Firefly
-
Posts
123 -
Joined
-
Last visited
-
Days Won
1
Content Type
Profiles
Forums
Blogs
Gallery
Downloads
Store
Events
Posts posted by Firefly
-
-
Sorry Iain, just realised you are talking about the pipe from the bottom of the h/t, not the bleed from the from the thermostat housing to the top of the h/t which is the one that needs the restriction, confusing myself now. 🤔
-
All the more reason to restrict the flow. Fluid like most things takes the path of least resistance, and its going to find circulating thro your h/t easier with that bore of pipe, than fighting its way thro` the rad matrix. Mac.
-
Yes use the caps as you suggested, if you are refilling the system you could fill the rad and replace the cap & then continue filling the header tank to required level. Although I fill mine just using the header tank, its the only cap.
The physics of the restrictor. Imagine you have a 12 dia. hose and fitting in the thermostat housing, the amount of fluid the water pump would push thro` into the header tank is significant, turning your header tank into a 2nd radiator which will do little to cool the fluid, but raising the engine bay temp. The 3 mm restrictor obviously limits the flow of fluid, but is sufficient to bleed the air out of the rad and engine. In fact I have noticed very little fluid if any circulates below 3000 rpm. If you have a spare hour or two do the calcs to see the difference in the flow rate between 3mm dia. and 12mm dia. that should convince you. 😵
-
Yes that would be fine, ideally brass bar, but mild steel is probably more readily available. 👍
-
1
-
-
Iain, hope this helps, would like to take out a "patent" but this is how modern cars have been plumbed in for over 30 years. Thinking about your set up, you intend sighting the swirl pot/header tank between the brake master cylinder and the heater box? Could you not tee the bottom tank connection into the 1/2" pipe that returns coolant from the inlet manifold to the water pump that runs behind the exhaust manifold? this is direct to the suction side of the pump, could save a lot of pipework. Good luck. Mac
-
Yes Iain, your swirl pot is the same animal as the Volvo tank. What may confuse you is that the Volvo dose not have a separate overflow it just spews coolant all over the top of the tank, should you over fill it, not so sophisticated as yours! 😃 If you would like me to do a sketch/drawing would be happy to do so.
-
1
-
1
-
-
NO, the overflow is just that, it dumps any over fill to the ground. The connection in the top of the tank is the one that should be connected to the highest point in the system, i.e thermostat housing so that any air will always rise to the highest point, and then it will be drawn back into the tank, because the bottom tank connection should be connected to inlet side of the water pump, where there will be a slight depression. Then you get a constant circulation pulling any air into the header tank, thats why its important to have a restriction.
-
Sorry Johny must disagree with you there. That is the beauty of this system, so long as you take the bleed back to the tank from the highest part of the system, in this case the thermostat housing, its better if you have a positive head in the tank, but if you haven`t once the engine starts it self bleeds. Hope that makes sense??🤔
-
Yes top one is just an overflow, if if your calcs are out and you over fill it, where do you intend connecting the top tank out let too?
-
Well done, sounds as tho` you are well on your way. Bit confused you saying 6mm return to the rad, do you mean from the rad as a bleed for any air. If that`s the case, bear in mind about putting a 3mm throttle in the line, you don`t want your tank becoming a second radiator.
-
Iain, another very important advantage with a modern tank, is most have a float switch built in, and a warning buzzer can be installed under the dash. In fact only last winter the GT6 engine was saved by this, when the Chinese rubbish water pump seal let go.
As Johny pointed out there is more room in the engine bay compared to the Vitesse. So if it helps the size of the one I have fitted is off a Volvo 940 (dims are mm) 210 long X 125 wide X 130 high from the top of filler cap to bottom of tank, you will need a further 65 ish to connect to the bottom tank outlet. Also a Volvo 850 tank may suit 160 X 160 X 130 high from top of cap to bottom of tank plus fitting of outlet connection.
If this is of any help the company who supplied the tank is called “Parts for Volvo” if you google that it should come up, and select the coolant section on the left hand menu. Mac.
N.B. the 240 & 740 tanks do not have float switches.
-
Sorry Iain.........to slow to do any drifting now.
The beauty of fitting a header tank, so long as you haven`t a serious leak, is that the system is constantly bleeding any air into the tank, so keeping your engine and rad full of coolant. The problem as you probably know, that the slightest air leak will prevent fluid being drawn back from the low down expansion bottle. and it continue to do this till the bottle over flows and your engine over heats. the system may be water tight but not necessarily air tight. Every one knows a Stag overheats, I fitted this system to that 15 years ago and then had to change the thermostat to 88 deg. to keep the engine running warm enough. Well worth fitting a header tank in my view. Mac
-
1
-
-
Johny
Its not only more spacious under the bonnet, its the inside too. I`m a Triumph man thro` & thro` having been employed by them all thro` the 70`s. Love the look of the GT6. but being a 6 footer, it was just too tight a fit, but had to have that lovely 6 cylinder up front.
Going back 6 months do you remember we had a discussion about the timing of the GT6, I and other found it performed running 16 deg. advanced. When I brought the Stag out of winter hibernation I tried the same. No no no, it was very unhappy, and had to return it to book setting of 12 deg. They both run similar compression ratios, so am wondering if its to do with the shape of the combustion chamber as the Stag is wedge shaped, or whether the valve timing is different giving better or worse scavenging. The jury is out on this one??🤔 Mac.
-
1
-
-
Be careful if you use the original vitesse tank that sits along side the rocker cover, its joints are soldered and only good for 7 PSI. Running at 14 or 21 PSI will rupture the joints, ask me how I know.
I have used a Volvo headed tank on my GT6 engined MGB, (£25-£30 brand new) which is see thro` plastic, i.e. check level without removing cap. I have attached a picture and hope you can see how its plumbed in. There must be a 3mm dia. restriction in the return (already fitted in Volvo tank) line to the top of the header tank, otherwise hot water will circulating thro` the tank not the rad. The bottom out let of the tank is connected to the inlet to the water pump. This is of course how modern car cooling systems work.
Mac.
-
2
-
-
.................a nice company to deal with too.
-
Johny is spot on..........as usual.😀
-
Looks like a Powerspark High Energy.
-
Poser !!!😃
-
Iain,
I know a chap with a Stag, he used this DIY, kit and is very happy with the result.
Mac
-
1
-
-
Tony White 07830226461 he`s a busy man and often difficult to track down, but he will have what you want.
-
Stag Tee is 7.7mm I/D & 12mm O/D.
-
1
-
-
Thank you Iain & Jonny, found that very interesting and have learn something. Think you will find those extra 10 horses, I`m off now, would hate bore anyone any further.
-
1
-
-
Iain,
My blasted modern starts ring bells and sending all sorts of silly messages when it "thinks" my tyre pressure needs attention.
Seriously tho` our findings on how much advance our engines need without doing serious damage, warrants some "scientific" analysis.
-
Well I live in my world, and listen and feel to what the engine is telling me, and if its happy at 17 Deg BTDC who needs Google??🙃😀
Expansion tank for Vitesse
in Cooling System
Posted
🍻 or two 🙂
I was going to wait for you to ask about the t/h fittings. I used 1/8" bsp, you can imagine its not very thick, and so that it ended up facing in the right direction, I used a lock nut (thin nut) on the inside with sealer. May have used a brass penny washer under the lock nut, its a while ago now. You are definitely heading in the right direction. Mac.