pvc intake

i decided to do a pvc intake onlt exept runing the filter out side of the frame i routed it back where the original was and used one inch pvc and some one and a quarter rubber drain conneters to mate it to the carbs it seems to work good with out the filter on there is no back fireing of hesitation what so ever befor i did this mod it ran worse with the original air box pics to come

 

heres a link to how the bikes looks now i didnt think to get pis of it before but we all know what the look like stock
http://s1044.photobucket.com/albums/b446/jer8716/

 

Dont know if it will make any better power. Certainly do like the bobbed rear end though

 

i dont eather ans really the fender isnt bobed its just the orginal wedged in where the struts are monted all i know for sure is it has better throtal response and pick picks up one heck of a lot faster i just wish i could ride it but i have to get the set finished and get my tail lights and turn signals

 

Must make the stress and apprehension of removing the carbies go away for sure.

 

thats no kidding its still a pain because the lenth is still the same but its a little easier to get to and makes more room and i was actully able to use the orginal battery tray and the ignitor and rectifier bracket

 

if any one could help me out i am doing this build as a momorial to my girl freinds brother who was tragicly killed because of a car fire this was his bike if any one could help me out and tell me where to get some cheap turn signals ans brake light its all i need besides a seat and ill be done and ready to do my momrial ride that i am going to start putting together so if any of you are near western kansas please help me out with my project

 

With the news that you have fabricated a PVC Intake Manifold System that performs well, ... I think you should take a Close Up picture of it and put it in the Gallery.

 

i will do that tomorrow as far as i can tell it wont get wet and it dosnt seem to bother the carbs i will be able to tell more when i am able to get it out on the road

 

ebay is your best bet..., and I'm sorry to hear about your loss.

 

heres the link to the pics of the intake
http://i1044.photobucket.com/albums/b44 ... ing054.jpg

 

Heres mine

 

i didnt copy it really i didnt i saw some that poeple have done on here and i thought insead of running out side the frame i would route it back where the orginal was by the way what size ovc did you use i used one inch and sone drain conectors

 

How are the PVC Intakes performing?

Do you have to regulate the size of the Main Opening?

 

as far as i can tell on mine it seems to be fine i haven't has a chance to take it out on the road but at an idel in my drive way it dose fine and when i open the throtle it respondes emidiatly and comes to life like i have never heard out of the old girl i dont have any other engine mods and i don't even have a air filter on it yet nope its not regulated at all its made out of one inch pvc witch i think is small then the orginal and with the close to ogrinal leanth i think works out grate

 

it could also be the fact that its only got five thousand miles its barley broke in

 

Have you checked you plugs?
extreme lean condition gives great accl
but will quikly burn a motor.

 

just checked the plugs and evey thing is good

 

please can you explain what you need to make the pvc manifiold i have pods and im having trouble getting to run right. From the posts i see you can get it running pretty much normal. just need list of what you need to make it.

thanks

 

sure i used once inch pvc i used two 90 degree elboes one t and one four way then i glued and painted and i used one and a quarter rubber drain conneters to mate it to the carbs

(i do not garnetee this to work for you your results my vary)

 

Are you sure it was 1 inch, I used 1 1/4 pvc.

 

yep positive

 

Can't seem to find 1 inch might have to used 1 1/4 in instead do you think there would be any downside to using the bigger ...

 

I used 1 1/4 and mine runs out fine I connected them to the carb with inch and a half rubber pvc couplers.

 

What would be nice is to have a Blueprint with the materials, parts and spacing measurements.

 

Yeah please do, i plan on doing this myself, but im thinking of an air filter on each end though.

 

Good work, i like the idea and i would want to plumb the gearbox scavenging line into the intake.

Also it would help in regulating a good restriction for the intake by using one filter as just after the filter would be the place to add the restriction and tapping in the oil line from the case so all carb intakes can evenly pull on the scavenging line.

I saw a post with a member running pods with a scavenger line rail that hooked up behind the pods, but the original airbox had the line coming in before the air went through the filter.
I don't want to end up sucking too many fumes or oil into the intake..

Any thoughts?
Good post by Robert on crank breather
Another 1 in 4 intake

Another airbox mod

Restriction issues

Pod vent mod, it answers a few of my questions

Just finding a balance is the trick..

 

My airbox (1982 xj750 seca) has the breather after the filter in the front of the box. So anything from the crankcase doesn't get filtered by the air filter from the factory. I think part of the discussion in one of the threads you quote points to the issue of filtering the oil and gas fumes...they'd probably clog a filter right up.

 

Here are my comments after looking at the LINKS and Prototypes.

It is not necessary to Plumb the Crankcase Breather to 4 Pods.
The healthier your Engine is; the LESS Crankcase gases and Blowby Gases are produced.

Recirculating the Crankcase fumes is a GREEN Thing.
For those who are going to Plumb the Line anyway... a smaller diameter "Clear Vinyl" Hose would suffice.

The Photo of the Prototype Manifold with the Filter at the side of the Number-1 Carb looks like a move in a positive direction.

I think, ... instead of the MANIFOLD being the same Diameter as the Connections to the Carb Intake Horns can be improved upon.

Force the Volume of AIR being Drawn-in by the Manifold to INCREASE in VELOCITY.

Instead of:
In:-->)0(O)OO(O)OO(O)OO(O)||
(try)
In:-->)o(O)oo(O)oo(O)oo(O)|| <-- Smaller Diameter Connecting Sections.

A Manifold with Smaller Connecting sections and the Pod Centered:
Left: ((O)oo(O)oⓉo(O)oo(O))

 

Thanks ManBot, i should have looked first, i stand corrected.

Good post as always Rick, thanks.

 

I'm going with 2 pods in the middle for increased and more consistant air flow. Right now I have good color on my plugs but still have some stumbling around 6000 rpm's. I may try slightly larger jets on the middle 2 carbs since they are probably sucking a little more air. I'm still working on some titling issues with this bike so I haven't taken it to far from home.

 

FJBell:

Here's a factor YOU have to consider with the Bike running Mikuni Carbs.

Your Main AIR Jets are covered by the Manifold.
The Mikuni Main AIR Jet is located on the Right Hand Side of the Carb's Intake Horn.

With the "Common Intake" it is (Possible) that the Manifold Pressure DROPS at the Main AIR Jetted Opening reducing pressure ... and causing a slight VACUUM at the AIR Jet rather than let AIR get down the Passage to surround the Emulsion Tube and BLEED Through the Emulsion Tube sending Atomized FUEL up into the Intake Stream.

Right when you need the whole Main FUEL Jets Supply.

 

I'm thinking some wind tunnel testing needs to be done :roll:

Off to check the pod setup on my Mikuni's now...

I've spent more time looking at my bike than i will ever get to ride on it..

 

wow i had no idea that my little post would go so far i just thought i would let people know what i did i had no idea that every one would take it and run with it but dont stop on my accout keep going with it if you can think of any thing else that would help out dont be afraid to mention it

 

great reading guys.... thanks for all of the info.