192º Thermostat - Parts Diagram/dimensions added page 1

kapalczynski · **Posted:** Sat Mar 20, 2010 8:06 pm

CATCRD wrote:

I'm really interested to see how this all shakes out. I think both of my CRDs are running cool.

I don't really see why the studs have to be stainless. Seems like it really jacks up the cost and making them out of allthread takes a lot of time. I have used studs from BMW for various projects on that car and they are cheap and readily available. Any dealer can order them up for you. I just search realoem.com with google for the size and find the part number.

Stud bolt, M6X25-ZN, 07129908100, $0.20
Stud bolt, M6X50, 07129908106, $0.60

Mainly concerned with long term corrosion. The whole idea of this part is to reduce maintenance and make a part that is good for the life of the vehicle with the exception of the thermostat itself and the gaskets. The studs will be threaded in with a bit of JB Weld to seal them and hold them in place so they will not be easy to remove (may be impossible) and replace if they become corroded over time. The CRD is hopefully around a 300,000+ mi motor and that means this part will be there for a LONG time. The original housing and the new water outlet parts are aluminum and good for the long term so the only thing needing replacement over time will be the thermostats themselves and the gaskets if the studs/washers/nuts are stainless.

Using the 2m long threaded stainless rod I can make 2 studs for about $0.84 + my time. I think I can cut the entire rod up in to the proper lengths and taper the ends in less than a couple hours. That will make 40 studs (enough studs for 20 of these housings) so that is an acceptable amount of labor in the long run (approx 6 min labor per housing).

So, when I do the math, really it is not too bad.

CATCRD · **Posted:** Sat Mar 20, 2010 8:17 pm

Still, most of the nuts and bolts under our hoods are not stainless. I'd just use some antiseize and sleep pretty well.

geordi · **Posted:** Sat Mar 20, 2010 8:26 pm

I gotta go with CatCRD here... What would be the downside to simply using aluminum studs anyway? Its not like we will need 50k lbs of clamping force. For a seal, is there a chance of finding a decent O-ring that could be used? 20 psi isn't that much to contain, and a silicon o-ring should be perfect in the heat environment.

I just dug out my alternator today for a bit to see about changing the clutch... And that was held in with aluminum-into-aluminum bolts. Granted it isn't the same environment, but if the aluminum housing is safe in the chemical bath, ordinary studs should be too.

K.I.S.S. engineering... Like Chrysler didn't do. :5SHOTS:

kapalczynski · **Posted:** Sun Mar 21, 2010 1:04 am

CATCRD,

The nuts and bolts for most items under the hood can be removed/replaced with factory parts, the studs will be permanent. The part will most likely have to be replaced if the studs are stripped/broke/corroded over time. The only way to get the part is to modify a $100 jeep part. Better to be on the safe side w/this one I think.

geordi,

I'd have to say no to the aluminum for roughly the same reason...a slight over-torquing by someone who isn't the most mechanically inclined would snap or strip the stud. You can't take the stud out if its JB welded in. We already established that threadlocker may not be strong enough to handle repeated removing and re-torquing to change thermostats...especially exposed to antifreeze where the threadlocker looses strength (verified by Loctite themselves).

So a JB welded stud...cant remove it and if you drill it you have to drill bigger and re-tap...not enough room for a bigger hole in the housing or a bigger stud on the water outlet housing. The core would be ruined and the customer would have to front a $100 new jeep thermostat to put in or $100 for the new jeep thermostat to send to me to machine/thread. Jeep would be disabled untill the part is replaced.

On the second part of the question,

There is not enough room for a factory styled slit o-ring seal around the thermostat. The thermostat w/the seal combined is too large of a diameter & barely fits between the studs.

A regular o-ring seal in a smaller diameter would work fine, but I would have to machine a slight recess for it which makes more work. There is a factory water outlet paper type seal that matches the water outlet that I am using so that seems the best option.

On the steel studs,
Regular steel premade studs would be about the same price as my hand cut SS studs with the exception of my cutting labor. Having peace of mind the nuts won't rust and be hard to remove or break is worth it to me to put the time in on my own part and I am definately doing it for my own jeep. I can only assume others may want this as well...either way is fine with me, but i don't mind spending a few minutes to cut some studs. I'm definately ok with going the extra mile to make a quality part for everyone to enjoy and not have any issues.

:BANANA:

We're still looking good at keeping the part total under the $100 mark just to reassure you all. :BANANA:

geordi · **Posted:** Sun Mar 21, 2010 1:29 am

kapalczynski wrote:

CATCRD,

The nuts and bolts for most items under the hood can be removed/replaced with factory parts, the studs will be permanent. The part will most likely have to be replaced if the studs are stripped/broke/corroded over time. The only way to get the part is to modify a $100 jeep part. Better to be on the safe side w/this one I think.

geordi,

I'd have to say no to the aluminum for roughly the same reason...a slight over-torquing by someone who isn't the most mechanically inclined would snap or strip the stud. You can't take the stud out if its JB welded in. We already established that threadlocker may not be strong enough to handle repeated removing and re-torquing to change thermostats...especially exposed to antifreeze where the threadlocker looses strength (verified by Loctite themselves).

So a JB welded stud...cant remove it and if you drill it you have to drill bigger and re-tap...not enough room for a bigger hole in the housing or a bigger stud on the water outlet housing. The core would be ruined and the customer would have to front a $100 new jeep thermostat to put in or $100 for the new jeep thermostat to send to me to machine/thread. Jeep would be disabled untill the part is replaced.

On the second part of the question,

There is not enough room for an o-ring seal. The thermostat w/the seal combined is too large of a diameter & barely fits between the studs.

Regular steel premade studs would be about the same price as my hand cut SS studs anyway. Having peace of mind the nuts won't rust and be hard to remove or break is worth it to me to put the time in on my own part. I can only assume others may want this as well. So I spend 6 minutes to cut some studs per housing. Like I said, I'm ok with that to make a quality part for everyone to enjoy and not have any issues.

I can understand your points about the aluminum. I've certainly busted enough bolts myself. I'm concerned about the JB weld tho, for exactly that reason - You don't get a second shot with it. One thing I'm wondering about however: According to the threadlocker test chart you posted, my read of it is that it isn't losing 90% of the strength, it is retaining 90%. I might be wrong about that, but that is what I read from it. Do you have a link for that test data? I'd like to read more about it to see if I'm misreading the data.

kapalczynski · **Posted:** Sun Mar 21, 2010 1:34 am

geordi wrote:

kapalczynski wrote:

CATCRD,

The nuts and bolts for most items under the hood can be removed/replaced with factory parts, the studs will be permanent. The part will most likely have to be replaced if the studs are stripped/broke/corroded over time. The only way to get the part is to modify a $100 jeep part. Better to be on the safe side w/this one I think.

geordi,

I'd have to say no to the aluminum for roughly the same reason...a slight over-torquing by someone who isn't the most mechanically inclined would snap or strip the stud. You can't take the stud out if its JB welded in. We already established that threadlocker may not be strong enough to handle repeated removing and re-torquing to change thermostats...especially exposed to antifreeze where the threadlocker looses strength (verified by Loctite themselves).

So a JB welded stud...cant remove it and if you drill it you have to drill bigger and re-tap...not enough room for a bigger hole in the housing or a bigger stud on the water outlet housing. The core would be ruined and the customer would have to front a $100 new jeep thermostat to put in or $100 for the new jeep thermostat to send to me to machine/thread. Jeep would be disabled untill the part is replaced.

On the second part of the question,

There is not enough room for an o-ring seal. The thermostat w/the seal combined is too large of a diameter & barely fits between the studs.

Regular steel premade studs would be about the same price as my hand cut SS studs anyway. Having peace of mind the nuts won't rust and be hard to remove or break is worth it to me to put the time in on my own part. I can only assume others may want this as well. So I spend 6 minutes to cut some studs per housing. Like I said, I'm ok with that to make a quality part for everyone to enjoy and not have any issues.

I can understand your points about the aluminum. I've certainly busted enough bolts myself. I'm concerned about the JB weld tho, for exactly that reason - You don't get a second shot with it. One thing I'm wondering about however: According to the threadlocker test chart you posted, my read of it is that it isn't losing 90% of the strength, it is retaining 90%. I might be wrong about that, but that is what I read from it. Do you have a link for that test data? I'd like to read more about it to see if I'm misreading the data.

That is correct and I believe that is what I posted. It brings the fail torque to 19.5 ft lbs on a M10 bolt/nut I am using M6 even less torque to break free. Again, it might work, might be fine, but may not.

The math -

260in lb / 12in = 21.66667 ft lb x 90% = 19.5 ft lb

Heres the link:
http://tds.loctite.com/tds5/docs/290-EN.PDF

Cost is also a slight issue...loctite 290 is about $23 + sh per 36ml bottle...I'm not sure how many housings I can do with that, but the cost does factor in a bit. May only be another dollar per housing, idk.
JB weld is about half that for 10 ounces (295ml) and can be bought locally to save shipping costs.

geordi · **Posted:** Sun Mar 21, 2010 1:49 am

You can't buy loctite locally? You don't have a Home Depot or Lowes nearby?

They don't sell the huge size AFAIK that you are looking at, but you also don't need that much on each bolt. 2-3 drops is about it, it is designed as a barrier to OTHER contaminants, that is the main benefit. Yes, it is a "glue" for the threads, but it is not the only thing holding them. In actuality, it is acting more to prevent something else from locking the threads up, so it can be removed later.

Personally, 21 ft-lbs is plenty for me, for a stud. I would MUCH rather have the option of replacing a stud if I screw something up, instead of losing the entire housing. The real clamping force isn't locking the stud into the threaded hole anyway, it is the socketed threads of the stud against the threads of the NUT. As long as the stud has teeth into the hole... It shouldn't ever rotate out. Witness head studs on the VW 1.9 liter engine. I installed those, with the instructions telling me to ONLY HAND TIGHTEN the stud into the engine block. No torque at all. Those are getting literally TONS more pressure and abuse than this will, without the manufacturer fearing they will back out.

Then, putting the nuts onto those studs, I had to put like 60, then 75, then 90 lbs of torque onto those studs. So I would be OK with a removable stud and locktite.

kapalczynski · **Posted:** Sun Mar 21, 2010 1:55 am

geordi wrote:

You can't buy loctite locally? You don't have a Home Depot or Lowes nearby?

Haven't been able to find 290, but I've only looked at walmart and all the auto parts stores. They have the red "high strength" which is not a permanent loctite and is crap. Maybe at lowes/home depot, but theri websites don't list it. If so probably only the small bottle - 6ml for $7.49 (amazon.com price) - still expensive. The 290 is more of an industrial product than a every day use type.

Here's the cheapest I've found it:
http://www.amazon.com/Loctite-Threadlocker-Green-Wicking-bottle/dp/B0002KKTRM $0.60 per ml
http://www.amazon.com/Loctite-Threadlocker-Green-Wicking-Grade/dp/B000IHLZ5E/ref=sr_1_2?s=automotive&ie=UTF8&qid=1269151001&sr=1-2 $0.80 per ml

If you want one, I'll be happy to do yours with loctite if you prefer. I'm not opposed to custom orders.

geordi · **Posted:** Sun Mar 21, 2010 2:03 am

Sorry, I was editing. Check out what else I had there, when I remembered about doing the head studs on my Jetta.

kapalczynski · **Posted:** Sun Mar 21, 2010 2:08 am

geordi wrote:

You can't buy loctite locally? You don't have a Home Depot or Lowes nearby?

They don't sell the huge size AFAIK that you are looking at, but you also don't need that much on each bolt. 2-3 drops is about it, it is designed as a barrier to OTHER contaminants, that is the main benefit. Yes, it is a "glue" for the threads, but it is not the only thing holding them. In actuality, it is acting more to prevent something else from locking the threads up, so it can be removed later.

Personally, 21 ft-lbs is plenty for me, for a stud. I would MUCH rather have the option of replacing a stud if I screw something up, instead of losing the entire housing. The real clamping force isn't locking the stud into the threaded hole anyway, it is the socketed threads of the stud against the threads of the NUT. As long as the stud has teeth into the hole... It shouldn't ever rotate out. Witness head studs on the VW 1.9 liter engine. I installed those, with the instructions telling me to ONLY HAND TIGHTEN the stud into the engine block. No torque at all. Those are getting literally TONS more pressure and abuse than this will, without the manufacturer fearing they will back out.

Then, putting the nuts onto those studs, I had to put like 60, then 75, then 90 lbs of torque onto those studs. So I would be OK with a removable stud and locktite.

You have some good points there, but we can't have the stud move at all or it will have to be re-sealed to prevent leaks right? So if it moved while loosening the nut you would have to pull the whole housing & the stud (to ensure the loctite would not go into the antifreeze), reapply loctite and reassemble. Again, it might be plenty strong and may never move with just the loctite, but I havent tested it and would hate to have it fail on a customer and them have to fix it themselves.

It would be hard to screw up the 316 stainless steel, it will never corrode, they are equivelant to a grade 8 in hardness and the aluminum housing would fail before the threads would ever strip.

geordi · **Posted:** Sun Mar 21, 2010 2:25 am

kapalczynski wrote:

You have some good points there, but we can't have the stud move at all or it will have to be re-sealed to prevent leaks right? So if it moved while loosening the nut you would have to pull the whole housing & the stud (to ensure the loctite would not go into the antifreeze), reapply loctite and reassemble. Again, it might be plenty strong and may never move with just the loctite, but I havent tested it and would hate to have it fail on a customer and them have to fix it themselves.

It would be hard to screw up the 316 stainless stell, it will never corode, they are equivelant to a grade 8 in hardness and the aluminum housing would fail before the threads would ever strip.

But that is the misconception - Once it is assembled, within a few minutes the loctite turns solid. You could just as easily use superglue, it would do the same thing. The purpose is to fill the microscopic air spaces between the threads to prevent possible corrosion so that someday, the mated threads could be intentionally separated. But you would need to actually WANT to separate them. Unlocking the nut might loosen the stud, true... But the likelihood of messing up the seal is low. As long as there are more than 3 threads holding the stud in, it shouldn't move from changing the t-stat. But even if it did... You would be working from the top, how hard would it be to re-apply some locktite when changing the t-stat once every 50k miles?

Lastly... The threads aren't forming the seal, the matching surfaces that are being clamped together are. A thin cork gasket between the two flat surfaces would be the seal, held in the clamping force of the stud / nuts. Actually... that makes more sense anyway, b/c making metal-on-metal liquid tight is nearly impossible. There needs to be a soft partition material to plug the microscopic errors in the metal surfaces.

kapalczynski · **Posted:** Sun Mar 21, 2010 2:36 am

geordi wrote:

kapalczynski wrote:

You have some good points there, but we can't have the stud move at all or it will have to be re-sealed to prevent leaks right? So if it moved while loosening the nut you would have to pull the whole housing & the stud (to ensure the loctite would not go into the antifreeze), reapply loctite and reassemble. Again, it might be plenty strong and may never move with just the loctite, but I havent tested it and would hate to have it fail on a customer and them have to fix it themselves.

It would be hard to screw up the 316 stainless stell, it will never corode, they are equivelant to a grade 8 in hardness and the aluminum housing would fail before the threads would ever strip.

But that is the misconception - Once it is assembled, within a few minutes the loctite turns solid. You could just as easily use superglue, it would do the same thing. The purpose is to fill the microscopic air spaces between the threads to prevent possible corrosion so that someday, the mated threads could be intentionally separated. But you would need to actually WANT to separate them. Unlocking the nut might loosen the stud, true... But the likelihood of messing up the seal is low. As long as there are more than 3 threads holding the stud in, it shouldn't move from changing the t-stat. But even if it did... You would be working from the top, how hard would it be to re-apply some locktite when changing the t-stat once every 50k miles?

Lastly... The threads aren't forming the seal, the matching surfaces that are being clamped together are. A thin cork gasket between the two flat surfaces would be the seal, held in the clamping force of the stud / nuts. Actually... that makes more sense anyway, b/c making metal-on-metal liquid tight is nearly impossible. There needs to be a soft partition material to plug the microscopic errors in the metal surfaces.

Solid, I know, but it only takes 19.5 ft lbs to break that bond on a M10 bolt. I will be using a M6 stud that has much less bonding surface area due to the smaller diameter of the stud.

I think you missed a picture from the first page of the thread. The area drilled/tapped has the seam on the bottom of the hole that can allow coolant to leak. Even if the hole is completely sealed around the stud, the coolant can seep up the threads and around the washer and nut. The studs NEED a thread locker/sealant of some sort. Could even use RTV, but has to have something.

CATCRD · **Posted:** Sun Mar 21, 2010 11:08 am

The breakaway torque will never even reach that high if you're using 290 on stainless and aluminum. Loctite isn't pressure activated, it's catalyzed by the metal it's on and the hardening reaction proceeds only in the absence of oxygen. Stainless and aluminum are very poor catalysts and you will only ever reach 25% the strength you would reach on mild steel. See graph on first page of the data sheet.

It's all academic really though, because the studs will never loosen just by removing the nut. Geordi is right - witness head studs and intake manifold studs that never spin even though they are only installed finger tight.

kapalczynski · **Posted:** Sun Mar 21, 2010 6:05 pm

CATCRD wrote:

The breakaway torque will never even reach that high if you're using 290 on stainless and aluminum. Loctite isn't pressure activated, it's catalyzed by the metal it's on and the hardening reaction proceeds only in the absence of oxygen. Stainless and aluminum are very poor catalysts and you will only ever reach 25% the strength you would reach on mild steel. See graph on first page of the data sheet.

It's all academic really though, because the studs will never loosen just by removing the nut. Geordi is right - witness head studs and intake manifold studs that never spin even though they are only installed finger tight.

Never, WHAT??? Where are you getting your math?

Ok, please follow me on this...in a typical scenario of a stud/block the stud is threaded much further into the block than the depth of the nut, 4 maybe 5 times as far, so in that case you are right, but not in our case.

It all comes down to the friction surface. Typically the friction of the threads of the nut/stud will not overcome the greater surface friction of the stud/block it's in because the block has 4 or 5 times the threaded surface area and friction.

Example:

If there are 2 people holding a pipe, one person on each end both twisting the opposite direction, Person A has 2 hands on it, person B has one hand on it, then person B will slip first. If they each have one hand on it, 50% chance either way...just like twisting an oreo apart

In our case however the housing is not threaded 4 to 5 x as deep as the nut. They are about the same - like 2 people each having one hand on it.

So if the nut/stud have the same contacting thread surface area as the stud/housing it really comes down to the coefficient of friction of the stainless stud/nut VS the stud/aluminum.

Coefficients of friction:

Steel/aluminum ( 0.61) vs Steel/Steel (0.74)
(only reference with aluminum I could find was mild steel, not hard steel, but they are close in values for comparison{.74 - mild/mild and .78 - hard/hard )

(See reference: http://www.roymech.co.uk/Useful_Tables/Tribology/co_of_frict.htm#coef)

Since the threaded friction surface area is the same and the coefficient of friction between steel/steel is greater than steel/aluminum, the threadlocker needs to be strong enough to overcome this disadvantage.

There could be hours upon hours of math to figure out whether loctite 290 is good enough for this application. We would have to factor in the total threading surface areas, coefficient of friction, modified coefficient of friction with threadlocker on aluminum/steel, so on and so on.

In the end just testing the designs will give us the facts. I will thread some aluminum the same depth as the housing, buy loctite 290 and JB Weld and see how many in lbs it takes to break each free and post the results. :frankie:

CATCRD · **Posted:** Mon Mar 22, 2010 5:30 pm

Bottom line, I trust you to build something durable, whether it's JB or loctite. And I'll buy two of them when the time is right. But check out the cure time graph on the first page of the data sheet. If it ain't reached full strength in 72 hrs on stainless, it ain't gonna reach it. It just doesn't set up as hard on stainless as it does on mild steel. I feel like this one little detail has become a distraction to the bigger goal of making a replaceable thermostat (which I applaud you for) so I'll shut up now.

kapalczynski · **Posted:** Mon Mar 22, 2010 6:31 pm

CATCRD wrote:

Bottom line, I trust you to build something durable, whether it's JB or loctite. And I'll buy two of them when the time is right. But check out the cure time graph on the first page of the data sheet. If it ain't reached full strength in 72 hrs on stainless, it ain't gonna reach it. It just doesn't set up as hard on stainless as it does on mild steel. I feel like this one little detail has become a distraction to the bigger goal of making a replaceable thermostat (which I applaud you for) so I'll shut up now.

Thx for the trust on the development side...and the applause. :rockon:

I value EVERYONES opinion very highly, especially since the best ideas come out of a good discussion like this. I promise I won't take offense from anyones opinion. Cheers! :5SHOTS:

A lot of trial/error can be avoided with just getting a few smart minds (yeah you're one of em

) together and coming up with newer/better ideas as the discussion rolls on. :frankie:

Good Call on the difference between stainless and mild steel. I didn't even see the stainless on that graph..my mind found steel and i didn't look any further at first glance.

http://tds.loctite.com/tds5/docs/290-EN.PDF
It looks like loctite used with stainless would reach only 25% of its full strength after fully cured. Heres some more math (I'm not sure if one should take 75% of strength away and THEN an additional 10% loss or just do the 85% total strength loss. Pretty sure you would take 75% and then 10 % of the reduced number since it will be cured before the 10% loss in antifreeze):

21.67ft lb x 25% (75% strength loss) = 5.4167 x 90% (10 % strength loss)
= 4.875 ft pounds to break the bond to the stainless.

If it was a straight 85% it would only take 3.25 ft lbs to break the bond.

On another note, I got the aluminum round/tube stock in the mail today so I can start cutting/machining intermediate plates, and I'm going to Lowes on a threadlocker/JB weld run today (hopefully they carry loctite 290).

I really want to do the test to see actual results. JB weld bonds very well to steel, but as you can see, stainless is a very different animal. It is very hard and very smooth, not porous like mild steel. I have a feeling I will be able to break the JB welded stainless stud free even after fully cured with out too much trouble.

Just a hunch, but we'll soon see.

warp2diesel · **Posted:** Mon Mar 22, 2010 6:33 pm

Motion Industries sells every Loctite product available. The industrial version of Loctite 290 (990?) is used to seal tiny worm holes in castings. I have saved a few Waste Water Treatment plant gear boxes over the years with Loctite 290. The problem with Motion Industries is they are slow to fill your order. JB Weld on the other hand is readily available and will seal up the holes in addition to securing the studs into the aluminum casting.
I hope the drink tastes good when you get your squeezed lemon or lime peals used for passivation. Spin the ends of the studs a couple turns into the inside of the peal after you have squeezed the juice into your drink, if you drop the stud into the drink, don't swallow the stud, pull it out of the drink and resume spinning the ends into the inside of the peal. :-)r

To passivate the cutting edge of a sharpened stainless steel knife, cut the lime or lemon, that is all it takes as long as you wait a couple hours before washing the knife. Don't lick the blade, it will remove the citric acid so it wont do the job. :ROTFL:

Chears

FYI: Chlorinated brake cleaner will force Loctite to cure and is a lot cheaper than the accelerant Loctite sells for Stainless Steel.

Squeeto · **Posted:** Wed Mar 24, 2010 11:38 pm

Thanks for the effort Kapalczynski.
I see from the GDE pic that my truck also runs a bit cold. I'll check with the scan tool tomorrow.

Put me on the waiting list :wink:

Rixram · **Posted:** Thu Mar 25, 2010 8:54 am

Yup. Put me on the waiting list as well. I don't care for my spaghetti diesel running at a mere 176*. I like the 192* option much, much better.

*subscribed*

Squeeto · **Posted:** Thu Mar 25, 2010 12:06 pm

Quote:

I'll check with the scan tool tomorrow.

69'C and no error codes.

192º Thermostat - Parts Diagram/dimensions added page 1

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