If you have a decent radiator, the heater core doesn't provide much cooling to offset the weight savings, (of course a Non-OEM radiator adds the weight of the radiator AND the weight of the water on the nose of the car)

The basic OEM system works by running all of the water through the engine, from front to back(correctly), through the heater core and back to the front of the engine. It is only when the themostat opens that the system is fucked.

Then, the water pump pushes some water through that same circuit, but sets up an additional loop through the thermostat to the top of the radiator and back to the pump. This loop is the course of least resistance, and so the back of the motor is neglected.

A good reroute makes the engine circuit, from front to back, part of both loops. In my reroute, the front thermostat fitting is blocked off. All of the water goes from the pump in front to out the back cooling everything as equal as possible. Before the thermostat opens(it is in the line going to the top of the radiator), all the water passes through the heater core and back to the water pump. When the thermostat opens, the water can then pass to the radiator, but all of the water is still going first through the engine.

In Paul's set-up, all of the water passes from the pump, across the engine front to back, and then back to the top of the radiator. Since there is no initial flow through the heater core, larger holes were drilled in the thermostat flange to allow a decent pre thermostat opening flow which goes directly to the radiator. This will cause the engine to come up to temperature more slowly, but, hey, it's THE MACHINE.

 

more slowly? that's an understatement. with two 1/8" holes drilled in the thermostat and my Godspeed radiator my temps never even reach the 160 degree mark to come out of warm up mode. If i drive it around when its under 50 the temps don't exceed 135. i had to fab a shield to block half the radiator because of this. i do have a new thermostat waiting to be installed. I plan on drilling only one 1/8" hole in that one. Hopefully that will reduce flow enough so i can remove my shield and still reach proper operating temps.

 

thats some cooling right thur, lol
once im over the MS headaches, i will be doing a re-route, thanks for all the ideas and knowledge guys...keep up the good work so i can copy you guys, lol

 

Paul, Ive studied the **** out of your re-route page, and im planning on doing it either this weekend or the following with my father. I have gone over all of the pictures, and have recieved advice on the diferences between the 1.6 and 1.8... none. I dont recall seeing any holes drilled in your thermostat, could you post a few pictures? Also, I think i have the general idea on how to do this re-route, but just want to check one more time... I am drilling into the head correct? where apprx. should I drill (i havent found this on a site), Or is there a location already there... ie a freeze plug?

let me know, and once again, all of you guys.. THANK YOU FOR YOUR HELP!!!!
Paul... could you explain a little more in depth about your pipe selection, and why you drilled the holes before the thermostat? Im not very knowledgeable when it comes to this..

 

There is no drilling into the head

 

where do i come out of the back? and what exactly do i do? to come out of the back of the engine. i understand the rest i think

 

You might want to go to an OEM thermostat next time also. Slightly higher temp and two different opening actions: one small flow, other large flow

F201-15-171A

 

wow. i didn't drill into the thermostat housing! that would just leak. i drilled the thermostat itself which is not visible when it's installed, unless you are very small and inside the t-stat housing too. you need to allow flow through the thermostat or you will build too much pressure behind it in this setup since there is nowhere else for the coolant to flow.

I don't know what you are talking about drilling into the head. I didn't drill into the head at all. i blocked off the front outlet with a freeze plug and plate. next i installed a 1.6 thermostat housing top at the back of the head where the heater core cap would usually be. orientation of the outlet is toward driver side. moved temp sensor to passenger side so it wouldn't interfere with outlet. it was already tapped there but i have a 99 head. not sure how others are set up. see pics below

at the water pump inlet i did away with the mixing manifold and mounted a 1.8 thermstat housing top cuz it angled it kinda toward the lower radiator outlet. see pic below

piping is 1.25" thin walled aluminum stock from mcmaster carr.

thermostat housing is aftermarket, got it through Shore Motorsports 732.364.7997

 

The cover on the back that looks like a thermostat cover is removed and replaced with a 1.6 thermostat cover. To keep your heater core you can use the spacer shown on some of the reroutes. I had mine revised by welding in an additional nipple.

 

slightly higher temp than what? do you know what t-stat temp i run?

don't know if factory thermostat fits the aftermarket housing i have.

 

I thought you used the one we first put in the old housing when you got the new housing. IIRC it was a 165 degree, but I could be mistaken.

For others making the conversion, the neck of a 1.8 thermostat housing can be filed round to accept a hose and the top can be either a 1.8 or 1.6 thermostat housing top. You can see it in my vb garage pictures.

 

nope, i bought a 180 with the new housing.

 

paul, is 1.25" piping a good solid diameter for the most efficient flow? my uncle was telling me about how cooling has to do with liters per hour or minute or something? is 1.25 enough? larger then normal?

 

Still under construction but, here's the Qmax page.
Pics when I get them.

 

No. it's way to restrictive. That's why my car runs too cool.


McMaster-Carr part #89965K74






ps. the factory thermostat & radiator inlet/outlet are 1.25". I didn't just pick the size out of my ***.

 

This is what I did on my current reroute, to be replaced with a setup very similar to paul's, as I have plenty of pipe left over from his.

You hacksaw the flange off the stock thermostat housing (the flange that bolts to the front of the cylinder head) and make it round to fit over a 1.25" hose. Use the existing 3/8" hoses to your throttlebody/oil cooler/etc to allow flow to the thermostat as it's warming up, or drill holes into the thermostat.

 

you said its too restrictive... doesnt that mean the larger the diameter the more it cools? but you also said you cant reach 160 right? i would like to run a lower temp thermostat and have your problem, cant reach 160, because ill be on a track and the tar temp will be over 100 degrees.

where is that inline thermostat that you have from?

 

SOMEBODY doesn't understand Paul's sarcasm.

 

chromosome 21 is fucked.

 

seriously, lets use my smiley for something a little less retarded than this.