3.2ss PMO's help

[Pierre911SC]

Hello Gents,

I took delivery of my new 3.2ss and put 1800 miles on it so far.
The engine is built as:
- 98mm Mahle cyl. & RSR pistons @ 9.5:1 compression.(Steve Weiner).
- GT2-104 cams. (John Dougtherty).
- Ported heads, PMO's, Electromotive ignition, single plug.(Carlos).
- And all other goodies.

I am very happy with the whole setup.
From now on, would like to adjust and tune my carburators myself.
I got an acceleration problem if I press to hars on the accelerator at low RPM,
The car sutter, jerk, hesitate...
I had it tune twice already with no progress.

First : I want to find out what I got in carbs, jets, ventury,mains...Where on carbs
can I find theses parts or numbers (I got the idle jets) ???

Second: What instrument, do I really need to fine tune, air/fuel ratiometer
or synchrometer ???

Any informations and pictures will be appreciated.

Thank you.
Pierre

Pierre

[Steve@Rennsport]

Originally Posted by Pierre911SC

First : I want to find out what I got in carbs, jets, ventury,mains...Where on carbs
can I find theses parts or numbers (I got the idle jets) ???

The build sheet that came with the carbs has all that information and your vendor should have that for you. If thats not available, remove one of each jet and read the numbers. You can measure the ID of the main venturi.

Second: What instrument, do I really need to fine tune, air/fuel ratiometer
or synchrometer ???

The Synchrometer is need for initial setup and balancing and a good AFR meter such as Innovate) really helps jetting and tuning the accelerator pumps.

[Pierre911SC]

Hello Steve

What I got so far,
Emulsion tube= F 11, at the end of that tube =160 (main ?)
Inside the carburator, 1/2 way down, big ring =40
Idle jet holder =60
Where do I find the rest, air corrector, idle air..?
And so far are theses figures OK for my engine ?

Pierre

[snbush67]

Probably not, you have 40's and you may need 46's. You can tune those for your set up but you will probably not get eveything that you need from those carbs.

Its like Lance Armstrong having a stuffy nose.

I know longer think you have 40's you probly have 46's, you really need to get a build sheet like Steve mentioned.

[Pierre911SC]

snbush67, what is your set up ?
Did you ever experience engine struggling at low RPM with
heavy foot on gas pedal ?

[snbush67]

I think your side to side balance is off. It creates a boxing effect and a stutter. Disconnect the short arms on the linkage.

Warm the car to operationg temperature.

Using a synchrometer check and adjust balance so that they are equal.

Then hook up the left arm so that it attaches without any change, then adjust and connect the right arm, check again for balance, synchronization.

The key check is then to check to ensure it is equal at 3000 rpms as well.

Have an assistant go into the car and step on the accelerator so it reaches 3000 (do not use the linkage arms to accelerate, it has to be done at the pedal).

If you are not equal on left to right sides then your linkage geometry is off.


You have to loosen the cross bar assembly slightly, and adjust it, then tighten and recheck.

All the barrels must open simultaneously or they will stumble.


Shane

[snbush67]

High Performance 3.2 Liter Short Stroke
1 Jan 2010 - 17 March 2010

3.0 Liter SC Case
Early SC Heads: Large Port 38mm
Stock Crank : Stroke Leangth 2.772"
Stock Rods

3.2 95mm Cylinders : Bored to 98mm (3.8582")from EBS
98mm J&E Pistons/pins/clips : Compression Ratio 9.5:1: Dome Volume 35.2cc
Gotze Rings : Top, 2nd and Oil : End gaps: .0015mm
GT2-108 Dougherty Racing Cams : Timing set at 3.2mm
High Lift Racing Springs and Retainers : Spring Height : 39.5mm, 110 lbs

PMO Carburetors and Manifolds : 46mm
Venturies: 38
Main: 160
Air: 190
Idle: 55
Idle Air: 130
Emul: F11

Thick flange SSI's
M&K Generation V, 2 in 2 out Muffler

Clewett Racing Wires
MSD 6AL Ignition
MSD Blaster Coil

Chain Housings gasket surface milled .1mm (modified for 3.2 Gaskets)
Rocker Arms resurfaced and reconditioned by C. Garret
Rocker Shafts reconditioned by C. Garret
New Valve stem seals
New Valves : 2E, 3I and 5I
New Oil Return Tubes and gaskets

New 3.2 Chain Housing Gaskets
New Chain Ramps
New Cam Seals and Gaskets
New Exhaust Manifold Gaskets
New Intake Manifold Gaskets

Used 3.2 Cam Bolts and Washers
New 3.2 Pressure Fed Tensioners
Used 3.2 Idler Arms and Sprockets

Here is the thread:

Shanes 3.2 SS - Recommendations and Advice

Shane

[rsscotty]

If you get through all the basic carb setup and adjustment issues and still have a hesitation problem, there is a trouble shooting guide on the PMO website that talks about accelerator pump bleed valve sizing. Something to think about is checking accel. nozzle injection quantity. Weber carbs have specs. on this, I don't know if PMO does, but Weber specs. would be a good starting point.