[catastrophe]

Ok, I'm going to rejet my carb and remove the restrictor in my tailpipe.....What should I use on my intake? Oh and adding maybe, the turbulator.

Bike spec's: stock 09' deluxe AVL & removed PAV

[Blue Ridge Wheeltor]

The velocity stack and the K&N filter about the same

ACE is the place, my man.

[Ice]

 My recommendation would depend on your intentions.
 Racing applications where engine wear is of no concern then the velocity stack would be my first choice.
 Racing applications where engine wear is only of some minor concern then the K&N should suffice.
 Street Performance or trail riding applications where engine longevity is just as important as performance then I can recommend the A.C.E. filter apparatus without hesitation.

[UncleErnie]

Right.  What do you want your bike to do?
For good performance in one focused area like top end, a velocity stack is the way to go.  Forced air, but no restriciton to junk getting in your engine.  In fact, it sucks more in.
For over-all performance in all gears, I personally belive a carburetor prefers to suck from a body of still air.  What I did;  there are essentially 2 airboxes;  the first is the triangle box that holds the filter.  The second is the square box between that and the carb.  I took off the whole filter box and put a pod filter over the protrusion of the square box.  It looks to me as if the Ace apparatus is kind of doing the same thing- only way cooler.

Sorry I can't remember what jet sizes I have... Anyway, removing the air conditioning, using a more straight through muffler, and the pod has not added top end- it did make top end more easily attainable, though.  I can hold 60-65 easier when going up a hill, for  instance.

The store doesn't say it, but unless you use the turbulator in conjunction with a high-qualiy Bourse collet- it's useless.  You'd be better off attaching a simple spray bottle to the intake and giving the handle the occasional squeeze when you want more power. 

[catastrophe]

um... what is a "high-qualiy Bourse collet- ".?

[UncleErnie]

    Most mechanics keep a box of Bourse collets on the shelf next to their muffler bearings.  In other words, the "turbulator" is a joke.  If you're old enough, you might remember them being sold on TV in the mid / late 70's when gas was being rationed.  Every news show of the time showed how they did absolutely nothing.
Save your money.

[ace.cafe]

As mentioned by others earlier, a velocity stack is basically a tuned device which has a length that works in sympathy with the engine harmonics to improve breathing in a certain rpm range. It has no filtration, and things will get in there.

The K&N is a high performance filter system, and it flows well, and has some filtration, and has been around many years, and is well proven.
It does not provide as much filtration as some other filters can, and  this has become a cause of concern for some people who want better protection.
In addition, the "pod type" K&N filters which clamp onto the carb mouth do not provide sufficient internal air volume for the inlet tract, and some people have noted some ill effects from this when using the K&N pod filters.

The Ace Air Canister is an alternative which was designed to give sufficient airbox volume, and better filtering, at the same time, thereby alleviating the known drawbacks in the options that were previously available.
You can now have your performance, and your good filtering too.
In a package that many seem to feel is an attractively-styled vintage look that is easy to install.
It has been tested with carbs up to 34mm, and flows well enough to provide better performance with them, which means it's well in excess of whatever flow volume a 28mm stock Mikarb can demand.
And it flows that well, even with the rain shield in place.
Filter replacements are cheap($5) at most auto parts stores.
The Ace Air Canister is more expensive than either of the other two systems, because you get an airbox and hose and bracket with it, and I personally think it looks alot better than the stock "wrinkled/bent" sheet metal airbox that's an eyesore in my opinion.

The Ace Air canister was designed originally to work on the 500 Classics, but it can be used on an AVL Classic which has the rectangular airbox on it, and can even be used on an Electra X, but you have to remove the right side cover/airbox from the Electra to make room for it. So, there's a bodywork change when using it on an Electra X.

So, there's your options.

[PaulF]

Ok, I'm going to rejet my carb and remove the restrictor in my tailpipe.....What should I use on my intake? Oh and adding maybe, the turbulator.

Bike spec's: stock 09' deluxe AVL & removed PAV

Ace is right. I ran velocity cones, (not really "stacks") on a Guzzi for a short time and for road use. Removed the float bowls to find what could only be described as a layer of "mud" in the bottom. Horrible dreams of hard particles scoring the crap out of my cylinders and ruined jets haunted me.

A guy I knew who built race Hondas told me to try DRY K&N's instead. Not much improvement. Still a lot of grime ended up in the bottoms of the float bowls.

Go with an oiled K&N or Ace's model. Play it safe and gain the breathing your looking for.

[catastrophe]

thanks for the info.... now on to bed....

[Ice]

The only purpose I can see that the tuborlator thigy could serve would be as an intake restricter to boost low end intake velocity and hence torque at lower speeds (at the expense of top end power).

 Trust me when I say there is a far far better way to do that. 

[1Blackwolf1]

  Put the turbulator in the same category I put the magnet you attach to the outside of your fuel line to improve gas mileage.  Never saw either do much.  Had a early design (late 70's) pre-installed on a car I bought.  Prior owner told me it increased his mileage/power.  A buddy of mines parents had the exact same car, and got better mpgs, so I reluctantly pulled the device, no seat of the pants torque change either way.  And mileage went back up to a respectable 18 mpg from about 12 mpg.  This was on a '68 Dodge Polara tuna boat, 383 cid engine.  Guess I'd spend my money performance dollars a different way.  Will.

[clamp]

Please explain why running with no filters get dirt on the fuel bowl?

    Ace is spot on with what a velocity stack is.

     What,---- air flows into the fuel bowls?

[ERC]

If the carburettor has an emulsion tube with a throttle plate I would think it possible to draw air into the bowl under certain conditions,like when you back off the throttle.   ERC

[PaulF]

Please explain why running with no filters get dirt on the fuel bowl?

    Ace is spot on with what a velocity stack is.

     What,---- air flows into the fuel bowls?

From the book "Guzziology", chapter 7 "In spite of having a screen on the petcock and another on the carb's fuel inlet banjo, some fairly chunky stuff often accumulates inside the accelerator pumps on these carbs. Maybe the particles actually from inside the carb - I don't know."

I had large amounts of grime in the floats and I don't know either - or care. I oiled the K&Ns and sold the bike on a day when the electrics were actually working. It broke down on the guy I sold it to - then he sold it.

Thus ended my foray into Italian machinery.

[ERC]

I'd say by the looks of it the Ace filter would be the best. Far better than the other choices and looks good also. The first choices don't support the carb.  ERC

[Adrian]

This is quite a timely topic for me as I will be using this set-up on my lean-burn engined project bike, though some fat-burn jetting will be in order.



(Picture from Dell'ortoUK web site.)

PaulF, did your Guzzi have the same carbs? I'm hoping the UK's damper/less dusty riding conditions will mean I won't have to have the float bowl off for cleaning too often with this stack on. 

Adrian

[ace.cafe]

Hi Adrian,

Nice looking carby and stack!

I'd recommend trying something.
These engines like about 6" of stack length for torque.
If you can get an appropriately sized piece of radiator hose, to put in between the stack and the carb, as a stack extension, you can try some different lengths to see how your engine responds to these different lengths.
It's the length that makes the difference in these things, and it might prove beneficial to try to find a length that gives best results. If you don't like using hose, any method of cleanly extending the stack while keeping the bell-mouth on the far end would be fine, but it needs some cut-and-try length modifications to see what works best.

It's highly unlikely that a factory-length stack of pre-determined length could be right for all engine applications. So, some way to play with an extension of it, to find the best working length for your engine, might pay benefits.

[UncleErnie]

How might he know if he needs a shorter stack?    Just try it without one altogether?

[ace.cafe]

How might he know if he needs a shorter stack?    Just try it without one altogether?

Sure, he could try without any.
But there's virtually zero chance of any improvment with that, because of the length of the inlet tract involved, vs the rpms of the port harmonics we're dealing with at rpms we can access.
Generally, in the rpms that we can access longer is always better.

For example, on my Iron Bullet, I needed a valve-to-bellmouth length of 16.25",which required a curved inlet pipe inside my pressurized airbox. Because there wasn't enough room available for a straight one.
And that was only good for down to a 5200 rpm tuning knee.
Lower rpms would be longer.

On the Iron Bullet with a Mikarb, the inlet tract from valve to carb mouth is somewhere around 9", and I can't remember exactly off the top of my head.
This required a rubber hose connector and about 7.25" of curved tubing with a bellmouth end to be put inside my airbox, in order to get my stack tuning down to 5200 rpm
For a higher rpm, such as 6000 rpm, I think a 6" pipe was called for. And the Electra revs higher than the Iron Bullet by a few hundred rpms, so it might be close, and I don't know the exact inlet tract length for an Electra. It might need to be even longer, but it needs measuring from the back of the intake valve out to the bellmouth to calculate it.

Much shorter than that,and the tuning of the length is so high in the rpm range that we will never see it, and therefore we get no significant effects from the stack.
Those shorter stacks such as shown in the photo are designed for much higher rpms than we see.

[UncleErnie]

So a store-bought stack is basically useless at -say- 3K RPM?
Have you ever tried a wound stack like a French horn or trumpet for optimum length for RPM's under 5K?

[ace.cafe]

So a store-bought stack is basically useless at -say- 3K RPM?
Have you ever tried a wound stack like a French horn or trumpet for optimum length for RPM's under 5K?

Yes, basically useless for those lower rpms.
I'm sure that it flows into the carb well, so it would be a low-restriction entry point.
But, as far as tuning the intake with it, it would need to be alot longer for doing that on the Bullet rpm range.

I haven't tried a wound one like a french horn, but I'm sure it could work if it was designed correctly.
I know that a slightly curved one works, because I use a curved one now.
Straight is the best, but we can't always get optimal, so if we have to compromise a bit, we can do that and try to make the least objectionable compromises
The less curve, the better.
Large radius curve is better than tight radius curves
Wound-up like a coil is not a very good compromise, but might still work.
Not as good as straight.

If you look at 72westie's race bike, you'll see he has the carb way out toward the rear, with the throttle cable going over the tank.
This is another way of lengthening the inlet tract, and you'll notice that his is quite extended too.
He just does his extending between the carb and the head, and that's fine too, except for most people's street bikes, the carb is hanging out too far like that.
And since his is a racer, it's tuned for a pretty high rpm range, and is about as short as would work, even at high rpms for us.
The important thing for tuning the inlet is that it has the right length to affect your desired rpm range, and for our purposes, that's pretty long.
There's more than one way to skin a cat, and perhaps a coiled one might work out ok.
I never tried one like that, so i can't really say how well it will work.

[Ice]

Please explain why running with no filters get dirt on the fuel bowl?

    Ace is spot on with what a velocity stack is.

     What,---- air flows into the fuel bowls?

The float bowl is vented to the atmosphere.
The Emulsion tube gets it air from an opening before the slide or butterfly.
 
Pressure and pressure differentials in your carby are not fixed. They are dynamic and ever changing.

 A bit of dirt flowing in with either fuel or air during a low pressure cycle will fall out of the air or fuel stream when the respective stream slows even if only for a bit.

[catastrophe]

Man you guys can talk... anyways the Ace Air defiantly seems the way to go. Look for my next questions on hp vs top speed... Thanks again.