LocostUSA.com

Way back when I had hair, I was working as a auto mech at a service station. Fall time was rad flush season. We had a machine that used water and air to flush a cooling system. I hated the Ford engines, you pre-tested the antifreeze before you did the flush, you couldn't read the gauge because the coolant looked like black coffee. You did a 20 minute flush, installed brand new antifreeze/water solution, tested the antifreeze and couldn't read the gauge because it was black like coffee.......explain that to the customer

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

I had hair once. I can't even grow out my bangs now.


I flushed it out today. Still green (thankfully no black coolant though the evapo rust stuff tends to make it so) but the rust was gone completely. During the flush, I saw a little brown when going through the htr core but otherwise a win for a 1/4 cup of metal prep. A gallon is about $15. If my radiator pops or pump leaks in the next few months, I'll post about it.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Awesome to hear. I'll try to flush mine in about a week from now. That will put about a month with several hours of use on it. The cars temp guage needle still gets uncomfortably close to the H mark in this hot weather. Hopefully with some real coolant, it will bring it down a bit.

Heat transfer is better with no antifreeze but a terrible idea without rust preventatives.
I'm sure there are a few things you could do to improve the cooling ability. Consider that your lower core tubes are probably clogged from sediment and flushing through the hose fittings does not force water through all the rows of tubes. You may need to have the copper brass radiator taken apart by removing the solder on the tanks, dipped to clean, then wire is pushed through each tube to ensure it is clear before resoldering. A few shops like that still exist but it may be a lot cheaper to replace it with a new aluminum radiator that will cool better than the original cleaned.

It is common for the old radiators to have pin holes after cleaning (acid dip) and require a new core between the old tanks. All that stuff is less common and much more expensive now.

I'd put a cheap, modern replacement in and put away the original in storage for the next owner.
A better than original engine driven fan with flexible stainless blades or fan clutch may be available for less noise and more power.

EDIT: I see there are a couple different style hose fittings available. Here is one: https://www.ebay.com/itm/125405443312?h ... R7aD5qW8YA

Here is one guys experience where he adapted a different style than what he had:
https://www.mgexp.com/journal/Charles-D ... get.18407/

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Heres one month and maybe 6ish hours of run time on the second flush of Thermocure.

The good:
It looks like non-oxidized metal in the jackets now and much of the mineral deposits are breaking down. I do believe you can restore your system to "like new" if given enough time.

The bad:
The car will over heat even after just a few miles.

I'm no chemist but some sort of molecular magic has happened. What was a black liquid has become a milky (not oil contaminated) substance. Maybe the lime is breaking up but there was very surprising amount of it. There was also a bunch of stuff like ground up chalk mixed into a paste covering almost the whole system (possibly more lime).

After a few hours (yes, hours) of flushing the system every which way I could, I finally managed to get clear water through it and looking through the thermostat hole, the jackets looked fairly clean. In that time I would take it for a short drive to heat everything up and get all the crud suspended and now the radiator must be mostly plugged up because it'll get too hot after only a few miles. The radiator allows water from the garden hose to pass through without and restriction but there must be some obstruction. I've flushed it each way a number of times but still the same result.

I replaced the thermostat just in case and am going to do another flush but with only short loops around town to prevent overheating.

Thanks for the like, Miatav8,MstrASE,A&P,F for the link. Once I get the block super clean, I believe I will go to an upgraded aluminum radiator and a better fan.

Pics:

Does this car have a thermostatic fan?

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

I would call that a success! Well done.

It has a fixed blade fan. The factory original I believe.

Ok cool, sometimes a thermostatic clutch fan will fail to lock up when hot causing over heat problems.

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

I will say that the fan isn't very effective. I may swap out for a plastic fan but I'm really looking towards going with an electric fan or duel electric fans with a shroud.

It looks like there isn't enough room to fit a flex fan and a spacer/adapter fan pilot to clear the mgb pump pilot and for the flex blades to clear the belt.

I suggest using the best bolt-on engine driven fan with shroud and as a back up, install a 12 inch (advertised size) hayden pn 3812 as a pusher, with the long dimension lateral so it only overlaps the tanks by an inch or so. The fan(s) you select to push should pull at least 15 amps (combined if two). The core height of less than 10 inches makes it tough to find a fan with enough output. I suppose you could run two 8 inch fans if you can find them. Beware of all the junk fans on ebay.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

You have a 68 which should be the first year for the metal six blade fan. It looks like the pump hub and pulley are different but worth the change. I wouldn't use the plastic seven blade fan which is fragile.

I'd restore an original fan and large pilot pulley like these:

https://www.ebay.com/itm/264701395835?chn=ps

https://www.ebay.com/itm/154966061411?h ... R8Th1L_BYA

This would be a good pusher add-on (Hayden "12 inch", #3911, 12.8 amp):

https://www.ebay.com/itm/165564076246?e ... R_aXrsHBYA

Derale stand alone- no engine driven, puller if you have room or pusher (thick fan):
https://www.ebay.com/itm/115152757528?_ ... =193147584

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Thanks for the suggestions.

I have this radiator ordered now.
https://www.ebay.com/itm/163705370168?m ... media=COPY

I found two sizes of the hayden electric fans at the auto parts store for a reason price.

I checked the fan fitted to the car and I see that its the same as the one in the link but yellow.

Also ordered a thermostat blanking sleeve to run without the thermostat.I have been reading about how they can be used together with a thermostat to keep temps down by preventing coolant from bypassing the radiator.
https://mossmotors.com/sleeve-thermo-bypass-blanking

I think the blanking with a stat is a great idea. Tough to restrict the bypass on that engine.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12