Intake air temperature

[BDA]

Thanks Peter! This is very helpful.

With regards to the dirt that is collected from the air intakes, did you try anything to reduce the amount of trash they pick up, for example, stretching an old stocking over the opening or putting some open cell foam in the entrance?

[Grumblebuns]

Very interesting article Peter. Initially I thought that the air box enclosed the Strombergs looking at the small photos in the original article. From your large pictures, it now appear that only the filter section is enclose.

A couple of thoughts came to mind reading your piece. The location of the stock filter does not appear to be too bad of a choice. It's in a fairly open area with probably some air flow from under the car. I wonder how much of that was forethought  and how much circumstance.

My other thought was to move the filter to the inside of the  luggage box. Totally seal it off and run ducting directly under the car. You'll lose some luggage space but not much. Just thinking out loud here 

[Bainford]

Thanks for posting the article, Peter. Very interesting.

[jbcollier]

Because of all the road debris thrown up by the rear wheels, air filters do not last long.  This was noted in a period long-distance road test back in the day.  I run my twin-sidedraft crossflow with the stock TC set-up.  Works fine but I notice the filter starting to affect performance at about 1500 to 2000 km.  I live in a dry, somewhat-dusty climate.  You may go considerable further in a moist climate.  Adding filtration inline just has things plugging up sooner elsewhere.  Better would be to fit an air cleaner that takes an air filter with a larger surface area.

[pboedker]

With regards to the dirt that is collected from the air intakes, did you try anything to reduce the amount of trash they pick up, for example, stretching an old stocking over the opening or putting some open cell foam in the entrance?

No, because the dust problem is really very small. 

The location of the stock filter was where I measured the highest engine bay temperature. It was a simple measurements and e.g. didn't take into account how the air was moving around inside the engine bay.

Oh, and I also need to add again, that all the work was done by the two guys from DOT Engineering. I did the temperature measurements and saw the need but the solution and manufactoring was thought up by them. 

[EuropaTC]

Peter, by any chance did you measure the temperatures in the section where the petrol tank lives ?

This has been an interesting topic and pushed me to look critically at my car with the result that I came away thinking, "hmm, yeah" after seeing the exhaust route and silencer distance from the intakes. 

It got me wondering if the RHS tank could be relocated backwards a few inches and an air filter assembly mounted in front of it with an air scoop to drag cold air from underneath the car in similar fashion to your tubing. If the air box was remade/reversed it could end up being a neat installation ?

Brian

[Pfreen]

That is exactly what I am doing after reading the comments on this topic.  i will let you all know how it works.  I did not have to relocate anything on my tcs.  Just making a new airbox, hose, and filter.  I am not fitting a scoop initially until I measure the results.

[EuropaTC]

Ah, now that is interesting. I did some quick measurements of the available space but it seems tight, whereas the tank itself could move backwards a couple of inches with some juggling of the filler pipe.  That might be enough to allow a modern housing (and filter) to fit in without having to custom make something although I'm not averse to that route.

I'd be interested in seeing any photos of your progress and snags/solutions that you come across.

Brian

[Pfreen]

I have completed my tc airbox and filter assembly.  It works very well.  With an air temperature of 100 degrees F under the car, the air inlet temperature at the carburetor was 105 degrees F.  Previously, with no airbox, I measured about 30 degrees warmer than ambient at the carb inlet.  I made the airbox from an aluminum bread pan (Vollrath 5216) which measured 4-1/2" x 16" x 4-1/8".  I epoxied in a 3-1/2"  diameter aluminum tube from Spectre Performance angled down at 30 degrees.  I fabricated an aluminum backplate from .090" aluminum. The filter assembly was also from Spectre, part number 9831.  I cut the bottom of the filter housing at 20 degrees so it would be flush with the bottom of the car.  The connecting hose was from Mcmaster.

If you have any questions, please let me know.

[EuropaTC]

Thanks for posting, the airbox is inspired !  I'm about a week behind you with my conversion which uses a different filter, a flat rectangular one as used on the UK Ford Puma but otherwise we're on very similar lines.

I've made a new fibreglass airbox molded off the original but it looks exactly the same as yours with the inlet pointed down towards the fuel tank well.

Temperature measurements are encouraging and I've been wondering if when you're on the move you'll get an even match with the ambient air due to a slight pressure flow into the filters ?

Brian   

[Pfreen]

i attributed the temperature rise to heat transfer through the aluminum airbox.  i tried to find an alternative airbox, but didn’t have the dimensions to see if it fit.  The Elan airbox may have fit, but I just wasn’t sure.

BTW, I measured the pressure drop between the cabin and the airbox, It was less than 2” h2O (0.5 kpa).

Please post pictures of your system when you can.  Thx.

[EuropaTC]

You could well be right on the heat transfer causing a bit of temperature lift, although compared with the data that Peter originally provided I think you're doing well. I would be happy with those numbers anyway.

As I said, I'm probably a week away from assembly and so things might change but this is where I'm at.  The Airbox is finished, it's basically the OEM one with a new inlet and looks remarkably like yours   

The filter has more surface area than the round one and the casing for that is still in the "scrappy" state while I tidy up the GRP. Today I have been learning how to make louvres in Al which I hope will both channel air into the filter and also cut down on water/spray ingress. That's what's been taking the time, trying to come up with a way to protect the paper filter from direct water splashes from underneath. I don't deliberately take the car out in the rain but in England it's a given that you'll get very wet at some point.

Dumb question time, how do you get your temperature and pressure measurements ?  Is it specialist or DIY kit ? Pressure measurements is sounding high tech !

[Pfreen]

I have a two channel thermocouple readout made by Omega.  For pressure, I have a digital manometer, but a simple clear tube with water in a “U” and a scale will make a water manometer.