Author Topic: Engine Guru Question  (Read 3067 times)

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PhilJ

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on: August 02, 2008, 02:38:25 pm
Has anyone taken the PAV off of the AVL engine that injects directly into the head?

If so does this cause the exhaust valve to run hotter?

What did you plug the hole in the head with?

And If there is a question I should have asked and didn't, just jump right in and tell me what I didn't know to ask. And then answer you own question for me.  :D


GreenMachine

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Reply #1 on: August 02, 2008, 02:53:16 pm
Good question..Not sure on the exhaust valve..I thought this whole PAV thing was strictly an emission standard upgrade...One would think this was done a few years ago and wasn't in the orginal design..I have a 06 iron and I plugged up the metal stem (tube) with one of those rubber caps that can purchase at most auto stores...Some people I have heard stop it up with whatever but I didn't think that would be prudent if I ever wanted to reinstall the original system..
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PhilJ

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Reply #2 on: August 02, 2008, 03:49:33 pm
True on the iron barrel. I'm not sure if the AVL uses the same valve components. And on the newer, at least newer AVLs the PAV injects directly into the head with a puff of cooler air, hence the wondering about elevated exhaust temps. 


Thumper

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Reply #3 on: August 02, 2008, 03:54:29 pm
Has anyone taken the PAV off of the AVL engine that injects directly into the head?

Yes. I documented it at:
http://members.verizon.net/allofusmorrows/PerfUpgrade.htm

If so does this cause the exhaust valve to run hotter?
In isolation, I don't know. However, as part of an overall performance upgrade, the engine now runs much cooler - due in large part to a richer air/fuel mixture.

What did you plug the hole in the head with?
The acorn nut came as part of the performance kit, although it is available by itself (item 91008    EX. PIPE BLANKING NUT, POLISHED STAINLESS )

Matt



REpozer

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Reply #4 on: August 02, 2008, 06:27:21 pm
2008 ( AVL) Classic Bullet in British Racing Green
REA member # 84  (inactive)


Gromit42

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Reply #5 on: August 03, 2008, 02:58:36 am
Ok...I know this is probably a dumb question but I'm going to ask it. What is the PAV and what is it's use on the Electra?
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PhilJ

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Reply #6 on: August 03, 2008, 03:08:13 pm
Other than cosmetics, I've heard it gets rid of the pfft pfft in the exhaust note. Key word "heard'.


PhilJ

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Reply #7 on: August 03, 2008, 03:09:23 pm
Oh! And thanks guys for the replies. I now can find what I need.

Phil


GreenMachine

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Reply #8 on: August 03, 2008, 03:28:06 pm
Advantage: Purist would argue that its not necessary, dam ugly and if you swap out the current exhaust you can gain 2-3 h.p and more authenthic sounding machine of that era.  Strictly a matter of preference nothing wrong with keeping it  stealthy either.

Disadvantage: Probably have to rejet carb/change needle position, cost of replacement exhaust and time spent checking spark plug color and effects of carb rejetting...also readjustment of air/fuel ratio.

The above is factors concerning iron...Believe Thunper AVL procedures are taking into acount his AMAL carb that he installed but the premise is the same. I've kept my 28 mm Micarb and all of the above took me approx 4 hours as it's been a long time since I done it....Throw in a Snidal book for a good explanation of both the Iron/AVL transformation..

Apparently the PAV location for the AVL on top of the exhaust valve vice where mine was at the top of the exhaust pipe...I see that CMW does sell different exhaust for the AVL .  AM I to assume that the AVL PAV can stay in place and you don't have to remove it..Just replace the OEM exhaust????
A blanking plug is mentioned but that can be used also for the Iron users who want to keep their existing OEM pipe and just remove their PAV connection..Some of these users have done so and remove some of their baffling inside the bazooka style OEM exhaust...Guess its a cheaper way to go for effects but I've found that the internal design of that exhaust isn't just take a long drill bit and run it thru as both ends have turns in them before entering the baffle chamber...

Bottom line: If the OEM enhaust fits your expectation, stay with it..If u want to experiment without any serious effect on the bike, go at it...Their is a noticeable difference in H.P.....cheers.
Oh Magoo you done it again


GreenMachine

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Reply #9 on: August 03, 2008, 03:36:45 pm
PhilJ:  Pfft Pftt definetly gone with a change of exhaust...Unfortuantely I didn't just remove the pav on the OEM and give it a try...Did the PAV removal and exhaust change at the same time...Hell if you gonna keep Mr. Bazooka, why even play with the PAV except as u stated cosmetic blanking plug thingie...Interesting difference on the AVL and Iron location re. PAV locations...Trying to cool and pollution control vice just pollution control on Iron...Don't ya just love it..
Oh Magoo you done it again


icarus

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Reply #10 on: October 01, 2010, 11:57:59 pm
Never mind... I posted a new thread about removing the PAV of my iron head in the Classic models section because (although it's an iron head) my PAV is also connects directly to the head. 
« Last Edit: October 02, 2010, 12:16:40 am by icarus »
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