Thermostat Housing

fc3sbob · Post by **fc3sbob** » Mon Sep 05, 2005 4:04 pm

would the coolant still flow through the head and cool it fine if I was to block off the thermostat housing from the back of the head and move it to the freeze out plug on the front?
I've seen it done before in a few pictures but I just want to know if it will still cool good.

it looks much easier to do this than hack up the firewall for it to fit.

peregrine · Post by **peregrine** » Mon Sep 05, 2005 6:12 pm

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (fc3sbob @ Sep 5 2005, 08:04 PM)</td></tr><tr><td id='QUOTE'> would the coolant still flow through the head and cool it fine if I was to block off the thermostat housing from the back of the head and move it to the freeze out plug on the front?
I've seen it done before in a few pictures but I just want to know if it will still cool good.

it looks much easier to do this than hack up the firewall for it to fit. [/quote]
ive talked to a few of the rwd guys and was told that if its a street driven car that you should have the crossflow through the head. if mitsu designed it that way thats what im going with.

GRNDSM · Post by **GRNDSM** » Tue Sep 06, 2005 3:20 pm

I have all the same concerns about this arrangements. But somehow, people have been able to get away with it.

I think that if you tap your heater core hose to come out of the original thermostat housing hole, you might provide “some” cross-flow.

Post by **DJpowerHaus** » Tue Sep 06, 2005 4:20 pm

Give it a try. Unless you really hack it up you should be able to make it reversable. Just block off the back and drill and tap the hole in the front and find a plug that will thread into it if you change your mind. You can then get one of those cool laser thermometers and monitor the temps on differnet spots on the head.

AbsurdParadox · Post by **AbsurdParadox** » Tue Sep 06, 2005 4:50 pm

</div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (DJpowerHaus @ Sep 6 2005, 08:20 PM)</td></tr><tr><td id='QUOTE'> You can then get one of those cool laser thermometers and monitor the temps on differnet spots on the head. [/quote]
Those things are amazing, and thats a very good idea.

Post by **DJpowerHaus** » Tue Sep 06, 2005 8:09 pm

They're not as expensive as they sound. (The expensive ones are just alot faster)

GRNDSM · Post by **GRNDSM** » Thu Sep 08, 2005 2:40 pm

Those would only give you the exterior temp, while it might be cool, that is not really important. What I want to know is your actual coolant temp in the rear of the head. I would think that putting a temp probe into rear block off plate should be easy.

But with water just sitting there, dormant, I can’t see how it would cool off. I would love to see the temps that people with such set-up see there!

You are right, however, this should be easy enough to try.

peregrine · Post by **peregrine** » Thu Sep 08, 2005 3:26 pm

look at it this way, is it cheaper to bang in your firewall or box it in, or is it cheaper to repair/replace warped heads?

Post by **DJpowerHaus** » Tue Sep 13, 2005 8:40 pm

Head warping? I dont think its that serious of an issue. I see it making cyl 4 more prone to hot spots and such though which could make getting the last 3% of tuning out of the engine impossible.

As for monitoring the temps externally, it shouldnt make too much of a differnece with an aluminum head. The only thing that would be different would be hot spots around the valves themselves. If these are the case they will still show up with external mesurments if you have any dead spots in your flow.

blue1 · Post by **blue1** » Thu Oct 06, 2005 6:03 am

The issues with swapping the water outlet from the back of the head to the front are only the small steam holes in the back of the engine, if you look at the rwd type head gasket against the 4g63 head gasket you will see what i mean! the 4g63 head has to have the two steam holes drilled in it and the front ones have to be blocked.
I am a fair way into my 4g64/4g63 hybrid and i will start posting the pictures onto my cardomain site soon. i am just waiting for the head to come back from the machine shop now.

Brent · Post by **Brent** » Wed Oct 19, 2005 6:38 am

I have a 4G63 DOHC in my Starion (JB).
When rebuilding the engine, my mechanic
changed the coolent path by exiting the water
from the front of the head, to make things easier.
I have had problems ever since.
I drove the car for about 5000kms,
with overheating issues.
I am in the process of having it returned
to its previous setup.
Now everything is apart,
the head has warped.
The good news keeps on comming!
As stated earlier in this thread:
Mitsubishi designed it this way for a reason.

blue1 · Post by **blue1** » Sun Apr 16, 2006 8:42 am

Hey dont loose faith in the front thermostat housing, your mechanic did half the job as is explained in my previous post, mitsu' also has standard front mount thermostats on their 4 cyls and they work because of minor differences to the rear stat mounts. without the staem holes pressure does build up in the back of the head which forces the coolant to the front cyls' allowing none to the back! GRDSM has another way by having a heater feed at the back to ensure flow but i would rather drill the head and plug.To reverse the flow of an engines cooling its not only where the water comes out its a bit more but easy to do!

TruckA · Post by **TruckA** » Sun Apr 16, 2006 10:34 am

I have the option to run the thermostat housing on the front since the guy I bought my engine from had a welder weld an aluminum pipe and plate to allow the mounting. But I decided to go with the stock location because I had already dented the firewall from the first engine I was going to use, and plus I was also concerned with the cross flow.

Post by **DJpowerHaus** » Mon Apr 17, 2006 11:26 pm

There was a member on here that made a really low profile water neck:

He used some square / rectangle pieces.. so it was tall and flat and went off to the intake side and under the intake.

I copied it best I could but couldnt make it as close to the head. I'll probably keep revising mine until I'm really happy with it.. and then dry sump and moving the engine farther back.... its a dream at least.

Bill Hincher · Post by **Bill Hincher** » Wed Sep 13, 2006 1:38 pm

You guys kinda figured this thing out, the flow of the coolant is the problem and that flow is controlled through the head gasket......the Mits engineers routed the coolant from the radiater and into the rear of the water pump. The pump forces the coolant into the engine block, as the coolant raises, its routed to the front of the cylinder head through holes in the head gasket, then its routed across the cylinder head from front to back so it picks up the heat from the cylinder head and its released by the thermostate when the temp comes up. Thats why you have over heating problems with the front exit, you never get the heat out of the back cylinders...........soooo you got create options.....take a close look at the coolant holes in the head gasket...yu gotta reverse the flow so the coolant exits the back of the cylinder head and flows forward, that means block off the existing holes in the front of the headgasket and put new holes in the rear...it gets better.....notice how the import cars keep getting smaller plastic radiaters? thats because they are using ' pull through ' thermostates instead of ' push through'.......in domestic V-8s all thermostates are mounted in the front of the engine and coolant is pushed through to the radiater, well....the heat wants OUT of the heads to cool in the radiater......if you create a ' pull through ' system....you put the thermostate behind the intake of the water pump and then the coolant exits the cylinder heads faster.....cooling is more efficiant.......

Just thinkin
Hincher

Bill Hincher · Post by **Bill Hincher** » Wed Sep 13, 2006 5:02 pm

this may answer the questions

Hincher

jeffball610 · Post by **jeffball610** » Wed Sep 13, 2006 6:39 pm

Well, making new holes shouldn't be a problem. However, how do you plug a hole in the head gasket? Can you just plug a hole in the head or block? What does the SOHC head look like? I seriously doubt it has the same coolant passages, but it might be worth a look. I know a small company called Jay Racing tha makes a neat outlet for the front exit coolant. Keep up the good work Bill.

http://www.jayracing.com/

Bill Hincher · Post by **Bill Hincher** » Wed Sep 13, 2006 11:32 pm

Hey jeff,
just tap the holes in the head and put an allen screw in it, then drill a small hole through the allen bolt so no air pockets form under the screws
then a second hole has to be drilled in the head at the back to allow more flow ( be carefull to avoid the EGR passage close by) then use a punch to open the second hole in the head gasket

The adaptor for the R 154 looks great.....I should be showing pics soon.....I been working until 10:00 every night after work sorting it out

Hincher

rarson · Post by **rarson** » Sun Sep 17, 2006 1:18 am

What about expansion of the different metals? Wouldn't the aluminum head and steel allen screw create issues when the engine warmed up?

I don't quite follow what you mean by "drill a small hole through the allen bolt so no air pockets form."

Thanks for the info though, this is some good stuff!

Bill Hincher · Post by **Bill Hincher** » Sun Sep 17, 2006 9:35 am

Yes expansion plays a role between steel and aluminum, but I will remind you that the spark plugs are steel, the studs for the rocker arms are steel, the camshaft studs are steel.......use some locktite if you want to hold it in place.
Steam.......is the worst thing that can happen to the coolant ..........the coolant looses all its ability to conduct heat when it makes the chemical change to vapor from fliud..........in order to work right ...it must remain in fluid form.......the same problem with air pockets....no cooling takes place if your dont have fliud in the given cavity...........so if your block the fluid completely, you create a pocket of air..........if you reduce the size of the passage way.......you dont loose VOLUME......you just DELAY the volume.....so you should always allow for coolant movement...........but by delaying movement out of the front of the engine ( near the front out let) and improving movement at the rear of the engine( near the original thermostate site), you push the heated coolant being released from the block and cylinder head to the top of the cylinder heads cooling ports FORWARD.......instead of BACKWARDS.............and while we are on the subject of fluid motion...........why would you exit the gravity flow of the Turbo into the rear of the oil pan? under excelleration, wouldnt that impede the flow of oil back into the oil pan?

Thinking out loud
Hincher

rarson · Post by **rarson** » Sun Sep 17, 2006 1:31 pm

Ah, I get it. So you are saying to block the holes but not completely, and thus drilling a small hole through the allen screw. I understand now, the reduction in flow through the holes will cause coolant flow to be reversed through the head.

jeffball610 · Post by **jeffball610** » Sun Sep 17, 2006 5:29 pm

I'm still not completely convinced. Maybe someone can try it out and see how well it works. I think it's a possible idea. I still have time before my car will be anywhere near ready to run, so someone has time to test this theory.

Bill Hincher · Post by **Bill Hincher** » Sun Sep 17, 2006 6:37 pm

The coolant is forced to flow forward because you are blocking off the rear exit and opening the front exit, it has no choice but to go forward, the difference is from where does it DRAW the coolant? from the holes in the back of the head........instead of in the front of the head

Getting Dizzy
Hincher

Fabritory · Post by **Fabritory** » Sun Sep 17, 2006 10:51 pm

Everyone is over looking what makes the coolant system work its not nessisarily the /direction of flow/the size of the passages...volume has somthing to do but not as critical .... What make the coolant system work is presssure the boiling point of the water is increased under pressure it stays cooler allowing more absortion of heat

Bill Hincher · Post by **Bill Hincher** » Mon Sep 18, 2006 9:35 am

Boiling point is ok.........that all brings up the question of pressure......its designed in the presure cap.......because fluid acts differently when it is taken out of its natural state.......the higher the pressure rating .....the higher the boiling point.....which means the coolant can still act as coolant long after its boiling point in its NATURAL STATE.......thats all about avoiding boil...........which is steam.
Flow, volume, and timing are all critical to cooling........because you have to circulate the coolant to all available engine surfaces to absorb the heat, you have to transfer the ( all) heated coolant from the cylinder head/engine QUICKLY to the radiater, you should create a turbulance at the radiater entrance, because turbulant coolant cool quicker than an organised flow ( lamanar flow) then you must slow down the coolant in the radiater so it has time to cool the preheated coolant. thats why you place the thermostate it the INLET of the water pump, so that the coolant stays in the radiater as long as it can and yet it exits the cylinder head as fast as it can. Timing is also critical at the radiater for air flow.........the final heat transfer is to the air.......so the air has to have TIME to transfer the heat to the air.....this is where proper fan srouding come in......a car can over heat by traveling too fast......the air doesnt have TIME to absorb the heat....you have to shroud the radiater to the coolant fan to DELAY the air flow in order to give it TIME to make the final transfer to the air.

Slept at a Holiday Inn Express last night
Hincher

Bill Hincher · Post by **Bill Hincher** » Tue Sep 19, 2006 10:46 am

remeber not to delay the flow of coolant at the cylinder head exit by restricing the coolant flow

The rear exit was bolted flush to the cylinder head with an opening at 35 mm...........the exit at the front is 35mm without any restrictions

So if you use the front exit I would encourage you to use a steel sleeve that could be pressed into the given hole or enlarge the exit BEFORE you install a water neck that might delay the flow out of the top of the engine, this is where all the heat is

Bill

Post by **DJpowerHaus** » Tue Sep 19, 2006 11:05 am

All the theory is nice, but is there any way we could do a comparision between the front and rear setups. Real world tests.. like same engine using different methods. Maybe even a comparison of a poor front setup vs. a good one.

I'd consider buying a laser thermometer to send out to someone to get some numbers. (Then you send it back!).

Bill Hincher · Post by **Bill Hincher** » Tue Sep 19, 2006 11:22 am

well....sure it can be measured....just by using temp guages.......one at the rear of the head , where the coolant is blocked and one at the front of the head where the coolant exits........the hottest place to measure heat is at the exhaust valve.....its the hottest place in the system.... if you place the gauge sending units in the exhaust side of the head...at each end.....you should get readable information about whats going on inside the system...........the other way is with pressure..........if you connect a pressure guage in the radiater cap placement and watch your cooling fan cylce after the engines hot, you should see that the pressure goes to the EXACT same given pressure ( lets say 10lbs) repeadatly as the cooling fan cycles............pressure will go up to 10lbs and then when the fan comes on the pressure will drop to the EXACT same low pressure reading you saw before the fan came on...........if it continues to build pressure.......say....1 lbs every time the cooling fan cylces.............you got over heading problems in the head gasket/ cylinder head area

I found coolant restricter allen screws at mcMaster-carr .com
part # 91348A251

Bill

Post by **DJpowerHaus** » Tue Sep 19, 2006 11:52 am

But hotter water coming out of the head can mean good things as more heat is being drawn out of the engine. How would this testing account for that?

Bill Hincher · Post by **Bill Hincher** » Tue Sep 19, 2006 11:59 am

well.....you could test the temp at the radiater out let ( bottom hose) measure the coolant temp there.............then measure the temp in the cylinder head ( by using two gauges at the same time) and measure that in real time............that would give you real world numbers.........at the cylinder head the temp should not exceed ten percent of the thermostate rating

Bill

Bill Hincher · Post by **Bill Hincher** » Tue Sep 19, 2006 12:04 pm

I guess what I have been saying all along is , that the coolant must not be stagnant in #4 & #3 cylinders after routing the coolant forward, it must be included in curculation, so if you measured the rear of the cylinder head and the front, you could tell if the coolant was moving forward

Bill

Post by **DJpowerHaus** » Mon Sep 25, 2006 12:22 pm

It would really clean things up on lots of swaps.

Bill Hincher · Post by **Bill Hincher** » Tue Sep 26, 2006 10:09 am

Remember kane, the thermostate should be designed into the return line of the water pump, not the the coolant outlet at the top of the engine, as nice as that piece looks, it also restricts coolant flow because it makes the passageway smaller...and it delays coolant in the block, not the radiater...............you want to delay the coolant in the radiater

Bill

Post by **DJpowerHaus** » Tue Sep 26, 2006 2:09 pm

We're waiting for you to make one that solves these problems, Bill.

Bill Hincher · Post by **Bill Hincher** » Tue Sep 26, 2006 4:13 pm

OHHHHHHHHHHHHHHH GEEEEEZ mike.............I gotta sleep sometime

Bill Hincher · Post by **Bill Hincher** » Wed Sep 27, 2006 1:27 am

well.............okayyyyyyyyyyyyyy smog.............all I gotta do is visit the local fluid / hydralic place.....they make hydraulic hoses and steel lines for heavy equipment......like backhoes and farm tractors.........they can build a steel line that would not take up so much space in the front of the head. Mayby even a different out let all together...........you know we aint restricred to one hole in the front of the engine, there could be two...mabe a couple AN fittings in the front and stay away from to major hole.........or even bore it out........what ever it is ....its gotta flow well..........

I get a kick outta some of the replies we are getting from the ' pro's '

' block off the front holes' ? oh yeah........yeah....we been working on that all along................what was that web site again???????? look for Bill who?????????????? sounds like the guy at the parts store who didnt order your part and gotta reorder it but cant rememebr what it was for

or........' found a guy in Austrailia ( out back I beleive, ate by an aligater and shit off a cliff last time I saw him)'..........does the same stuff.......

I remeber once...........long time ago...........I showed up for a dirt track race after winning the last event.................5 other guys showed up with the same racing number

I guess imitation is the greatest compliment

Bill Hincher · Post by **Bill Hincher** » Mon Oct 16, 2006 12:12 pm

Here are some better details

I hope this clears up what we been talking about

Robert Venable · Post by **Robert Venable** » Mon Oct 16, 2006 2:47 pm

I like it. Thanks again Bill.

4g63opelgt · Post by **4g63opelgt** » Fri Oct 20, 2006 6:31 am

Bill and everyone else reading this topic,
Have you all seen this?

http://www.evanscooling.com/main25.htm

If the link doesn't work, sorry, just cut and paste. Apparently, this stuff doesn't vaporize and insulate like water based coolant does when you need it most.
Hi, Bill.

David

Bill Hincher · Post by **Bill Hincher** » Fri Oct 20, 2006 9:18 am

Hi Dave,

yeah I have read about it,but its kinda confusing, everyone involved with cooling bluntly say there is no substitution for water, its the best coolant available period! and I kinda stay away from ' wonder oils' they usually wind up just taking your money.
evans cooling did get involved with ' reverse' cooling , which I think is great but I got a lot of negative input from Corvette guys who tried it.

How ya doin on Th Opel?

Eric · Post by **Eric** » Fri Oct 20, 2006 11:22 am

Bill, I like the 2 drawings in your previous post and I want to build mine like that. Being familiar with BMWs I had this type of thermostat in mind: http://cgi.ebay.com/ebaymotors/Thermost ... enameZWD1V

It is "self-contained" similar to the one on the dsm's, but all the inlets and outlets are setup to take radiator hose. It could be mounted anywhere in the system without having to make adapters. Then use the Jay racing front outlet (like FWO2-12K). Then the temp sensor would have to be mounted somewhere else. Maybe tap a hole in the Jay racing outlet.

Bill Hincher · Post by **Bill Hincher** » Fri Oct 20, 2006 12:07 pm

that sure is a clean setup Eric,

It could be mounted right in the outlet of the radiater and not even be near the engine, here is another site to check out that shows another alternative to the BMW http://www.rollaclub.com/faq/index.php? ... Thermostat

look it over and see what you think

Bill

Bill Hincher · Post by **Bill Hincher** » Fri Oct 20, 2006 2:57 pm

You know Eric?
Your right, that BMW unit would allow you to use a much larger hose from the rear exit and handle a lot more volume, it would make good sense to use that unit

Bill

Eric · Post by **Eric** » Fri Oct 20, 2006 9:55 pm

That wiki site is pretty useful... I've never had to put any thought into making a custom coolant system before. The more information the better.

I checked www.bavauto.com to see their prices on that thermostat and they have them listed for $20. I wouldn't have guessed they'd have it cheaper. You have to enter "your car" as a '85 318i (amongst other models, but not the inline 6 cars). This is what I'm getting.

Eric · Post by **Eric** » Sun Dec 31, 2006 6:37 pm

I created my cooling system according to Bill's diagram. I ran the engine today for about 8 minutes, allowing the engine to warm up to 190 degrees before I turned it off. I don't currently have the radiator fan connected to a relay, as well as, having that circuit configured to turn on at a certain temp...

Just a quick update. I will, obviously, do more testing when I have the fan connected and configured.

Bill Hincher · Post by **Bill Hincher** » Mon Jan 01, 2007 9:11 am

did the engine purge all the air out without any trouble? the thremostate opened right at 190? cooooooooooooooooooooool man................

I better hustle on the drive shaft, I been behind on it because my steel supplier took the week off between holidays, I will keep you posted

Post by **DJpowerHaus** » Mon Jan 01, 2007 10:34 am

4g63opelgt wrote:Bill and everyone else reading this topic,
Have you all seen this?

http://www.evanscooling.com/main25.htm

If the link doesn't work, sorry, just cut and paste. Apparently, this stuff doesn't vaporize and insulate like water based coolant does when you need it most.
Hi, Bill.

David

Evans coolant is also very flamable. A friend of mine had an engine fire due to a leaky coolant overflow. I have also read FAA papers where they request people switch back to water if they are using it. There has been at least 1 death due to the flamability of Evans coolant.

Eric · Post by **Eric** » Mon Jan 01, 2007 12:34 pm

I ran across that website about a week ago and thought it was a great idea. It seems like great stuff. But, there's no way I'm going to spend over $100 on coolant and then have to keep extra on hand because it can't be contaminated with other fluids. Not at this time.

I have to imagine the system purged all the air only because the surge tank was about half full. I mounted the surge tank it so it was feeding right into the water pump inlet, tee'd into the line right after the thermostat.

I'm not sure how to determine that the thermostat did open. Need clear hoses

Well, when I get the fan going...

GRNDSM · Post by **GRNDSM** » Wed Jan 03, 2007 10:10 am

You know guys, there is a reason why most tracks REQUIRE you to run WATER at a certain point. Cooling systems on race cars are prone to leaking, be it due to a engine failures (like blowing a head gasket) or just plane over-heating. It would be irresponsible to use such volatile coolant on any kind of race car…

Bill Hincher · Post by **Bill Hincher** » Wed Jan 03, 2007 10:16 am

shit, we had guys charging A/C with propane when the cost of freon went out of sight, its illegal as hell but they did it, can you imagine having an accident with propane under full charge in the system? whooooooooooooo

there is no better coolant than water.....period! antifreeze is just weather related

Project Zero G Forums

Thermostat Housing

coolant

coolant pics

restrictions

coolant passages

wheres the commitment Jeff >;o)