Scorpion Radiator Modification

[davidb]

I'm about to pull mine for a boil out . Was thinking of having my
radiator guy drill a hole @ the top which would be accessible later
thru the grill . Solder/weld a female threaded brass ring on the
radiator body then screw in a brass plug . That way I could "top-off"
the radiator w/coolant . I'm sceptical of my ability to fully purge
the air in the radiator after a coolant re-fill . Thoughts ??????

[Will]

Look in the hole by the left side hood hinge, from inside the luggage compartment. (may be covered by carpet) You can't top off from there, because it's not the high point of the sytstem, but you can bleed off air from there- you shouldn't have to though.

[davidb]

As stated "about to pull the radiator". Now that it's out I see the plug
Will . I rather thought Lancia would have made some nature of pro-
vision to bleed/purge the radiator of air while designing the cooling
system . I'll look further later to se how accessible it is . Failing that
I'll have a 2ND soldered in . Thanks .

[John Allen]

easily accessible with a long (3"?) 8mm allen key.... Mine had a foam sealer around it. Just don't overtighten it...

[Will]

Is that foam sealer, or a piece of foam that holds the radiator to keep down vibration?

I'm having a BITCH of a time with my system- went over to a Davies Craig EWP and I can't seem to get the radiator hoses to even get warm- surely there's air in the system but water comes out the front purge hole, I can hear the damn pump running, the only thing I can think of now is that some air is trapped in the pump although it's oriented correctly. This is starting to really piss me off because I'm tired of mopping coolant off the garage floor. It is gradually getting diluted with all the added water though.

[davidb]

AH HAH ? Mssr. "Know-It-All" has an issue [just kidding Will] .
Me-thinks my idea of another more readily accessible 2ND
radiator plug might be a nifty idea . After two months w/
this Scorp. & cranking it over 2-3 times I've found many coolant
leaks: hose connects principally but still a bitch . Good luck Will . . .

[John Allen]

Will

Sorry to hear about your issue. Are the pipes going to the radiator getting hot at all? Is it overheating? If it were anyone else, I'd suggest you look at the external t-stat and make sure the orientation is correct.

The only place I've had air problems with is in the heater lines. I aded a bleed valve in one hose and haven't had any problems since.

[davidb]

Gauges didn't work when I got it so don't know if it was
overheating . Just starting the re-furb so as for the
cooling system a radiator boil out, pump replacement
& hoses that look bad is a beginning . I'll address other
leaks/issues as they appear in the future .

[Will]

Hi John;

Here's the lowdown (current):
Mechanical pump in block removed and new water inlet pipe runs through "hub" of old pump housing. Remote catchtank/recovery bottle feeds to flange at rear of old pump housing. Thermostat Tee modified so it points forward only, connects to hard line on firewall (upper rafdiator pipe). top vent from modified tee goes to recovery bottle/catchtank. Single pass radiator retained with stock plumbing up front (will change to double pass rad, I have it but haven't got it in yet), radiator lower hose hard line comes up firewall and goes to Davies Craig electric pump (EWP) w/ceramic seals. Outlet from EWP goes to aforementioned pipe that goes into hub of old water pump housing.

Rear head outlet: Connects to front outlet using Abarth scheme: 1/2" direct pipe.

OK, did ya get that?
Future: EWP will be moved up front, have to refabricate radiator tubes because double pass (obviously) has inlet/outlet on same side, and will try to fit EWP in front (lower hose/rad outlet)since I think that will help. Head rear outlet tube to main water outlet has sensor fitted for EWP controller, but I'm not crazy about the "dshort circuit" given there is not the pressure differential across the pump as with stock motor. I think I am going to run rear outlet forward and use a monoflow heat tee to force controlled flow (you may be familiar with these, used in residential heating systems circa 1950's, has cone-in-a-tube type configuration).

The problem: I can hear the pump running biut it doesn't seem to pump, i.e. I don't think it's pulling prime up the hard tube on the firewall, even though the block is filled and the radiator is filled. Without cutting back the hard tube, I don't have room for a fill/bleed port there. I think it's time to tear everyhing back out and start from pump up front on new radiator.

Thoughts/suggestions? (If you got this from the description you're better than I am , I tried to explain best I could!)

PS> pump is in correct orientation not to trap air as drawn in Davies Craig documentation.

[sprintcarfan]

Where is the drain (the large line) from the coolant expansion tank plumbed in? It should be on the inlet side of the EWP, or else the pump will be more likely to cavitate. From your description it sounds like it's on the outlet side.

[Will]

Well, it physically is on the outlet side, but in such a way (flange at old water pump housing) that it should be in negative pressure differential IF there were any flow. I don't have room to put it in before the pump but I think cutting the tubes out and refabricating them is going to be the next step. I don't think the problem is cavitation per se, I think it's air entrapment- at least, that's what I'm assuming because I'm hearing the pump run and getting nothing. If it were cavitation,I should hear the air bublle collapse as the pump sped up/slow down but I don't think the pump is anywhere near strong enough to cavitate. I have some 3600GPH mag-drive pumps I use in my fish pond that are powerful as all hell, and even they don't cavitate until they have less than about eight inches of water over them. I think I have trapped air/priming issue and I agree that pre-pump is the *correct* placement for the overflow, I'll consider that when I mocve the mess up front.