A another quicky...

While I am torn down, should I replace the thermostat? My original one has 125k in 3 years or so. They oring/seal thing was pinched and tore when it was removed...so I need to replace that at a minimum.

I am also thinking about drilling mine...

BUT, I still don't see the point...once the truck is at operatiing temp...the t-stat is wide open anyways...I can't see that mod relieving any pressure from the rear freeze plugs?????

So new or not?

 

I would mod your old one and get a new for colder times of the year. The thermostat is not always open . Our cooling systems are made to tow at max gvwr in 90 + of heat. So they are overkill 90 percent of the time. Driving empty your thermostat is probably just barely cracked or cycling at best. Tim

 

So...mod to what extent...

cut off 1 or more barbells?

drill out to?


Thanks in advance Tim...I have enough pump, injector, air, and electronics to hit 750-800 once everthing is broken in and retorqued!

 

Depending on your outside temps, but if they are like ours here I would just cut the 2 brass bells. You will want a stock t stat for the winter though just to get the motor up to temps. I am well aware of your sticks and air, a friend of mine with a similar set up as you (06 though) will have, did 785 uncorrected the other day. Good luck with your new set up it should be great. Tim

 

Also while your head is off, make sure you block your rear block freeze plug. It seems more and more 555 motors are loosing that plug. Tim

 

Working on the block now...

Thanks for your advice Tim.

 

Just doin my tstat the other day I am suprised at how much cooler the truck is running. I drove home from a fiends house last night and it was 60 degrees on the overhead at about 11 pm. After the 15 mile trip back home the truck still was not up to the normal 195-200. I would estimate it at about 175.

I dont know what the temps are up there but you may cut off one barbell now and then do the other in a month or so when it warms up some more.

At 80ish outside my truck warms up a lot better than at 60 but still a lot slower.

IMO I wouldnt drill it out until you see what it does with one clipped, then two. Unless it was a full out race truck.

FWIW.

 

I agree with Will, if you are not in the 70s to 80s, start with just one barbell. When it is 80 outside mine will stay in the 185-190 range during normal driving. It is amazing how little flow will cool these trucks. The barbell holes are only around 1/8". Tim

 

I thought 200 is the optimal temp for combustion efficency? Is there any worries about loss of efficency, popping head gaskets, etc at 10 degrees cooler?

I know the older motors ran at a cooler temp but???

 

Have not had any problems with gaskets on any of the trucks I have worked on. I took my head off last year and the gasket was fine (cant say the same about the valves and seats though). Ilike to keep mine around 190. Tim

 

Thats a new one to me. I knew there was an optimum temp for efficency but what could the cooler temp do to the HG?

Also, back to the tstat. I am sure I will buy a new one this winter. Even this far south I dont think the truck would ever warm up in the winter months.

 

Cummins told me a couple of years ago that 180 degrees was optimum. Has that been challenged ?
Im old school , 180 is hot enough for me.
1 bar bell removed on a 180 thermostat.
Its seems fine at 50 degrees and up but for colder weather , best keep a stocker in place.
I tried running 2 bar bells removed at 30 degrees & if you get caught in traffic she will drop to 140.

 

With fiends like that - who needs enemies?

 

Good eye, I guess I should proof read a little more.