15 replies to this topic

[oliver122]

Model: mini city e
Year:1989

hi guys i just wanted to know the pro's and con's of running the heater hose through the inlet manifold from my stage one kit, it's from mini spares by the way , i wanted to make my engine bay look tidier , also it is abit of a bodge job that the previous owner has done , so thoguht about putting a genuine heater vavle on , and running the pipe round the back of the rocker cover?

and advice would be appreciated

ollie

[Guess-Works.com]

what makes you think it does not already have a genuine heater valve ?

The valve on the head was replaced by a inline valve located between the engine and the bulkhead to the left of the carburettor in 1989.

[oliver122]

ahhh i see , mine is on the right hand side of the carb when you look at the engine , and isnt bolted down to anything , just attached to the hoses

[Dan]

That's standard on your car.

Pros are a constant tune in all weathers, more consistent fuel atomisation and delivery and better economy. Providing it's plumbed in properly, meaning independant of the heater tap.

Cons are, in a road car at least, none. Despite what people will no doubt now tell you about higher temperatures and air density.

[oliver122]

cheers dan , its my first car and its my daily drive + its a 998 only running a stage one kit so not to bothered about performance to much , and what do you mean , independ of the heater tap ?

[Dan]

Tee it off the heater circuit so the heater and heated inlet are separate, otherwise it will shut the flow through the manifold off when you close the heater tap.

[oliver122]

Tee it off the heater circuit so the heater and heated inlet are separate, otherwise it will shut the flow through the manifold off when you close the heater tap.

so would it go from the block , into a tee , one pipe running off to the heater tap , one to the inlet manifold , but then where would the outlet for the manifold go ? im slighty confused now

[Dan]

To another tee fitted into the hose from the heater that runs back to the bottom hose.

[oliver122]

To another tee fitted into the hose from the heater that runs back to the bottom hose.

ahh i see sort of defeats the object as i could just run it straight from the heater valve on the head through the heater and back in not using the inlet manifold , i was thinking of using the inlet manifold as both my heater hoses are to the right of my carb , save me moving them about , but if i did go down the lines of fitting tee's in , what ID hose would i have t buy , as i could just buy some lengths of silicone hose rather than buying a kit and cutting it up, and just by the bits i would need

[Dan]

Your heater circuit is 5/8" diameter, the inlet probably uses 1/2" hose though so you might need some adapters. Actually you could use brach reduced tees. Measure the size of the inlet stubs.

[oliver122]

how badly would it affect it if i was to run the pipe through the inlet manifold , but then connect it up to my heater valve?

[Dan]

It just won't give you the benefits of having the inlet heated unless the heater is on. You will be back to having an eratic tune that changes with the weather and the possibility of fuel condensing in the manifold. People think that the manifold can look after itself if its warm enough for the heater to be off but the cooling effect of all that vaporising fuel and the air rushing through the engine bay serves to keep the manifold cool all year round.

[AVV IT]

Your heater circuit is 5/8" diameter, the inlet probably uses 1/2" hose though so you might need some adapters.

If you do need some 5/8" - 1/2" adapter/reducers, I have some brand new Minispares Ones that I now don't need

[Tommyboy12]

I have my inlet manifold hooked up in series (not my doing) with my heater matrix and when the knob is on cold the car runs quite differently to when the valve is open. Especially in the winter. Its worth doing them on seperate circuits.

[thebullet]

I never connected mine when changing my head, the little metal tubes at each end of the manifold had just rotted away and I was told that it can cause high tempretures. Too late now!

The only thing I noticed is in the winter, the car dosen't hold revs when idle and struggles to warm but this may not be anything to do with it.

Also could be an airfilter issue with me, not having the standard one with the tube.

Matthew