29 replies to this topic

[Rubbershorts]

I've read so many opinions on this subject that I had completely no idea what I was supposed to do. Therefore I asked AC Dodd, during one of his awesome live YouTube sessions, whether it should be fitted or not. He reckons yes, as it helps with fuel economy. Based on that I think I'm going to connect mine.

Edited by Rubbershorts, 29 October 2024 - 06:57 PM.

[Cooperman]

In all my engine builds I never connect the heated inlet manifold. A Mini always starts easily and the best inlet air is the coolest inlet air. Having always liked the idea of cold air intakes, why would you want hot air going into the carb whilst having a heat shield between carb and ex. manifold?

[stuart bowes]

perhaps with a thermostat controlled shut off valve or something...  

 

but a lot of effort to go to for what can surely only be minimal differences at best

 

and I suppose the mpg issue might depend on whether you're dailying it or just having it as a fun weekend car 

Edited by stuart bowes, 29 October 2024 - 09:13 PM.

[acorn]

In all my engine builds I never connect the heated inlet manifold. A Mini always starts easily and the best inlet air is the coolest inlet air. Having always liked the idea of cold air intakes, why would you want hot air going into the carb whilst having a heat shield between carb and ex. manifold?

I suppose a heated manifold, being after the carb, is better than a heated air intake. I couldn't get my head around open sports filters seeing as they sit above the exhaust on a Mini.

[Icey]

The heated manifold has little to do with cold running. It’s to replace the ‘hot spot’ from the original conjoined inlet/exhaust manifold. The purpose of that is to ensure fuel doesn’t pool in the inlet track, staying as a vapour between valve openings. Vizard covers this in his book.

Yes, on an engine where every single bhp is important you’d exclude it, but on road going engines he [Vizard] suggests it aids general smooth running.

I have always connected it, not only because of that but also because it makes routing pipe work across the bay neater.

[Rubbershorts]

Photo

Edited by Rubbershorts, 30 October 2024 - 06:27 PM.

[Rubbershorts]

Any thoughts on the neatest way I can plum my manifold in? Would I split the yellow circled union, or the red? I understand there's some reducing of diameter to carry out too. Anyway I look at it, it's going to add to the mess under the bonnet. Any neat ideas floating about?

[Rubbershorts]

A

Attached Files

•  instasize_241030172726.jpg   49.87K   7 downloads

Edited by Rubbershorts, 30 October 2024 - 06:28 PM.

[Lplus]

The shortest route woud be to break downstream of the valve (red), run a pipe round the back of the carb to the rhs of the manifold and connect the lhs of the manifold to the pipe into the bulkhead.  I doubt the pipe from valve to bulkhead would stretch to the manifold so extra bits of pipe and maybe a right angled solid bit of pipe could be necessary.

 

Still going to look heath robinson though.

[Rubbershorts]

The shortest route woud be to break downstream of the valve (red), run a pipe round the back of the carb to the rhs of the manifold and connect the lhs of the manifold to the pipe into the bulkhead.  I doubt the pipe from valve to bulkhead would stretch to the manifold so extra bits of pipe and maybe a right angled solid bit of pipe could be necessary.

 

Still going to look heath robinson though.

Hey Lplus. 

 

Would that look something like my doodle? Only slightly more shonky?

 

Daz.

Attached Files

•  heated manifold re piped.jpg   76.83K   3 downloads

[Icey]

Just to add an alternative approach - drill out the original heater outlet over #4 and remove the sandwich plate. Has the added advantage of adding a little extra flow across the head.

[Rubbershorts]

Just to add an alternative approach - drill out the original heater outlet over #4 and remove the sandwich plate. Has the added advantage of adding a little extra flow across the head.

Cheers Icey. It does look a lot simpler if the valve is that side. Would the head need removing from the car to do this? 

[coopertaz]

Any thoughts on the neatest way I can plum my manifold in? Would I split the yellow circled union, or the red? I understand there's some reducing of diameter to carry out too. Anyway I look at it, it's going to add to the mess under the bonnet. Any neat ideas floating about?

however you do it always fit into hot side of heater, red circled.

[Lplus]

 

The shortest route woud be to break downstream of the valve (red), run a pipe round the back of the carb to the rhs of the manifold and connect the lhs of the manifold to the pipe into the bulkhead.  I doubt the pipe from valve to bulkhead would stretch to the manifold so extra bits of pipe and maybe a right angled solid bit of pipe could be necessary.

 

Still going to look heath robinson though.

Hey Lplus. 

 

Would that look something like my doodle? Only slightly more shonky?

 

Daz.

 

Heh, yep that's the principle I had in mind - maybe running it behind the air input trumpet if there's room, but only trial would show the best alignment.  Icey's suggestion of changing to a head connection at the other end has merit, you could do away with the floating valve, though the outlet on the thermostat housing would need blocking and some means of getting some water to pass the thermostat body developed. (whatever some say about not needing any flow past the thermostat when closed)

 

If the threads are tapped for the head mounted valve you just need to drill through in the area between them.  It could be done with the head on, especially if you have a magnet to catch the swarf before breakthrough.  Even then flushing out the system afterwards would be advisable in my opinion.

 

 

Got to be honest though, For all that faff, I wouldnt bother at all.  I doubt you'll notice the difference

Edited by Lplus, 31 October 2024 - 11:08 AM.

[Icey]

Just to add an alternative approach - drill out the original heater outlet over #4 and remove the sandwich plate. Has the added advantage of adding a little extra flow across the head.

Cheers Icey. It does look a lot simpler if the valve is that side. Would the head need removing from the car to do this?

No, just make sure to catch the swarf.