Porting..Theory...Tools..Techniques - Yamaha YFZ450 Forum : YFZ450, YFZ450R, YFZ450X Forums
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post #1 of 250 (permalink) Old 05-21-2012, 09:21 PM Thread Starter
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Lightbulb Porting..Theory...Tools..Techniques

this will be a project of several days...maybe weeks... so if you guys would so good as to not get on any huge derails or debates until i can get it done, that would be appreciated...

i have wanted to chronicle all for the interested do it yourselfer on the 3 different yfz head styles... but WOW is picture compiling and cataloging...plus darn slow/ dead stop being my 2 typing speeds making this a BIG undertaking for me....

at least i will be able to say i have all the pics now, and have at least begun the writing...

Porting ... Theory....Tools....Technique
this is a HUGE topic...and it's going to be hard to explain everthing i detail on the first go around... especially since i am a 2- finger typer...
i have to assume that the majority of you do not do engine develpoment for a living...and i also know that there are many quite versed in engine dynamics, but have yet to add porting to your engine building/tuning skills...... so i will explain a lot of stuff that some of you already know, to put a little background theory in for those just starting their engine addiction...

i want to be able to do a beginning draft and then come back in and fill in all the blanks and tangents that would be too time consuming to finish on the first go around... or even the third go around....

first i have to say that in engine dynamics...everything has an effect on everything...

so i guess i just have to start somewhere and talk my way in widening and meandering circles....

OK ... you need to think of an engine as a complete unit, rather than a collection of parts... if all the parts are trying to do the same thing, then it's like all the members of a tug of war pulling simultaneously...if not, all parts may be stallar, but not working together at the right time in the powerband...

simplified, our engines are an air pump... except that between the getting in and the pushing out... we have a bit of gas mixed with our air so we can burn it an make a powerstroke in between...

the collection of the parts... intake.. carb ... cams ...exhausts ..etc.. all are trying to add their part of efficiency to an engine.... and no matter what part you put on or in, they all need to make use of the engines flowparts/ ports /porting in the cylinder head... those flowpaths are sort of a hinge piece in the puzzle, since they infulence the connection and efficiency of all the other parts....

beyond the mechanical, there is another dynamic force that affects engine performance:

Pressure waves... intake tract resonance / waves that can be timed to have an extra , above atmospheric, pressure right behind the intake valves as they open over a desired rpm band...the waves can be positive OR negative.. good or bad... sometimes they are tuned to advantage...sometimes the engineers come up with clever ways to dampen or negate them altogether ... less of the good to also make for less of the bad...

there are also waves the work in the exhaust system.... propery managed they add efficiency to exhaust evacuation... and can also be used to work past the open exhaust valves and pull fresh intake charge into the cylinder before the piston can even start making vacuum....

timing those waves to work together during the short time when the cam has both the intake and exhaust valves open during overlap (piston near top during exhaust stroke + intake valves slighty open before intake downstroke begins) you can have resonances in the intake pressurising the intake charge above atmospheric AND the exhaust pulses creating sub atmospheric pressure in the combustion chamber.... that's where the engine sort of thinks it's supercharged... because it is... only by pulses rather than a mechanical supercharger....

still, all of it works through the ports in the cylinder head....
i really hope to go back and fill in and expand on all this...it's a lot of ground to cover if you dont already have a good technical base in engine dynamics...

from my experience and viewpoint, i also consider valve and valve seat geometry part of the "porting"... they are right smack in the middle of the flowpath..and their shapes influence airflow quite a bit when the valves are in the low to mid portions ot their lift... which happes twice per intake valve event... during opening and during closing....

on the same line of low to mid lift flow... the combustion chamber itself is part of the flowpath... when the valves are open at lower lifts, combustion chamber walls can also either block flow or promote flow , depending on the geometry / proximity to the valve

lets cover "valve unshrouding" first... for no other reason than i typically start there first.. . at lower valve lifts the flow is referred to as "curtain dominant flow" what that means is that the valves are lifted below a point where the overall limit to flow is at a point in the port itself... the amount of available flow area is still limited by what can get past the valve seat, the valve, and the crowded / shrouded parts of the combustion chamber...
once the valve is open a certain amount, the port itself will become the "limiter of flow"... cams and ports cam be changed to bias an engine to make use of one type of flow more than the other... big topic to cover later for sure...

back to unshrouding.... combustion chamber walls that are close to the perifery of the valve are a limiter of low to mid lift flow.... the very best combustion chambers as far as the design not shrouding any low lift flow potential, is found in the yamaha 5-valve heads... more valves means more area available for low lift flow, when compared to just one bigger valve... one of several reason multi valved heads were developed in the first place... and yamaha wasn't about to let any of that low lift flow potential be wasted by shrouding those valves.... we can clean up around the yamaha valves, and smooth out the combustion chamber, just because we want to, but not becasue the yamaha engineers left meat on the table...

first a bit on the tools... what they are and where to get them... then the unshrouding / combustion chamber pics... then i will have to call it a night

Good Place to Get :

CC Specialty.... family owned and i have been a customer of these fine folks since 1974... sure there are lots of places to get stuff from, but these are very good people to deal with for all things porting... even info !



good lord, i wish they would change the cartoon drawings they have though... still the same catalog cover as the one i had in 1974

Tool Types next.... i use hand held die grinders and a variety if cable driven tools ... mostly all of that helps me with work flow since i dont have to change tools in a handpiece all the time... i just swap to a pre-loaded handpiece... if i had to pick one tool setup though, i could get it all done with the stronger / square shaft drive cable tool, and just swap,tool pieces in the handpiece...



then the carbide cutters for fast material removal... these are my 2 most used styles of carbides.... "egg shaped" and "rounded tree shape"




then Stones , for cutting down valve guides...and Cartridge Rolls (aka tootsie rolls) which are for smooting, blending, polishing... depending on the grit you choose.... i would from 60 grit coarse for quick blending /shaping , to 180 grit with jewelers rouge for polishing...and 100grit and 120 grit for in-between those levels








and another essential tool for porting is the shop stereo system... lol... if you dont play at least one Alice In Chains tune during the job, i'm sorry, it just isn't porting...


Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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Last edited by mixxer; 05-21-2012 at 09:26 PM.
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post #2 of 250 (permalink) Old 05-21-2012, 09:22 PM Thread Starter
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now... like i said, the yamaha head come unshrouded right from the engineer's specs... but for illustration and fun... we will go ahead and work it a bit...

from the factory:




bit of blending with the small egg carbide... this is where a lot of non yamaha engines need improvement in the unshrouding dept... you get the idea that if the combustion chamber wall was close to the valve, it would block some potential flow at lower lifts...




a bit farther along... 120grit sandpaper rolls to blend after the carbide...





and done.... 180 grit sanding roll.. some yellow jeweler's rouge... and a bit of oil....





sooooooo much more to cover... lots of theory and comparisons of the the 3 yfz heads... cant write it all with 2-fingers at one sitting... there aren't big differences in the combustion chamber portions of the 3 yamaha head styles...so this is generic and applicable to all 3... even though it isn't really needed...lol

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$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
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Last edited by mixxer; 05-21-2012 at 09:41 PM.
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post #3 of 250 (permalink) Old 05-21-2012, 09:23 PM Thread Starter
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i'm going to start day 2 with a post of a head that CAN make use of some unshrouding... a honda trx head... this will show you a better pic to illustrate how a valve can have low /mid lift flow blocked by tight chamber walls




and then with less shrouding to give some breathing room





ok...now back to yamaha....

next up is the exhaust port....

port volume affects the port's velocity... naturally.... same gas volumes moving through tighter spaces would need to go at a higher velocity....

in ports, what you are looking for is to have an "efficient port" not necessarily just a "big port".... if volume itself were the only trick needed for efficient flow, then bigger and bigger would always be better and better.... but it definately isn't.... if you look into the hot rod muscle car era of the 60's and early 70's.... and then check out engines now... the engines they make now make more power over a wider band, as well as just plain more overall power... in the 60's the "bigger is better" rule was the word of the day for port sizes...now, the more powerful engines are making all that extra power with smaller ports.... big ports are lazy and slow flowing, and slow responding... efficient ports use the energy you get from velocity to make good things happen...

later, we will look at how both yamaha and honda made more power over a wider range when both of their 06 models ...and both of them made more power and throttle response everywhere by using higher velocity / reduced volume ports compared to the 04-05 models

the key is that VELOCITY is a huge factor in EFFICIENCY.... and an efficient port just plain flows more by making other things work ....

now...

in porting, the biggest influence is the shape of the infamous SHORT SIDE RADIUS.... hereafter referred to as SSR since i am typing with 2 fingers...and now i know i need to include a port diagram drawing with labels of what everything is at some point....if someone can find some good existing drawings to add, that would be great...and save me some work...

so SSR... the area directuly behind the closed valve is known as the BOWL or THROAT where the bowl takes a turn towards the port RUNNER, the tight bottom turn is the Short Side Radius... the more relaxed turn at the roof is the Long side Radius....

the big airflow enhancing trick is to get airflow , moving at high speed, to stick to that SSR and make that turn to feed the back side of the valve.... high speed air ...like anything with mass at a high speed...doesn't like to make sharp turns... if the airflow separates from the SSR a couple of bad things happen... no flow to the back of the valve AND the port sort of chokes itself to a smaller volume with that overshot airflow making a restriction of its own....

so to get airflow to make a good SSR turn, you need to have a wider port floor (wider parts of a river slow the flow rate) and you need to make a smooth / gentle radius that the airflow can track...early on, ports with a wider SSR floor were called "D" ports because the wider floor looks more like a capital D laying on its back...and the making of the gentler SSR radius is called "laying it back", because yo take some liberty with moving the radius back a bit right where the turn is made....

NOTE: you can't.. or make that shouldn't have a radius that goes all the way to the valve seat... once the flow makes the turn it needs a good 1cm of straight bowl wall to let it adhere and straighten out before it needs to circumvent the valve....

looking down the yfz exhaust port:





and looking in from the exit:



tough to get port floor / SSR pics to turn out good .... hard to show 3D in a 2D medium




so... grinding stones on the valve guides.... then carbides (i like the egg shaped here) to rough cut everything.... then progressively from 60 grit ... 100 grit ... 120 grit... 180 grit with yellow jewelers rouge and oil to polish










and dang it! i couldn't find a pic of the smooth / laid back SSR on the exhaust port... so i will have to replace this pic later with one or two different ones... but these are done intake sides for now




more coming tomorrow... the more i do ,the more i know i have so much more to go back and go over too.... once the posts are built, i will modify until its what i envisioned it to be from the beginning....no judging yet

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
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Last edited by mixxer; 05-23-2012 at 06:16 AM.
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post #4 of 250 (permalink) Old 05-21-2012, 09:23 PM Thread Starter
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remnant from last posting on exhaust port.... decent pic of wide / smooth port floor;







ok... here we go with the 800 pound gorilla of port flow power makers.... the Intake Port...

and what i write tonight will, by no means, be the end of the info and discussion... just the beginning...

the combustion chamber and exhaust ports can be polished (and no, they don't have to be) in order to reduce surface area and heat sinking that comes with it.... in theory it slows heat absorption by the head and keeps it where it will work for us...in the combustion chamber and exhaust...

and it makes clean up a bit easier the next time around....but the polishing is really just part of the smooting and blending, only taken a bit further....and it all gets covered up by carbon after only a short run time anyways.... so maybe the reduced surface area helps a tiny bit in heat build up resistance...and maybe not....but it doesnt hurt either way when dealing with combustion chamber and exhaust ports...

now... on to the port that DEFINATELY shouldn't have a polished finish : the INTAKE PORT...

airflow behaves as fluid flow...same dynamics apply...and airflow moves faster...with less surface tension/friction...if there is a rough texture to the surface...i dont mean potholes and waviness in the port...that's bad for airflow... i mean the surface texturing should be rough where you don't want air to "stick" to it....

same reason golf balls aren't smooth...they fly farther with the dimples breaking the air tension on the surface...

same reason race boats and fish have a scaly texture to their sirface.... bird feathers too.....

so, i do all my port re-shaping with carbides...then rough sanding rolls...then go a bit more towards polish with finer rolls because that helps me see fine areas of imperfections that need a bit more blending work...and after its all the way it should be, i rough things back up with 60 grit sanding rolls or lightly texturing with a carbibe cutter....

intake port inlet should be same size as cab outlet... then neck down to the ALL IMPORTANT HIGH SPEED CHOKE AREA before the bend towards the bowl.... motoman has lots of stuff written on the topic...and this neck down region is the main reason that todays ports make more power than early muscle car era sewer pipe ports....it acts as sort of a "flywheel' to the intake charge...it provides speed and inertia to the intake flow...and that is what supercharges the cylinder while the cam still has valves open after the piston has reached the bottom of its stroke and would want to push the charge back into the intake port.... todays performance cams will hold the intake valves open some 60 to 70 degrees after the piston reaches the bottom and starts up on the compression stroke.... they can do this because flow SPEED and from a well designed intake port will have enough INERTIA in the intake charge to keep packing more charge into the cylinder even though the volume is decreasing with the piston on its way up the bore....

people will all have their own ideas on percentage of choke area vs valve seat area (both big topics) , but my own development and testing has shown that a choke area of 83~87% of the intake valve head diameter makes for the widest and best overall power... early torque peak combined with good peak power to the rev limiter....

i also broaden the top "shoulders" of the long side radius around the guide boss, but the port floor has to be the widest part to ensure slower flow speed at the floor to get the flow to make the tight bend of the SSR without separating..... laid back / smooth radius / and wider at the SSR floor is the way to get it to work....

on to some pics for illustration

stock pics first;









note that the top and bottom of the port runners is rounded on the stock / oem port


now to the modifications....



cut down guides with stones and then widen out the shoulders with long shank carbides:






next pic is of blending in the bigger carb size of a 42mm Sredrum taperbored carb into the throat of an 06 style intake port...
note that the pic shows that only the top of the port is raised and the bottom is the same... whn the carbs are bored, the floor of the carb is the same point and the bigger circle is from there up... sort of like setting a penny up on its edge, and then rolling a nickle right up behind it... bigger circle, same base point





tough to get angles that show everything good in the pics.... but you should be able to see that the individual runner / port is less oval in shape and becoming more rectangular








and finally the laid back SSR / port floor.... wider...smoother .... blended radius...




still much more to cover.... coming soon will be the differences in all 3 yfz heads... the bowl / valve sizing / seat work / high velocity porting with epoxy fill....and on it goes

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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Last edited by mixxer; 05-30-2012 at 10:40 PM.
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post #5 of 250 (permalink) Old 05-21-2012, 09:24 PM Thread Starter
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coming up ....comparison pics of the early carb model 04-05 intake port..... the higher velocity 06 and up carb model intake port.... and the Fuel Injected model intake port


first up, the one that needs the most work, the FI intake.... no bosses even casted to smooth flow over guides.... huge , wavy open port / low velocity / needs less cam duration to prevent backflow stock....and short/steep Short Side Radius (fine for a base with big bucket/ high lift cams)... not good for 450cc wide band power without some serious work



VERY rounded floor to the SSR too.... all not so good for power....







not a lot of height between valve seat and radius of the SSR either.... this makes the shape of the SSR even more critical to get flow to come around the back side of the valve











those were all the FI intake.... i will come back as soon as i can and fill in the other 2 models....




next up will be a few pics of the 06 and up carb models intakes....man do i ever take a lot os pics, and what a drag it is to try and find ones that show in 2D what you need to show in 3D.... my apologies... as i post i see that i have to do better at getting better pictures to replace what i have posted....


this is one where i have already started to cut down the valve guides... but notice the raised aluminum leading up to the guides... that is a guide boss, and i'ts job is to start to smoothly and efficiently get port wall flow around the valve stem.... the FI bikes dont have them, the guide just sticks out into the port.... also the port floor is raised and the port roof filled in and radiused to give a smooth flow path and raise intake charge velocity






good pic to show the filled and radiused roof




good height of port floor allows for nice downflow radius to feed the back of the intake valves












next to fill in will be pics of the early 04-05 port.... its somewhere in the middle of the 06 up carb and the FI models....open /not HVP port... but has refined features over the FI model

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #6 of 250 (permalink) Old 05-21-2012, 09:25 PM Thread Starter
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"Drag Port" really has no meaning at all in the 4-stroke world...


in 2-strokes, which i have ported since my very first dirt bike as a teenager, it is the equivalent of port flow and camshaft when you work the ports....all open and closed port timing as well as mass flow is done by the port layout....so, porting a 2 stroke controls the same thing as porting + valve sizing + camshaft in a 4-stroke... so Drag Port actually has meaning in the 2-stroke world


in the 4-stroke , the ports have to match EVERYTHING ELSE.... from camshaft to valve size to carb size.... you can't just do what you want, you have to know what to do to maximize efficiency of the other factors already present in the engine.... if your porting doesn't match the rest of the components and engine size.... if it works at all, it will work only over a very narrow range

i have to tell you that port dynamics are not dependant so much on what riding you intend to do...

a LOT of it is fixed based on what size carb and valves you run... the valve size itself sets all the ratios for bowl and choke point size in an engine....

you can lift valves with big bucket and high lift cams...adn then it would change what you did with the port to change its bias from flow around the valve , to flow over the open window, shooting across the valve....

what you do with porting is actually sort of fixed most by valve size, you need to keep velocities up to levels that promote swirl, charge the cylinder after BDC with inertia... and a big / low velocity setup has terrible atomization and terrible vacuum signal delivered to the carb... the port volume being too large end up acting like a capacitor... not good

next up... you are fixed on port volumes based on carb size... big carb feeding a small port is not ideal... nor is a small carb feeding a sewer pipe of a port....

camshaft being used and engine displacement is another set of factors that determine flow around or flow over valve...and engine size being fed has a big effect on velocity in the port... you can HVP with port volume... or you can HVP by upping the size being fed....

anyways.... bottom line is there are lots of factors that determine what you can do , given valve size being the biggest factor....

you can bias a bit one way or the other, but valve sizes are the factor that you need to work with to make the port as efficient as possible....

engine performance has gone up and up since the early performance years...and the ports have gotten smaller as all these efficiencies have gone up... efficiency , not just a big hole...

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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Last edited by mixxer; 06-19-2012 at 06:39 AM.
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post #7 of 250 (permalink) Old 05-21-2012, 09:39 PM Thread Starter
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dibs,,, lol

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #8 of 250 (permalink) Old 05-21-2012, 09:42 PM Thread Starter
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porting and camshaft / valvetrain are absolutley married topics.... so i thought i would throw this in for some thought provocation:

i used to have a big pinned article on cam testing that Sredrum and myself took his yfz and my dyno, plus a lot of time and effort test / compile /share...

those files are long gone....and the thread was deleted....


the topic of camshafts is a weekly event in the forums... and i get asked questions about them all the time....


also... when talking about cam selection, engine size plays a HUGE part in what works and where it works in the rpm band

a quick look into the automotive cam world will show you that duration numbers that are high rpm use only on a small block setup are good as a midrange torque cam on a bigger displacement big block.... bigger engines need more duration to operate at the same rpm bands compared to smaller engines....

now... moreso than ANY other manufacturer...the 5-valve yamaha engines are SUPER SENSITIVE to LOSING bottom end and midrange torque and HP from duration and lobe center changes....


know why??


more valves per cylinder is an engine advantage because you have lighter valves... lighter spring pressures.... AND, the BIGGIE, you have more open area available for flow at low to mid valve lifts compared to a 2 valve per cyl setup... the combined circumference of multiple small valves has more flow than less/ single valves.... 2 valve per cyl setups need to open the big single valve to relatively high lift to make use of open flow.... the multi valve can start good flow earlier at lower lifts .... and not need high lift to get more flow per valve event



NOW... since the multi valve can flow the most at low to mid lifts...and yamaha having 3 intakes to everyone elses 2 intakes... the yamaha has the most low to mid lift potential...

modern performance engines have cams that close the intake valves 50~70 degrees AFTER the piston has passed the bottom of the intake stroke and is well on its way up on the compresion stroke.... and modern engines also make use higher speed ports to keep feeding the cylinder with charge due to momentum after the piston reaches the bottom of that stroke and changes from vacuum to positive pressure....



REVERSION is what happens when there isn't enough speed / inertia in the intake port to keep things flowing into the cylinder during the 50~70 degrees the intake valves are still open while the piston is moving upward on its compression stroke..... flow stops moving forward into the cylinder and is pushed back into the intake port...charge is lost, and so is power....

reversion is worst at low speeds where there is less speed in the intake port...and more time available for flow to reverse before the intake valves close....

and that is EXACTLY why the 5 valve heads are so very sensitive to intake cam duration and lobe centers.... those 5 valves have a LOT of low to mid lift flow potential... BUT they also have the MOST possibility for REVERSION and loss of low to midrange power when reversion occurs... they can let a lot of flow into the cylinder at low lifts, but they can also let a lot of flow escape back out .... double edged sword....



now... back to camshafts.... anybody remember the crower cams?? and in particular the GEN 1 cams?? those were some of the worst cams ever in a yfz... they made less power everywhere compared to stockers..all loss and no gain... but in true "emperor's new clothes" fashion.... people were selling them and promoting them... nobody tested them...and everyone said they couldnt feel any power on top, but boy oh boy they helped in drag racing and holeshots because the bottom end got them out of the hole like mad.... then somebody actually dyno and track reported on them... less power everywhere on the dyno...idle to rev limit... and slower in real track conditions too....


another set of super turd.... yet highly touted mysterious cams were ones offered by duncan racing... X1 intake & X2 exhaust... mistakenly referred to as "X12's" by putting the numbers together.... the cams were expensive... and they lost so much power everywhere that the tests had to re-run and double checked... but once runs were finally published... you couldnt give those cams away either.....


now.... back to all the testing that Sredrum and myself had done...


many...and i mean MANY cams lost power everywhere compared to the stock cams....


and the cams that made more power than the stockers really lost more power below 8000rpm than they gained above it....



dyno results were even more dramatic when riding..... cams that made power on top were only good wide open and shifting above 8k... their early torque and on track or woods throttle response was lacking compared to the stock cams....and they were slower in all instances except wide open / top rpm shifting....


the most radical cam we tested was not quite +2hp on a 60hp machine...and the stockers still got to 58+HP... but made WAY more torque and WAY more power up to 8000rpm.... the small gain on top was made at the expense of making an overall weaker curve....


we had tested more yfz cams than anybody, and i have never seen one that didn't lose more on bottom and mid than it gained on top....


now... remember that bigger engines... big bore strokers will need more cam duration to feed the same width powerband as a 450 class machine with less cam duration....

and if all you do is drag race and only use wide open throttle and dont see below 8000 rpm.... then any cam that makes more peak hp will be fine for your situation...


BUT... if you are stock bore.... or close to 450cc.... and ride mx, woods, anywhere where you see varied rpms and throttle positions...the stock cams represent a LOT of engineering from the same engineers that developed the same 5 valve head the cam sits in.... they make great throttle response and a great early onset of the most and earliest torque and HP...and they are the very best for long / safe valvetrain life to boot....


cams that require the oem cam as a core to weld / re-grind on are a bummer imo... because the stockers truly represent awesome engineering and are the best torque cams you can get.... so to give them up to get another cam is not my favorite idea... because if you wanted to switch to the best torque / response cam sometime... that ship sailed as a core :(

anyways.... if anyone has done comparison cam dyno testing... this would be a great place to share the runs and info to help others decide if its the right choice for them....

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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Last edited by mixxer; 06-03-2012 at 09:25 AM.
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post #9 of 250 (permalink) Old 05-21-2012, 10:32 PM
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Mixxer i must say you are quite the man..... I like where your going with this.
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post #10 of 250 (permalink) Old 05-22-2012, 12:35 AM
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mixer are you a chains fan also... lets hear some more.


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post #11 of 250 (permalink) Old 05-22-2012, 06:43 AM Thread Starter
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i will do my best to devote about an hour a night to making this super complete and useful info for everyone wanting to add porting to the list of their engine building skills....

i will go back into parts i have already finished to add drawings / illustrations to make it all better visualized than with pictures alone.... it should be fun and useful...

thanks for the patience...

and yes, i am a serious chains fan :)

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #12 of 250 (permalink) Old 05-22-2012, 01:17 PM
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I don't have a clue how to port. Would love to learn about it. Can't wait to hear more!!

-Leoric


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post #13 of 250 (permalink) Old 05-22-2012, 07:54 PM Thread Starter
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ok.... filling in some more on day 2.... so check the saved posts above in a bit^^^

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #14 of 250 (permalink) Old 05-22-2012, 09:51 PM
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This is not an advertising thread, just a simple words with pictures thread to help people understand how some ways to port is and what all is involved.

Pm-s are usefull tools.
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post #15 of 250 (permalink) Old 05-22-2012, 09:52 PM
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Here are some visual aids...



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post #16 of 250 (permalink) Old 05-23-2012, 06:09 AM Thread Starter
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Quote:
Originally Posted by Terse View Post
This is not an advertising thread, just a simple words with pictures thread to help people understand how some ways to port is and what all is involved.

Pm-s are usefull tools.
by the time i am done with this, i hope to have made the most useful guide ever made for anyone wanting to know the language and theory behind airflow and porting.... there are lots of people who want to do everything for themselves...but not a lot of people willing to share info and experience....

there is sooooo very much more to go back in and fill in all the blanks with once the base with all the first run of pics is laid down....

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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Last edited by mixxer; 05-23-2012 at 06:19 AM.
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post #17 of 250 (permalink) Old 05-23-2012, 06:09 AM Thread Starter
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Quote:
Originally Posted by Terse View Post
Here are some visual aids...




awesome pics.... thank you!

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #18 of 250 (permalink) Old 05-23-2012, 04:48 PM
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Mixxer, what do you do with the inner surface of valve guide when it is cutted?

thanks
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post #19 of 250 (permalink) Old 05-24-2012, 06:53 AM Thread Starter
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Quote:
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Mixxer, what do you do with the inner surface of valve guide when it is cutted?

thanks

smooth and radius the ends with 180 grit sanding roll..... i will add more stuff today...too busy last night...

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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post #20 of 250 (permalink) Old 05-24-2012, 06:54 AM Thread Starter
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Quote:
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Here are some visual aids...





the port picture is missing an INSANELY IMPORTANT feature to make power with.....

ANYBODY know what it is????

Venom/ VooDoo Headwork PORTING: +10% Power increase entire rpm band
$275 complete combustion chamber and port mods for carb models
$375 HVP epoxy work for Fuel Injected models
10 day turn around /
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