Planning upgrades to cooling system: need input

[n8in8or]

My understanding of the 96 is the actual housing for the stat is angled differently than the early ones and clears things such as db2 linkage.

I installed a 96 housing on my truck. The reason it is important for a 97-2000 6.5 is that it works with the existing accessories on the engine. It clears the driver side AC compressor and it uses the same upper radiator hose. The reason it was better for me than the dual thermostat housing is that it gives more clearance for a DB2 pump than the dual housing does. It isn't plug and play as far as a DB2 goes, but it does give some more options. You can make the dual housing work with a DB2 as many others have done. The other advantage the 96 housing has is that it uses the block-off style thermostat that has the advantages that have been talked about earlier in this thread. So far I am happy with my change from dual thermostat housing to 96 housing - my coolant temps are more consistent than they were before. I haven't had a chance to really work the cooling system in this configuration yet though, that will be this summer towing the camper....though to be fair, I didn't work the dual thermostat housing with this much fuel either so it isn't really a fair comparison.

 

[n8in8or]

I fail to see the difference in this rare housing. Is the thermostat bigger in diameter? Sure the angles of the head to T-stat housing pipes are different, but, I still see the bypass on it that is blocked by the secondary thermostat valve when hot on the older models. Put a thermostat in the older ones without the bypass blocker for the same effect?



You have to be careful with alternate designs to actually get the hot coolant in the area to open the thermostat before it boils locally somewhere in the engine. The bypass keeps coolant moving in the engine, and most important, the warming up coolant is going past the thermostat wax container also heating it up. Note the bypass is just below the thermostat making sure coolant is moving past the thermostat wax container. I find the peak ECT is slightly higher if I block the heater flow off before the thermostat pops open for the first time during warm up - Usually stomping it for a 65 MPH zone. So any remote location of the thermostat has to be in the coolant flow to prevent ECT spikes from getting out of control.

Long time ago I attempted to put a thermostat kit on a 454 jet boat. It didn't have enough flow past the thermostat to heat the 160 thermostat before it got too hot and steam locked the cooling system. The second short lake trial had several bypass holes drilled in the thermostat. After listening to the 454 sound like a boiler for the second time the thermostat itself is in the bottom of a lake somewhere. What a waste of money that ill designed kit was.

One last consideration to cooling system design is "cold shock" from the cold coolant in the radiator suddenly flowing in. Shocking a very hot engine with cold coolant can contract the cylinder enough to scuff or seize the hot pistons because it simply runs out of clearance. (On a 6.5 this would first be the #1 cyl. due to the most coolant flow hitting that bank first.) Thermostats move gradually mixing the coolant at first making use of the bypass before going full open. it's like adjusting the hot and cold tap water to get warm to wash your hands. This warms the radiator up and keeps the temps from extreme swings. Modern cooling systems with the low mount thermostats are even more precise at temperature control keeping the temperature swings to a minimum. This precise temp control is done out of need for tighter emissions control and CAFE not concern for the wide temp swings itself.

The above bypass description with thermostat controlled bypass blocker is one reason I do like the single thermostat design over the dual T-Stat.

I just had another idea for doing a remote thermostat: one could take the 82-95 single thermostat housing and cut the ends off of it. Then adapter fittings could be made for the cylinder heads. Once that is done just connect the dots with hoses. The only downside to this (if it is a downside?) is that you're limited to the flow of the single thermostat....but if you can make it work with the load you put on these engines and cooling systems, then I think the single stat will work for pretty much all of us.

 

[Will L.]

What about going with a universal inline thermostat holder and getting the bulky housing out of the way altogether? Here's an example of one. I have no experience with one and have no idea on the specs that you would need to make sure it would be sized appropriately, but I just wanted to introduce the idea....

https://www.summitracing.com/parts/wsn-500321/overview/

I have used those before, good for most, except we want that 2 level thermostat whenever possible. If they made those with the bypass like the single stat bypass, it would be ideal.

This be what you want!

http://www.ebay.com/itm/6-5L-GM-GMC-CHEVY-6-5-DIESEL-COMPLETE-THERMOSTAT-HOUSING-PART-NUMBER-23500374/112281547283?_trksid=p2047675.c100011.m1850&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=20140602152332&meid=98755d35d4e94f90bc36cde880fab9ca&pid=100011&rk=1&rkt=2&sd=261242399611

DUDE! You are the man! I suck at looking daily for stuff like this. I read your post at 12:12, texted my wife to order for me, and it was done by 12:15. Be here Wednesday! Yeah! Ya, I also dont know how to order crap from ebay or even Leroy, my wife does it all for me- she rather do it than here me whine about what I did wrong, haha. Will + computers usually = trashcan.

@WarWagon the balanced flow helps that shock also by splitting the output to both side equal, and the single stat keeps the level more balanced by not flowing as fast. Using 2 of the single stats lik i wanted to do (have done in the past) sheads heat SO FAST, but you do get the bit temp swings. Racing use is all I did it for. Did drive that setup on the street a little bit, and it would swing from 185-200 back and forth the whole time on the freeway about 2 minute cyclye peak to peak.

 

[n8in8or]

I have used those before, good for most, except we want that 2 level thermostat whenever possible. If they made those with the bypass like the single stat bypass, it would be ideal.

What is a 2 level thermostat?

 

[ak diesel driver]

I believe he's talking about 2 stats with 2 different temps.

 

[Will L.]

I was meaning the bypass blocking thermostat. Sorry. Multi controlled valves get called by "levels" or ports opened and closed by 1 function in my work world.
So the top and bottom of the thermostat is 2 ports so 2 level. Wrong industry application.

Should have said bypass thermostat.

 

[n8in8or]

I was meaning the bypass blocking thermostat. Sorry. Multi controlled valves get called by "levels" or ports opened and closed by 1 function in my work world.
So the top and bottom of the thermostat is 2 ports so 2 level. Wrong industry application.

Should have said bypass thermostat.

Gotcha. That makes sense. The more I think about the idea of taking a crossover manifold, cutting off the ends and remote mounting it, the more I like it. It keeps all the functions we want in a thermostat, but gets it out of the way if that's wanted or necessary.

 

[Will L.]

Take 2 blockoff pieces like the rear of the heads have, build everything from there in steel. Tie together where you want it, and do inline thermostats.

If you have just the stat area of the the single thermostat housing with block off portion duplicated from steel, or can cut up some of the older versions and turn the material down to receive a hose properly, it would be great.

About doing one for each side -the supply has to connect the 2 heads together first, then go to the stats. Because if 1 stat sticks closed, half engine is fine and other half cooks, and you may never know it depending where the gauge is reading.

For dual block off stats on the street it will want to cool too much sometimes as previously mentioned. What I didnt think about before was a 2" ball valve to regulate flow by closing part way. Not a regular ball valve, but there are ball valves design for flow control. Those didnt exist until this last decade...

 

[FellowTraveler]

I have used those before, good for most, except we want that 2 level thermostat whenever possible. If they made those with the bypass like the single stat bypass, it would be ideal.


DUDE! You are the man! I suck at looking daily for stuff like this. I read your post at 12:12, texted my wife to order for me, and it was done by 12:15. Be here Wednesday! Yeah! Ya, I also dont know how to order crap from ebay or even Leroy, my wife does it all for me- she rather do it than here me whine about what I did wrong, haha. Will + computers usually = trashcan.

@WarWagon the balanced flow helps that shock also by splitting the output to both side equal, and the single stat keeps the level more balanced by not flowing as fast. Using 2 of the single stats lik i wanted to do (have done in the past) sheads heat SO FAST, but you do get the bit temp swings. Racing use is all I did it for. Did drive that setup on the street a little bit, and it would swing from 185-200 back and forth the whole time on the freeway about 2 minute cyclye peak to peak.

Glad to be of help!

 

[FellowTraveler]

On the dual stat setup you can completely shut off the bypass by using drilled high flow thermostats from Stewart which are drilled w/3 1/8th inch holes x 2 will result in the same volume of bypass flowing through to the water pump bypass hose "except the bypass flow will go straight to the radiator."

 

[n8in8or]

On the dual stat setup you can completely shut off the bypass by using drilled high flow thermostats from Stewart which are drilled w/3 1/8th inch holes x 2 will result in the same volume of bypass flowing through to the water pump bypass hose "except the bypass flow will go straight to the radiator."

It would be cool to find an "inverse" thermostat (for lack of a better term) to use with those. Put the inverse thermostat in the cooling circuit that goes back to the block. This way you get the coolant recirculating through the engine during warm up, but then when it's up to temperature have it close so then all of the flow goes through the radiator.

 

[FellowTraveler]

It would be cool to find an "inverse" thermostat (for lack of a better term) to use with those. Put the inverse thermostat in the cooling circuit that goes back to the block. This way you get the coolant recirculating through the engine during warm up, but then when it's up to temperature have it close so then all of the flow goes through the radiator.

I'm of the opinion that using radiator full flow is best using bypass stats w/o bypass from the stat housing to the water pump but I'm in the sub tropics while you are in the cold. The 6.5td already has built in cooling issues requiring a steam port to vent steaming created by EGW mixes that's why I prefer water-less coolant of which allows for faster warm up too.

 

[n8in8or]

I'm of the opinion that using radiator full flow is best using bypass stats w/o bypass from the stat housing to the water pump but I'm in the sub tropics while you are in the cold. The 6.5td already has built in cooling issues requiring a steam port to vent steaming created by EGW mixes that's why I prefer water-less coolant of which allows for faster warm up too.

That makes sense. Up north we need to help the engines get to full temp more. I will say though, that since changing to the single thermostat with bypass blocking my temps stay more constant than they did before with the dual thermostat and restricted bypass. That has to be worth something.