The BORA

So there's no opening in the bodywork for access to the drain plug?
I modified my radiator by putting in a thicker core but re-using the header tanks and connection pipes. So if you want to upgrade radiator you could do the same thing or they could copy it and construct it out of aluminum. One suggestion when filling is to look at the top RH part of the header tank where you will a connection point for the hose that goes over the top of the roof. This makes for a great place to insert a 1/8" brass tee and then connect a brass fish tank valve on the end of say a 2 ft piece of 1/8" ID rubber hose. When not using this to bleed off air that accumulates in the header tank by dropping the valve in an elevated container of coolant and then opening up the valve until the bubbles are purged. Once the bleed is finished you can windup the hose and valve and place it in the area behind the bumper where the bumper mount attaches .

 

PO installed custom aluminum radiator. I’ll jack it up and look for a hole and drain plug.


I saw your comment about the bleed hose earlier in this thread but I understood the description you just gave me much better. Thanks.

 

On my Bora there is no cutout to access the radiator drain. Bob has the last Bora therefore they may have later figured out that adding a cutout would be a smart thing.

I disconnect one of the lower radiator hoses. It is messy and a pain as the front carpeted area needs to come out.

Ivan

 

If you can accurately figure out where the drain plug is you can always use a hole saw with a shorty pilot bit to cut one. Good luck.

 

Well some good news. There was a hole in the lower valence and the drain bolt above it. Was thinking no such luck for a 74. Could have been added by PO I suppose. Semi offset but I got it out pretty easy. Getting it back in took a while. The car only took three gallons total. Test drive everything seems ok. Will remove the coolant tank cap tomorrow to see what the level is.
Thanks again to everyone for their suggestions and to Ivan for the online guide.
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How fortunate are you? Now onto the bleeding ... nose down low and rear up high. Add the bleed hose I mentioned and it will all go much easier. It may take a while to get the air out. Patience & persistence.

 

How does one know the air is out ie: for all those peeps that didn’t do the bleeder hose mod. I order the T and the ball valve. But I wish I could find a picture of the exact hose that needs to be spliced into.

 

This is a long history of how we got where we did.

The parts diagrams that Maserati just aren't complete enough for you to see how all of this goes together. Every Bora has a radiator with a tap on the top of the radiator on the passenger side but ... yours is a much earlier car so access may be a bit different than my much later (last one) car. When I added this there were not the cooling system tools available that there are today. I got some help on this from a fellow Bora owner George Marin (RIP) who ended becoming my best friend. He ran a company called Marvac that's still around and is now run by his son and nephews. They are a part of the Jacuzzi family that split off to make different sorts of pumps, vacuum. George's mother was a Jacuzzi ... that sounds bizarre until you learn Jacuzzi was originally a company that manufactured in ground agricultural water pumps driven by the wind. The family sold off the business a long time ago but kept on one of the family members to run it. That's when they got into the Jacuzzi whirlpool business. He became a TR owner in the 1980s. Jacuzzi also had experience in early aircraft development post WWI. They designed and manufactured propellers and were requisitioned to do so in WW2.

Marvac no longer make vacuum pumps which they sold for AC work. The Chinese drove them out of that marketplace. They transitioned to automotive & truck cooling system tools so they manufacture a tool to fill your cooling system by sucking the air out via compressed air. They supply all kinds of cooling system tool adapters etc. and they are sold through Snap-On and other vendors. They design the tools but those ARE made in China. Isn't just about everything?

Anyway, back when he and I were working on the Bora's cooling system issues we'd use a simple but well built hand suction pump and pull, as much of the trapped air in the cooling system via a tap on the reservoir RH tank under the hatch. That's also the filling point. It's also a huge PITA access wise. If you pump it down too much it is possible the introduce air by pulling past the lip of seal on the water pump so caution is required. Now all of this was before any of the fancier more capable tools had become available. He also made modifications to the cooling system to combat cavitation in the water pump. He modified the pump to accept the impeller from Mercedes 6.9L engine. It has curved vanes instead of the stock straight ones which are more efficient. The curved ones reduce the possibility of cavitation. This was to address a problem he had which I never did. His car would sometimes spew coolant after very spirited jaunt through the gears. It wasn't heat related though ... damn weird.

If you do get too much air in the system it won't work at it's optimum and the air is "supposed" to collect in that little tank but we found that some would wind up in the header tank on the radiator. Air in there is "supposed" to get drawn through that tap on the top of the radiator and go over the roof and into that reservoir. My modification is there to eliminate any stubborn air pocket from the top of the radiator. The way I have mine oriented the tap on the radiator goes straight to the tee, the other end on that goes to a hose that connects to the copper? line that's in the roof. There's no downward loop . That way coolant and bubbles "should" flow freely with the bubbles rising. On the split of that Tee is where I put the hose with the brass fish tank valve that has an O-ring seal. That loop always has coolant in it. That way when you submerse the valve in a clear or visible container some coolant will already in it and there's no chance of trapped air from improper operation being detected as air that came from header tank. So when you're done bleeding with no bubbles coming out you need to close the valve while it's submersed AND THE COOLANT IS NOT TOO HOT YET FOR YOUR HAND!

 

Will try to install that vent line tap when the parts arrive and give it a try. Thanks again.

Dean

 

Maybe tryout one of these cooling system fillers?

https://www.amazon.com/s?k=cooling+system+filler&crid=1FSCDFHEOVXEW&sprefix=cooling+system+filler%2Caps%2C106&ref=nb_sb_noss_1

The adapter for the neck of that tank might be a bit fussy to find. Good luck.

 

Yeh there’s little room for those. I did the craptastic cylinder head leak test thingy but had to Macgiver the fitting. It passed for what that’s worth.

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https://bringatrailer.com/listing/1973-maserati-bora-8/

 

And now that has sold, there’s another Rame coloured one to replace it…already North of $100k.

 

Its raining Boras!

 

Yeah mine passed too but it did have a failed head gasket and was overheating. That's when I rebuilt the heads and lost all confidence in that testing fluid. Now I find a garage with an emissions tail pipe sniffer and have them test the radiator header tank.

I would think you could adapt one of those tools to utilize a remote hose that would fit in there no? If not then insert a fitting in the large hose after if comes out of the that little cubbyhole.

 

I’ve been driving the car since changing the coolant without issues. I’ll look in the tank after it cools off to see if it burped itself. Temp guage was less than half.

 

Sounds good. Sometimes it takes a bit to get all the air out. If after a while you're not having issues in warmer weather then just leave it alone and consider yourself blessed.

 

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also an FYI. I put valvoline VR1 synthetic racing oil in and the engine is very much quieter and runs smoother it seems. It has the high zinc content for classic cars. I don’t know what the noise was. Maybe timing chains but it was obnoxious and now zero. If anyone’s motor sounds noisy give it a try.
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synth 20W50 is not the recommended oil grade, it's synth 10W50 as per the manual.
Nowadays, a ful synth 10W60 like Mobil 1 or Shell Helix Ultra Racing seems th way to go imho.

 

Redline makes. 10w50 synthetic that seems to be for cars but most 10w50 seems to be for motorcycles

 

Oh dear oil wars strikes the Bora thread!

 

No need to go to war. I just wanted to post my observation that the racket the motor use to make while cold completely disappeared with this oil. I'm realizing that the 10W may provide better start up lubrication than the 20W and I have to think if its worth changing it out again. But silence is golden. In any case the car is now road worthy. I have grills and bumper off to do a thorough detailing before the local car show end of March.

 

You're not going to be running the car in actual cold weather so 20W should be just fine. There were no synthetic oils like Mobil 1 when these cars were manufactured. I never ran it in mine.
The fact that they now formulate one with zinc additives is great for the older engines.

 

Castrol 20/50

 

Note the valve springs pressures in these Italian engines are not high as is the benefit of having overhead cam with direct actuated tappets. 65lbs closed valve spring pressure is normal for all old Ferrari/Lambo/Maserati. Big American engines on the other hand have a lot more valvetrain stuff to move around, pushrods, rockers etc, thus necessitating much high valve spring pressure with performance engines often seeing 160-190lbs closed spring pressure, so 3x more pressure on those cam lobes than Italian engines. The ZDDP argument in oil more applies to engines that really see massive metal to metal forces. I wouldn't worry about it much with old Italian engines that aren't seeing extreme forces applied to components.