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Re: spider in-head thermostat gooseneck WANTED

Posted: Mon Jan 14, 2019 12:25 pm
by rridge
Actually the right combination of o-rings and gaskets can make a decent seal on either style coolant outlet base. See this thread from last summer and the suggestions from Seabolt and Scurria. I also like studs rather than mounting bolts, if you think you are going to keep it. ... et#p508798

On the other hand getting a good seal on a gooseneck is more difficult because the feathers fight you the whole way. Also used ones are seldom listed on eBay. Ninety percent of the success in searching for old parts depends on knowing what to call them:>)

Re: spider in-head thermostat gooseneck WANTED

Posted: Tue Jan 29, 2019 5:13 pm
by jseabolt
Rather than starting a new thread, let me add to this one. Since the subject of 124 Spider cooling systems always seems to crop up.

Has anyone ever wondered if one of the reasons Spider cooling systems are so hard to bleed is that when the engine and radiator are empty (well basically empty) and you refill the radiator/engine, there is an air pocket between the lower radiator hose and the external thermostat? That is until the engine starts to heat up then finally the thermostat opens and the level drops in the radiator.

I've been using this funnel and it seems to help: ... gKzOfD_BwE

However I find it usually takes 2 cycles before I get all the air out. I fill the cooling system through my flush tee which is mounted on the highest point of the engine until I start seeing coolant leak from the bleeder screw in the tee. Then screw in the bleeder screw and cap on the flush tee.

Then I top off the funnel and start the engine. I found allot of times the engine starts to overheat so I shut the engine off and let it sit for about 30 minutes. Then open the bleeder screw and I hear this "swoosh" and see level start to drop in the funnel. Then start the engine again and see what happens.

Then after the engine has cooled down open the flush tee and see if there is level and if not add more coolant.

I got my nice and shiny new aluminum radiator awhile back but have not been in any major hurry to install it. Not like it's going to be top down weather anytime soon.

I'm thinking about drilling a small hole in the thermostat which will let this air pocket bleed off. Does this sound like a good idea? Anyone ever done this with success? I'm thinking a 3/16" hole would be the right size. Or should I go smaller?

I did drive my Spider the other day to a friend's house and noticed the fan is still kicking on around 205 to 210F. Or what the gauge seems to indicate. I kind of doubt the engine is really getting that hot. Not that 210F is going to blow a head gasket or do damage to the engine. I think most GM cars built in the last 20 years use a 210F thermostat.

I aimed one of those heat pens at the various points on the head and got some crazy readings. Anywhere from 175F to 190F. When I aimed it directly at the guage sensor is was 190F.

Going down the road, the gauge reads 190F. So I don't know what to believe.

Right now I have one of those VW 185F fan switches so technically the fan should kick on before that. I'm wondering if these fan switches get's weak over time and simply do not kick on and off when new. I thought about just replacing the fan switch with my new radiator.

Re: spider in-head thermostat gooseneck WANTED

Posted: Tue Jan 29, 2019 7:06 pm
by SimcaBertone66
Cheap easy fix, turn the T into an L with a big "freeze" plug on the remote thermostat side and pop a stat in the head, remove remote, and do a single hose pump to lower radiator

Re: spider in-head thermostat gooseneck WANTED

Posted: Wed Jan 30, 2019 1:22 pm
by friedman
I hate it when I have to agree with JD, but yes, the solution is an in-head thermostat and a Prestone T fitting in the heater hose coming from the head and you will rarely, if ever, have an air pocket caught in your spider cooling system.

And if you think properly filling a spider cooling system is a pain, then you have never done this to an X1/9.

And thanks to James who provided me with a proper goose neck as requested at the start of this thread.

Re: spider in-head thermostat gooseneck WANTED

Posted: Wed Jan 30, 2019 2:28 pm
by cgranju
Okay, maybe because at the moment I am only enjoying vicarious Fiat wrenching, remind me...for the in-head thermostat, are there 2 o-rings that sandwich the thermostat? I suppose I can just look at any ‘74 twin cam exploded view to remind myself what is “correct.” Almost all my twin cams have the thermostat in the head (using a 74 model housing) & the ones that don’t have the housing waiting to be installed. What I remember is that it was rather obvious by feel how it all goes together & doesn’t leak, but I recall explaining it to someone a few months ago & didn’t remember....I guess I’m spoiled with a vast pile of semi-pilfered through gasket sets so I can always find what I need, but if you’re stocking up ordering stuff it’s good to know on the front end.

Re: spider in-head thermostat gooseneck WANTED

Posted: Wed Jan 30, 2019 3:00 pm
by jseabolt
I know this gasket looks like a large brake caliper seal. That's what was in the gasket kit when I replaced the headgasket years ago.

Now as to whether or not this same gasket fits the necks with the in block thermostat, I don't know.

I do know on other makes there is a rubber gasket that slips over the lip of the thermostat and that's what makes the seal. I replaced the thermostat on my Chevrolet Van and don't recall any flange type gasket.

Also I seem to recall from IAP's catalog (back when they used to sell FIAT parts) there was a single year they went back to the inblock thermostat. Then went back to the external. It I was either 73 or 74.

Anyone ever notice that Fiat twin cams heat up quick?

I wondered if it's due to the external thermostat. Coolant circulates better.

All V8s I've owned/own take 10 miles to reach normal operating temperature when freezing. My spider seems to heat up within 2 to 3 miles! Not sure about my Subaru.

Re: spider in-head thermostat gooseneck WANTED

Posted: Wed Jan 30, 2019 5:34 pm
by friedman
A single gasket (rubber ring) between the thermostat and gooseneck should do it.

Re: spider in-head thermostat gooseneck WANTED

Posted: Wed Jan 30, 2019 8:33 pm
by vandor
friedman wrote:
Wed Jan 30, 2019 5:34 pm
A single gasket (rubber ring) between the thermostat and gooseneck should do it.
Then water would leak between the head and the t-stat. There is usually a gasket both below and above the t-stat. I've also seen single o-rings that were U shaped and went around the t-stat's circumference so there was rubber both above and below it.

Re: spider in-head thermostat gooseneck WANTED

Posted: Thu Jan 31, 2019 8:46 am
by friedman
I have also seen the gaskets that wrap around the edge of the thermostat but I bet that's not a Fiat part, probably comes with the new thermostat.

Re: spider in-head thermostat gooseneck WANTED

Posted: Thu Jan 31, 2019 4:18 pm
by jseabolt
So I have gravitated toward the "dark side". I bought the MGB I always wanted to begin with. But I am not selling my Spider! I just added this car to my collection. People ask me, "How can you afford all these old cars?". Well I have not bought a new car in 16 years so each one of these cars represents the depreciation value if I trade for a new car every three years like most people do.

I asked a foreign car auto mechanic back in 1992 I had my choice of buying an MGB, Triumph Spitfire or a Fiat 124 Spider, which car would he choose being more reliable. He said the Fiat, so I bought the one I own today and have been into Fiats ever since.

However a couple of months I had the opportunity to buy an MGB. The good thing is I don't have to depend on other people to work on my cars like I did when I was a teenager.

MGBs suffer from the same cooling issues as Spiders do being both cars have those sexy sloping hoods so the radiator has to be lower than the engine. The MGB suffers from no radiator cap on the radiator but rather one on the expansion tank.

One trick with refilling the cooling system on an MGB (I've read) is to disconnect the heater hose from the highest connector and lift it above the heater core and fill coolant through the heater hose until it runs out the snout on the heater core. I've yet to do this. I'm still working on the brakes on this car which is a mess. One piston was seized (dual piston calipers) , someone had installed the rear brake shoes incorrectly on one side. And to make matters worse, the axle seals had leaked oil onto the brake shoes and one wheel cylinder was leaking. So it was just as well. I have no idea if the master cylinder is good. I'll know once I get driver's side rear brakes put back together and pump the system.

After that it's onto the "botched" cooling system.

Look at this monstrosity below. Someone added one of those Moroso inline deals in the upper radiator hose commonly used when using a VW Scirocco radiator in something else. I don't know why people choose the Scirocco radiator in hot rods. Something about their design. I've heard about this on Hotrod forums multiple times. I think it's because they are short? Summit Racing used to sell a kit for this.

I was trying to figure out what this person had done. And how to go back to the original. And what parts to use. Not knowing what parts are correct and what parts are mismatched.

So I ordered a later model thermostat neck and upper radiator hose. I believe this car should have this newer type anyway. I thought about just drilling and tapping the top out for a pipe plug but wasn't sure what radiator hose to use. And even if this car even has the correct radiator.

This thermostat housing has a brass plug in the top which makes purging the air easier. It looks like the outlet snout is pointing in the wrong direction but when compared to the newer radiator hose seems to be correct.

Also one of the pusher radiator fans had died so someone added a third radiator fan to this thing!

I'm getting rid of this mess. I have a Perma-Cool fan I think will look good on this thing. I don't like those fasteners that comes with those aftermarket fans that go between the cooling fins. It's hard enough to keep the copper fins from rotting from within, let alone having a piece of nylon rubbing against the outside of the core.

I may end up having to replace the radiator.

The joys of owning 40+ year old cars!