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-   -   Hemi Build #3 -Boogie Woogie Woogie (http://www.diygokarts.com/vb/showthread.php?t=38596)

bob58o 01-31-2018 02:11 AM

Hemi Build #3 -Boogie Woogie Woogie
 
https://media.tenor.com/images/e0212...7e1e/tenor.gif

Since I finished converting my new Hemi Predator 212 to Electric Start with Charging, I am bored again.

So let's plan to modify it...
I like to have a plan so I can pick parts with purpose.
And I like to build on paper first.
This will be for an off-road mini bike.
Main Goal - Torque!


FLYWHEEL
Kohler 1702530S Electric Start 3Amp Charging Flywheel
https://www.jackssmallengines.com/ja...ohler/1702530s

I think this should survive 5500 RPM. I think the Kohlers are governed to 4k RPM if I read correctly. Fingers crossed.


STATOR
Kohler 1708509S
https://www.jackssmallengines.com/ja...ohler/1708509s


CAMSHAFT
NR 280-0211
https://www.nrracing.com/product-p/200cam-280.htm
280 SERIES- The original NR camshaft. King of midrange. GREAT FOR MINI BIKES & MARINE APPLICATIONS

Approx .280 lift and 220 duration (at .050). This is a nice cam that works well on both stock and modified motors. This cam produces lots of low end torque. One of the best all around cams we offer. Honda blocks may need to be clearanced to install. 26 lb springs required. Bored or Aftermarket carb needed.

280-0211: THE ULTIMATE TORQUE CAM. Special grind for Marine and Winch Boarding applications. Extreme torque. Designed for 2000 to 5500 RPM, 11 to 1 or Lower compression ratio required, HD Springs required

Note: Block or crankshaft may require clearancing to clear camshaft lobes



VALVE SPRINGS
26 lb Valve Springs
https://www.nrracing.com/product-p/dcs-cl1.htm
Spring, Valve, 26 lb at .850, Coil Bind at .425 lift (.425 spring) , Price Each, 7500 max rpm, Use with F200 and 280 cams. Small diameter spring. Can be used with stock retainers. Reinforced or Billet Rocker arms Recommended.
Fits all GX120 to Gx200 Hondas, 6.5 Chinese OHVs, and Old Style Predators. Can be used on new style Predators, but spring pressure will be slightly higher.



CONNECTING ROD
+0.020" Billet Rod (3.328") - Hoping for 0.005" In the Hole
http://www.nrracing.com/product-p/6254-6256-6252.htm
Rod Connecting, Predator Billet with Bearing, Mandatory for all HP applications. Long rod for use with Wiseco Piston and Stock Cranks Available in Standard length, +.020", or +.040".

The Std and +.020 are for use with the stock standard compression height (.570 to .575) Pistons. The +.040 is used with the aftermarket .550 compression height (.550) Pistons.



HEAD
Stock Hemi Head
www.shameonme.com/becauseitlooksright
Milled 0.025" - Hoping for 19.5cc
Little to No Port Work Done -
3 Angle Valve Job
Stock 27/25mm Valves
Stock Retainers
Stock Pushrods
Stock Lifters
Stock Rocker Arms


HEAD GASKET
0.027" Gasket (triple stacked) x 70mm bore
https://www.nrracing.com/product-p/mls200hg.htm
Excellent Sealing. Can remove layers to make thinner. Available in .018", .027", .036"


COMPRESSION RATIO
http://www.csgnetwork.com/compcalc.html
70mm Bore (2.756")
55mm Stroke (2.165")
Stock Flat-top Piston 0.005" In The Hole @ TDC
0.027" x 70mm Head Gasket
19.5cc Combustion Chamber

10.35 :1 Static Compression Ratio
93 Octane Premium Pump Gas -Want to run Pump Gas with this build. I know in some automotive builds, people can ran above 11:1 static CR with aluminum heads on 93 octane (depending on the camshaft profile).


IGNITION TIMING
26 Degrees BTDC.
www.foolyoutwice.com/shameonyou
Since I MAY be close to knock with this cam, pump gas, and 10.35 :1 static compression ratio, I'll start at 26 BTDC and maybe advance to 28 BTDC from there. I don't want any less compression and I don't want alcohol or race fuel - so I'm left with timing to tune. And jetting.

CARB AND INTAKE MANIFOLD

The cheaper 22mm option...
OKO 21 (22mm)
https://www.aliexpress.com/item/26mm...BoCdP0QAvD_BwE

Manifold for 6.5HP Clones & Predators
http://www.gopowersports.com/manifol...nes-predators/
Alloy manifold for a 6.5 Clone and 212cc Predator to boot style carburetor such as a flatslide.
Comes with gasket and 2 M6-1.00 x 20mm Allen bolts.
Flange Thickness: 8.15mm
Overall Lenght: 69.75mm
Tube OD: 32mm


The more expensive 22mm option...
VM22-133
https://www.ebay.com/itm/Mikuni-22mm...m4383.l4275.c1

Manifold For Mikuni VM 22, with gasket (48mm long)
http://www.gopowersports.com/manifol...ket-48mm-long/
Overall length 48mm
Venturi 26mm
Mounting holes are 48mm apart, carburetor mounting holes are slotted so carburetor can be twisted as needed


The manifold I want if I get a VM22...
Inverted Chrome Mikuni 22 Manifold for Predators
https://gokartsusa.com/Mikuni-22-Inv...-Manifold.aspx

I want a slide style carburetor for mainly part throttle riding.
Haven't yet figured out what carb is too big for this.
I'd like to do a 22mm if it doesn't cost me much on the low end.
I'm not exactly sure how it will affect me 3-4.5k RPM.
Looking into PZ style, VM style, OKO (PWK) style....

I've read 22mm are bolt ons that provide gains on low and top end, but not sure I buy the sales pitch.

The cam description says Bored or Aftermarket Carb Needed.
Russell said 22mm shouldn't be too big, but never tried anything smaller as far as aftermarket slide carbs.

I don't want to build an engine for low end and then throw it away with too big of a carb, but I also don't want to leave power on the table by being too conservative on the carb size.

24 CFM is more than this engine will need based off displacement and RPM.

I've been looking into intake and exhaust tuning, but unless I make something custom - the exhaust will probably what ever fits the minibike frame I use.

ezcome-ezgo 01-31-2018 06:31 AM

Do the hustle.

bob58o 01-31-2018 10:39 AM

4 Attachment(s)
So I have convinced myself that due to the design of a slide carb, I can afford to go bigger than I could with butterfly design.

I also want to keep using the style carb I am already using. This way I only need one style of jets, needles, ... for all my carbs.

OKO 21 (22mm) Flat-Slide Carb PWK

48mm OD Air Horn
35mm OD Spigot Mount
$23.64 shipped
https://www.aliexpress.com/item/26mm...xoCHT4QAvD_BwE

Intake Manifold for Flat-Slide Spigot Mounting Carb
70mm Long
32mm OD
http://www.gopowersports.com/manifol...nes-predators/

Metal Screen Air Filter
https://www.treatland.tv/OKO-air-fil...er-g1-48mm.htm

so nice screen air filter for limitless flow. fits on OKO 21mm, 24mm, 28mm and 30mm carburetors.
OD of the chromey part = 65mm
OD at the largest part = 75mm
total length = 37mm
ID = 48mm


Dry Charger / Pre-Filter
https://www.knfilters.com/search/pro...prod=rc-0170dk
3.5" Diamter
1.5" Long

I was looking into longer velocity stacks, but since I will mostly be running at part throttle, I don't think I'll see the benefits. The intake wave will bounce off the slide, not the end of the velocity stack. The length of the intake tract will be from the valve to the slide at part throttle, from the valve to the end of the velocity stack at WOT.

ezcome-ezgo 01-31-2018 12:08 PM

They said "chromey".:D

Randy H 01-31-2018 12:16 PM

Quote:

Originally Posted by bob58o (Post 493430)
So I have convinced myself that due to the design of a slide carb, I can afford to go bigger than I could with butterfly design.

No doubt you have good reason for that statement. I'm curious why though.

One thing to consider is that for a given carb size a slide carb will flow better. I say that because you don't have a butterfly and shaft in the way.

Also I've been running your specs through Pipemax. If interested I'll post my findings.

KartFab 01-31-2018 12:17 PM

snowmobile intake FTW!!! What about push rods?

bob58o 01-31-2018 01:11 PM

Quote:

Originally Posted by KartFab (Post 493436)
snowmobile intake FTW!!! What about push rods?

What about a snowmobile intake?
Show me.

I plan on using stock pushrods.
If I need shorter pushrods, then I'll look into CrMo replacements.

---------- Post added at 01:52 PM ---------- Previous post was at 01:42 PM ----------

Quote:

Originally Posted by Randy H (Post 493435)
No doubt you have good reason for that statement. I'm curious why though.

Without any really good reason... The way I see it....

A bigger slide carb at half throttle is kind of similar to a carb with a smaller venturi at WOT. Say 22mm Diameter Round Venturi (which has an opening of 0.60 sq inches at WOT) at half throttle may have an opening of half that area (0.30 sq inches). Working backwards... 0.30 sq in opening is what you would have if you had a 16mm round venturi in a carb at WOT.

As opposed to a butterfly, which has a "fixed venturi" and a pivoting butterfly.

Not sure this is correct at all. Might just cost dollars and make no sense.

Quote:

Originally Posted by Randy H (Post 493435)
Also I've been running your specs through Pipemax. If interested I'll post my findings.

Of course I am interested. I would love to see what you got.

I've looked into some calculators, but I don't have the full specs for the camshaft. I can do some calculations, but I was basing those off of the 0.050 Duration Specs. Exhaust should be very long if tuning for peak torque.

Is this the sort of thing where you have to pay to play, or is there a free trial version of this magic genie program?

---------- Post added at 02:11 PM ---------- Previous post was at 01:52 PM ----------

Anyway a 212cc engine at 9,000 RPM with VE of 0.95 only requires 32 cubic feet per minute. 212cc at 5500 RPM and VE of 0.85 requires 18 cfm. At 3600 RPM, you only need 12 cfm, but the stock carb flows more than triple that.
People racing use heads and carbs that flow over 100 cfm on the bench IIRC. Again, Triple the engine needs. So I don't exactly know what I'm doing here. LOL

ole4
4 Cycle Advanced User


These are the numbers I got on my bench at 28"H2o
Tilly HL304A 94CFM
PWK 24mm 97.9
VM22 china mikuni with oval bore at slide 88CFM
24mm Molkt 97CFM
26mm NIBBI Bench calibrated for 110 CFM and it pulled past 100% on the inclined manometer so it is a bit north of 110CFM
HUAYI 39.6 and 41.2 CFM (I had two)
SP 41.8CFM
and the RUI was 43CFM

ezcome-ezgo 01-31-2018 01:29 PM

1 Attachment(s)
Did you say Magic Genie?

KartFab 01-31-2018 01:34 PM

Quote:

Originally Posted by bob58o (Post 493438)
What about a snowmobile intake?
Show me.

i think thats what you got a picture of already.

bob58o 01-31-2018 02:02 PM

1 Attachment(s)
I really like that inverted chrome intake for the VM22, but it is $60 and I'm not very confident that I could fab/weld something like that. It is long, which should help. I've read longer is better (pretty much an improvement at across the whole RPM range). From what I've read, it seems like the length of the stock intake tract is very short (when compared to what a tuned length might be).

And with a velocity stack style filter facing the front of the bike, maybe it'll bump the VE a bit. Not sure if RAM AIR really works. But in the picture below, that filter is not going to get the type of Ramming I would with a velocity stack style with open front/top.

And yes I also want that manifold for the Supercharger too. Seems like I can make that align with the output of the blower and just cut off the flange. But that is a different thread (I think). I still haven't given up on the idea that this engine might eventually get the AMR300 blower.

ezcome-ezgo 01-31-2018 02:07 PM

Ram Air is the biggest scam perpetrated on the American public since One Hour Martinizing.

bob58o 01-31-2018 02:28 PM

Quote:

Originally Posted by ezcome-ezgo (Post 493459)
Ram Air is the biggest scam perpetrated on the American public since One Hour Martinizing.

Ok I have hit that point where I need to stop for while.LOL
Now you have me considering fluid dynamics and the the air flow around the filter in a wind tunnel. Air flow, speed, low pressure, high pressure. Guessing air density will be higher in front of the filter than the air density around the sides of it????

And I knew I needed to stop when I imagined sitting upon an air molecule and starting considered relativistic air pressure and airplane wings. I'll get back to that once my my minibike is flying and approaching the speed of light.

Still think open front filter would be better than closed front filter.
Denser Air has to be more better. If not denser, than at least directed directly down the manifold has to be more better.:cheers2:

ezcome-ezgo 01-31-2018 02:40 PM

1 Attachment(s)
The stuff of nightmares...

bob58o 01-31-2018 02:49 PM

Other carb Options.
 
1 Attachment(s)
On other sites people has suggested a carb from a Briggs LO206 engine, which I think is a PZ20.

Think this is a 20mm ID
48mm bolt spacing.
https://www.ebay.com/itm/Carburetor-...4383.l4275.c10

https://www.ebay.com/itm/Carburetor-...-/121124844665

ezcome-ezgo 01-31-2018 03:07 PM

Other sites indeed. Who are you? Are you not a Juilliard trained bartender?

bob58o 01-31-2018 03:25 PM

I taught myself to make myself drinks. Sometimes other people also wanted drinks. So I started making them drinks too. I never stopped.

bob58o 01-31-2018 09:00 PM

I also found that stock Hemi Heads will flow around 50 cfm.
https://karting.4cycle.com/showthrea...r-flow-numbers

Randy H 02-01-2018 06:39 AM

Pipemax
 
1 Attachment(s)
No demo for Pipemax. $75.
It doesn't claim to be a full fledged engine simulation program. It's intended for four stroke exhaust. The exhaust data will be on my next post. (Exceeded 10000 characters. ) I didn't include metric data, but I will if you want.

I guessed at the exhaust port centerline.

Not sure about the degreed Centerline.

5.5mm valve stem? Now I'm thinking it should be 5mm.

85% VE. Maybe to conservative. I'll try to dial that figure in a little better.

Let me know if you want to make changes. I will use the head flow numbers posted and rerun.

Argh! Haha. I carefully formatted everything in edit mode. Now it's somewhat jumbled.

HP Torque Intake

12.915 Cubic Inches @ 5500 RPM with 85.00 % Volumetric Efficiency PerCent

Required Intake Flow CFM @28 in. = 42.1 to 44.6 at .288 inch Valve Lift
Required Exhaust Flow CFM @28 in. = 35.8 to 38.8 at .237 inch Valve Lift

600 RPM/Sec Dyno Test Lowest Low Average Best
Peak HorsePower 9.3 9.5 9.6 9.7
Peak Torque Lbs-Ft 9.8 10.0 10.1 10.3

HorsePower per CID 0.719 0.734 0.743 0.753
Torque per Cubic Inch 0.757 0.777 0.787 0.797
BMEP in psi 114.1 117.1 118.6 120.1
Carb CFM at 1.5 in Hg. 17 19 20 21

Recommended Intake Valve Lift to prevent Choke = .288 Lift @ 5500 RPM
Recommended Exhaust Valve Lift to prevent Choke = .237 Lift @ 5500 RPM
Recommended Minimum Normal Maximum Time-Area-Duration Lifts
Intake Valve Lift = 0.2560 0.2884 0.3172 0.3468 0.3655 0.3843
Exhaust Valve Lift = 0.2179 0.2369 0.2606 0.2845 0.3023 0.3202
IntOpen= .00 IntClose= 40.00 ExhOpen= 40.00 ExhClose= 0.00
Intake Duration @ .050 = 220.00 Exhaust Duration @ .050 = 220.00
Intake CenterLine = 110.00 Exhaust CenterLine = 110.00
Compression Duration= 140.00 Power Duration = 140.00
OverLap Duration = 0.00 Lobe Separation Angle (LSA)= 110.00
Camshaft Straight Up = 0.00 degrees Cylinder Ignition Interval= 720 deg.

-- Operating RPM Ranges of various Components --
Best estimate RPM operating range from all Components = 3204 to 5204
Intake Flow CFM @28inches RPM Range from Flow CFM only = 3157 to 5157
Intake and Exhaust Systems operating RPM Range = 3127 to 5127
Intake and Exhaust Time-Area operating RPM Range = 2927 to 4927
Camshaft's Intake and Exhaust Lobes operating RPM range = 3254 to 5254
Intake Valve Curtain Time-Area at 0.280 Lift RPM Range = 3341 to 5341
Exhaust Valve Curtain Time-Area at 0.280 Lift RPM Range = 4501 to 6501

Intake Valve Close RPM = 5352 Exhaust Valve Open RPM = 4962
Intake System RPM = 4973 Exhaust System RPM = 5282
Intake Time-Area RPM = 4441 Exhaust Time-Area RPM = 5412
Intake Mach Z-Factor = 0.499866 Exhaust Mach Z-Factor = 0.539998
Intake Z-Factor Lift = 0.291589 Exhaust Z-Factor Lift = 0.229090

Curtain Area -to- Valve Area Convergence Intake Valve Lift inch= .266
Curtain Area -to- Valve Area Convergence Exhaust Valve Lift inch= .246

Target EGT= 1441.6 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
Octane (R+M)/2 Method = 91.5 to 96.1 Octane required range
Air Standard Efficiency = 61.28010 % for 10.350:1 Compression Ratio

------- Piston Motion Data -------
Average Piston Speed (FPM)= 1984.58 in Feet Per Minute
Maximum Piston Speed (FPM)= 3279.627 occurs at 73.49475 Degrees ATDC
Piston Depth at 73.495 degree ATDC= 0.9409 inches Cylinder Volume= 92.0 CC
Maximum TDC Rod Tension GForce= 1232.6168 G's
Maximum BDC Rod Compression GForce= 627.5572 G's

----- Engine Design Specifications -----
( English Units ) ( per each Valve Sq.Inch area )
Engine Size CID = 12.915 Intake Valve Net Area = 0.850
CID per Cylinder = 12.915 Intake Valve Dia. Area = 0.887
Rod/Stroke Ratio = 1.537 Intake Valve Stem Area = 0.037
Bore/Stroke Ratio = 1.273 Exhaust Valve Net Area = 0.723
Int Valve/Bore Ratio = 0.386 Exhaust Valve Dia. Area = 0.760
Exh Valve/Bore Ratio = 0.357 Exhaust Valve Stem Area = 0.037
Exh/Int Valve Ratio = 0.926 Exh/Int Valve Area Ratio = 0.857
Intake Valve L/D Ratio= .263 Exhaust Valve L/D Ratio= .285
CFM/Sq.Inch = 47.4 to 50.2 CFM/Sq.Inch =50.3 to 51.2

Intake Valve Margin CC's Exhaust Valve Margin CC's
1.00 CC = 0.0688 1.00 CC = 0.0802
0.50 CC = 0.0344 0.50 CC = 0.0401
0.25 CC = 0.0172 0.25 CC = 0.0201
0.10 CC = 0.0069 0.10 CC = 0.0080

- Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 34.182 (usually this Length is never used)
2nd Harmonic= 19.401 (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 13.544 (ProStock or Comp SheetMetal Intake best overall HP )
4th Harmonic= 10.661 (Single-plane Intakes , less Peak Torque good HP )
5th Harmonic= 8.650 (Torque is reduced, even though Tuned Length)
6th Harmonic= 7.277 (Torque is reduced, even though Tuned Length)
7th Harmonic= 6.280 (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 5.524 (Torque is greatly reduced, even though Tuned Length)
Note> 2nd and 3rd Harmonics typically create the most Peak Torque
4th Harmonic is used to package Induction System underneath Hood

Plenum Runner Minimum Recommended Entry Area = 0.449 to 0.505 Sq.Inch
Plenum Runner Average Recommended Entry Area = 0.516 Sq.Inch
Plenum Runner Maximum Recommended Entry Area = 0.527 to 0.624 Sq.Inch

Minimum Plenum Volume CC = 27.2 ( typically for Single-Plane Intakes )
Minimum Plenum Volume CID= 1.7 ( typically for Single-Plane Intakes )
Maximum Plenum Volume CC = 211.6 ( typically for Tunnel Ram Intakes )
Maximum Plenum Volume CID= 12.9 ( typically for Tunnel Ram Intakes )

--- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---
108 FPS at Intake Valve Curtain Area= 0.935 sq.in. at .280 Lift
114 FPS at Intake Valve OD Area and at Convergence Lift = .266
141 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 0.719 sq.in.
--- 5500 RPM Intake Cross-sectional areas in Square Inches ---
350 FPS CSA= 0.288 Port has Sonic-Choke with HP Loss ( too fast FPS )
330 FPS CSA= 0.306 Port may have Sonic-Choke with HP Loss ( too fast FPS )
311 FPS CSA= 0.325 Highest useable Port velocity ( possible HP loss )
300 FPS CSA= 0.337 Smallest Port CSA ( Hi Velocity FPS good TQ and HP )
285 FPS CSA= 0.354 Smallest Port CSA ( very good TQ and HP combination )
260 FPS CSA= 0.389 Recommended average Intake Port CSA (very good TQ and HP)
250 FPS CSA= 0.404 Largest recommended average Intake Port CSA ( good HP )
240 FPS CSA= 0.421 Largest recommended average Intake Port CSA (less Peak TQ)
235 FPS CSA= 0.430 Largest recommended Intake Port Gasket Entry area CSA
225 FPS CSA= 0.449 Largest Intake Port Gasket Entry CSA ( Slow FPS )
215 FPS CSA= 0.470 Possible Torque Loss with Reversion ( Slow FPS )
210 FPS CSA= 0.481 Torque Loss + Reversion possibility ( too slow FPS )
200 FPS CSA= 0.505 Torque Loss + Reversion possibility ( too slow FPS )
Note : these are calculated average Port cross-sectional areas and FPS

--- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---
99 FPS at Exhaust Valve Curtain Area= 0.866 sq.in. at .280 Lift
113 FPS at Exhaust Valve OD Area and at Convergence Lift = .246
139 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 0.616 sq.in. at 5500 RPM
--- 5500 RPM Exhaust Cross-sectional areas in Square Inches ---
435 FPS CSA= 0.197 Sonic Choke at Throat Area (too fast FPS velocity)
380 FPS CSA= 0.226 Sonic Choke at Throat Area (possibly too fast FPS)
350 FPS CSA= 0.245 Exhaust Port has Sonic-Choke with HP Loss (too fast)
330 FPS CSA= 0.260 Exhaust Port has Sonic-Choke with HP Loss (too fast)
311 FPS CSA= 0.276 smallest Exhaust Port ( very high velocity FPS )
300 FPS CSA= 0.286 smallest recommended Exhaust Port (Hi velocity)
285 FPS CSA= 0.301 smallest recommended Exhaust Port (Hi velocity)
265 FPS CSA= 0.324 Recommended average Exhaust Port CSA
250 FPS CSA= 0.344 Recommended average Exhaust Port gasket area
240 FPS CSA= 0.358 Recommended largest Exhaust Port gasket area
225 FPS CSA= 0.382 Largest Exhaust Port Exit gasket area (Slow FPS)
210 FPS CSA= 0.409 Largest Exhaust Port Exit gasket area (Slow FPS)
190 FPS CSA= 0.452 Torque Loss + Reversion + Scavenging loss (too slow FPS)
180 FPS CSA= 0.477 Torque Loss + Reversion + Scavenging loss (too slow FPS)
Note : these are calculated average Port cross-sectional areas and FPS

Valve Intake Exhaust Curtain Area Cross-Sect Area Minimum Flow
Lift Choke Choke Square Inches 280FPS 280FPS CFM @ 28 In
inches RPM RPM Intake Exhaust Intake Exhaust Int Exh
.050 954 1161 0.167 0.155 0.063 0.053 7.3 6.2
.075 1431 1741 0.250 0.232 0.094 0.080 10.9 9.3
.100 1907 2322 0.334 0.309 0.125 0.106 14.6 12.4
.125 2384 2902 0.417 0.386 0.156 0.133 18.2 15.5
.150 2861 3483 0.501 0.464 0.188 0.160 21.9 18.6
.175 3338 4063 0.584 0.541 0.219 0.186 25.5 21.7
.200 3815 4643 0.668 0.618 0.250 0.213 29.2 24.8
.225 4292 5224 0.751 0.696 0.282 0.239 32.8 27.9
.250 4768 5804 0.835 0.773 0.313 0.266 36.5 31.0
.275 5245 6385 0.918 0.850 0.344 0.293 40.1 34.1
.300 5722 6965 1.002 0.927 0.375 0.319 43.8 37.2
.325 6199 7546 1.085 1.005 0.407 0.346 47.4 40.3
.350 6676 8126 1.169 1.082 0.438 0.372 51.1 43.4
.375 7153 8706 1.252 1.159 0.469 0.399 54.7 46.5
.400 7629 9287 1.336 1.237 0.501 0.425 58.4 49.6

Randy H 02-01-2018 06:43 AM

Exhaust

Cylinder Ignition Interval = 720 degrees 5500 RPM Hertz frequency = 45.8 Hz
Target EGT= 1441.6 degrees F at end of 4 second 600 RPM/Sec Dyno accel. test
12.915 CID Exhaust System operating RPM Range from 3500 to 6000 RPM

--- Single Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
Diameter= .792 to .917 Total Length= 37.6 to 40.2 inches long
--- 2-Step Primary Pipe Specs --- ( Low to Mid-Range RPM Torque and HP )
1st Step Dia. inches= .792 Length= 18.8 to 20.1
2nd Step Dia. inches= .917 Length= 18.8 to 20.1
--- 3-Step Primary Pipe Specs --- ( Low to Mid-Range Torque and Hi RPM HP )
1st Step Dia. inches= .792 Length= 18.8 to 20.1
2nd Step Dia. inches= .917 Length= 9.4 to 10.1
3rd Step Dia. inches= 1.042 Length= 9.4 to 10.1

--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= .992 to 1.117 Total Length= 37.6 to 40.2 inches long
--- 2-Step Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
1st Step Dia. inches= .992 Length= 12.5 to 13.8
2nd Step Dia. inches= 1.117 Length= 25.1 to 26.4
--- 3-Step Primary Pipe Specs --- ( Higher RPM Horsepower, possible TQ loss )
1st Step Dia. inches= .992 Length= 12.5 to 13.8
2nd Step Dia. inches= 1.117 Length= 12.5 to 13.2
3rd Step Dia. inches= 1.242 Length= 12.5 to 13.2

Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness

---- Primary Pipe's Harmonics ----
1st Harmonic = 158.1 inches long ... typically never used
2nd Harmonic = 61.3 inches long ... longest recommended
3rd Harmonic = 37.6 inches long ... highly recommended , best Torque Curve
4th Harmonic = 26.9 inches long ... shortest recommended
5th Harmonic = 20.8 inches long ... typically never used
6th Harmonic = 16.9 inches long ... typically never used
7th Harmonic = 14.1 inches long ... typically never used
8th Harmonic = 12.1 inches long ... typically never used

---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 170.9 inches long ... longest with Mufflers and TailPipes
2nd Harmonic = 85.5 inches long ... longest recommended with Mufflers
3rd Harmonic = 42.7 inches long ... more bottom-end Torque
4th Harmonic = 21.4 inches long ... highly recommended , best Torque Curve
5th Harmonic = 10.7 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 5.3 inches long ... reduced Torque , not recommended

ezcome-ezgo 02-01-2018 06:50 AM

The fuel of GAB.


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