Just checking I got this right...Thermostat ?

[kennyrodgers]

Hi folks,
I changed the fan clutch (Hayden severe duty), bottom hose and thermostat today. I went for a 180 degree one I used the original O ring that seats around the T.stat base (didn't realise I needed one ). I fitted the T.stat with O ring into the machined seat in the manifold then I put the gasket on top and buttoned her up. What threw me was the diameter of the O ring was slightly larger than the I.D on the gasket.
I've not noticed any leakage but thought I'd better check I got it right before we head off on Wednesday.
Cheers all.

ps, 454 tbi motor.

[Rickf1985]

The O-ring was probably square shouldered was it not? It would have had a groove in the center and the thermostat would sit in the groove. This is how all of the stats I have done on Chevys were that had the "O-ring".

[kennyrodgers]

Hi Rick,
If I understand you correctly then yeah, the outer edge of the t stat sat in the groove of the oring then the whole thing sat neatly in the machined seat then the gasket which also had a rubberised ring i sat up top.
If ya get me lol.

[Rickf1985]

It is possible that the gasket was designed to work without the o-ring. If it isn't leaking then don't worry about it. It might be prudent to get a spare gasket just in case. Inquire about the redundant gaskets or if it should only use one or the other. To be honest I do not remember ever seeing a gasket with a rubber lip.

[EldoradoBill]

The 454 uses EITHER the O-ring with thermostat or a gasket, not both, depending on year. My buddy's 88 with TBI has a gasket, mine the O-ring which I found was improperly installed by a PO. But when I replaced the stat I put the O-ring on and smeared some Permatex on the neck before assembling the whole thing as I wasn't planning to disassemble everything once again after filling with coolant.


As a side note I put the standard 195 stat in mine, temp gets right to 210 on the gage (straight up) and never moves. The only indication anything is getting warmer is the fan clutch roaring for a second after idling for a few minutes when its warmed up.


Bill

[kennyrodgers]

Cheers Guys,
As it was the P O had fitted the o-ring above the Thermostat skirt  Hm?
If I hadn't re used the o-ring it would have been a loose fit in the ID, with it fitted it was ever so slightly proud with the top of the ID. I also used a bit of permatex as there was small amount of pitting on the mating surfaces. I suppose i got a triple whammy then.
For reference this is the gasket I used.
https://www.amazon.com/Fel-Pro-35562-Water-Outlet-Gasket/dp/B000C2E4GM


Thanks again guys.

[Rickf1985]

That is for a standard thermostat so it should not interfere with what you have. The o-ring gasket is to prevent coolant from bypassing the thermostat also so you are well covered. I usually keep a spare thermostat gasket with me just in case I ever have a thermostat failure and I have to pull it out. The one you show is reusable but since you use Permatex it all depends on which permatex you used as to whether it could be reused.

[kennyrodgers]

Hi Rick,
Thanks for clearing things up buddy.
I took her for a quick spin tonight to get fuelled up for tomorrow. A couple of things to note..Straight of the bat after no more than a mile the new fan kicked in pulling away from a junction. I was a little surprised about that to be honest, didn't think it would come on so soon. The gauge is definitely reading lower but......When I got back to park her up for the night i left the engine idling whilst for a couple of minutes whilst i had a quick look underneath. I dropped the front hood and the heat coming off the motor was incredible. I'm not sure If I'm imagining it but it seemed way more than normal.
I'm slightly worried but i guess we'll see in the morning......Fingers crossed. !

[Rickf1985]

Probably the fan moving more air than you were used to before.

[kennyrodgers]

Hopefully so mate, I guess we'll see in the Morning.
We've a two hundred mile trip into Wales tomorrow, Scotland last week....Quite the jet setters us ya know.
Thanks again Rick, If I could buy you a beer you'd be getting a case of it.
Pete.

[Rickf1985]

And how much is gasoline over there? Or are you running on propane? I don't drink anymore except for two outings. One was back in May and the other is coming up in two weeks. But of coarse if I could pull off getting over there I could always make an exception.

[kennyrodgers]

LOL.
Don't get me started....have you heard the phrase "Rip Off Britain"

At today's exchange rate as of this morning I paid $6.50 per gallon although i think ours is 10% more volume than yours......We're like that us Brits.
She's got 20 galls of Gas and about the same in Propane which is 50% of the price.


We're off in an hour......hopefully I won't be posting again for at least a week.  W%

[Rickf1985]

Well, If you do check in I hope it is just to say you are having a good time. See you in a week.

[kennyrodgers]

Well,
Just done a 400 mile round trip and everything was hunky dory. I used the ALDL Droid set up on the way home. temps were from 188 on the Motorway up to 195 whilst pulling some fairly steep grades. The new fan kicks in at 195 and she's back down to 188 in under two minutes.
Happy days and thanks all again.

[dickcarl]

Thinking of going ahead and replacing the thermostat on my '88 454.  Guessing it's in the middle of the top of the engine, based on where the top hose goes.  Lots of stuff on top of it to remove.  Is that correct?

[Rickf1985]

I don't remember if the emissions pump bracket is on top of it or not. I do not believe it is but yes it is on the front left of the intake manifold looking at it from the dogbox.

Thinking about it I know the bracket is not over the thermostat because the only thing keeping me from removing my bracket is the need to make a spacer for the AC bracket which is over the emissions bracket on front of the engine. I am pretty sure you have free access to the two bolts that hold the thermostat housing.

[kennyrodgers]

Very easy access on our 94 coach but the air pump/s have been removed by a P O.

[EldoradoBill]

On my 91 it's a straight shot once you remove the air cleaner. But thats TBI you might have more in the way with a carb...


Bill

[Rickf1985]

I forgot my upper air pump is removed but that is not bolted to the thermostat housing, may just be in the way.