Powerland 420cc GAB 2.0

[Jrgunn5150]

Being somewhat new here wtf does GAB stand for? Are you using as chit chat. Or some other meaning.

Also kinda low compression compared to other new engines. Easy starting since a few of us got recoil starts.

Go All Bob, a term I coined for making a simple thing complicated. Bob tends to analyze every detail and option, in painstaking depth.

I looked back, i did pay 189 for mine, for whatever it matter's.



---------- Post added at 12:32 AM ---------- Previous post was at 12:29 AM ----------

To add some more, Bob, is a very smart guy. But learning from scratch. So he's like a Terminator, trying to understand humans. Learning how quickly a flame propagates across a piston, when he really just want's to buy a header lol.

 

[Jfive]

I remember you showing what you paid. I looked and there was one at 199.00 then someone posted they where almost gone so I looked and only recoils where avail. So I bite the bullet. Might buy a second if they come back out with more electric starts. It's suppose to be for the wife. I know she can pull start a 5hp Briggs lawn mower but we'll see on this.

 

[Jrgunn5150]

I remember you showing what you paid. I looked and there was one at 199.00 then someone posted they where almost gone so I looked and only recoils where avail. So I bite the bullet. Might buy a second if they come back out with more electric starts. It's suppose to be for the wife. I know she can pull start a 5hp Briggs lawn mower but we'll see on this.

I don't think it will be a problem, they use them on generators and stuff. Just keep the compression stock.

 

[bob58o]

Go All Bob, a term I coined for making a simple thing complicated. Bob tends to analyze every detail and option, in painstaking depth.

I looked back, i did pay 189 for mine, for whatever it matter's.



---------- Post added at 12:32 AM ---------- Previous post was at 12:29 AM ----------

To add some more, Bob, is a very smart guy. But learning from scratch. So he's like a Terminator, trying to understand humans. Learning how quickly a flame propagates across a piston, when he really just want's to buy a header lol.

WARNING: ANYTHING I POST IS NOT FROM PERSONAL EXPERIENCE. I READ IT ON THE INTERNET SO IT MUST BE TRUE, RIGHT?
OFTEN I COPY OR INTERPRET POSTS THAT HAVE BEEN COPIED AND/OR INTERPRETED. ANY CLAIMS ABOUT CERTAIN PARTS BEING ABLE TO WITHSTAND 3600+ RPMS OR 5500+ RPMS ARE BASED OFF FORUM POSTS FROM A PERSON I NEVER MET!
AND I MAKE MISTAKES!!!
ANYTHING BEYOND STAGE 1 MODS IS LIKELY TO CAUSE FAILURE OF THE CONNECTING ROD, PUSHRODS, VALVES, ROCKERS, FLYWHEEL,.....
IF YOU UPGRADE THE CAM, YOU SHOULD UPGRADE MOST OF THE COMPONENTS ALONG WITH IT.
THESE ARE NOT RELIABLE ABOVE 7000 PRM
THESE ARE NOT RELIABLE ABOVE 30HP ( EVEN FULLY BUILT)




6000 RPM is what I will be shooting for with this engine.

 

[chancer]

G.A.B. This is Bobs thread and he goes ALL OUT. Like the first post, soooo much info.
GAB is a DIYGK thing means Going All Bob!
Check out his other thread 60 pages in under 3 months to modify a 212hemi. But boy did he learn! Everything! and shared EVERY SINGLE DETAIL with us.
We Love our Bob!

---------- Post added at 10:23 PM ---------- Previous post was at 10:21 PM ----------

Funny that JFive asked! Bob is not the Terminator he is Johnny5 "Need More Input"

---------- Post added at 10:57 PM ---------- Previous post was at 10:23 PM ----------

This 420 thing is gonna get good! 199 dollar engines GABbed out needing 300-400 dollar Torque converters!

 

[bob58o]

Calculating Exhaust Pipe Cross Sectional Area based off Displacement and RPMs

For any newcomer.... This is how you GAB!!!

Calculating Exhaust Pipe Cross Sectional Area based off Displacement and RPMs

6000 RPM
25.6 cubic inches (419cc)

Exhaust Pipe Cross Section =
(Cylinder Displacement * RPM) / 88,200 =
(25.6 * 6000) / 88,200 =
153,600 / 88,200 = 1.7415 square inches
Exhaust Pipe Cross Section should = 1.7415 sq inches

pi*r^2 = area

1.7415 = pi*r^2
1.7415 = 3.14159 * (r^2)
r^2 = 0.554"
r = 0.7445"

Radius of Exhaust Pipe should be 0.7445"
Diameter = Radius * 2
Inner Diameter of Exhaust Pipe should be = 1.489"


Let's find a match!!!

1 5/8" (1.625") Steel Round Tube with 0.065" Wall Thickness has an ID of
1.625 - (2 * 0.065) =
1.625 - 0.130 = 1.495"

ID of 1 5/8" (0.065" Thick) steel tube is 1.495"
Radius is 0.7475"

Let's find the flow area for this tube.

Cross Sectional Flow Area of the 1 5/8" tube is

3.14159 * (0.7475^2) =
3.14159 * 0.5588 =

1.7554 square inches

Let's compare the 1 5/8" (0.065" thick) tube to the optimized tube!

[(1.7554 - 1.7415) / 1.7415] * 100 =
[0.0139 / 1.7415] * 100 =
0.00797 * 100 =

0.797% larger than optimized Exhaust Flow Area.


+/- 1 Percent is good enough for me!!!!!!

FYI, a 5000 RPM 420 wants and Exhaust ID of 1.36" instead of the 1.49" for 6000 PRM.
7000 RPM 420 wants 1.61" ID

ACCORDING TO THIS FORMULA...

Exhaust Pipe Cross Section =
(Cylinder Displacement * RPM) / 88,200

FROM HERE...
http://www.musclecardiy.com/perform...t-system-math-build-high-performance-engines/

 

[Jfive]

Garbage I say.

https://m.youtube.com/watch?v=azPKIjxmmdU

 

[ezcome-ezgo]

You're getting better at this. This was easier to follow for someone with the attention span of a gnat.

 

[bob58o]

You're getting better at this. This was easier to follow for someone with the attention span of a gnat.

I'm trying to be concise in this thread!

---------- Post added at 12:07 PM ---------- Previous post was at 12:04 PM ----------

Garbage I say.

https://m.youtube.com/watch?v=azPKIjxmmdU

The FR hammer Test!!!!!

I don't have the experience to dispute your claims that my math is meaningless, but the math comforts me.

 

[ezcome-ezgo]

I like math. Math is good.

 

[Jrgunn5150]

I also watch Engine Masters regularly, I found that test pretty unsurprising. I've never believed a little steering shafts dimple is going to cost me any measurable amount of power.

On the flip side, I still wouldn't advocate smashing your tail pipes flat, or making them with kinked bends. Every little bit helps.

You'd think this video would disprove the whole "engines need a little backpressure to run good so I'm running these tiny pipes" myth that never goes away.

 

[bob58o]

Thinking this is going to stay around 23-23HP and 6000 RPM or under.
(at least for a while)
So why 6000 RPM and under 30HP?

I didn't cover it here, but posts I shared in other threads state....
The Stock Valves (35mm IN / 31mm EX) won't make power past 6500 RPM.
Most TC's for 22-23 HP engines are rated for 5500-6000 RPM max.
The engines are unreliable above 7000 RPM.
Performance cams need a Billet Connecting Rod and Upgraded pushrods. Also may need upgraded rockers and valves.
Even Billet Aluminum Rods wear down pretty fast and need replacing when using performance cams.
Billet steel rods are expensive.


Looks like I will be sticking with original plan.

1. 8 degree Offset timing key $6.99
"These offset timing keys will advance the timing of your clone engine. 8 Degrees advance will bring the 440s to 29 Degrees BTDC.
8 Degree Key Recommended for all Golf Cart owners who want to get the most out of their engines."
http://www.vegascarts.com/product-p/tkey.htm


2. High Flow Exhaust

GAB TO COME LATER

3. 35 lb HD valve springs $15.99
(Stock Springs on the Big Block may float at 4500"
""These 35lb HD Valve Springs are OEM on our 440cc Clone Engines and work on all GX340/390 and 420/440/460cc Clone Engines.
THESE SPRINGS ARE HIGHLY-RECOMMENDED WHEN REMOVING YOUR STOCK GOVERNOR! Without them, the engine will not rev much past 4500 and the stock valves will float, eventually causing engine damage.
These springs are sold as a set...Thats right, You get 2 Springs!
And the best part is .... they're made in the USA!"
http://www.vegascarts.com/product-p/gp966.htm

I think these are the same @ $4 each.
http://www.arcracing.com/dj-3055hd-gx390-heavy-duty-valve-spring/


4. 92mm 0.020" MLS Head Gasket $11.19
Should bump compression up to 9.2:1
http://www.nrracing.com/product-p/mlshg28.htm
The one at Vegas Carts is 94mm.

5. 32mm Intake Adapter $39.99
"Our Billet Intake Manifold / Adapter allows you to easily mount a Mikuni or Keihin style carburetor to your GX340 / GX390 / GX420 / GX440. It fits all GX-Series Big Block engines and has a 32mm Inner Diameter.
CNC Machined from 6061-T651 Aluminum Stock"
COLOR="Blue"]http://www.vegascarts.com/product-p/inman.htm

6. 32mm Ebay Mikuni / Keihin style Carb $29.95 free shipping
All the air a 420cc could ask for.
http://www.ebay.com/itm/like/262164767869?lpid=82&chn=ps&ul_noapp=true

7. VM30, VM32, VM34 Air Filter $26
Kamikaze Moto Air filters
Fits the Mikuni VM30 VM34 carburetors
Nice tight fit
Made in the USA!
Tapered Oval filter
http://www.speedmotoco.com/vm30-vm32-vm34-air-filters-filter-oval-tapered-p/121005.htm

8. Head Porting Done by Me.


What did I forget???
Avoiding Fuel Pump if possible, but an easy addition.

Please share input. I think I got it right. Other cheaper options for air filter?

GAB 2.6 would involve a performance cam, longer billet rod, 69mm stroker crankshaft (440cc) with bearings, cr-mo push rods, SS valves, 3 angle valve job, Dual HD Springs, billet rockers, a milled head,.....

That might be close to 30 HP and 7000 RPM. Nearing or surpassing the limits of the TC, the Block, the flywheel,.....

I like building the engines, not rebuilding them!

 

[rk970]

Ok Bob.... look up helmholtz resonance and how it effects the tuning of intakes and exhaust systems when combined with cam timing, rod ratio, cylinder volume and air density..
All the exhaust pipe formulas you are posting are very lacking when you start taking other factors into account.. Most were based on V8 iron sbc/sbf..
The exhaust header length, dia will not effect the peak torque rpm,, It does effect the torque curve before or after the peak. Cam profile combined with efficiency of the chamber design (intake port and exhaust port ect) is what determines peak torque rpm.

 

[bob58o]

Like the man said,
$170 for the engine
~$230 for the parts and shipping?

$400 for 22 -23 Reliable HP around 5500 - 6000? RPM.

Should work with a regular 40 series????
Maybe a 780?

 

[Jrgunn5150]

I intend to run mine with a regular 40 series.

IMO, anything over a 16hp engine and a 40 series clutch, cost wise, get's into the "I may as well use a streetbike engine with 100hp" range.

 

[bob58o]

Ok Bob.... look up helmholtz resonance and how it effects the tuning of intakes and exhaust systems when combined with cam timing, rod ratio, cylinder volume and air density..
All the exhaust pipe formulas you are posting are very lacking when you start taking other factors into account.. Most were based on V8 iron sbc/sbf..
The exhaust header length, dia will not effect the peak torque rpm,, It does effect the torque curve before or after the peak. Cam profile combined with efficiency of the chamber design (intake port and exhaust port ect) is what determines peak torque rpm.

I will look it up.

I was kinda under the impression that if I wanted a broad, flat torque curve up to my max around 6k, I could set the diameter of the pipe for 6000, then use a long tube to fatten up the torque curve under 6000 RPM.

I know length has to do with cam timing and the speed of sound (negative pressure waves traverse the length of the tube and help pull exhaust out and pull intake in).

---------- Post added at 05:19 PM ---------- Previous post was at 05:08 PM ----------

Ok Bob.... look up helmholtz resonance and how it effects the tuning of intakes and exhaust systems when combined with cam timing, rod ratio, cylinder volume and air density..
All the exhaust pipe formulas you are posting are very lacking when you start taking other factors into account.. Most were based on V8 iron sbc/sbf..
The exhaust header length, dia will not effect the peak torque rpm,, It does effect the torque curve before or after the peak. Cam profile combined with efficiency of the chamber design (intake port and exhaust port ect) is what determines peak torque rpm.

I am not prepared to get into this yet!

 

[rk970]

The header will move the "area" under the torque curve, it will usually never move the peak.. it is a compromise if you want a little more torque before the peak, at the peak or after.. The idea when building a engine is to maximize the area under the torque curve in its usable rpm range. In other words build it with the broadest power band that the cam will support.

 

[bob58o]

You just don't find this kind of stuff!!!!
http://www.ovka.com/files/Tech-Corner/2013_10_03_Clone-Update.pdf

Stock 420 Cam Specs!!!!!!!
I think I copied from that link before.

Doesn't seem to match the specs I listed in the fist post. Those may have been 390 specs?

These are from

420cc Builder Modified Predator OHV engine Technical Specifications
5/27/13

which says...
Camshaft Requirements: Stock camshaft only, ez-spin assembly must remain as
stock. The duration check for Intake and exhaust lobes is listed below. (Measured at
top of valve retainer).

 

[bob58o]

Monkey See. Monkey do.

Looks about right...

 

[bob58o]

lol