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Discussion Starter · #1 · (Edited)
Im sure youve heard of the term BLUEPRINTING by seeing the term Balanced and Blueprinted Chevy 350.....Im sure alls that pops up in your minds is a set of build sheet type blueprints.........LOL...

At one time many moons ago when I was a kid reading Super Chevy Mags in middle school I thought that too until they came out with a whole Magazine dedicated to blueprinting...

After that my life literally changed but that story is for another time...First the info...


The piston ported or reed inducted 2 stroker engine thats on your mini wasnt designed for vehicles with wheels..They were designed for brushcutters,,augers,,backpack blowers..Basically theyre commercial grade engines the chinese gleaned ad used to adapt these engines quite easily into frames with wheels for us to enjoy......

Unfortunately the thing needs more uumph and more power in order to satisfy the need for speed so the first choice is buying bigbore kits,,hp carbs and exhausts....They work minimally because theyre not refined to maximize their true potential and even if they were youd still only be limited by a bone stock bottomend with flow restrictions.....

Thats where Blueprinting comes in......These crude engines dont have the ability to flow the type of velocity needed to produce extra revs and more lowend/midrange power thats true performance until you BLUEPRINT the low end of the engine case to smooth all sharp edges,,abruptments and shelves that cause turbulence and cause low pressure pockets that interrupt the velocity by scattering it...Scattering causes erratic performance.....

Heres some pics to show you where to look.............

The red lines and the red semi-boxouts in subsequent picture shows where the sharp shelves and abruptments that scatters velocity are in the lowerend





Here youll see the head skirt has been trimmed to eliminate the part that obstructs smooth flow into the transfer ports and causes scattering that causes poor power and performance...The arrow shows the way the velocity is gonna flow....The redline represents the sharp edge thats another hinderance to building performance



Here you should be starting to see how a flow path into the transfer ports is being defined into the lowerend case...........

 

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Discussion Starter · #2 · (Edited)
In this picture youll see the way the mixture flows through the crankcase......all sharp edges and abruptions have been smoothed to enhance the flow of velocity..............



If you look here youll see the difference between a cylinder thats blueprinted for performance versus an engine designed for industrial purposes

its illustrated to show the smoothness of flow versus flow with a hinderance and will show the reason why we grind the sharp edges off......



Heres both sides fully blueprinted....Flow has been improved 45% or more............



Heres the lowerend fully prepped with both halves together......Iin the middle of the case where the bost ports are if your cylinder is equipped with them you must grind in a defined unobstructed path by reshaping the case so it doesnt block the boost port channel.......



When this engine is built it will be one very powerful screaming demon posessed monster when paired up with a properly ported and modded cylinder.............LOL
 

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Discussion Starter · #4 ·
Can u take a stock intake and drill the hole out to make it bigger to get more fuel/power????
Yes you can but its best to match the mount holes and resculpt the way the mix flows into the reed petals or into the intake runner on piston ported engines..........

Heres a hp pumper carb intake for a cag I modded..........



Heres a piston ported intake modded forperformance



heres how to blueprint the reedstopper to open more efficiently..The key is to slightly shorten and reshape the end smooth to eliminate warped reeds.......



Heres how I blueprint the reedplate to welcome the enhanced flow and slightly larger volume..........

 

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Discussion Starter · #5 · (Edited)
When Blueprinting a Piston ported engine its the same principal...you want to eliminate obstructions and hinderances to define aswell as smooth the pathway for strong uninterrupted velocity...........

As you can see here in this picture the 90 degree corner radiating off of the cylinder skirt,,,as soon as the flow hits that corner it makes the atomized mixture erratic.....An erratic mix cant make true performance...



Heres the bottomend with the shelves and abruptments all smoothed away thats pertinent only to the flow and velocity path..........Its vital to only remove enough to improve and dont do it because it looks cool...Too much blueprinting can and will hinder performance too......



Heres the cylinder skirts blended into the transfer ports to ensure a smooth but very strong and uninterrupted flow into the combustion chamber



Here you can see the difference after reshaping the skirt so it doesnt impinge with-in the flowpath of powermaking velocity and atomized mix



The steps and instructions with illustrations in this thread are for the showing the basic practices of BLUEPRINTING to refine the engine from farm impliment into a true performance engine and must not be construed or confused with Power Porting...

Thats another segment sequel to follow this thread and will be coming soon.........This entire thread segment superscedes my first thread that shows how to give your engine a wakeup call and make it more reliable.................. http://www.pocketbikeplanet.com/showthread.php?t=79905

Now the story to add moral to the thread.........

My whole life Ive lived a pretty competitive life starting from an early age and you always need an edge in areas not everyone looks into enhancing to build performance.........After reading that Segment in SuperChevy about Blueprinting I used to mod everything from nitro r/c cars,briggs and techumseh powered carts and minibikes,,2 and 4 stroke dirtbikes,,outboard boat engines and even the family mower...We had the loudest lawnmower with straightpipe that was de-governed and modded with a better carb and stiffer valvesprings ........It was an 84 Montgomery Ward ride-on mower with a 12hp briggs that had electric start and a generator.....My dad gave me a week to finish the mods and have the mower working for the scheduled grass cutting schedule he had and was pretty impressed with its pulling power when he saw it could pull our 19ft bowrider boat with I/O V6 on the trailer across the yard pretty easily......LOL

Alot of my friends when I was a kid had minibikes and gocarts with 5hp briggs aswell as Techumseh engines and I was torching them with 3.5 and 4hp engines......They couldnt wrap their heads around it..........LOL
 

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The 2-Cycle DocToR
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If I port the intake ..won't I also have to port the vacumm hole in the carb so it sucks MORE gas? Or do you suggest using larger fuel lines instead?
 

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Discussion Starter · #7 ·
If I port the intake ..won't I also have to port the vacumm hole in the carb so it sucks MORE gas? Or do you suggest using larger fuel lines instead?
The pulseport hole gets opened up to 1/8"...I do the intake,,insulator if equipped,,gaskets and the head when I pop it off.........Dont touch the carb though........
 

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The 2-Cycle DocToR
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Ok thanks CAM, I was under the impression that If I ported the pulseport..that the carb would draw more fuel enhancing my performance.
 

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Git R Dun PBracer
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Sweet. Great thread CAM2. Ill have lot of time Sunday and Monday. So ill be doing this to my x2. Thank you. :)


Can you post a pic of what bits and grit you use.
 

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Discussion Starter · #10 · (Edited)
Sweet. Great thread CAM2. Ill have lot of time Sunday and Monday. So ill be doing this to my x2. Thank you.


Can you post a pic of what bits and grit you use.
I use the 3/16" and 1/8" diameter barrel cutter bit

5/16" sawcutter bit

150 grit emery paper

320 wet/dry sandpaper

precision 7pc fileset from harbor freight...$9bux

coarse grit 6" flatfile

medium grit 6" flatfile







 

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The pulseport hole gets opened up to 1/8"...I do the intake,,insulator if equipped,,gaskets and the head when I pop it off.........Dont touch the carb though........
Hi cam2.!! a couple of questions for ya.! I appologize in advance but, with limited time I have to stay on the internet, I couldn't quickly find info on pulseport theory and operation. Will you please enlighten me?
Next is Balancing. Have You Noticed a Big Difference Balance wise if standard cag crank vs. F/C crank, betweeen the two with less vibration throughout the RPMs or even top end rpms? From Experience, I Have seen as much as 800rpm gains from having a well balanced crank and/or complete rotating mass assy.plus the satisfaction of a smooth running engine throughout the rpm range and more benifit with great /polished or high end bearings.?
 

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Discussion Starter · #12 · (Edited)
Hi cam2.!! a couple of questions for ya.! I appologize in advance but, with limited time I have to stay on the internet, I couldn't quickly find info on pulseport theory and operation. Will you please enlighten me?
Next is Balancing. Have You Noticed a Big Difference Balance wise if standard cag crank vs. F/C crank, betweeen the two with less vibration throughout the RPMs or even top end rpms? From Experience, I Have seen as much as 800rpm gains from having a well balanced crank and/or complete rotating mass assy.plus the satisfaction of a smooth running engine throughout the rpm range and more benifit with great /polished or high end bearings.?
The theory behind the pulseport mod is alot like taking a lighter spring and putting it on the needle lever without even disassembling the carb....The enlarged hole gives the pulse a more defined in and out without over pressurizing the diaphragm....Whats easier to suck a shake through... A thin straw or thick straw?

Of course Ive noticed a difference balancewise.........Its hard to totally balance a stock crank without making the piston overly fragile from over-lightening it to make it truely balanced although Ive gotten 43cc - 49cc engines between 13,000 - 14,000 rpm's on a stock crank and over 16,000 with a full circle crank........The full circle crank mod I did in my stand-up scooter has that engine revving smoother than it ever did with the stock crank..







Polishing makes a huge difference aswell,,,When theres less drag on the endseals and less friction between the crankbearing rollers,,piston,,rings,pin bearing,and cylinder the temps go down and revs go up.......
 

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Git R Dun PBracer
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When modding the head to match the case you only mod one side of it like in the picture?
 

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Discussion Starter · #15 · (Edited)
When modding the head to match the case you only mod one side of it like in the picture?
Yes you only blueprint the flow side...You only want to remove enough to improve..........The skirt on the intake side only needs to be reshaped........






This is the impingement Im talking about..........





You can see the difference between a smooth flow to an interrupted flowpath..You can see how the skirt on the left blends in with the lower crankcase more than the skirt on the right............

 

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Git R Dun PBracer
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Cool i just wanted to double check on that. TY
 

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Lots of good info here, thanks for posting.

I thought I would add that the shown flow direction will differ and some of the ground out parts will be redundant when a full circle crank is being used. This is due to the air not coming up the sides and into the transfers any more but rather through the middle of the crank and across.

On a different note it's a trivial correction but I thought "Blueprinting" meant to restore something to it's intended factory specifications? Not modding? As in when something like the Chevy engines are Blueprinted it would mean that the faces are surfaced true to each other so everything bolts up in line like how it should. It compensates for loose quality control / tolerances from the factory.

One of the things I did to my Cag engine in this regard was with my engine cases, it was to machine the mounting feet flat perpendicular to the clutch mounting surface. It was amazing how far they were out. Attached is a pic of me checking my work. With the clutch mounting surface of the case rest flat against my surface plate I looked to see if the case mounts end up all touching the upright of the 90 degree block. It's not perfect but close and massively better than what it was. Today I wish to do the same to the barrel mounting threads and put some Heli-coil type thread inserts in there at the same time as I hear that these threads are prone to strip and pull out.
 

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Discussion Starter · #19 · (Edited)
Lots of good info here, thanks for posting.

I thought I would add that the shown flow direction will differ and some of the ground out parts will be redundant when a full circle crank is being used. This is due to the air not coming up the sides and into the transfers any more but rather through the middle of the crank and across.

On a different note it's a trivial correction but I thought "Blueprinting" meant to restore something to it's intended factory specifications? Not modding? As in when something like the Chevy engines are Blueprinted it would mean that the faces are surfaced true to each other so everything bolts up in line like how it should. It compensates for loose quality control / tolerances from the factory.

One of the things I did to my Cag engine in this regard was with my engine cases, it was to machine the mounting feet flat perpendicular to the clutch mounting surface. It was amazing how far they were out. Attached is a pic of me checking my work. With the clutch mounting surface of the case rest flat against my surface plate I looked to see if the case mounts end up all touching the upright of the 90 degree block. It's not perfect but close and massively better than what it was. Today I wish to do the same to the barrel mounting threads and put some Heli-coil type thread inserts in there at the same time as I hear that these threads are prone to strip and pull out.
When you build an engine you have two choices,,,build it as-is and slap it together and get what it gives or you can take the time to make everything fit and flow to a better potential which yields a more fluid and broader power over its thrown together counterpart..

Kinda the same difference between an regular ZX10R and a ZX10R thats been blueprinted and retuned to race in the GP circuit...............Its like apples and oranges

As far as the whole gist theres tons of what I do to my engines not totally outlined in this thread because just by doing this simple little process you yield quite a bit of engine power but you can piece together the rest from prior threads n postes in other members threads n such........Like using a scale to weight match the clutch arms and better balance the rotating assembly etc...

On your FCC crank theory ....Its a lil off.....The gasses come between the crank journals and are instantly transferred into the transfer ports through a little thing called crankcase pressure from the downstroke of the piston................Its a many splendered process thats very overlooked and without those sharp shelves and abruptments impinging on an unobstructed flow and preventing the engine designed for yard tool engines from delivering maximum velocity..........

As far as the squaring of the engine to make sure the engine is at its maximum pinion alignment to the rear wheel you can find that info in a tread posted maybe 5-6 years back in my Cag cag cag thread,,a member named Jaloos' threads or another member named N!pples threads............
 

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Remember this, at 10,000 RPMs your engine is firing 166 times a second, large good flowing intake & exhaust passages and big carb & high performance exhaust are everything. The modifying possibilities or endless. Many ways to port the cyld. You can widen the case main side transfer ports out and the cyld ports to match, to make them bigger.
 

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