4 replies to this topic

[ecky]

Hi, how do i pipe a heated manifold , and is it worth doing ?, Thanks

[cal844]

I leave them disconnected

[PeterG]

For an A Plus with 5/8" hoses, no bypass hose, and a floating heater valve I did it this way:

 

Moved the floating heater valve inside the car and shortened the heater cable. Situated a couple of inches above the heater core, still floating. 

 

Opened up the heater port on the head where the old heater valve used to be. Connected with 5/8" adapter and hose to the adjacent tube on the inlet manifold. On the other end connected with 5/8" hose and an aftermarket heater valve set at 25% open then connected into the heater return circuit. The 25 % open valve restricts the flow though the manifold so it doesn't rob the heater circuit. It also keeps a bypass flow running when the heater is off and the thermostat is not yet open.

 

I also added bleeder tees into the hose from the old heater port and also into the heater hose from the thermostat spacer tap.  These are really useful for coolant fill. Take the caps off and fill in no time flat with no air pockets.

[lsto]

Here is an old photo when I was putting mine together. I piped it from the heater take off, through the manifold, to the heater matrix then put the floating heater valve on the pipe to the water pump. Mine is a 998 with by-pass hose.
I think the heated manifold is meant to help prevent carb icing up, helps the engine warm up quicker and helps vaporise the fuel instead of pooling in the manifold. I connected it because in my head I have a more consistent inlet air temp as the coolant temp doesn't vary much under running conditions once up to temp so I can set the fuelling and the air temp won't have as a dramatic effect on performance. Wether it makes any difference I have no idea. I generally leave the heater valve on all the time so it should always have coolant flow how I have piped it up, bear in mind if you turn the heater valve off then you won't get any flow through the manifold.
Also I think it looks neater being connected lol

Attached Files

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Edited by lsto, 23 July 2024 - 06:12 PM.

[Spider]

I plumb them pretty much as Isto has done.

The water 'heated' (warmed) manifold is in place of the one piece exhaust - inlet manifold of the lesser models. Have that bit of heat in the inlet manifold helps with smooth running at low engine speeds and also improves fuel economy. For most street cars, even performance ones, it's a good thing to have. Certainly, if you are after all out power, you wouldn't use it.