Technical 1500 intake system

[Lagdti]

Hello all,I've recently bought an '83 X1/9 1500 for restoration,and would like to know what the purpose of the 'heater fan' type unit is on the end of the engine air intake.Is it just for cooling the engine or does it work as a rudimentry type of super-charger?Also,can I bin it(as mine doesn't seem to work anyway!),and just take a cold air feed from the side grille?.

Any ideas or information would gratefully recieved.

Thanks.

 

[murcielagoGTR]

i had one that didnt work once, and i ditched it, w/ no illeffect. if cool does start to pose a broblem, then you can always do the "rain-tray" removal, or you can use a dremmel tool and cut the plastic "mesh/screen/slats" out of the side intakes. i have done both these to my curent car.

 

[Lagdti]

Excellent,thank-you for your reply.

Thats another job to add to the list.

 

[jimbro1000]

That fan is supposed to cool the carburettor after the engine is switched off or while the engine is running particularly hot.

If you are going to keep the original airbox I would suggest you keep the fan as it does work and the airbox acts as a heatsink (in reverse) for all the hot air rising from the engine. This in turn heats the carburettor and vaporises fuel and that can cause a lot of grief.

If you swap to an aftermarket filter you'll find a lot of the heat problem vanishes.

It also pays to use an electrical fuel pump which can prime the carburettor far quicker and better still before the engine is turned over.

Between the two modifications you should find the fan becomes completely redundant and just so much excess weight to carry around.

 

[Lagdti]

Thanks for that,it all begins to make sense now!

I'm thinking of junking the whole original intake system and fitting a K&N filter,possibly with a cool air duct run from one of the side grilles.Does this sound sensible,or could it lead to any other problems?.The car will only be used in the summer,so the lack of a hot air duct off of the exhaust manifold shouldn't cause any carb freezing troubles,although it sounds as though hot temperatures and not cold ones are the problem!

Thanks for all the advice and info so far!.I am open to any further opinions/ideas.

 

[jimbro1000]

The inlet manifold is temperature controlled with water from the cooling system, it really helps to keep the carburettor temperature under control in cold weather but not so great in hot weather.

The initial hurdle of getting the engine to run from cold is an issue regardless on most cars but thanks to the confined engine bay once you get the car going it quickly ceases to be too tricky as long as you don't ditch the choke mechanism. I've had a car without a choke (on big twin-40s) and it was a nightmare to get started sometimes.

Just make sure the semi-auto choke mechanism on your car works correctly and you can sleep easy. This more than anything else is the important factor in cold starting (well maybe ignition timing is as important but that affects everything).

When you swap over to an aftermarket filter try to get one that includes a vent for the engine breather. The old SOHC tends to breathe quite heavily and even throw oil up from the crankcase which needs to be fed back in to the induction system. You can get seperate oil breather filters but they quickly clog up with oil and combined with damp air this turns into that lovely white emulsion we all know and love (not).