After market radiator issues

[svxfiles]

Originally Posted by svxhunter

Thanks SVXFiles. That's helpful.

You are welcome, Sir!
The Imperial temperature probe and fan control was $19.88
and the Advance Auto Part # is 226203.

[cdigerlando]

I feel for you. I just went through a bunch of crap with my engine, that has never overheated...overheating. I've got a temp guage on my coolant, so this was easy for me. Check and see if turning the heat on dissapates heat and quickly reduces your temps. If that is the case, then it is probably a radiator issue, since your flow is good, just not enough radiator capacity. Was the Griffin new? One thing that resolved the issue for me. I purchased a 1" pvc reducer bushing, and threaded a hose connector into it. Then I used a 1" pvc for the other end. I wrapped them in duct tape, as these are quite a bit smaller than the radiator hose (1 1/4 won't fit, I've tried it). Then clamp the hose end in the bottom to do a reverse flush. Pipe the water away from the car, and periodically cover the end for short bursts so that you don't blow your hoses. Once I did this, the radiator seemed to recover from whatever crap was causing it not to cool. Didn't see anything blow out, but the flow sure changed.

Of course you should check your thermostat. If your water pump is not leaking or making noise, it should be OK. You can also flush your engine this way too, since you have all the gear made. Just remove the thermostat, and blow water through the hose. I did not reverse flush the engine though. Didn't want to turn the water pump backwards, or jam anything into it.

Good luck and let us know if you have any luck.

Chuck D.

[svxhunter]

ItsPeteReally: sorry if I was starting to sound a bit testy. You were helpful.

I think I made some progress. I pulled the radiator again, added some gasketing to seal the perimeter, flushed the system and the block, got a good mix of 50/50, and worked hard on the air pockets. So far it seems to be running OK- I need to drive it for a few more days.

I'd like to understand the MPI controller a bit more on this. It runs 2 fans, one of which is known as the "primary", and one the "secondary" through a mystic series of relays. One of these fans has 1 more blade than the other. Does that mean the fans are run seperately for different purposes? (aka one kicks in at a different temp than the other, or the secondary kicks in when the primary is not enough). If so, then it would matter which circuit I use for the new fan. If not, then I don't understand why there are so many cicuits and relays. The easiest way to wire 2 fans would certainly have been to run them in series on only 1 circuit. It appears to me that there are 6 seperate circuits.

[TomsSVX]

One fan is the radiator fan, the other is the A/C fan.

Tom

[svxhunter]

Really? They are both mounted on the radiator. How does one affect the AC more than the other??

[svxfiles]

Originally Posted by svxhunter

Really? They are both mounted on the radiator. How does one affect the AC more than the other??

One comes on when you turn on the AC to keep the additional heat from the AC from heating up the engine.
Now I can remove those now useless relays to save three grams!

[michael]

Another clue to why so many wires: I believe the fans run at different speeds, also why there are so many relays. I don't know if Trevor posts here any more but he knew alot about the fans.

[ItsPeteReally]

Originally Posted by svxhunter

ItsPeteReally: sorry if I was starting to sound a bit testy. You were helpful.

I think I made some progress. I pulled the radiator again, added some gasketing to seal the perimeter, flushed the system and the block, got a good mix of 50/50, and worked hard on the air pockets. So far it seems to be running OK- I need to drive it for a few more days.

I'd like to understand the MPI controller a bit more on this. It runs 2 fans, one of which is known as the "primary", and one the "secondary" through a mystic series of relays. One of these fans has 1 more blade than the other. Does that mean the fans are run seperately for different purposes? (aka one kicks in at a different temp than the other, or the secondary kicks in when the primary is not enough). If so, then it would matter which circuit I use for the new fan. If not, then I don't understand why there are so many cicuits and relays. The easiest way to wire 2 fans would certainly have been to run them in series on only 1 circuit. It appears to me that there are 6 seperate circuits.

I explained in my earier posting that fan relay 1 runs both fans through one of their windings, which are connected in parallel and triggered by the MPI controller.

There is also a secondary set of windings on both fans which kick in when the MPI controller decides they should, through a multiplicity of relays! How the MPI decides to fire them up is beyond me! These fans can be driven independently of each other, and even possibly independently of the main fan power supply switched via relay 1.

The MPI knows what the engine water temperature is, and whether the A/C is running or not (and possibly other arcane stuff that the A/C system knows about too - such as the external air temperature and perhaps the sun load too -who knows!). The MPI controller must also know about the engine power demand, but whether or not it uses this information to determine how the fans are run is unknown to me.

It should now be perfectly clear that I do not pretend to understand how all this works, other than understanding that it is all pretty bloody complicated!

If you want to find out what happens dynamically to the fans then four light bulbs connected to each of the four circuits would give you a pretty good clue.

Congratulations on getting your home-brew cooling system working, but as you are aware it needs to be tested out under a wide range of conditions, before you can feel truly confident.

Perhaps the SVX cooling system is over-complicated, I can only surmise that it was designed to keep the engine operating at just the right degree of hotness.

As for appearing testy, well you're lucky that there is an ocean between us

[Earthworm]

People insist that only one of the fans can run at a time. I have never seen this happen and would like to know how I can do this on my car.

Until then both fans will be on at the same time or off at the same time. They do have a low, medium and high speed though.

[SSSVX]

Originally Posted by Earthworm

People insist that only one of the fans can run at a time. I have never seen this happen and would like to know how I can do this on my car.

Until then both fans will be on at the same time or off at the same time. They do have a low, medium and high speed though.

+1

Agree

[svxfiles]

Originally Posted by Earthworm

People insist that only one of the fans can run at a time. I have never seen this happen and would like to know how I can do this on my car.

Unplug one of the fans!

Actually I often see just the pass side fan running, as I hardly ever use my AC.

[SSSVX]

Originally Posted by svxfiles

Unplug one of the fans!

Actually I often see just the pass side fan running, as I hardly ever use my AC.

You don't have AC, do you? If you don't use or don't need AC, you could take out the other fan to save more weight!

But Tom, even if I don't turn on my AC, I let it idle for like 10mins or longer, (either one of my SVX), both fans will kick it at the same time to run for few mins to cool down the engine and then turn off.....(my hood was opened so I could see that too )

[svxfiles]

Originally Posted by SSSVX

You don't have AC, do you? If you don't use or don't need AC, you could take out the other fan to save more weight!

I have AC, and it is connected.
I just don't use it much.
I did run with only one stock fan to save weight for a while but our stock fans flow much more air than my 10" replacements.
The thicker rad I installed precluded the use of the stock fans and wireing.