Warm air intake

[EJ_Dave]

As I live in Canberra it is starting to get a bit cold and the old grey motor is getting a bit temperamental. Runs fine when it's warmed up but that is only the last 2 blocks before I get to work each morning. Because I have extractors the inlet manifold isn't being warmed like it used to in its cosy former relationship with the exhaust manifold so I was wondering if sucking warmer air (drawn over the exhaust manifold) into the carby might help things. A lot of more modern carby cars do this (usually ones with cross-flow heads I've noticed).

If anyone has ever done this, did it work? Do others think it might have a beneficial effect?

On the technical side I was thinking of welding a length of exhaust pipe along one of the header pipes (I have seen extractors with a similar setup) and attaching that silvery ribbed tubing stuff (or whatever it's called) and plumbing it into the air cleaner somehow. Any more comments to here??

I think that the easiest way of plumbing the warm air into the carby might be to get an air cleaner from a later model that is set up for this. Did later model Holdens with strombergs have this setup?? Or can anyone think of an air cleaner from any other car that would drop onto a stromberg (something with the same diameter throat?

Any suggestions appreciated.

Cheers,

David

[ChrisB]

Dave,
That is always going to be a problem here in ACT. Have a look at Slims for sales and you will see a twin inlet manifold that I am going to fit up to my old bus. It had a water tube up the inside.
This was what GMH did to the X2.
A friend I know once made up a piping setup and attached the heater hose to it, then clamped it to the inlet manifold. Hes comments were "looked shithouse but served the purpose.

Cheers ChrisB  

[Dr Terry]

Hi Guys,

This is one bit of ‘pollution gear’ that works well. Fit the lid of a ’76 to ’85 (HX to VK) red/blue/black motor air cleaner to the base of a ’59 to ’75 (late FC to HJ) air cleaner and weld a matching piece of steel tube to the extractors to attach the "Kopex" tubing (the silver ribbed stuff) to the lower air cleaner snout. Have a look at an HX to VK 6 cyl. Fit the little temp sensor from the pollution air cleaner base to the earlier base so it will fit your carby. Connect the small vacuum tube to the inlet manifold for vacuum supply. The whole will work automatically.

When they introduced the ADR27A pollution engines in mid ’76 they ran them very lean at low revs, to the point that even with choke they stumbled & carried on in cold weather. To overcome this they used a hot air tube to get hot air for the carby to vaporise the fuel mix better & improve cold driveability. We all know that cold dense air is good for power, but we still have to drive to work on cold mornings. The idea of the small temperature sensor inside the air cleaner is to check the temp of the incoming air. When it’s too cold the vacuum flap moves & air is supplied by the hot air tube from around the exhaust manifold. If it’s too hot the flap moves back to fresh air.

Hope this helps.

Dr Terry

[EJ_Dave]

Thanks for the advice guys- also Gertie in the General technical section.

Chris- couldn't find the manifold in Slims classifieds. Could you give me some more clues (approx. date, post title maybe)- I'd be interested to see what it looks like.

Does anyone have an air cleaner from a HX to VK they would be willing to part with in the Canberra area?

Sounds like Dr Terry's suggested setup could be the best of both worlds- warm in winter, cool in summer. Within my technical capabilities too.

Good to see you on the site Dr Terry. I learned a lot from some of your contributions on the Fastlane Holden forum although I haven't seen you make an appearance there for a long time (I don't visit there much myself these days). I hope you become a regular on this site. Your knowledge spanning such a breadth of different Holden's would be a valuable addition.

Cheers,

David

[EJ_Dave]

Just wanted to report that yesterday I rigged up the warm air intake using a HZ air cleaner as suggested by Dr Terry. It worked a treat. Idled without choke after around 2km whereas before I was sometimes still having trouble after 10k. Fantastic- thanks for the advice. Only cost $50 all up too including a lot more  vaccuum hose and kopex tubing than I needed.

The only thing was I didn't fit the thermostatic control to the old air cleaner base because it is curved instead of flat in the HZ and I'm not sure it will fit. I might give it a go in the near future. At the moment warm air is drawn into the carby whenever manifold vacuum is high and cold air when it is low (ie when throttle is open). In winter this will be fine but can anyone forsee problems in summer if I left the system as it is? If so I will either fit the thermostat (probably the best option I guess) or stop the system from operating (by fitting a tap/valve to the vacuum line or disconnecting the hose feeding).

Cheers,

David

[Digger]

Hi David,

One way you can control the vacuum is to use a thermaticly controled vacuum switch mounted in the head.
As used on Comadore blue motors, you need the switch that is normaly open when cold and shuts at a determined temp.
Just a thought.

Steve.

[EJ_Dave]

Dave,

thought I'd bring this thread to the top for you. Gives details of how I rigged up a warm air intake. Slightly different situation to yours but may be useful.

I have also been thinking of fitting twin carbs and pondering how to rig up the same system. What I have come up with so far is to find an air cleaner setup from a modern(ish) carby car that is an oval shape (ie long enough to go over both carbies) and has a similar  thermostatically/vaccuum controlled cold/warm air intake. The only two cars I can think of that might fulfil this requirement are (gasp) an XE/XF Falcon or an early twin carb Mazda 323/Ford Laser/Meteor. No doubt there are many others. The base of the air cleaner would need to be modified to fit the twin carbs.

Cheers,

David