BlacktopSR

for a 87 turbo rx7..im down to one pulley and i think that's why its overheating..i need another belt around the water pump..???>>???? what are your recommendations???please help i cant get it to stop overheating

need RX7

iTrader: (4)

Double alternator pulley.

BlacktopSR

website???price??? why double alt just curious it just seems to me that it still covers the same amount of surface area...why not full coverage across the top????im learning here so please dont shoot me down:X

need RX7

iTrader: (4)

Racingbeat.com, part number: 11479
When the water pump has 2 belts on it, it slips less (think traction on 2 tires vs. 1 tire)

BASTARD

iTrader: (4)

how is it overheating???... while cruising on the freeway? driving on surface streets or high RPM runs?... is your motor stock? how many miles are on it?


more then likely it is not your pulleys... either a bad belt, air bubble trapped in the system, bad radiator, bad thermostat(should run an OEM one) or if your motor is really old then you probably have a lot of mud that needs to be flushed out

BlacktopSR

Overheating FC3s Rx7 turbo
i have a 1987 mazda rx7 turbo...I have the following enigne mods..
Street ported 13B
TO4E turbo with S5 exhaust side
corksport 3" wide front mount
mazdatrix intercooler piping
hks bov
Rtek 2.1 standalone system
Full turboback apexi exhaust
550cc primary injectors and 1600cc secondary
etc....

now this is my issue...about 2 weeks after i purchased the car it started overheating...the guy who had it before me told me the radiator was bad and it didnt have a shroud fan or belt driven fan but instead was powered by an electrical fan...i hardly ever drive the car and i have never pushed it past 3/4 temp...The following stats are 50psi of oil pressure at idle and around 75psi at full boost, 12.1 across the wideband at full boost and no misfire condition that could make be believe its heating up from leaning out...the overflow tank does boil over and results in an aftermarket overflow tank cap to blow off...the car doesn't overheat at idle and i have even left it running for almost 20mins and still no overheating...its only when i put the car is first gear and drive the car for over 10mins and even if i do a hard pull you can see the temp actually go down until i come to a complete stop and the cars temp gradually starts to clime..i replaced the following parts
installed new OEM radiator
new thermostat
installed fan clutch and fan shroud
brand new electric universal fan 16inches
also p/s and a/c have been eliminated
also turbo exhaust side has been wrapped for heat reduction and charge pipes are about 2 1/2 inches wide
car is running a universal coolant temp sensor which controls the electric fan only and works very effectively

The car won't overheat at idle but starts overheating when i start driving it...The car dynoed 386rwhp and 311 torque which i no is much more than stock oem...I have noticed the follow symtoms which make be have about 4 theories...

1. water pump can be turned by hand even with the belt...now when i pinched the belt and take out some of the slack the water pump cant be turned by hand, so maybe the belt is slipping at high rpms which isn't rotating the water pump fast enough...But i dont hear a belt squeal...theres is now only one belt on the car and it runs the water pump, altenator, and rotor shaft pully..

2. Water pump could be bad but i see no leaks of any sort...which could maybe go back to my original theory...

3. Radiator cant support the amount of power that im putting down and the heat cant disperse fast enough...i currently am running the belt driven clutch fan, fan shroud, and an electric fan at the same time...the radiator that i installed in the rx7 came with another cap which was rated at .9psi which turns the stock one cap housing system into a 2 cap same bar system...i eliminated the radiator cap by installing a sealed cap and ever since i did that the aftermarket overflow tank cap keeps blowing off...the aftermarket overflow tank cap isnt a screw on type....
4. and the worst of them all...Blown coolant seal...There is absolutely no water in the oil and the car does not smoke unless for sitting for a long period of time...and when it smokes it only smokes for about 45 seconds and its not even alot then clears up...

BlacktopSR

also already did a compression test came out around 101 so i know its still a great motor

jackhild59

iTrader: (7)

Your answer is the double alternator pulley. Get it now!

OR get a yoohoo belt from Pineapple racing.

Bottom line, you need the second belt because your waterpump is slipping.

Don't overheat that nice engine.

Good Luck!

BASTARD

iTrader: (4)

if the radiator wasn't capable of cooling the high horsepower more then likely it would only get hot when the engine is under heavier loads

a lot of times the shrouding in front of the radiator can be overlooked... what do you have for pre radiator shrouding?



your overflow bottle system could be a source of air getting in to your system


some other items that have been talked about... the use of an OEM thermostat and the differences between various water pumps... some waterpumps use a straight cut impeller and others use a curved blade, it has been stated that the curved blade will be less susceptible to cavitation

your belt could be slipping, is your belt a thin belt that falls down inside the V of the pulley or is it thicker and sit up on the V of the pulley.. I have found that belts that situp work better

updating your alternator pulley to a dual sheave one is easy, there are a number of aftermarket ones available or you can look in the yellow pages for a local alternator repair shop and ask them for one(much cheaper) I got one from my local shop for 5 bucks... just make sure that the two belts are the same brand and close to the same diameter and condition

jackhild59

iTrader: (7)

Come on, don't make this more complicated than it needs to be.


Here is a little troubleshooting logic: Take care of the known problems first in order of importance. Then, if the trouble still exists, work your way down other less probable problems.

That said.....

YOU KNOW THE BELT IS SLIPPING! You knew the solution was double pulley when you posted. Do that first, or you will have the blown coolant seal to deal with as well (if you haven't already f-ed it up!) You can have EVERY other factor done right with the car and this one thing will make the engine overheat on the highway. Until the slippng is corrected you can't tell anything else. Period.

Make sure that you have only an OEM thermostat.

Put the radiator caps and overflow back the way Mazda intended, not because the other config won't work, but because it confuses the issue. OEM caps only here too!!!

Do the coolant bubble test while you wait for the pulley to come in-ITS FREE! That's a great price.

If the pulley doesn't entirely solve it, then look at the under belly tray-make sure you have one on the car.

Then look at upgrading the rad only after all the above is done.

BlacktopSR

next step is new water pump and another type of pulley system..have decided which one to use yet double alt or something diff...it has an oem t stat and its the rad caps from mazda 0.9.. at idle the car is fine until you boost it and red line the car then thats when it starts to overheat after 10 mins of driving..then even at idle it goes up but a simple rev and hold at around 3000 rpms will bring it back down...another issue is i cant even look for bubbles because it just overflows out of the radiator..i know it has to be something very simple and cheap and im so close to finding it..but i just dont know where or what todo after the pump and pulley...i dont want to dump money into useless items that will have no effect..the temp goes down very quickly after its shut off after 10 mins its at 1/4th temp again????

BlacktopSR

the belt sits inside its a thinner belt but i wouldnt say its thin its brand new just bought a new one but it didnt fix it..im pretty sure i need another pulley system because i can see the clock on the dash flicker on and off real quick under acceleration should i remove the clutch fan to relieve stress on the water pump ????????

BlacktopSR

is this what i need...will this work??


http://cgi.ebay.com/ebaymotors/_Car-...4506.m20.l1116

BlacktopSR

is there a bypass pulley for the air pump...anyone have a setup..im just not sure the double will work id rather have full surface area around the water pump to ensure no slippage ..could i put the air pump back on just as a bypass for the pulley?without it working just mounted>

Hazard15301

iTrader: (5)

Yes, get it. After reading through your post, I agree with what everyone is telling you. Your belt is slipping and until that is corrected you cannot possibly begin to diagnose anything else.

BlacktopSR

sweet well im going to get on that somtime next week i got to order it..or maybe i can find one but i will check for anymore replies the help is greatly appreciated..will post what happens as soon as i find out