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Ok ladies and gents. I have a question about this main pulley. It was on the engine when it was installed a few years ago and I never bothered to wonder what brand it was til now. From the google images I found it didn’t look like the oem one. I think it kinda looks like the other thing pictured, an adkinsrotary main drive pulley but I can’t find any pictures from the front to really confirm. The reason I need to know is that the belt is about done, as you can see from the picture. I need a proper sized belt for one with this greedy pulley set with an air pump delete. Thanks in advance for any help on the matter. Also the lettering on the belt is too far gone to read any part numbers off of it.
That also looks a lot like the Pettit Racing pulley with black anodizing.
A PO has also removed the air pump and added an oversized water pump pulley in an attempt to get enough belt contact to the WP.
You can probably just remove those two belts and take them to the parts store. But I suggest strongly you consider an air pump delete idler pulley to get proper belt contact on the water pump. As your’s is, there’s a tendency to slip, which leads to over tightening, which leads to pump failure. https://www.pineappleracing.com/fdidlerpulleykit.aspx
Sgtblue you sir on definitely onto something with that. Ever since I’ve had the car, it’s had a hard time staying cool when ran hard. The fact that the water pump possibly or definitely isn’t keeping up with the engine speed explains so much. I’ve put in place numerous different countermeasures on the car such as as low temp thermostat, Mishi aluminum radiator, coolant additives. all seemed to help a little but never completely corrected the issue. Figures that I would not have known with it being my first REW to tinker with. Thanks a lot for that attachment too. An idler pulley to help make better contact will be first thing I buy on pay day.
The low temp t-stat will just lower the opening temp, but I don’t see it doing much once the engine is at operating temp. In addition to your WP pulley issue, there are other things that I usually recommend for cooling....
* Fresh coolant mix with as much distilled water to coolant that you can get away with in your climate...but not less than say 20%. Search in the 3rd Gen tech section or stickys for tips and methods to fully ‘burp’ the system of air.
* If you’re still on the stock ECU, search the 3rd Gen tech section for info on the S5 FC thermoswitch/fan switch which lowers the threshold temp for the low speed fans from 108 C. to 95 C. It’s a little fiddly to change but is p n p with the stock switch. I think most aftermarket programmable ECUs allow you to do the same.
* check all your hoses, including/especially the turbo coolant hoses for swelling or signs they’ve exceeded their expiration date and need changing.
* if you look thru the nose of the bumper at the face of the radiator you’ll see several gaps that can be easily and cheaply plugged with some upholstery foam.
* clean and straighten any bent fins on your oil cooler(s).
Advanced measures would include a simple boost-activated water injection system. This reduces a lot of load on the engine’s cooling system and has additional benefits of carbon control and knock suppression...both important on a rotary.
Your right about the thermostat. All it did was delay the temps rising. I auto x the car so between runs I’m able to let it cool off but it does get annoying. The coolant hoses are all in good condition. The car is running the power fc and the fans are coming on earlier already. Lol it’s funny you mentioned the oil cooler fins because that was one of the things I did this year before the scca season started was go through straighten them had contemplated buying the necessary parts to set a second one up like the r1 has I think ( not sure if that is factory or just an aftermarket set up I saw on one ) figured that would help temps too. I’m pretty mechanically inclined but I don’t know if I’d attempt the water injection system by myself as I’ve never done anything like that before. I will however go find that sticky you mentioned about the coolant mixture. Every little bit helps. I’m in Tennessee so freezing temps do happen but not often and I usually bring the car in the garage during the real cold times anyway. I should be able to get away with a good amount of water in the mix.
Last edited by Ogan Hudgens; 04-20-21 at 06:20 AM.
I don’t think it’s a priority for you now either, but if/when the time comes a SIMPLE WI system is really pretty easy and relatively inexpensive. Hell, if I can do it anyone can. I used to autox too years ago (ASP) and the only caveat is to check your class rules.
Without getting too big-brain, water has a high ”specific heat” which allows it to carry out a lot of the heat from the combustion event with the exhaust, along with those other benefits, and reduce the cooling system load. Mines been reliable for years (after autocross days) and since I don’t tune with it, even if it does fail there’s no danger. https://www.rx7club.com/auxiliary-in...ion-fd-959565/ (pics reloaded at the end)
I agree on the water being better for heat exchange than antifreeze. My dad told that long ago though I was too young at the time to care. Honestly after I receive this idler pulley kit, i believe that it combined with the aforementioned things I will never again have any type of cooling issues so long as my pump hasn’t sustained any wear from the slipping, so the water injection is probably gonna be a pass for me for now. On another note..... wow that is one clean engine bay ( saw your pictures in the thread you linked ) I can only hope to clean mine up to that standard one day. Anyhow thanks a ton for your input I’ll be ordering that pulley on Thursday if not before. Hopefully they are in stock with the correct belt. I’m calling it a day. Night shift is rough. I’ll check back on here when I get back up.
Thanks a lot sgtblue. Ordered the idler pulley kit and now it makes significantly better contact with the water pump pulley. I know it took a lot of time to get to me but it was well worth it. I didn’t even know that part existed so again thank you very much for the heads up on that one. Would have had it earlier but I messed up and ordered the regular kit and not the big turbo version. The regular version would not clear my turbo. I also took the time to give the engine bay a real good cleaning and got rid any rust I could find.
Last edited by Ogan Hudgens; 06-12-21 at 04:50 PM.
04-19-21, 06:13 PM
