H4Inf

Just wondering if it matters which way the oil goes through the oil cooler on a series 2?

Cheers,

Paul.

trochoid

iTrader: (6)

Oil goes in the top, short line, out the bottom, long line. The valve is a thermostat that bypasses the the main part of the fmoc until the engine oil is up to operating temps. Oiling system is covered in Sec. 2 of the FSM.

H4Inf

When you say in the top, do you mean it enters the engine at the top, or the cooler at the top?

Looking at the FSM diagram, the by-pass valve is in the bottom connection of the oil cooler, so you'd want the oil to go there first. This section does not make it clear at all about the direction of flow or how the hoses are supposed to connect up.

Sorry I swear I had seen a diagram somewhere showing the oil flows within the engine, but I cannot find it.

Do you think it would matter having the hoses connected back to front?

Thanks!

Paul.

trochoid

iTrader: (6)

The diagram is listed in the FSM as I noted in my 1st post. The 85 edition that I have is the most complete one, Sec. 2, p. 3. Front of engine to top of cooler, bottom of cooler to rear iron are the connections and flow direction.

Rogue_Wulff

It does matter which way the oil flows into the cooler. The inlet (from the front of the engine) of the cooler is the top connection, and the outlet (to rear of engine) is the lower one. This holds true for all FMOC models installed by mazda, whether it's from an RX2 or an S5 RX7. I cannot say how the FD and RX8 coolers work, having never had the chance to look them over.
Various models had different fittings, but they all flow the same direction.

H4Inf

ok, thanks for clearing that up! do you know how the bypass valve inside works?

Rogue_Wulff

The bypass valve is thermally operated. Until the oil reaches the pre-set temp, it allows most of the oil to flow from the inlet to the outlet, without flowing thru the cooler. Once the outlet temp reaches the pre-set temp, it closes, forcing the oil to flow thru the cooler.
It opens/closes as needed to keep the oil above the temp prescribed. Just as the T-stat opens/closes as needed to keep the coolant at the prescribed temp.
Many racers will remove the bypass, and plug the passage, so that the oil always flows thru the cooler. The downside to this, you have to allow the oil to reach the proper temp before running the engine hard.

H4Inf

Thanks for the info, it makes more sense to me now I will switch the hoses around asap..

Cheers,

Paul.

H4Inf

OK. I did not switch hoses soon enough.. i was burning up a hill today about 7500rpm and i noticed my steering felt weird.. i was steering to the right to continue going straight.. but it was smooth.... oh.. oil.. oil pressure = 0 and was coating my left side tyres! BAD

luckily i was logging the trip at the time, it was pumping oil out the front cover for 3 seconds @7500rpm, then engine was running at idle for about 9 seconds after that before i noticed oil pressure and shut down.... should be ok. There was still a tiny bit of oil on the dipstick when i checked.

Oil hose pushed off it's fitting.. probably from excess pressure from being the wrong way around??

If you'd like to visit me, just follow this:


Lucky I made it home actually, had to head to a wedding 5 mins later lol......

3rd and final 7

iTrader: (9)

im glad you ok and not hurt that could have been really bad also glad that your engine is ok :crossing fingers:

H4Inf

I think the engine is ok... hard to tell.. it drives ok although feels like it has some flat spots but that is probably due to the tune and the mega hot weather we are having now!

one problem i found is the brakes were caked in oil so when i hit the brakes, the car would pull to the right, as the front left brake had much less friction... so i just drove up into the hills and did this really long downhill section twice, real heavy on the brakes, had smoke pouring out of the left guard now they work good... also visited the carwash and degreased as much as i could.

i have put hose clamps on my hoses now... havent switched them around yet as i dont have the appropriate sealants to do so.. will do pretty soon though.

Thanks!!!

H4Inf

Fixed Made these myself to the perfect lengths and cable tied on some conduit to protect parts of the hose that rub on the engine mounts and other bits of metal..



Now have the right sort of hose!!!!! Pirtek messed up bad..