Interesting /6 cooler set-up, RX-7 cooler in the lid. Options

[Mark Henry]

Here's an interesting cooler set up, done on a 3.0 245hp engine running in cali heat with no issues. Done for an original /6 that the owner didn't want cut up for a front cooler.
What do you guys think?

BTW before you totally knock it it was done by Henry Schmidt at Supertec, so the builder does have some credibility.(IMG:style_emoticons/default/shades.gif)
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[patssle]

Very nice, but doesn't the hot air go directly into the engine?

[bmtrnavsky]

I'm not really an expert on these things, but that's a low pressure area with not much air flow... Maybe a fan would help though? It sure is a clean looking install though.

[J P Stein]

I'm one of those guys who thinks that if a little bit is good, then a lot is better.
Consequently my motor never has seen an oil temp of over 100C.

Getting the motor up to temp is a bit of a problem. I used to throw a towel over the GT style lid to get it warm faster.....blocking off about 80% of the air flow. Goose the throttle and the towel would quickly conform to the grid pattern of the lid. (IMG:style_emoticons/default/dry.gif)

You don't need an aux cooler till you *really* need it. Then it had better work, IMO. I've never had that problem. This set-up would seem to create a heating loop
that would not satisfy the *really* part.

[brer]

That cooling fan pulls huge amounts of air through it. I do not think the oil cooler makes enough heat to effect the air temp in any significant way.

[J P Stein]

My thermostat opens at 185 deg F then the oil goes to the aux cooler. When it leaves the cooler the line is only warm to the touch. That gives the engine relatively cool oil. In this set-up, where does the extra 80 deg air go?

[Mark Henry]

Quote Henry Schmidt: "The engine never had temperature issues even in California on a hot day."

My question: Henry, wouldn't that pre-heat the cooling air?

Quote Henry Schmidt: "Not enough to matter appearently."

Keep in mind this is a 914/6 street car and would also be using the stock cooler as well.

[J P Stein]

There's a missing number there. Mine was 100C (212F) under extreme usage.

[Krieger]

This location is less than ideal. It is directly over the COOLING fan sucking really hot air (oil thermostats open around 200 ferenheight) and blowing it over your engine. A really hot day in the desert: 115 degrees.....Sure your oil temp is cooler, but

[Brando]

Oil cooler on a /6 should always be in the front.

Always.

[Rotary'14]

I'm one of those guys who thinks that if a little bit is good, then a lot is better.
Consequently my motor never has seen an oil temp of over 100C.

Getting the motor up to temp is a bit of a problem. I used to throw a towel over the GT style lid to get it warm faster.....blocking off about 80% of the air flow. Goose the throttle and the towel would quickly conform to the grid pattern of the lid. (IMG:style_emoticons/default/dry.gif)

You don't need an aux cooler till you *really* need it. Then it had better work, IMO. I've never had that problem. This set-up would seem to create a heating loop
that would not satisfy the *really* part.

Hey JP,, while you and I agree that if a little is good, too much is better. BUT when it comes to oil you really should let it get above 100c because that's when the moisture in the oil gets evaporated out of the mix. I would think an operating temp with slight load that hits 100c and spirited driving up to 120c would be a good range. It will prevent sludge build up, but then again I'm the guy with the rotary engine. I did stay in Holiday Inn before. (IMG:style_emoticons/default/biggrin.gif)

-Robert

[IronHillRestorations]

Oil cooler on a /6 should always be in the front.

Always.

I respectfully totally disagree. I've built at least two conversions with external oil coolers that were not in the front. Neither one runs too hot, both are still going strong one is 15 years on the conversion, and one is 8 yrs.

What is your basis for "always"?

[J P Stein]

Water will boil at 212F. It will evaporate down to absolute 0.
At 185F it evaporates very quickly.
I've never had a sludge problem but a mag case will turn to sludge (rhetorically) if it gets too hot.
I'd accept the lesser of 2 evils.

[URY914]

I don't like coolers above the engines. Oil drains down when shut off.

[Supertec]

Mounting the cooler in the deck lid is not the best location but given our options it works very well.
The customers desires quite often offers some challenges but we were pleased to accommodate his needs.
We try not to let the "Perfect" get in the way of the "Good".
Cheers

BTW: only a small portion of the air used to cool the engine actually comes through the cooler.
Picture the ac condenser located on earlier 911 and 930 in the deck lid.

[McMark]

Nice clean install! Whatever works is the perfect solution. Sorry all you armchair engineers, but if it works fine and keeps the motor and the oil cool, then all your BS about 'perfection' is irrelevant. If you want to go down that road, then ditch your aircooled BS motors, because water is FAR FAR more effective for cooling motors.

[Elliot Cannon]

Mounting the cooler in the deck lid is not the best location but given our options it works very well.
The customers desires quite often offers some challenges but we were pleased to accommodate his needs.
We try not to let the "Perfect" get in the way of the "Good".
Cheers

BTW: only a small portion of the air used to cool the engine actually comes through the cooler.
Picture the ac condenser located on earlier 911 and 930 in the deck lid.

(IMG:style_emoticons/default/agree.gif) Totally.

[Mark Henry]

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I have one of these coolers and I think it's a good solution. Maybe it's not for an all out track car, but for a Canadian summer car it's added protection. One of our members here is running a 3.0 with just the stock cooler with no issues.
For me this isn't California, I rarely drive in heavy traffic and maybe I'll do a DE/AX one day.... but I doubt it.

[tradisrad]

FWIW High Performance House likes to install the aux oil coolers on the engine lid.

[ArtechnikA]

Wouldn't be my choice but it's not my car.
However - I don't like forged 90º hose ends in any part of the oil circuit.
OK - space might be tight for that front one, but the back one needs a bent-tube 90...
But since it'a a compromise solution, and scavenge oil is basically foam anyway, probably not a big deal.

Why not just use a heat exchanger with the ports on the ends to start with, and avoid the 90's completely?...