is this really stupid?

[19_again]

https://www.villagephotos.com/pubbrowse.asp?folder_id=1844904
I really like the look of the K&N air filters, (hey I live in NH, whattya expect?) and I thought that maybe this sheet of 1/4 lexan would seal them as well as the standard covers and even let in more air. Any obvious downsides here? /bcforum/images/%%GRAEMLIN_URL%%/nonono.gif

 

[tony barnhill]

Now if you encase them completely & run a hose to the front of the radiator panel, you'll have a proper cold air box.

 

[19_again]

The advantage being only cold (non-engine compartment heated) air is fed to the carbs? Performance implications?

 

[tony barnhill]

Cold air intake is a system to bring down the temperature of the air going into an engine for the purpose of increasing the power of the engine. Cold air is much denser than warm, humid air. Since this is true, cooler or cold air holds more oxygen. The more oxygen going into an engine the more powerful its combustion. Thus, you get more horsepower with the same or better fuel economy.

 

[19_again]

Thank you.

 

[vping]

Not my idea but I made these at work. I can bolt the stock air filter pans & spacers to the carbs and leave then there. If you ever want to jst pop off the filters, hang the filters & add you stock covers back on. Each end is threaded and acts like a large nut. The ends are bored & tapered to account for the grommet that is in the top of the cover. Beats trying to hold all those piece together when trying to re-assemble.

 

[Baz]

[hijack]
How does one run a hose, from where to where?
[/Hijack]

 

[tony barnhill]

About 4" in diameter...from front of the cold air box thru the radiator support (you'll have to cut a hole) ending out in front of the radiator behind the grille.....some factory Works cars actually had them ducted into the grille itself.

 

[Dave Russell]

Air density & engine power increases about 1.8% for each 10 degree F temperature drop. If outside air temp is 100 degrees & underhood temp is 200 degrees, you do the math. The mixture would need to be set richer of course.
D

 

[Hap Waldrop]

If you run a completely sealed cold air box you have to vent the vent tubes from the SUs directly into the cold air box as well to equalize the pressures. Look at the picture inside the cold air box on the race car I drove a few seasons back the tube you see sticking thru the cold air just beside the velosity stack is a tube running from the float bowl vent into the cold air box, the second picture is the cold air box from the outside view, when the nose of the Bugeye was close shut, a section attached to nose clamshells the entire unit closed and it takes in air from one of the headlight openings. I don't recommend cold air boxes for street cars, makes them too hard to work on.

 

[Hap Waldrop]

Here's another K&N filer application on a MGB, that is simple and better flowing than most offered in the marketplace. I made a simple mod to the factory filter bases, by counter boring them and using sockethead allen fastners, but you can achieve the same thing without the counter boring by using button head fastners, then use a K&N unversal cone filter that slip over the OD of the factory filter base and then clamps to hold it in place. This set up has no fastners passing thru the inside of filter assembly and allows for better flow. Another bonus is it is simple to remove, loosen the clamp and simply pull the filter out of your way.

 

[tony barnhill]

See, the things we learn here......

Hap, where'd ya get that cold air box?

 

[RickB]

Looks like something custom made. I've seen things made of material very much like that. If it's an 'off the shelf' piece I could imagine a bunch of people wanting one.

 

[ronzi]

I had a pair of aluminum velocity stacks & wanted to put them on my '64B, because, well, velocity stacks are cool.
After some monkeying with trying to use the stock MG air filters, I ended up with this ...

The filters are from a 10-12hp Briggs engine.

 

[vping]

I like that set up HAP. Simple.

 

[Hap Waldrop]

See, the things we learn here......

Hap, where'd ya get that cold air box?

Tony, that was on the Huffaker Bugeye race car, it was a custom carbon fiber unit, mucho bucks. Funny thing is that Huffaker did alot of on-track, on board dyno testing with cold air boxes and never saw any real gains with on anything other than the 948s with cold air boxes, and those are the only SU carb cars he ever used them on after his testing, his set up for the 1275 SCCA FP cars, which use HS4s (MGB carbs) used a K&N filter set up simular to the one I have on my street MGB pictured above. The above K&N air filter set up I used on my street MGB is something we racers have been doing for awhile, I just adapted it for my street car.

 

[tony barnhill]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Funny thing is that Huffaker did alot of on-track, on board dyno testing with cold air boxes and never saw any real gains with on anything other than the 948s with cold air boxes[/QUOTE]

So, then everything we think about cold air being more dense & helping to improve horsepower is either a myth or the MGB engine compartment doesn't get hot enough to affect air density?

 

[jlaird]

Or it does not use build enough pressure with the configuration available, cold or not.

Who knows, he was an expert, guess I have to beleive him.

 

[Hap Waldrop]

Many of a racer have done a cold air box on a race car, and I'm sure had some minute gains, the thing about cold air boxes is that you can't test them easily, a engine or chassis dyno can't test their effectiveness, so a elaborate on board system is all you have to work with, and even in racing very few have went this route, Huffaker being one of the few. Here's the bottom line, if you do a cold air box right, it's a cumbersome set up and makes working on the car even harder than it is stock, so for me, I want a gain in air delivery and I want it simple, so I don't mind working on it, and it doesn't get any simplier than what I did with the cone K&N air filter, I do the same thing with my race car, and I have a prottype cold air box I had custom made form hi impact plastic, new hangin on the shelf for a 1275, I doubt anyone would ever buy it form me, because it cost a pretty penny to make to begin with.

 

[Hap Waldrop]

I will add this, Tony mentioning of ducting air thru the radiator support thru to the carbs is a good idea, and a much more practical way to get good air flow to the carbs than a cumbersome cold air box. Just cutting out the triangled shape hole on the carb side of the radiator support would be a good start in getting more cool fresh air to the carbs, and it's a simple and cheap mod, if you want to take it further then make a divider for the radiator shelf that extends all the way to the grille.