Questions:
1. What are the differences between the T-Stat housings with & without the pressed in 90° metal tube? (Other than the obvious pressed in metal tube).
2. Will the metal tube design interchange with the older tubeless design on a 350, 400, 455?

To the point, I can no longer locate the OEM spec thick USA made 90° molded hose.
The replacements (likely chineasium junk, shocker) are twice as thin and swell with water pump pressure at high(er) RPM... when new!

The 68 442s had the non-metal tube design.
I am taking the 68 442 (and the 68 Vette) to The Hilliard U.S. Vintage Grand Prix at Watkins Glen in September, yes around the track and around town. I do not want to wash down the car or the track with coolant. I just don't trust that weak link. I'm thinking the metal tube design is more robust.

I will assume the metal tube design will fit the stock 400 intake?
Or am I missing something on the interchange?
Tube angle to pump nipple different?

 

Following

 

All of these are made in China??



Seems I saw a recent thread about the pressed-in pipe getting pushed out under pressure. Not sure if that's significantly less likely than one of these hoses bursting.

 

Hard to find anything that’s not made in China

 

I think the change was a important change. In 68 I bought a new 442. That curved hose has the first problem I had with the car, Blew out on the freeway, was lucky to get of and to work, and fixed it after work. I don't think it was more than year old,and less than 10Kon it. They must of had a lot of complaints, that they changed the design.

 

Don't worry about it. They aren't going to let you go fast enough on the track to blow a hose....lol

I've done the track at the Glen twice with my 442.....there's no inspection....

And that's my kids in the car (my wife took the pic). My younger daughter was in her car seat

 

Great pic Mike. We'll do a double-vision pic if you show up this year.
The problem is if I drive it to the event I will be going faster on 90...lol. Trying to locate an enclosed toy trailer. Might need to finally buy one.

Johmmy so far I've sourced 5 or 6 of these hoses from various suppliers. They are all the same thin wall design. Fusicks too.
I'm running a 45 yr old hose right now. It's still pliable and does not swell on throttle blips.

 

The later one with the bent metal tube will work fine on your car.

 

What he said....and on the "pre cast iron" housings....

>The "first" ones (I'm just starting around mid '60's) they all seemed to have an OFFSET upper rad hose outlet...these were typically numbered with a "1" or a "2" on them as an example.

>At some point (I don't know exactly), they changed the design to a CENTER oriented upper rad hose outlet. These are typically seen w/a "5" on them.

>I have no idea if there were "3" and "4" numbered housings.

There may be some differences in the bypass hose hole size (the ID) but I've never compared them exactly.

FWIW - the Fusick reproduction housing is a OFFSET design (as shown in your pic as Classic Industries...I THINK Fusick was responsible for making these...not 100% sure). I don't think anyone has repro'd the "center outlet #5" design.

I believe a #5 housing is what came on a 1970 car...not sure about '69 but I'm thinking the same one was used.

 

The air conditioned cars and those with HD cooling had a restrictor in the bypass nipple of the aluminum housing. Around 1972 there was a recall, campaign, or whatever they called it, to replace all the aluminum housings with curved bypass hose to the iron/steel tube housing with a short straight piece of hose. Because of the forward position of the housing on Tri-Carb cars, there was no change for them. They continued to use the original aluminum housing with a hose shaped like a partially bent staple, going to the water pump port at 11 o'clock instead of the one at 12 o'clock as on 2 and 4 barrel carb cars.

 

Humm... all interesting info. Thanks for the responses guys keep it coming. I been curious about this for many years.

My 68 is an AC car. It was a used car when I bought it 40 years ago! The engine and trans were both rebuilt. So I'd like to say it never had a restrictor in this location but it had a few years to be altered. The housing could be original. Dam near everything else on his car is.

I've had many Olds engines apart. I can say I have not witnessed this restrictor.

In '86 I put a "life time" aluminum pump on it. Forget the brand name. Of course I turned in the original for the core charge (kick kick).
That same pump is in it now. Back then there was zero chineasium junk. Life time apparently means life time.

I'm on the hunt for an NOS tube type. The coolant measures 12VDC! TIME TO FLUSH!

 

The cast iron housing with the metal J-tube was a running change made in Nov 1970. Here is the engineering order documenting the change.

 

Excellent Joe, Thanks. I have plenty of hoses to cut to make the jumper. Now to locate that NOS tubed stat housing.

409009 is the 455 part number? Cant quite read it. Looks like 409008 is 350?

The tube gets engine paint color right? I dont think GM would have masked it off.

 

Gang,
I think this is really simple.

The second generation 425/455 big blocks were originally delivered with the upward facing metal tube which was attached to an inverted “J” shaped hose, which I think was a bypass from the Thermostat to the water pump.

From what I know (and I’m no engine/coolant expert) Olds had enough failures in the field to warrant a redesign of that bypass such that the 180° turn that was rubber became more durable metal so they could use a short completely straight hose in place of the inverted “J” hose. I believe the later design carried on until the end of Olds Big blocks, and maybe small blocks so the run of the later, simpler design might have been 15-20 years.

For the record, both my ‘66 big blocks have the inverted “J” rubber hose and I’ve never had a problem in 40 years. But I’ve thought about converting to the later, simpler style since it seems to be better design.

Hope that helps.
Chris

 

As an aside, here & there I help maintain a 2005 Jaguar XJ8. Cool car. But the thermostat housing is plastic.

Yes. Plastic.

Guess what happens to a plastic part whose natural life is heating & cooling constantly? Yes it fails at 70k miles or so.

Where we Oldsmobile people can just flatten our iron thermostat housings on a belt sander to flatten and use them again, Jag owners have to buy new parts with a shorter lifespan designed in.

Must say the Jag air suspension is fantastic. Perfect balance between smooth ride & good cornering.

Cheers
cf

 

Correct, except with engines having aluminum manifolds. In that case the thermostat housing, tube, and engine lift hook were unpainted (except for a bit of spray that leaked around the large mask put over the manifold).

 

Interesting topic. I've noticed the difference in the hose vs. metal tube T-stat housing but never really put much thought into why they changed it. I've run a molded hose on my '69 442 since the '80's (not the same one) and never had a problem. I currently have a 'reproduction' GM stamped hose on it, likely from Fusick, that's about 5-ish years old. Again, never had a problem.
Also interesting to hear Olds had some sort of recall or field campaign to switch out the molded tube design with the metal tube. Guess my car was a fish that didn't get trapped in that net. Engine has always had the original T-stat housing on it.

 

Ya the Fusick is the thin wall. Rev the engine and watch it swell.

I just got off the phone with my favorite professional parts store. My girl said Stant is no longer.

Would anyone happen to have the old Stant number for the OE 195° T-Stat? Both the std and HD part numbers?

I might have a stash of NOS in my stash but I didnt mark what the applications was.

Looks like Motor Rad is the go to now? Made where who knows?

My parts store said they make a fail-safe stat too. Fails open.

 

I like the SBC internal bypass.

My 68 has the hose, my 72 has the pipe. My 67 has the hose I found some other hose that would work and cut it to fit.

This is the sort of thing that I would find an overbuilt modern hose of the right geometry that had a length that matched and cut it correctly.

 

I read that the original "J" hose wore out from the coolant flow or a least put extra pressure on it, and blew out. I have a 69 which I use a Gates J hose on it, I replace it every 5 years, I don't push the car hard or put many miles on it though.

for another Olds V8s, I have found for that some metal tubes stick out too far forward from the housing, and do not line up straight with the water pump thermostat inlet, I did find one that lined up straight.

https://www.goodyearrubberproducts.c...s/page0029.pdf

I use Goodyear Hy-T 200psi 3/4" hose no problems, I bought a short bypass hose rated at 50lbs and it blew out on the freeway and only a year, can't remember brand..

as a side note, However, I've had Goodyear radiator hoses blow out after a short while, have had good luck with Gates so far..
If I were you, I'd get rid of the J hose, and use the metal tube stat housing, a goodyear Hy-T for the straight bypass , and Gates hoses for the upper and lower radiator hoses. These have worked for me so far, for a 1979 I really push hard at times.

Fred

 

Anyone able to dig up the old Stant numbers. For the correct thermostat. The Stant Superstat and or the HD Superstant. 195°F

 

For the "J" shaped bypass hose, I used Continental PN 63602; Rockauto.com has it for $5.90. The part description says fits '69 Cutlass 350.

Rodney

 

TX for that PN.
Still looking for the old Stant part numbers. Zero luck digging it out online.

I have not yet tried the Rock Auto hose. It looks thicker in that pic.
From Fusick, I ordered the double-wire hose clamp kit to do all the rad hoses on the car. I ordered upper lower & bypass hoses too.
The OEM-style double-wire clamps would not fully engage the bypass hose due to the hose being so far off the original OD spec. I was forced to put a 40-year-old thick wall USA-made hose back on or use the unsightly worm gear clamps on the new junk hose.
The new double-wire clamps were obviously made to the old spec ID spec.

Engineering and change control failed miserably to identify this. Thanks again china....for nothing!

I told Fusick about it, but I'm unsure if it went any farther. I can't be the only one to experience this rapid decay of common sense and proper change control.

 

Sorry, but none of this is making sense to me. The 'Fusick' hose I run doesn't seem to have a thinner wall than any of the others I've used going back to the '80's. Granted, I don't know how thick the "original GM" hose was and I haven't observed this latest one in operation to see if it's swelling but, like I said, never had any problems. I've used my original wire hose clamps and also repops (I think from Fusick) and have never had a problem with it bottoming out or not getting tight on the bypass hose. What is the thickness of what you're considering 'thin' vs. an original style?

 

What I have noticed in the newer heater hoses, bypass units and others are less of the nylon threads inside the hoses which makes them weak.

 

To continue this thread...Yes, the OEM 3-rib hose is thicker than the new smooth replacements. It does not bulge at all. Tried 3 different new hoses, they all bulged quite nicely with RPMs.
Stil want to replace my OEM housing with the metal tube style.

Joe, your TSB doesn't list Group # 1.153, part # 231256, housing cast #409038. However, it does say 409037, etc...Does 409038 supersede 409037?

The original stat housing on my engine is casting #2 P/N 392099, aluminum (for an A/C car w/HD cooling).

In the first picture below...the part I'm looking at is Group # 1.153, part # 231256, housing cast #409038.
Does this P/N have the same FFF(form fit function) as the 392099 or:
-Is the diameter of the neck smaller?
-Different angle on the neck BB vs SB?

All the repros appear to be aluminum. (second pic). Not sure I trust that press fit.
Has anybody had a bad experience with the aluminum $30-40 repros?

I prefer NOS cast iron Oldsmobile, not chineasium in either metal.

Pic 1:
This part is listed as 231256, housing cast #409038



Pic 2:
This is a repro part, no P/N provided, but says fits 307 330 350 400 403 425 455. The tube dimension looks different...longer and a different radius?




Housing on the engine now...original to the car...with a 40-year-old Gates bypass hose. Still supple too.