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Robert Shaw thermostats ?

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Sleeper

Member
Joined
May 24, 2001
Messages
894
I have been following the different threads on cooling problems, and I was wondering if anybody had done any digging into different thermostats, specifically high flow?
I have a slight cooling problem, and have gone the usual route of RMI-25 and distilled water, stock 160 stat, bigger cooling fans and shroud, OD H2O pump pulley, etc. But noticed that not much has been mentioned about thermostat flow, just their opening and closing temps.

We have a pretty good flowing pump (10GPM at idle) to start with, and Flowkooler make a pump that flows about 20% more. But the size of our thermostat flow area, seems to be the bottle neck in our system. I know we are also limited by the size of our thermostat housing, but using what we have... A better flowing thermostat wouldn't hurt.

I did a little digging and came across a Robert Shaw stat, that flows a lot more that all the other stats. Digging in the garage, I found an old one that I had, and looking at it and testing it, it is easy to see why it flows more. The only problem is that it is off an old Mopar (too big) and is rated at 180 deg.
I know the Flowkooler site list one for our engines, but I have read that it doesn't fit. (Big board Archives)
Has anybody found the correct Robert Shaw stat for our cars? And have any comment's on it's performance?

Paul
 
I am not certain but pretty sure that Autozone carries the Robert Shaw line of thermostats..

Goodluck and good info...
 
Sleeper, Can you be more specific about your setup. This may help in determining the root cause of your problem. In cooling some times too much flow can be as unrewarding as not enough. If the coolant does not stay on the block and heads long enough, it can not absorb the heat from the compnents and transfer it to the rad to be dissipated. I personally have never had any problems with the stock thermo at 160 degrees. I have a stock rad with a High Efficiency core and ran a front mount with Distilled water and Water Wetter. I never ran above 172 with the AC on in traffic. I have since gone to a CAS V4R stock location and by mistake of destoying the stock fan, added a dual fan from ram chargers. AT BG this year running 11.83 I never got above 174 degrees and it cooled down to 162 before the end of the pits. Maybe some of the people in the hotter climates can comment?
 
I agree with machinegun, the coolant flow is probably not the problem on this engine. It's a heat transfer problem. Could you radiator be clogged? or radiator baffles out of place?
 
Sorry guys, I forgot to let you know I've got a hybrid.
I usually don't post all the setup details in my sig, unless I'm asking for specific help. I do appreciate all the input though :)
This thread was leaning more towards details about the Robert Shaw stat. My cooling problems really aren't too bad... I just don't like to settle for "good enough"

I really think I am dealing with more of a radiator heat saturation problem, caused by not enough air leaving the engine compartment. Car runs fine for a while with the stat doing it's job at 160 deg, then once the under-hood temps start to climb, I think the rad just gets hear soaked. It isn't too bad on the hwy, but in the city or stuck in traffic, that's where the temps begin to climb.
It's a hybrid, so it is really tight in the engine bay. I am limited to the stock 17 x 19 rad dimensions. It is a custom built 3 core copper brass unit with bigger tanks and a high fin count. I used to run a 14" PermaCool fan, then switched to 2 x 10" shrouded fans. They helped a bit.
I run the ATR billet OD pump pulley, RMI - 25 and distilled water, and am now trying the biggest B&M tranny cooler with a couple of fans on it, (it sits under the passenger side frame rail in a pretty good air stream) with the in-tank rad cooler disconnected. (It works really well... On the highway today, the tranny temp has sitting at 155, while the coolant temp was at 170)
I have also opened up the hood louver's, and removed the weather-strip, as well as made a small shroud for the front of the rad.

Every bit made a difference. Thats why I am thinking about the stat.
My next step is to try and make some draft tubes to mount in the engine compartment to try and help suck some of the hot air out at hwy speeds.

Paul
1972 Toyota Celica with an 87 GN Engine.
Motor 30 over, 10/10 crank, high vol.oil pump, SpeedPro 194/204 Cam, Comp Cam 980 valve springs
PTE 44 turbo, 0.65 Ex housing, Dutweiller Big neck intercooler, Jay Jackson’s 62 mm Throttle body, ported and polished plenum with upper part of EGR tower removed, Power Plate, solid MAF pipe, K&N Filter.
Postons drivers and passenger side headers and 2 pce crossover pipe. Hand made TH style DP, 3” exhaust split to 2 ½ “ dual Magnaflows.
52 # Siemens low imp. injectors, Red A’s modded ECM, Translator Plus, LT1 MAF (Mounted in the up-pipe) Extender chip, Boost Commander, Adj. Fuel Reg, Hot wired Walbro GSS 340 intank fuel pump, Poly Mount.
ATR billet OD H20 pump pulley, 2 x 10” Flexalite electric fans, RMI 25.
Type II coil pack and module, 8.5 Magnecor’s, AC CR43’s.
DirectScan, Caspers Knock gauge, Autometer 30/30 boost/vacuum gauge, Autometer tranny temp gauge.
200 4R tranny, B&M 28,000GVW SuperCooler, remote filter, stock D5 converter, B&M Megashifter, Chopped Ford 9” @3:25 Trac Lok rear with a 300 ZX disk brake setup. Air bags, 85 Supra 57 mm piston 10” vented rotor front brake setup, Nissan 300 ZX 15/16 master cylinder, Dunlop SP 5000 205/50ZR 15’s, Hurst Roll control, Ford power steering rack, Bilstein Rally shocks rear, Tokico race struts front, heavy duty coils.
 
Originally posted by Sleeper
I have been following the different threads on cooling problems, and I was wondering if anybody had done any digging into different thermostats, specifically high flow?
I have a slight cooling problem, and have gone the usual route of RMI-25 and distilled water, stock 160 stat, bigger cooling fans and shroud, OD H2O pump pulley, etc. But noticed that not much has been mentioned about thermostat flow, just their opening and closing temps.

We have a pretty good flowing pump (10GPM at idle) to start with, and Flowkooler make a pump that flows about 20% more. But the size of our thermostat flow area, seems to be the bottle neck in our system. I know we are also limited by the size of our thermostat housing, but using what we have... A better flowing thermostat wouldn't hurt.

I did a little digging and came across a Robert Shaw stat, that flows a lot more that all the other stats. Digging in the garage, I found an old one that I had, and looking at it and testing it, it is easy to see why it flows more. The only problem is that it is off an old Mopar (too big) and is rated at 180 deg.
I know the Flowkooler site list one for our engines, but I have read that it doesn't fit. (Big board Archives)
Has anybody found the correct Robert Shaw stat for our cars? And have any comment's on it's performance?

Paul

ROBERTSHAW Balanced brass thermostat IS only available in the larger 54MM SIZE.
THIS is the best design but ONLY for HOT AIR intakes.

THE ROBERT SHAW 44MM NEXT GENERATION II is DOG ****, the opening apperature is to SMALL, GET A STANT SUPERSTAT!!!!!!!

LOOK at the two side by side , and you will see what I mean, BIG robert shaw OK, smaller ROBERTSHAW < NOT OK

I also have the FLOW-KOOLER 1621 waterpump, RMI-25 , PURPLE ICE, and a KENNEY HOLMLES big tube GN radiator.
I am suprised that NOT more TURBO BUICK owners DON't use this waterpump?

GOOD LUCK
 
Thanks
FlowKooler pump is on the way. Found a couple of "MotoRad" ? high flow thermostats. Just need to find a 160 deg, that is close in size.

Paul
 
Can the 54 mm Robert Shaw t-stat be cut down to 44 mm?

Thanks,
Buzz White in Houston, TX (sumnerw@flash.net)
 
That's what I have been doing. Buy a 160 larger thermostat locally and cut it down to size. Works perfect.
Mitch
 
A bit of an update:
I have been doing some searching, and found that Mr Gasket carries a stat that is identical to the RS stat. (Maybe they bought the rights to it?) This has also been confirmed by (MotorHead Mike, Mr T) It is for a SBC and must be cut down as well, but at least it will be easier to find.

Paul
 
54MM robert shaw 330-160 CAN not be CUT DOWN

Originally posted by Sleeper
A bit of an update:
I have been doing some searching, and found that Mr Gasket carries a stat that is identical to the RS stat. (Maybe they bought the rights to it?) This has also been confirmed by (MotorHead Mike, Mr T) It is for a SBC and must be cut down as well, but at least it will be easier to find.

Paul

THE balanced SLEEVE all brass high flow robert SHAW 330-180 or 330-160, the last three digits being the opening temp, CAN NOT BE USED on the 86-87 cars,

YES, mr gasket puts their name on it a re-sells it in JEGS and SUMMIT , but this is for the larger 54MM unit, the Opening mechinism is of to large of a diameter, if you cut it down, you'll RUIN it.

STANT super STAT with a 3/16" hole drilled in a 180 if you can not find a 160

Regards
 
Ok facts:
Good news, sort of. ;) Yes, the Robert Shaw/ Mr Gasket 330-160 thermostat can be cut down to fit the 86/87 motor.
Bad news. It may not work very well. :(
I spent this afternoon playing around, and ground down the lip on a old RS 330-180 stat to 1 3/4", to fit inside the manifold. It fits really well. (And is still very solid)
Here is the problem:
The body diameter (part that moves) of the stat is 1 9/16".
The ID of the inner step of the manifold bore is 1 11/16".
The wall thickness of the manifold casting where the stat seats is 1/4".
The stroke of the stat is 3/8"
So since there is only 1/16 clearance between the stat body (part that moves) and the housing bore, not a lot of flow will happen until the stat is almost fully open.
1/4" of 3/8" stroke upon the initial opening, is restricted by the casting thickness, so that leaves 1/8" of unrestricted flow when the stat is fully open, kinda defeats the purpose. :(

Stant SuperStat seems to be the route to go. :)

Paul
 
Ok another update...Maybe I should rename this thread "as the thermostat turns." ;)
I just physically confirmed that the Robert Shaw/ Mr Gasket 330 series stat actually works in the 86/87 motor.
In a conversation I had with Mike, (MotorHead Mike/ Mr T) he had stated that he was using a stat from Mr Gasket (#4368 for a SBC) that was cut down to fit. Today he pulled off his thermostat housing to verify that the stat was indeed the RS style stat. (Thanks Mike) :)
He has had no cooling problems with his car and his temps stay at 160 deg. (Kinda blows my previous measurement theory out of the water ) He also runs a stock setup (no fancy fan/ rad setup.)
He can elaborate on what he has, if necessary.

Soooo... We have options as far as high flow stats go.
RS 330-160
Stant SuperStat
Any reputable brand high flow, or larger SBC
They all require trimming, but a bit more flow and the added turbulence provided, will aid in the cooling. (However slight it may be.)

Paul
 
With all this talk of a good 160 deg stat, Why not use a NAPA stat p/n 88?
Jim
 
Yeah people, what Paul said. It works... and works well. :D

Originally posted by Sleeper
In a conversation I had with Mike, (MotorHead Mike/ Mr T) he had stated that he was using a stat from Mr Gasket (#4368 for a SBC) that was cut down to fit. Today he pulled off his thermostat housing to verify that the stat was indeed the RS style stat. (Thanks Mike) :)

...Err, you mean Mr. G P/N 4363, don't you? ;)

Funny how my rad was out during all of this, wasn't it? :)
Maybe you put that hole in my core tube? ;) :D
 
"...Err, you mean Mr. G P/N 4363, don't you?"

Err, yup!

"Funny how my rad was out during all of this, wasn't it?
Maybe you put that hole in my core tube?"

It was those pesky squirrels again Mike...Honest ;)

Paul
 
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