ROBx718

Hey guys!
Esmeralda here. Owner of a 2nd gen Mazda Rx7. Recently I had posted a thread regarding my blown radiator, well its been about two weeks and I've finally had the time to lay down some wrench work. I went to a local auto hobby shop due to me not being able to work on my car in the dorms. I love that place now!.. Although I did have one problem...

I ordered an aluminum radiator to replace the broken one I had, problem was that as I went to compare the old one to the new one, the fan cover (shroud) didn't seem to quite fit with the new radiator. The new radiator is almost twice the size in thickness against the broken one, and some mechanic guy at the shop said that I should just take the old radiator and get it fixed, because my plan was just to install the new radiator and keep the fan shroud off. I have a couple friends that don't have fan covers and their engine doesn't overheat or anything. There is a little bit of space between the radiator and the fan, that may allow the car to get warmer than normal, but my thing is I WANT THE NEW RADIATOR installed. What should I do? Keep/fix the old one + shroud? Keep the new and leave it without a shroud (maybe get a custom one later)?

Also, when I went to put in the new radiator, it didn't flush completely with the bolt holes and stuff because some hoses and bolts were in the way. I'm going to get the excess welded off so it can fit in perfect.

I posted pictures up of todays work.

farberio

iTrader: (7)

Who makes your new radiator?

If you intend to keep the stock clutch fan you MUST run the shroud. If you want to remove the shroud you should switch to an electric fan.

lonetlan

I hope this helps...

Trim the fan shroud(do at your own risk). You need this piece of plastic to ensure airflow through the radiator.

Wait for supporting evidence for this dilemma you have before doing so...

rotaryride

Hello forum,
Okay I was wondering, my friend does not have a fan on a different 13b that he bought since the old one blew. Does it really need a fan?
Also, I have seen some rotaries that don't have fans..Why is that?

farberio

iTrader: (7)

^ Yes it needs a fan. End of story.

lonetlan

The fan is activated at low speeds to keep the engine cool. So, keep it.

Now, if you or your friend have a strictly race only car, that wouldn't see much action at 10MPH, a fan is not needed.

Much of this is explained in threads about "E-fans vs Stock fans"

ROBx718

Hey guys! My car has been doing just fine without the shroud. I apologize for taking so long to post up the pics.

Flash

iTrader: (2)

I've had rotaries for nearly 10 years now and I know of no experienced owner who would ever recommend running without a fan on a street car, EVER!

I'm stating the obivous for new owners who may not know yet: Overheating ONCE can kill a rotary engine. That is the major weakness of these motors. Why do you think Mazda made these cars stock with one of the biggest oem oil coolers from the factory? Why do you think it had a radiator stock that is as big as radiators used with some V8 engines?

Sure, you've bought a new radiator that is twice as thick. What you've done is increase the heat capacity of your cooling system, but it can still over heat, it may just take a bit longer before it does. The stock clutch fan setup moves MASSIVE air, which is why electric fan recplacements have to be really heavy duty.

Honestly, how would you know if it is or isn't doing fine? The stock gauge? Keep in mind that the stock S5 gauge isn't incremental. It has off/on/blown engine.

If you run without a fan, do so at your own risk. It is not recommened by anyone reputible. It is not recommended by anyone with a proper gauge to mensure coolant temp either. Understand that you are taking a big risk with the rotaries biggest weakness.

s0apgun

RUN a clutch fan... in fact go buy a BRAND NEW one from Mazda that way you KNOW the coupling works perfect.

I hate electric fans and unfortunately the car I own now has one and I already ran into a problem with it and overheated the car in dead stop traffic. Surprised I didn't blow the engine... although I haven't done a compression check since it happened.

Gray90rx7na

iTrader: (1)

Just go e fan them **** are cool, and you can put them on switch that way you can turn them on when you want and not have them running all the time. Also give you more space in the engine bay and to me make it look better.

ROBx718

Thank you. I am buying a shroud, decided not to take any risks. Car is worth too much to me.