Single vs. Dual Thermostat

[Aftermath]

I hear people talking about the dual thermostat housing being better. Seems to me that the single would be better. Also, I just ordered a 130 gpm water pump with screw on clutch and fan. Should I get a plastic or steal fan? for Duramax?, and what year clutch and fan??

I have a 95 3500 6.5 T/D

Thanks in advance,

[trbankii]

You need the dual thermostat housing to flow the higher volume from the high flow water pump. I used Kennedy’s fan setup: https://www.kennedydiesel.com/categoryresults3.cfm?Category=1&SubCategory=65&SubCategory2=10

[More Power]

Seems we re-hash this same topic every once in a while....

A single hi-flow GM t-stat can pass about 90 gpm when fully open. A hi-flow gpm water pump can move about 130 gpm above 3000 rpm.

The hi-flow t-stats, coolant crossover housing and water pump were all made to work together without creating excessive pressure or cavitation.

Back in the day I conversed with a GM cooling system engineer about the then new components. He reported that in their lab tests, they saw overpressure cooling system problems during extreme tests, and that the full set of components were necessary for the full effect of the improvements.

With that said... I know people who have installed a hi-flow water pump without any of the other components, and haven't reported a problem. I also know people who don't wear safety glasses when they use a grinder, and haven't lost an eye.

So... do what you think is appropriate for your situation.

[Aftermath]

Hahaha....funny. Thanks for the replys. I do have the dual t stat crossover and the new pump arrived today. So which fan should I use? Year? Steel/plastic? I couldn't open the Kennedy link. I do have several parts already, I just need to match the proper fan blade. Thanks yall

[Nessmuk]

I run a single stat with the h.o. pump. So what if the eyepatch bothers people, the chicks dig it.

[phantom309]

Seems we re-hash this same topic every once in a while....

A single hi-flow GM t-stat can pass about 90 gpm when fully open. A hi-flow gpm water pump can move about 130 gpm above 3000 rpm.

The hi-flow t-stats, coolant crossover housing and water pump were all made to work together without creating excessive pressure or cavitation.

Back in the day I conversed with a GM cooling system engineer about the then new components. He reported that in their lab tests, they saw overpressure cooling system problems during extreme tests, and that the full set of components were necessary for the full effect of the improvements.

With that said... I know people who have installed a hi-flow water pump without any of the other components, and haven't reported a problem. I also know people who don't wear safety glasses when they use a grinder, and haven't lost an eye.

So... do what you think is appropriate for your situation.

Over 3000 rpm,. not too often that high rpm i'd guess,.

I think a lot of engines over pressure their cooling stsrem under extreme duty cycles,.

I think there is a very strong feeling on this forum that GM is god around here too,.
and whatever gm does it must be the best,.

I personally don't think so,.i have met many engineers over the course of my life,. they are like doctors or mechanics of chefs,. no two can agree exactly on anything,.and quite often can't see the wood for all the tree;s they've tested,..

The internet is full of unproven statements,. but they get repeated so often after a while folks begin to think the fake facts are true,.

[Aftermath]

So I believe I'll use the dual stat. I still heed to know which fan to use

[Scooby]

I ran the stock fan with a Hayden clutch with my hi flo pump and dual tstats. That fan was always able to bring the temps down in Florida with AC on. You can definitely hear when that clutch engages and disengages. No trailer you never hear the fan.