E fan mod test for Rodney Red Rad update

[OLDBULL8]

If you were wondering still. I yanked out of my old 6.9 a plain jane thermostat.

It was a stant, stamped 195 on it. Kept the ****** cool too with a gas radiator!

You must be registered for see images attach

Its the same size as the thermostat for my old 351w, the thermostat i took out was fairly new so we shoved it in a 351 i had that was stuck. Still there too.

Sure that t'stat will work, but not like the OEM t'stat is meant to do by staying closed so the engine warms up faster, and the coolant flows to the radiator tranny cooler to warm that fluid up quicker.
You can't compare a gasser t'stat to a diesel t'stat, thats like apples and oranges.
Here is a t'stat that was in one of my engines a guy tried to revamp it to get quicker cooling, when he had other problems. That is an OEM stat.

You must be registered for see images

 

[OLDBULL8]

OLDBULL...from the measuring I have done the t stat doesnt reach the seat to block bypass flow.

RLDSL...the t stat is just like the robertshaw high flows. So you are thinking that cool coolant is getting through the bypass to the t stat?

The bypass has to be open to let the coolant circulate until the temp rises, then the t'stat will block the bypass so coolant flows to the radiator thru the t'stat modulated by how far it opens to maintain the max temp it's set for. If Roberts temp is exceeding that, then the stat is either defective or not the right kind. I would test it in hot water to see what it's doing. It has to be the long stem so it blocks the bypass, like I show in the other post.

 

[RLDSL]

Sure that t'stat will work, but not like the OEM t'stat is meant to do by staying closed so the engine warms up faster, and the coolant flows to the radiator tranny cooler to warm that fluid up quicker.
You can't compare a gasser t'stat to a diesel t'stat, thats like apples and oranges.
Here is a t'stat that was in one of my engines a guy tried to revamp it to get quicker cooling, when he had other problems. That is an OEM stat.

You must be registered for see images

That thermostat isn't a factory one. That looks like a regular reverse poppet thermostat where the ones from the dealer are a balanced sleeve design that looks more like the one pictured below, except it has a rubber cover around it. The balanced sleeve thermostats are designed to overcome a problem inherent in standard reverse poppet thermostats where they can get held closed by high volume water pumps at high rpms . THe balanced sleeve design is supposed to maintain a neutral pressure. I imagine that is the problem that some folks had with regular thermostats like that in these things , if they wound teh engine up real tight the flow would stop, but that's not supposed to happen with a factory thermostat.

 

[Ataylor]

Any updates? I have been following this thread. I have been thinking about doing the Rodney Red radiator with electric fans. So is the thermostat the culpret? Also, is a high flow thermostat different than the Motorcraft one?

Thanks,
Archie

 

[itsacrazyasian]

That thermostat isn't a factory one. That looks like a regular reverse poppet thermostat where the ones from the dealer are a balanced sleeve design that looks more like the one pictured below, except it has a rubber cover around it. The balanced sleeve thermostats are designed to overcome a problem inherent in standard reverse poppet thermostats where they can get held closed by high volume water pumps at high rpms . THe balanced sleeve design is supposed to maintain a neutral pressure. I imagine that is the problem that some folks had with regular thermostats like that in these things , if they wound teh engine up real tight the flow would stop, but that's not supposed to happen with a factory thermostat.

I have a OEM IH thermostat in my motor now, that thermostat was in the 6.9 i yanked out. Funny thing is that motor stayed cool towing, even with a gasser radiator!

 

[f-two-fiddy]

I've had the Robert Shaw High Flow/OEM T-Stats side by side, they look identical.

 

[RLDSL]

I've had the Robert Shaw High Flow/OEM T-Stats side by side, they look identical.

I'm fixin' to order a Robert Shaw high flow from Summit today along with a top hose adapter to thread my sensors into, and hopefully I can find an extra waterneck I had that has the check ball missing . . If I can find that one, I'm going to clean out the port so it has another added flow spot. I've been toying with the idea of getting some aluminum and welding up a custom waterneck and get real fancy, but I haven't gone that nuts yet.

I also realized that I removed teh restrictor on the outlet to the heater core when I changed that over to JIC fittings and the return hose from the heater core is pretty darn cool so the thermostat is getting washed with cold return from both sides at high flow rate, so I realy think a high flow stat with some holes in it to get the coolant flowing past the pellet long enough for some hot water to reach it so it doesn't get locked in a loop is going to do the trick

 

[f-two-fiddy]

I believe I got the Robert Shaw High Flow over the counter at Napa. So it is available locally, if needed.

 

[RLDSL]

I believe I got the Robert Shaw High Flow over the counter at Napa. So it is available locally, if needed.

Thanks, Thats good to know, but I'm ordering some other goodies from summit so I'll probably just put it on the ticket and save a trip to town.

You're right, I was digging around and found one of my old stats and cut the rubber thingy off and it looks exactly like a regular Robert Shaw balanced sleeve stat

 

[RLDSL]

Well, I did a little testing with the old thermostat I had found ( there was nothing wrong with it when I removed it, I just replaced it as a matter of course ) and found a few interesting things that are confirming my suspicions .
On testing in water, it opened like you would think, starting to open at 195, but getting real picky while running these tests, I noticed teh time that it took for it to open and at 195 it barely moves, at 200 it will open to 1mm, but it takes over a full minute to get there. To fully open to a point of 4mm takes 210 deg and another minute + to get there.
Now to make things interesting at the 1mm open point, I took water the temp of the water in my lower rad tank as it enters the engine and poured it on teh pellet and the stat closes INSTANTLY every time when exposed to a splash of colder water.

Now another thing I checked. The overall depth of teh body of the stat where it would drop into the block is 14mm. with the maximum opening being 4 mm that makes the maximum drop into the block 18mm. The depth to the top of the bypass port opening is 30 mm, so there is simply no way this thing could ever block off that bypass port. what about the pellet you say, couldn't it drop down in and block it off, , well almost . The stat extends to a max of 28 mm leaving a still 2 mm opening plus the pellet diameter is only 14mm where the bypass hole diameter is 20mm leaving plenty of room for that nice cold water to flow by, and guess where it flows??, right onto the part of the stat that is the most sensitive to temp changes.

The more I look at this setup, the more it looks like it was designed for a different kind of stat originally, but they must have run into a problem with that nice hefty water pump


Its all making sense now.

 

[Black dawg]

are you going to try blocking the bypass?

 

[RLDSL]

are you going to try blocking the bypass?

I could try setting a freeze plug in there, but without a smooth machined surface, I don't know how well I'd be able to set one down in the hole that far where it wouldn't be so loosened up that it would want to walk out under pressure and that's the last thing I need is a small freeze plug rattling around in there somewhere to where I can't access it without having to pull a head.

I think just getting a real high flow thermostat with a lower opening temp in there with some extra holes to where it has a constant flow going into the rad will get enough hot water in there and running all the way through the system to where it should be able to ignore the cold looping . With the colder thermostat, I can set the fans to come on above the thermostats operating range easier so , with any luck at all it shouldn't get so cold in the rad .

 

[FORDF250HDXLT]

so really what your saying is,the radiator selection was too large for winter months and is making the the t-stat shut back up to early.
so if you put your winter cover on,the water coming out of the bottom of the rad wouldn't be over cooled and she'd run fine probably.why try so hard Robert?

well look at it this way,
what happens if you alter the t-stat in such a manner that the massive rad doesn't make it shut?
if you reach this goal,then your likely to be stuck with an engine that doesn't come up to normal operating temps in the winter.
ok,you could combat it with a winter grill cover perhaps,but you'd be stuck swapping out t-stats summer-winter.the in between temps around fall and spring could be a hassle.
if your worried about blocking off uneven sections of the rad,i see that.but why not build a custom easily removable perforated block off plate then to keep the sucker from over cooling the coolant and eliminate the issue?

added note;
you could even customize it further by making adjustable openings etc to match the season/solo/towing duty etc.
she could never over cool the coolant with this reduction of air flow.would put a stop to that 85 degree lower rad hose temp real quick and effortlessly with just a slide/turn of a custom built adjustable radiator screen if you will.

 

[riotwarrior]

Hey, just a thought here I am not certain if this would work but we used to occasionally insert restriction washers or restrictor plates in the location the thermostat normally would reside in something like these here.

You must be registered for see images

Perhaps playing with one of those maybe

 

[RLDSL]

so really what your saying is,the radiator selection was too large for winter months and is making the the t-stat shut back up to early.
so if you put your winter cover on,the water coming out of the bottom of the rad wouldn't be over cooled and she'd run fine probably.why try so hard Robert?

well look at it this way,
what happens if you alter the t-stat in such a manner that the massive rad doesn't make it shut?
if you reach this goal,then your likely to be stuck with an engine that doesn't come up to normal operating temps in the winter.
ok,you could combat it with a winter grill cover perhaps,but you'd be stuck swapping out t-stats summer-winter.the in between temps around fall and spring could be a hassle.
if your worried about blocking off uneven sections of the rad,i see that.but why not build a custom easily removable perforated block off plate then to keep the sucker from over cooling the coolant and eliminate the issue?

added note;
you could even customize it further by making adjustable openings etc to match the season/solo/towing duty etc.

The big problem is because of the combination of things going on here, the dang fans keep wanting to come on too soon and basically never shut off once it gets up near operating temp no matter what I do to teh controller because I'm getting temp pulled off a different flow path than what is coming off the bottom of the rad and screwing up the works, so once I get the fan sensors in the upper rad hose to where they cant get a high enough reading to kick on until water that is actually hot enough to do it has actually made it's way through the thermostat, then the rad won't be getting overcooled, but that will require the modified thermostat to get enough steady water flow through the system to be getting more accurate readings.

I'm also toying with the idea of going to the big truck boneyard and seing if I can find an old set of air powered thermostatic louvers wouldn't take too much to cut them down to fit, but mostly because it would just look really cool