. Not sure if it's got enough juice to keep a rotary cool.

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PostPosted: June 3, 2008, 11:21 am 
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there are some higher-performance versions of the Civic radiator that ought to do the job. If you want to get fancy:

http://www.absoluteradiator.com/Product ... ?idProd=10

Just found this on eBay, 0.5" thicker than normal, 3 cores:

http://cgi.ebay.com/ebaymotors/93-97-Ho ... enameZWDVW

Oops, bad feedback on seller.

Here's some interesting stuff:

http://www.evanscooling.com/main23.htm


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PostPosted: July 22, 2008, 1:32 am 
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What’s wrong with the early Rx7 radiator and the Mazda oil cooler? They are compact and effective.


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PostPosted: October 7, 2008, 10:50 am 
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thomson2008 -
The third gen RX7 also has a couple of turbos.
They kinda heat things up...

Locofinn, I can't see how any car will overheat within 2-3 mins of driving with a normal radiator that fits in the nose.
Oh, and if you're going with a big oil cooler keep an eye on oil pressure.

Moti

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PostPosted: October 7, 2008, 7:18 pm 
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I think thomson2008 is a rather clever spambot for the 'budapest property' link in the signature. His/hers/its' other posts seem to be snippets of text with the same keywords as the discussion.


Last edited by 00000 on October 7, 2008, 8:18 pm, edited 1 time in total.

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 Post subject: Re: RX-7 Rotary Cooling
PostPosted: October 7, 2008, 7:38 pm 
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thomson2008 wrote:
The 3rd generation RX-7 has been known to overheat easily when driven aggressively on the street or track.

For a 60-second auto-x run?

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 Post subject: Re: RX-7 Rotary Cooling
PostPosted: October 7, 2008, 9:04 pm 
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KB58 wrote:
thomson2008 wrote:
The 3rd generation RX-7 has been known to overheat easily when driven aggressively on the street or track.

For a 60-second auto-x run?

I don't know about where he's from, but for every 60 second run you spend 20 minutes idling on the grid. :? Not a good way to cool your car down. I shut mine off and push it around like a skateboard and use a garden sprayer on the rad.

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PostPosted: October 7, 2008, 11:28 pm 
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I used to do the same with my miata when I autoxed it, shut it off and push it.
If it's at work temp, there's no point in letting it heat soak.

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PostPosted: October 8, 2008, 8:46 am 
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Oh lord, now we're letting the spambots steer the direction of our discussions. :lol:

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PostPosted: October 8, 2008, 11:59 am 
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there seem to be a few RX7 powered cars under construction. Has anybody here actually got an N/A RX7 powered Locost running for some time on the street or track? If so what did you use for a radiator? The Civic radiator is about 1/2 the size of my stock '91 RX7 radiator. Even with the high performance thicker core Civic radiator, I think it will be too small. On the other hand, can the RX7 need as much cooling as a V6 or even a Chevy small block V8? What are these cars using?

FYI, I have a Champion book chassis and a CMC front nose (at the moment). I want to fit these. Crazy idea: has anybody tried running 2 radiators back to back?


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PostPosted: October 8, 2008, 12:23 pm 
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Well there was a link on the front page to a guy in Canada's build that was RX-7 based. (some jerk replaced it with a pic of his own car) It was yellow and the guy's name escapes me at the moment. Anyway, I read his build log on his website (which predates this place) and he mentioned going through at least a couple of engines before finding a way to keep them cool. I'll poke around and see if I can find a link on here.

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PostPosted: October 8, 2008, 11:58 pm 
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He went through two engines because of autoxing or track use?
I can see how cooling of a rotary becomes a major issue at the track but how hard can it be to keep a non turbo rotary cool for a minute?

The guys at 7's only (a well known RX7 race shop located at Buttonwillow raceway) run a massive radiator on their GT2 cars and two (!) of the OEM oil coolers connected in series.

Moti

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PostPosted: October 9, 2008, 12:16 am 
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Blackbird wrote:
He went through two engines because of autoxing or track use?
I can see how cooling of a rotary becomes a major issue at the track but how hard can it be to keep a non turbo rotary cool for a minute?

The guys at 7's only (a well known RX7 race shop located at Buttonwillow raceway) run a massive radiator on their GT2 cars and two (!) of the OEM oil coolers connected in series.

Moti


It was a track machine. IIRC he took off the front cycle wings because they were making too much lift at high speeds. :shock:

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