Lancia Beta Forum

I found a Gates inline bypass thermostat from Car Builders Solutions which was preferable to the inhead option. All 3 outlets are 32mm,so somewhat in between the original fitment.
I made up a right-angle solid piece reducer using 28/35 copper plumber fittings,including a hose rib at each end.
I had to source some random hoses from a local breakers.
The end result should work fine.
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Could you not get the original one?

Nice work, and a very neat installation, but how does it improve on the in-head thermostat arrangement?

Hi Nigel

An interesting solution. What was the temperature range on the CBS thermostat? Could you not get new hose solutions from CBS given the effort of strip and re-fit?

Well done

Eric

I think GC is adamant that the in head stat is best it just doesn't offer as good warm up as the standard stat plus I realised that on the late cars the extra pipe to relieve head pressure means that the in head stat is partially bypassed. Can't do anything about that as the top pipe had already been modified wth the lower exit cut off

Interesting - so not quite as cut and dried as I first thought. I think for my usage, with the car living in the south of France, an in-head thermostat (but the standard one, not a hot climate one) and with the bypass from cyl 4 to the top rail added would probably be the best solution. If needed, then it would be a simple matter to replace the standard stat with a hot climate one.

For large parts of the year in the S of F, 'warm-up' isn't normally a problem...

I expect some criticism for saying this but the GC in head thermostat is not acceptable for road use and I wouldn’t even use it on track for the reason below.

I’ve recently changed my Volumex to ‘in-head’ and feel it’s a very poor conversion.
There are a number of reasons for this, not least the slow warm up.

The head has a significant flow of water through the outlet at number 4 cylinder end of the head when the stat is closed. So one end of the head runs hot and the other cold until the stat opens. On some production engines this causes head gasket problems.
In winter the engine doesn’t even get off of the cold indicator if you use the heater which is barely luke warm.
When you stop at lights for long enough the engine warms up. Then you pull away and the flow through the rad via the open pipe at number 4 causes the temperature to plummet to cold again.
This is thermal shock as far as an engine is concerned and it’s bad in every way.

I’m currently changing both my cars away from the inhead  setup with one similar to the gates bypass setup (to keep the original look) and another with a top hose inline unit that I’m making up. The later will be simple to open up and change the stat to whatever temp is preferable. This will do away with all of the problems associated with in head stats.

Very much my thoughts but probably only applies to very late cars with the extra bypass pipe(mainly VXs) , GC refurbished my top pipe but cut off the small pipe to the standard stat as a matter of course so I'm kind of stuck! Unless I can get another top pipe and at the moment with more important things to do and the car in bits I've kind of lost all interest in it really! Are you thinking to put a stat in the rubber pipe from the top metal water pipe?

Interesting stuff. So as I understand it, if you're running the VX top water rail (or one modified to VX spec) then connecting a thermostat housing in the flexible hose line to the radiator would be a suitable modification, ensuring that head temps are consistent across all 4 cylinders? The only problem would be locating a suitable freestanding thermostat housing, I suspect.

This is today’s work. A pair of thermostat housings from a Renault etc and thermostat. I fabricated the flange to allow the pair to be bolted together and now it’s ready to be fitted in-line between the top rail and the top radiator inlet.  Of the 2 smaller bleed pipes, 1 will be blanked and the other will go to the plastic expansion bottle via a t-piece where the small radiator bleed pipe originally fits.
I hope to fit a test this in the next few weeks while the weather is cold.

Assembled

This is the intended installation position

I think the problem is very much the same for early cars as it is for late cars with the modified top water rail.

On early cars the head will still have varying temps end to end and warm up issues because the thermostat is still only controlling the temperature at one end. 

I have found a suitable (not tested or proven yet) bypass thermostat for under £15 that will fit in the original location and should operate exactly as the original. 

Don’t be put off by the slightly smaller body. Inside the original stat there is a lot of casting blocking flow. I expect the replacement to flow equally well. 

Very Interesting. I have an in head stat and h section link on my Montecarlo and the temperature is stable and the warm up time reasonable for an older car. I also run the water pump faster by using the Beta Crank Pulley with the Monte WP Pulley. I did try a lot of different stat temperature ranges. I will need to check but think I used 82 in the end to keep the car in a sensible and safe range. Of course the 037 Supercharger creates a lot of power and heat and the alloy radiator is on a long run.

I have built an in head conversion for my tuned FI VX but have the bits to convert back minus a better (lower) temp range stat. The later pass through on the top rail I will be using because without it there will be a high chance of head damage/ blown head gasket given even standard early cars blow head gaskets far to easily.   

I am using head studs and a Cometic MLS gasket I commissioned along with a custom alloy radiator with a thicker core. NB this is far from a standard VX.

I look forward to following this thread because I cannot test my set up yet in a Beta and a better external stat might be just what is needed.

Eric     

Greetings all,
I was reluctant to go the in-head route as i'd never done that and also the in-line method makes for easier changing and fault-finding.

Alan,I looked for an original part but didn't find one before the CBS unit came up!

Mango, I wouldn't think it's an improvement,just closer to what Lancia was thinking back then. Maybe a quicker warm-up?

Eric, it's rated at 87 degs,no range mentioned. From your comments, this may be a bit high? Yes,hoses maybe.
As with many things,it's not necessarily the final version!

Squigly,I do like your idea...that's 'right up my street' out-the-box thinking!


The radiator has been re-cored and there's a new water pump in there.
I'm hoping for a cooling system fill this weekend,leak check and start up.
I'll be back....

Thanks to all for the encouragement so far. This HPE is never going to be a pristine example, but it's intended to be a
reliable and usable car.

Nigel

Apologies if I've got the wrong end of the stick here, but wouldn't using the existing setup as fitted to carb engines (no in-head stat, standard branch off top water rail to OE stat) but with the VX takeoff to the head spigot near cylinder 4, do effectively the same job? You'd lose the ability to run a hot climate thermostat, but would benefit from consistent temperatures across the cylinder head water jacket.

Or am I missing something?

Unless GC has chopped one outlet off your top rail  :D

Yes, that would certainly put a crimp in any such plans...  ;D

Yes that is an ideal factory setup. But as you say, no adjustability with different temp stats.

Thanks for that confirmation. So in an ideal world we'd be able to find a replacement for the OE stat housing that can be dismantled to change the thermostat element... ? I'd be surprised if something of that nature didn't exist, although I doubt that tracking it down would be simple. You might get lucky and find a cast item that fits the bill, but I suspect it's more likely that it would need to be machined from billet (and expensive).

I think they is nothing wrong with the factory layout and stat, I think it was Fiat that changed this as didn't early TC have in head stats? Why would they have moved to a more expensive layout with no benefit?

They changed the layout for faster warm up lower emissions less engine damage from cars being thrashed before warm. BUT the temp in the OE stat is too high for a tuned car even with the 19 x 235 oil cooler that is essential on tuned cars. I will have no problem with the external set up and a cooler reliable thermostat. The VX/IE water rail bypass is staying I like my engines to keep working.

Cheers

Eric

Does this look like it might fit the bill?

https://www.specialist-components.co.uk/index.php/shop/twinkam-16v-conversion/accessories/twin-kam-remote-thermostat.html (https://www.specialist-components.co.uk/index.php/shop/twinkam-16v-conversion/accessories/twin-kam-remote-thermostat.html)

<Edit> Just realised that the flow and bypass ports in the housing above are in the wrong orientation/position. I think I'll give them a ring and see if they have anything suitable for Betas.

Used to use one of their housings on an MG ZT good quality, they made a few specially for the Rover75/MG ZT forum a few years back. I think it might do for what I'd want? Let me check the tech books

I rang them up and spoke to a very pleasant lady about this query, and she suggested I drop them an email with some pictures and dimensions and they will see what they have available or what could be modified without too much trouble. So that's what I'll do.

They used to do the rover one which was much the same as shown but without the bypass pipe, that would be ok if you have a standard top pipe with the bypass in place, you could maybe use the stat in the rubber top pipe to rad (assuming diameter s are the right size .....)  then hollow out the original stat to make it into a connector only (if the insides are easy enough to access)

Update on homemade stat housing in top pipe. (Similar in principle to the inline Rover stats discussed but this version has a small take off which I have ‘T-eed’ into the expansion tank) this take off is necessary to allow a flow of water to the thermostat ‘bulb’ along the top pipe or the hot water from the head may never get to the closed stat. Something to consider with off the shelf inline stats without a bypass/bleed. You could drill a bleed hole in the stat itself but I reckon that will slow warmup.
So,
It’s installed and fitted with 82C stat.
Engine started from cold with Ambient temp of 6 degrees.
Engine warmed up to just below mid point within 2 miles of very gentle driving (police car behind) and then sat there for 20 miles of normal to thrashed driving.
Couldn’t of wished for a better first run.
Looking forward to summer so I can see if the results are the same, but if not, a 75C stat is waiting to go in.

Excellent work, Ian. Very much liking the home-brewed stat housing - lots of options. I can't see from the photos, but have you retained the lower smaller outlet on the top water rail, or had it blanked off? I'm guessing the latter, as that is the outlet which feeds the thermostat on standard unmodified S2 Betas.

And is the bracing strut between the shock tops an over the counter purchase, or something you had fabricated? Something along those lines is on my wish-list.

Yes the smaller lower outlet has been blanked off although the top rail was originally a Strada 130tc/105tc regatta 100s assembly (can’t remember when I saved it).

The strut brace is more or less off the shelf. Originally Peugeot 309 with minor mods to fit. I have modded it some more with a removable 6 inch section (not in shot) just above the timing belt to allow easy removal of timing belt cover. I like making things easy to inspect/maintain, can’t stand unnecessarily removing unrelated components just to do a simple job. That’s when things strip etc and a simple job becomes a pain.

Unless summer throws up some expected results with the inline thermostat mod, it’s the only way to go for me now.

 RIP in-head stats.

I was very impressed with Ian's (squiglyzigly) thermostat modification and vowed to copy it. It's only taken me a year and a bit, but here's my take on the mod that Ian has pioneered. The hardest bit was probably getting hold of Renault Clio/Megane/Scenic /Kangoo thermostat housings in aluminium. It seems that Renault have moved to plastic for these components, which I didn't really want. I'm sure that modern hard plastics will do a perfectly good job, but I just prefer metal.

I then acquired a standard Mini thermostat, but in the hot climate (74 degree C) version - part number GTS102. The 84 deg C (temperate climate) version is GTS104 and the 88 deg C (cold climate) version is GTS106. I got mine from Rimmer Bros (www.rimmerbros.com (http://www.rimmerbros.com)) who charged me a paltry £4.32 inc VAT for the privilege. These stats are fractionally larger than the Renault housing, but a few seconds with a flap wheel in an angle grinder soon encouraged it to fit snugly.

The lip on the Renault housing has a depth of 3.5 mm and the i.d. is 53.5mm, so I tracked down a suitable o-ring to fill the gap. I got a pair of Viton o-rings (you need two) from simplybearings for £6.47 delivered. They are actually a British Standard (BS 828) and measure 3.53 mm in cross section and 46.04 mm internal diameter. They serve a dual purpose of sealing the thermostat on both sides and stopping it flapping about loose in the housing.

Both housings (you need two) have a small relief port, one of which will need to be closed off. I removed the spigot on one of the housings and then had my local welders seal the port with some weld inside and out. If using plastic items I guess a hacksaw and some epoxy resin would work.

The last thing I needed was a gasket. I'm sure I could have tracked down the Renault part, but instead opted to make my own from some 1mm thick gasket material I had. On reflection, tracking down the Renault gasket would probably have been simpler. I haven't done final assembly of the unit yet (the bolts in the pics below are just finger tight, but when I do I shall probably use Threebond liquid gasket, as that has never yet failed me when being used on motorbikes. Again, probably overkill but I hate doing jobs twice.

So thanks again to Ian for the initial inspiration and here are the pictures.

I am following this with interest. I currently have Nigel's Lada lower temp 3 way thermostat waiting to fit and try.

Eric   

I hope your in-line thermostat mod works to your liking. Mine has covered around 1.5k miles now and for me it’s been all positives and no negatives.
I like your detail of welding up the un-needed 2nd bleed pipe on one of the housings. I promised myself I’d do the same if it works but so far I’ve not got around to doing it but it’s on the list.
I’ve got a 75 degree stat with no bleed hole and it runs in the lower green most of the time only rising to mid green when idling and driving hard.
I did find a stat with a bleed hole warms up a little slower and it’s apparent that warm water water does pass the bleed hole when cold and thus slows warm up slightly. But it’s no biggie. I only discovered this when swapping different temp stats for testing purposes. You don’t actually need a bleed hole in the stat because the housing self bleeds via the bleed pipe that you return to the expansion tank.

Your choice of hunting down a pair of alloy housings is a good choice in my opinion and I have done the same for the same reasons as you. There are many aftermarket plastic housings for sale for many cars and the reason for that is simple, the plastic ones distort and crack more often. A friend has had 2 plastic housing failures on 2 cars (a Ford and a Mazda) in the last 12 months.

Hope your test goes well

Ian

Thanks, Ian. At my current glacial rate of progress it could be quite a while before it ever gets tested...

The stat I'm using does have a bleed hole with what can only be described as a tethered bung attached to the hole. It's a plastic ball, slightly larger than the bleed orifice, with a brass tag that holds it loosely in place. I'm very tempted to dispense with it and just seal the hole up with a rivet; as you say, the bleed hole in one of the housings will do that job perfectly well.

Glad that you agree with my choice of aluminium over plastic for the housings. I'll always prefer metal over plastic for stuff that deals with hot liquids.

Hi all,
Thought I'd post a follow-up to the original installation.

The engine has always taken a long time to warm up, so I removed the thermostat
and tested it yesterday and found it bleeds through to
the radiator outlet quite considerably when cold. I also found that
it opened with just hot tap water i.e. no more than 65 degrees, despite
being rated at 87 degs.

I've now ordered a BMW E30 Gates stat rated at 80 degrees.
A slight re-jig of the hoses might be needed!

Nigel

Anyone want some Lada Thermostats never used!

I will have to test mine before fitting now!

Eric

I've now installed the said E30 thermostat.

I had to remake the junction to the heater/top rail pipe, now it's
just a straight through 28mm with a similar 90 angled T-off.
With the 45ish degree top outlet on the stat, it actually turned out to be a much
neater layout.

Nice work Nigel!

A.

So what's the conclusion? Are the original thermostat housings still available as those listed seem to be mutual right angles rather than a T shape?