914-6 cooler

Porsche1VW · 06-29-2003, 02:42 PM

Has anyone had experience or would like to comments about the suitability of an RX7 oil cooler with a built in thermostat for cooling a 210HP 914-6 2.7L engine (In the oil return to tank line)? Also, how about mounting this cooler in the rear if the 914 under the rear fender in front of the wheel, possible with outside air ducted? Commernt appreciated

06-29-2003, 08:18 PM

I have a 2.7 twin plug putting out about 240 h.p. The car had a aux cooler mounted under the rear trunk back by the rear bumper with a shroud to direct air to it and a fan on top to suck air through. On the track it always ran hot, about 250 deg. I just spent this weekend moving the cooler to the front mounted behind the air dam. I would not bother trying to mount in the rear wheel well. I doubt you'll be able to divert enough high pressure air through it and I don't see how you could run the lines and keep them out of the way. Just my opinion. I have a cooler from a 930 Porsche. I know a lot of guys use the RX7 cooler so I'm sure it will work fine if you find the right spot for it. Do a search on "oil cooler" and you should come up with some helpful info.

Clay Perrine · 06-30-2003, 05:16 AM

I have an RX7 oil cooler that I ran for years on a 2.0 /4. I removed the factory cooler from the engine, and the engine temp never got above 185 degrees even at the height of summer in Texas. The work great. Plenty of surface area to disperse heat. But make sure that you get it cleaned out before using it. Mounted in the rear of the car will help it, but it would work better if it was mounted in the front trunk area.

Good luck.

Jim Smolka · 07-01-2003, 01:48 AM

What size are the fitting for the RX7 cooler? They need to be a min of 3/4" (AN-12) The best place to install a cooler is in the front. Especially for a 6 cyl car.

Brant · 07-01-2003, 06:39 AM

this is not meant to disrespect Clay. I do not have a RX-7 cooler and do not know for a fact if there is a problem or not...

but I had heard 2 problems with the cooler.
1) that the inlet fitting necks down and is restrictive (for sure on a 6) and that the solution was to cut the fitting entirely and tig an AN onto the cooler tank.
2) that the built in thermostat was restrictive/incompatible/and prone to failure. The solution being to cut the entire side of the cooler tank open, gut it and then weld on a new aluminum side tank.

When I spoke with some fabricators the price for modifications equalled the price of just buying a new cooler and it still needed to be properly cleaned.

your mileage may vary.
brant

campbellcj · 07-01-2003, 09:57 AM

I wouldn't bother with anything but a front-mounted cooler on a six (or a track-driven four, for that matter). I know some guys have reported good results with the cooler under the trunk or in engine-compartment locations, but it just doesn't seem like there is sufficient airflow there. The under-trunk cooler in my previous 914/4 2.0 barely reduced temps by 20-30F which is not enough for hard, hot-weather use. The huge cooler in the front of my current six is so effective that it will have to be partly blocked-off in anything but the most insane conditions.

Mr9146 · 07-02-2003, 03:52 PM

I run a long storke, high compression 2.4S in my 914 and I don't even run a front cooler. I have switched to a GT-style engine lid (all mesh) and a bigger fan pulley to boost fan speed. On a hot day in my hometown, the San Fernando Valley, it reaches about 110 - my car never sees the high side of 210.

In fact, I have only seen 210 once or twice since I switched to the faster pulley. Average temperature is 180.

campbellcj · 07-02-2003, 08:43 PM

Quote:

Originally posted by Mr9146
I run a long storke, high compression 2.4S in my 914 and I don't even run a front cooler. I have switched to a GT-style engine lid (all mesh) and a bigger fan pulley to boost fan speed. On a hot day in my hometown, the San Fernando Valley, it reaches about 110 - my car never sees the high side of 210.

In fact, I have only seen 210 once or twice since I switched to the faster pulley. Average temperature is 180.

That's a good point. The street 911's and 914-6's for the most part did/do fine without auxiliary coolers, for 35 years. Even some of the 911's that did have secondary coolers were kind of a joke -- the loop/banjo type.

But have you ever run at 6000+ rpm's for a half hour or more, nonstop, in 90-110 degree weather?

(That's why drew365 and various other track junkies, including me, are highly concerned with this cooling issue.)

M. Hendrix · 07-02-2003, 08:50 PM

Aren't short storks better for racing?

M

WOODPIE · 07-02-2003, 09:15 PM

You are correct, sir!

Short storks will always spank he!! out of the taller storks.

HaHAHAHa...

Ed

fetus · fetus's Garage

I had a 2.7 in my 914 and it got up to 260 degrees on the freeway during the summer even with a GT engine lid.
I installed a front mounted RX-7 oil cooler in a GT shroud and it rarely reached 200 on the freeway. The RX-7 oil cooler had the thermostat and end cut off and has AN fittings welded onto it. I bought it this way for $75.00 used. I'm also running an external Mocal thermostat. After I put about 100k miles on the motor it started pulling head studs. It was a used motor when I bought it. I'm now running a 3.2 and it rarely reaches 190 in LA Traffic.

Steve

propricer · 07-05-2003, 08:20 AM

Have a full race 914-6 with a Twin plugged, crank-fired Euro 2.7L putting out upwards of 280HP ... have always used a front mounted RX-7 which works fine, even at very hot race events ... remove the thermostat.