cpa7man

iTrader: (2)

http://www.mazdamotorsports.com/wcsc...ing_Edited.pdf

Mazda at one point recommended a Fluidyne unit, looks like all orginal bigger coolers are now discontinued. Some of us run a Fluidyne cooler. Larger than stock...but won't work for thead orignator. You gotta pay to play

wolf_walker

Only other good pic I have really. Mounted it inside the front bumper for lack of anywhere else. Cut oval openings in front and wire mesh screened them over. Worked well for the last 100K or so. Another side benefit was it increases oil capacity by a quart and a half or so as I recall.

One thing to note is that was about a $300 retail price cooler I believe, we got it off ebay for $100 or so. I think it was actually used on a NASCAR racer.. It really probly would be cheaper to find a used stock one unless you just want to do something different.

chedda_j

I just dont like used parts, thats what it really comes down to in my mind. But i dont really want to spend like 500 dollars on a stock OC itself. I like your cooler there, im going to ask the rad shop if they can make me one to the specs that were listed. BTW, if a stock used one was cheaper, why did you go with an after market one?

Now trochoid, i know that the stock one was the 4.5 x 2.5 x 22. I know that the oil piping is 1/2". So the runners would be 1/2? i only ask this because on many after market ones the tubing is actually larger than the fittings themselves, they mech down for the fittings on most.

trochoid

iTrader: (6)

An oil cooler is a high pressure radiator. Are the tubes in you radiator larger than the coolant hoses on your engine? Get those creative juices flowing. You are not understanding how/why the cooling process works yet.

While new is just ducky, we can't always get what we want. Why did you buy a used car, and a 20+ year old 7 yet? 80%+ of the car is NLA.

wolf_walker

This was put on an 82 VW Pickup with an imported Canadian IDI 1.9L turbo diesel. The stock setup is the same oil/water heat exchanger VW and Audi and Volvo used though most of the 80's, and it's better than nothing, but still not all that hot(no pun intended). So we were starting from scratch essentially. Used a thermostatic sandwich adapter to plumb in the cooler off a Volvo, had lines made up. Temp is extremely stable with this setup.
We went through such lengths after a collective 1.2 million miles of VW diesel driving between Father and I, just under 500K in a turbo diesel, and our considered opinion after observing wear patterns, oil anylisys and such was that overheated oil was a serious issue.

We fixed that.
The 1.9 should go a good 700K with a head rebuild at around 300 and 600. Beyond that is uncharted territory, even for us.

peejay

Without reading the whole thread, a stock RX-7 oil cooler will be the best thing you can get.

People who race OTHER CARS find RX-7s in junkyards and grab their oil coolers, because they are the best oil coolers commonly available. Maybe 911s have better oil coolers, but they are a wee bit harder to find.

peejay

Not over 180-200 degrees, if your cooler is any good.

The oil is responsible for removing 40% of the engine's waste heat. Because the oil flows faster through the cooler and not all of it goes through the engine (meaning some of the oil goes through the cooler twice without having to pick up heat) the oil cooler has to be about 1/3rd the size of the radiator.

Midwest 7's

iTrader: (4)

this is true.
around here it's the only japanese part you'll see at a swap meet.

Kentetsu

I say if you can find an aftermarket unit that costs less, and performs better than the stock unit then go for it. However, from what I've read you may not be able to find one out there. However, if you do find one then you might become everyone's hero!

elwood

iTrader: (1)

For those that have fat pocketbooks, the Setrab COM cooler is a good choice. It's built like a tank, is slightly larger than the OEM Mazda unit, and fits in the OEM FB location perfectly. http://www.hrpworld.com/index.cfm?fo...action=product

diabolical1

iTrader: (3)

First, I don't think anyone is trying to make you look dumb. What's going on is you're not getting the answer you want to hear and you're trying to ride it out and persuade others (Trochoid, Doc and others) to endorse your excuses to cheap out.

Second: what Peejay said ...
I've seen a few 911 and 911 Turbo guys seek out Rx-7 oil coolers (new and used) when they get serious about a buildup. That should say enough without any further words.

I chose to buy a brand new cooler when the welding and re-welding got to me. Was it expensive? Yes. Would I do it again? Hell yes! When it comes to these engines you MUST keep them cool. Period. This is not the system to get frugal with. I understand wanting to improve on some things, but there is nothing lacking with the stock parts. See what oil cooler DF uses in Kramer or Revhed uses in his car ...

That said, you may want to check the Gen III section for ideas. I know some of those guys use aftermarket units (usually 2 of them), but a few years back when I was looking for alternatives, I remember seeing a few in that forum.

Bottomline, it's your car, your engine. It would be unfortunate if you kill it over being stubborn, but it's your decision.

chedda_j

Im not that dumb, just stubborn. I like to think that some of my ideas are actually good, yet i should know that every idea i come up with theres a 99% chance its been covered and already figured out. Ive always tried to invent new things, ever since grade 1, when i tryed to build a robot out of old stereo. I thought that the little tabs in pop cans were microchips. But thats besides the point. Im really not that stubborn i just like alot of answers. I have to admit this has been a very well covered topic already. I just would like a new one to tell you the truth but i think i might have sourced a SA in the area. Thanks, il let you know whats up.

Siraniko

iTrader: (13)

Stick with the stock factory oil cooler. If you need one, let me know. I have several but the ones I will sell are the FC ones since Im kinda low on old school parts right now.

chedda_j

il let you know if i need one. Price btw.

DAVID GRIMES

But if you are, how would you know?

mustanghammer

iTrader: (3)

When I decided I needed to correct high oil temps on my racecar - 240-250F. I looked at allot of after market coolers. The Setrab and Fluidyn coolers look really good but to get the same performance as the OE cooler the cost was too high - $500+. So in the end I determined that a good used Mazda cooler priced anywhere from $100-150 is a bargain.

So, I now use two 1st gen coolers in series on my IT car in the summer time. I got the second one from The Rotary Doctor at very reasonable cost. They are pumbed with -10 areoquip lines using AN adapter purchased from Mazda Trix. Because I don't like any variables in the cooling system the thermo-stat is removed and a slug is installed in it's place so that oil is always circulating. For water - an important part too - I use a 22x19 dual pass aluminum radiator made by Ron Davis. On a hot day - 90-100F - I am happy with 200-210 water and 220-230 oil in hard racing conditions.

If you cruise the paddock at an SCCA club race you will also see OEM coolers on all of the Production and GT rotary cars. Most of these cars have oil to water and stock coolers plumbed to keep there engines cool.

So while there is nothing wrong with looking around and exploring all of the options it seems to me that the oil cooler is one of the things that Mazda really got right. I have been racing cars for a long time and I learned early on that it is really hard to beat a good OEM part.

Jason Guthrie

What options do I have?

I have an 85 se with a working oil cooler but the lines went bad. I bought some stainless steel lines from RB(?) (the ones with the cliche blue and red ends) and whelp, they didn't match up to the factory IN/OUT on the oil cooler. Basically, it looks like the oil cooler has to two hollow nuts/bolts going into the oil cooler that are to be replaced with the RB supplied size. Nobody has been able to remove them so it is assumed they are actually welded in there or stuck as fuc. Anyway, at this point I'd prefer to just get some factory(ish) lines for the thing and move on. Any ideas of what size all the fittings are or lengths I need are? Also, what can I do to dress up the oil cooler it self? I'd like to de-gunk it and paint it but not sure it can be painted due to heat or compromising the way it functions. What after-market options have you guys tried since most here say grab oem or FC or the $800 new one. I gotta get my car started (after 4-5 year parking) and this oil cooler issue was the only show stopper when I had to park it.

elwood

iTrader: (1)

To adapt your new lines, remove the current adapters (if all else fails, use heat and a pipe wrench -- you have nothing to lose), get the correct adapters from RB, and follow the tips from the rest of this thread. If you read the earlier posts, you know there is no good economical substitute for the RX-7 coolers.

Jason Guthrie

I tried a 3'-4' breaker bar on that nut. I don't have heat options so maybe that is the trick but to be honest, if I got them out, I'm not sure the RB nuts would go in. Too much of a risk. Plus, with the stocks in there so snug, I can pretty much count them as permanent and not worry about them leaking.

I need to find a way to dress the thing up now though. I was considering polishing the whole thing but worried I might bend the crap out of all the fins. Maybe just a degunk, power wash, and matte black redo...

I grabbed my OC and the RB hoses and am taking them to Home Depots plumbing/piping section. I'll just get an adapter there that screws onto the stock mounts and into the RB hoses. Thing is, its been so long since I took this thing out, I don't recall where those hoses go (other side of OC). LOL

sgieldon

Upper Inlet=Short Hose From Front of Engine Cover
Lower Inlet=Long Hose From Rear of Engine
sgieldon
steve

Jason Guthrie

Cool. I will have to peek in the hood to see what sort of thread connections I'm facing. It would be nice if the RB just matched up to that side at least.

Jason Guthrie

Incidently, the stock Oil Cooler connections are 1/2" Flare while the RB hoses (Stainless Steel with blue and red ends) are 5/8". Home Depots' plumbing section has a brass adapter for $2.50 labeled A-360 (PB46) light blue package... Now, so far as getting this O/C back in, I just need to find those two IN/OUT holes on the engine and figure out how they connected before. I'm hoping through the same kind of threaded connection in which I have an adapter for.

trochoid

iTrader: (6)

Sorry to burst your bubble, but all of the oil cooler fitting are metric, not SAE. Almost sounds like RB sent you FC fmoc lines instead of the SE ones.

elwood

iTrader: (1)

Hey man, you're talking to people who have done this sort of thing before. We're trying to save you a lot of suffering:

Trochoid is right -- the OEM fittings are metric -- not 1/2". They might be close, but this isn't horseshoes. The stainless hoses you got from RB have -10 A/N fittings on them. -10 stands for 10/16 of and inch or 5/8", so you got that part right. What you can't see is that the bevel angle on the home depot fitting will be 45 deg. whereas the RB fittings are 37 deg. It won't seal.

The name for the RB-sytle fittings is "A/N". This stands for Army/Navy, and the 37 deg fittings were designed many decades ago for aircraft usage. They changed the angle from the SAE 45 deg angle to make sure inferior automotive parts (or Home Depot parts) wouldn't end up on planes.

Here's what you need to do:
1. Remove the fittings from your oil cooler
2. Get the correct adapters from RB
3. Connect RB oil lines as outlined already.

If you break or crack the bungs on your oil cooler, there are many ways to fix it -- my favorite is to get weld-on -10 male bungs in aluminum and have a competent welder make it all better.

Jason Guthrie

****, that ruined my day. Guess I gotta repay RB to get things right. Still don't think I will get the stocks out of the OC though, Many people/shops have tried. Crap.