Hemi Build #3 -Boogie Woogie Woogie

[bob58o]

Hey Goose, you Big Stud!
https://www.youtube.com/watch?v=DKgcThjYBHs&feature=youtu.be

 

[bob58o]

I think it is all the way in.
???

 

[65ShelbyClone]

That's what she s....oh never mind.

 

[KartFab]

I drilled a jet out to 1.6mm.
I hope when NR says the inverted manifold needs a 160 jet, they that is what he meant.
GoKartsUSA says 170 to 180.

I know this is not a VM22 and the stock jetting is a little different.
Stock VM22 Jetting is 100. Going to a 160 is a 160% increase in area of the jet hole.

I assume if the manifold requires a larger main jet, then the low jet and clip position should be richened as well?????????????

A 30 low jet, if enlarged by 160% in hole area, would become a 48 jet, but neither distributor mentions the low jet.


Where is all this fuel going????
It can't all be getting burned. If a manifold requires twice as much fuel and all that fuel gets burned at the same AFR, then it would make twice the power right? Not likely that a manifold swap with the same carb will double the power.

This manifold appears to be not very fuel efficient. Where does the extra fuel go?

They must know I was using a filter with a chromey part and limitless flow.
Or want me ready to switch to methanol if I ever switch to a normal manifold.

so when i see a mikuni 160 jet,or a 260 jet, or a 500 jet, that is 1.6mm jet, 2.6mm jet, and a 5.0 mm jet?

 

[bob58o]

so when i see a mikuni 160 jet,or a 260 jet, or a 500 jet, that is 1.6mm jet, 2.6mm jet, and a 5.0 mm jet?

You are correct Sir (more or less)....
Mikuni and Keihin are slightly different, as is Dynojet.

This drill bit kit I have gives 100, 105, 110, 115,.... up to 150
Then 160, 170, 180, 190 and 200

 

[bob58o]

Here is a comparison between diameter, Mikuni, Keihin, and Dynojet

http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm

This shows a 160 mikuni jet is 0.074" diameter, which would be 1.88mm.
Show a Keihin 160 jet is 0.062" diameter, which would be 1.57mm.
I went small and used a 1.60mm.
Harder to un-drill a hole than it is to drill one.
I will go bigger if I need to.

BTW, I put a 48 low jet in there for now. Needle clip in original position, (which I'm guessing is in the middle? I didn't look yet).

 

[bob58o]

I'm still waiting on that 3/8" Lexan Plate.
It should have been here on Monday.
All I get when tracking is "On Way to Next Destination" or some BS. No specifics.

The thin sheet I had seems to give slightly different measurements when I flip the plate over. It is not flat as I would like.

If it is 21.5cc and I mill 0.035", I should get around 18.25cc for 11.09 :1 SCR and 8.46 :1 DCR.
If it is 22.0cc and I mill 0.040", I should get around the same.

Hopefully with the thicker Lexan plate, I can get a bit more accuracy and then I'll send the head off for a valve job and milling. 0.030" Minimum, 0.040" Maximum. Probably will mill 0.035" anyway, but I paid for the thicker plate so I will wait for it.

 

[bob58o]

Lexan Plate is here!!!!
I don’t remember what I got from NR, but that is here too!!!

 

[bob58o]

It was ponies in the box.
Can’t cut and weld till I get me a Minibike.

Now it’s a three stage (if you count that last flared bit).

 

[bob58o]

Now I’m consistently getting between 21.75 and 22.00 CC’s. Since I used up all my Windex, I’m going to call it 21.75 CC’s. Better safe than knocking.

Going to mill 0.035”.

If 0.9338 cc’s per 0.010 milled, then milling 0.035” removes 3.25cc’s.

18.5cc chamber.
10.97 :1 SCR
8.37 :1 DCR (if using 71 ABDC intake valve (seat) closing).

I think I started off wanting to mill 0.035”.
I bought a burette, a 3/8” Lexan Plate, and used up a half bottle of windex (last tests were watered down). Still going to mill 0.035” but now I feel better about it.

 

[Noseoil]

With a VM22-133, I ended up with a 130 jet on the modded hemi motor. I would start there for your build & see if it needs more fuel or less fuel, but that should be fairly close. With the VM22 Chikuni, I never got it running right & jet changes were a PITA due to dropping the bowl. The -133 is a better choice & is easy to swap jets in a minute or two, just costs more...

 

[bob58o]

With a VM22-133, I ended up with a 130 jet on the modded hemi motor. I would start there for your build & see if it needs more fuel or less fuel, but that should be fairly close. With the VM22 Chikuni, I never got it running right & jet changes were a PITA due to dropping the bowl. The -133 is a better choice & is easy to swap jets in a minute or two, just costs more...

I have a flat-slide carb. Ok it is a "D" slide, but not a VM22 round slide. And I did not pick my jetting at random.

https://gokartsusa.com/Mikuni-22-Inverted-Intake-Manifold.aspx
Inverted 22mm Mikuni Intake for Mini-Bikes and other custom applications. Mounts 22mm to GX200, BSP Racing "Clones, & 212 Predators.

Will typically require jetting in the 160 range


or

https://gokartsusa.com/Mikuni-22-Inverted-Intake-Manifold.aspx
MADE-IN-USA designed for the Little BadAss Mini Chopper, use this Inverted Intake Manifold to install a Mikuni VM22 carburetor on a Honda GX120/160/200, Titan TX200, Predator 212 and others.

170-190 Mikuni Main Jet Recommended (the stock is 100)

 

[Whitetrashrocker]

Windex? Doesn't the ammonia speed rust? Why not gas or solvent?

 

[bob58o]

Windex? Doesn't the ammonia speed rust? Why not gas or solvent?

Windex is blue and you can see it?
I think most people use rubbing alcohol. The green stuff?
I wipe down with WD-40 after I measure.

 

[Whitetrashrocker]

Hey it's a fluid you can measure.

I was hoping for a gab on Windex.

 

[bob58o]

Well why not some 1.2 Rockers?

 

[bob58o]

I was guessing that I needed heavier than 26lb springs if I wanted to run the 1.2 roller tip rockers. This is an issue, because the 37lb springs need the the pockets cut wider to accomadate the larger-than-stock diameter springs.

So I asked NR which springs and what length valves I might try...

Can I run 1.2 roller tip rockers in a hemi head with the custom 280-0410 cam I recently received?

Which valve springs might I need?

What length valve would I need?

I currently have 26lb springs and my SS valves came from ARC and measured around 0.055” longer than the stock ones if I remember correctly. Not sure if these are the same as the +0.070” valves you offer or not?



Hi,
Yes, but with Hemi you need to watch for valve to piston issues, although a 280 should be fine'
37lb Springs
Std Length (we list as .070")
However, the ones from ARC are the same and 26lb springs will be fine. So I would just stay with them

Thanks,
Russell Thompson
NR Racing LLC
248-767-0421

Looks like I will be trying out 1.2 roller tip rockers. Can you feel the excitement? I'm excited. This is exciting.

Needing new shorter pushrods when I already purchased CrMo P-rods, not so exciting.

http://www.nrracing.com/product-p/nrrock-hemi.htm

 

[ezcome-ezgo]

Roll Baby roll! But wait... what kinds of bearings are in those lifters? Maybe you should upgrade them. Also, a little sintered brass in the pushrod pocket might reduce friction 0.000004%.

 

[65ShelbyClone]

It's probably just a hardened bushing on the rocker tip. Roller bearings that size would fail immediately under the forces involved.

 

[bob58o]

Roll Baby roll! But wait... what kinds of bearings are in those lifters? Maybe you should upgrade them. Also, a little sintered brass in the pushrod pocket might reduce friction 0.000004%.

The lifters are not rollers, but only cause I don't know of any that will work with these cams and pushrods..

The piston has not yet been modified. Nor has the ignition coil.

If you want a recap....

Governor Removal
Low Oil Sensor Removal
Kohler Flywheel
Offset Flywheel Key
Kohler Fan
Kohler Stator
Clone Fan Shroud
Clone Starter Motor
Clone Key-Switch Box
Economy Top Plate
Side Cover Studs
Head Studs
SS Valves
Aluminum Retainers
Middle Groove Keepers
Lash Caps
1.2 Rocker Arms
CrMo Pushrods
Billet GX200 Lifters
26lb White Stripe Springs
Valve Spring Shims
NR280-0410 Cam
ARC +0.020" Billet Rod
0.027" Head Gasket
Head milled 0.035"
Three Angle Valve Job
Basic Port work
Inverted Chrome Manifold
Rubber Flange Adapter
OKO 21mm Carb
Metal Screen Air Filter
Dry Charger Prefilter
Rear High Center Exhaust Header (10" x 0.87" ID)
45 Degree Exhaust Pipe Extension (12" x ~1.00 ID)
AR3910X Spark Plug
12V 1 Amp Fuel Pump
1/4" Fuel Line Tank Petcock (M10 x 1.25)
Performance Crank Bearings
Crankshaft Tall Journal Lips Ground for clearance
Bottom of Cylinder Ground for clearance
Outside of Block (near Governor Gear Area) Ground for clearance
Top Plate Modified for Clearance
Fan Shroud Modified for Clearance