hey guys...

i have web 44's with 3" stacks and 3/5" air cleaners. to fit the rainshields on the carbs i had to use .75" aluminum spacers on the threaded rod instead of spacing it..id like to run taller air filters. do they make a 4" or a 4.5"? i made longer studs.....so height isnt an issue. is ther any magic to velocity stack height vs aircleaner height?

please advise

I have seen IDF type filters in all heights up to like 8". K&N has several sizes.

I think you basically want as much room as possible between the top of the stack and the filter plate but it probably doesn't matter that much after a certain distance.

I'll measure mine for you, I put new K@N's on last summer, which are as tall as I could fit and still get them on and off reasonably well. I noticed an immediate improvement in idle and low speed tractibility (likely because the old filters were really clogged and one was melted from a fuel fire-which the PO didn't know anything about..) I think I got them from summit, but I'll go look... I dont think that the filter will be a factor in the velocity stacks performance, afterall you set the carbs up with filters off, and so long as the filters arent way to small or really dirty and clogged they shouldnt be much of a factor...which is why I also dont really believe the KnN performance gain claims...

what do you all think?

A K&N may help a bit if your comparing it to a stock paper type filter, doubt it is any better than other filters in an application like ours though.

At Sebring a while ago I talked to Alwin Spring from Porsche Motorsports and he said that any filter at all, even a coarse screen, hurt peak horspower compared to an open intake.

It always blows my mind when I see race cars with open stacks. Some of these engines cost over $100,000 and they don't seem to give a damn about sucking in dirt and grit. I guess they have deep pockets and lots of parts in the trailer.

bump.... im looking for about an inch taller 4.5 to 5"

Clearance at the top of the velocity stack is not critical, unless the plate at the top of the filter is acting like a lid on a pot. All the velocity stack does is smooth the flow of air into the venturi.......and what is more critical is the radius of the roll at the top of the velocity stack as opposed to it's length.

Save your money for something worthwhile.....like education!

And yes, we ran with open carbs....the engine was torn down after each race anyway.