Single thermostat housings?

[FellowTraveler]

Interested in single thermostat housings w/bypass blocking however I'm not sure it's the best idea to convert from dual stat housing w/latest HO water pump considering it would potentially become a choke point maybe even lead to water pump cavitation.

Is there a data base on these single stat housings?

I know Will had mentioned there was a single stat housing w/o bypass blocking to avoid, are there any high flow capacity single stat housings or are they all about the same as flow capacity goes?

 

[FellowTraveler]

I searched the web and found information from former GM 6.5 R&D man pointing out that there is no single thermostat housing that can meet the flow requirement needed with the 130 gpm water pumps.

 

[THEFERMANATOR]

I searched the web and found information from former GM 6.5 R&D man pointing out that there is no single thermostat housing that can meet the flow requirement needed with the 130 gpm water pumps.

Probably one of the same engineers who designed it and said it was good to go. MANY run the single stat housing with the 130 gpm spin on water pump. HEATH even reccomends the single over the dual last i checked.

 

[FellowTraveler]

Probably one of the same engineers who designed it and said it was good to go. MANY run the single stat housing with the 130 gpm spin on water pump. HEATH even reccomends the single over the dual last i checked.

Interesting thought!

 

[WarWagon]

Considering they missed the balance flow issue forever... It's not so much a upgrade to 130 GPM as it is getting even coolant flow through the engine at any GPM that the HO waterpumps offer.

 

[Will L.]

Yeah the 130 gpm bolt on had the volume and did not fix the problem. Thats why they went to the alterations in the spin on to balance the flow. The problem with the old single stat like the stock one for my hummer is the short throw of the tstat doesnt allow the flow that the ones that use the block off tstat opens up way more and allows far more flow.

 

[NVW]

Did the spin on block flow from one side?

 

[WarWagon]

Did the spin on block flow from one side?

The pump was re-designed to even the flow with slightly different passage size by the impeller. We had a thread somewhere with photos. IMO going with the reverse spin that the serpentine belt has brought on this unintended balance flow issue. It also affected 350 gas engines esp in the 1995 MY. (You could boil over with the gauge reading normal on a 350.)

 

[NVW]

The pump was re-designed to even the flow with slightly different passage size by the impeller. We had a thread somewhere with photos. IMO going with the reverse spin that the serpentine belt has brought on this unintended balance flow issue. It also affected 350 gas engines esp in the 1995 MY. (You could boil over with the gauge reading normal on a 350.)

Then older pumps could be modified to balance the flow.

 

[Will L.]

Idk about the reversing being the issue. The older hmmwvs has the old v belt foreward drive and had overheating bad that didnt go away 100%, but got much better with the bigger impeller pumps. Keep in mind it was the resaerch forced on gm by the military contracts that got them to find the issue. Even when they realized the balance flow, they tried the higher gpm as a work around first. When it didnt do it good enough thats when they released the info of the unbalanced flow issue to the new pumps.

The old 6.2's didnt have the issues, but also had no turbo. And oh boy does the increased iat from your favorite asthma turbos amplify the problem.

 

[FellowTraveler]

Sometime ago I had lost the rubber sleeve on the bottom the passenger side thermostat in my dual stat housing, never found it and always wonder if it could have been sucked into the bypass and onward to block up something.

I did notice the engine temps stabilize better w/water pump bypass restrictor.

I did the math on dual drilled full flow stats 3/8"x3 holes in each stat x 2 = about the same size of the water pump bypass ID however I have not tried to completely block the water pump bypass and use these drilled full flow stats yet they work as bypass but all coolant except the heater hose coolant is routed to the cold side of radiator.

I'm not anywhere near some of your ambient temps in the summer however we see very high UV which increases the heat load exponentially.