372 X-torq Mod Discussion Final Woods Port Video Posted

[XP_Slinger]

Due to growing interest in another thread I'd like to get a conversation going on x-torq mods and porting.

So here's where I'm at. My 372XT has had the base gasket deleted (.024 squish), a muffler mod and reshaped lower transfers to more effectively "funnel" the crankcase charge into the transfers.

Today I am going to remove all strato dividers in the intake chain of components (filter mount, carb, intake boot). In addition to this I'm also going to reshape the cylinder intake to enhance flow and possibly make it favor the main intake passage vs the small strato ports that are above it. Another member was kind enough to provide me with some of his porting numbers and I intend to document the numbers on my stock cylinder to compare. I'd like to get some brain storming going on porting and even general mod theories for this model as there seems to be a growing interest in them.
I will be posting pics of before and after of what I do today to aid in understanding of how this design works for those that may not be familiar. For starters, here is a pic of what I did to my lower transfers a few weeks ago. The first pic shows the difference between the stock lower transfer.

 

[mdavlee]

I say do the other stuff first before you gut it. Once you do there's no going back. You can try the other mods first and if you decide you want to see if more is there gut the stratos

 

[Keith Gandy]

I say do the other stuff first before you gut it. Once you do there's no going back. You can try the other mods first and if you decide you want to see if more is there gut the stratos

Ever gutted one Mike??

 

[mdavlee]

Ever gutted one Mike??

Nope. I've only ported one with good results.

 

[Keith Gandy]

Nope. I've only ported one with good results.

Yes Ive ran a 372xpw Mike ported setup for long bar. Very strong!! He knows how to build one

 

[mdavlee]

The xtorq has torque like the Xpw does.

 

[Keith Gandy]

Do u favor replacing the carb on the xtorq and pre x ? Replace with wj6 ?

 

[mdavlee]

Do u favor replacing the carb on the xtorq and pre x ? Replace with wj6 ?

Nope. Xtorq carb or modded zama from Rich.

 

[Spike60]

I like that reshaping of the lower transfers. Thanks for sharing that pic. I'm going to add that to my 2166 test mule that I've been working on.

 

[Keith Gandy]

Another question. Why r the strato ports over the intake on husky and under on Stihl?

 

[XP_Slinger]

Currently out on a mission to find a sleeve to extend the crank shaft so I can mount my degree wheel.

 

[Mastermind]

I've done them both ways......and I don't gut them.

If you do decide to gut it......leave the divider in the carb.

 

[XP_Slinger]

I've done them both ways......and I don't gut them.

If you do decide to gut it......leave the divider in the carb.

Wish I would've checked the forum throughout the day. I already removed the divider and now that you mention it, it makes sense to leave it in to "aim" the fuel + air charge towards the the main intake passage. I'm fixin to post pics in this thread of everything I did today. Might take a bit, Big fingers, little phone...lol

 

[XP_Slinger]

I like that reshaping of the lower transfers. Thanks for sharing that pic. I'm going to add that to my 2166 test mule that I've been working on.

No problem Spike, glad I was able to help. Looking forward to running these mules.

 

[XP_Slinger]

Step 1: Filter Mount

Pretty straight forward, I clipped the majority of the divider out with dikes then smoothed everything out with a dremel. TIP: keep the dremel speed low, too much speed melts the plastic very fast and makes it a little more time consuming to clean up after the cutting is done.

 

[XP_Slinger]

Step 2: Carb Divider (Or not, to try a different method mentioned by mastermind above).

This step is a little more intricate. To remove the divider you have to remove the throttle butterfly and shaft. Once the shaft is removed simply pull the divider out of the carb via the slot that it resides in. My divider needed gentle persuasion with needle nose pliers. TIP: The retention screw for the butterfly had low grade thread locker on it. I reapplied low grade locker upon reassembly. Cheap insurance to keep a saw killing screw out of your crank case.

Before:


After:

 

[XP_Slinger]

Step 3: Intake Boot

This step is very delicate, if you're not careful you WILL cut a hole in your intake boot. Take your time and pay close attention to what collateral damage could be done by portions of your blade that aren't cutting the intended material. The hobby knife in the picture worked especially well for this.

Before:



After:

 

[XP_Slinger]

Step 4: Cylinder Intake

This step is more experimental than the previous ones. I had 2 schools of thought, 1st; blend the edges between the ports to smooth out the flow, or 2nd; blend them but make the flow favor the main (lower) intake passage. I opted for the 2nd option. I continued the intake roof angle up through the material between the main and strato passages. I didn't make the intake wider down lower because the intake boot was actually fit to its shape very closely. The stratos were largely untouched with the exception of bringing the edge together with the lower intake.

Before:



After:



Sorry about the rotation...but I thinks it's still easy to see the difference.

 

[XP_Slinger]

Step 4: Cylinder Intake

This step is more experimental than the previous ones. I had 2 schools of thought, 1st; blend the edges between the ports to smooth out the flow, or 2nd; blend them but make the flow favor the main (lower) intake passage. I opted for the 2nd option. I continued the intake roof angle up through the material between the main and strato passages. I didn't make the intake wider down lower because the intake boot was actually fit to its shape very closely. The stratos were largely untouched with the exception of bringing the edge together with the lower intake.

Before:

View attachment 12124

After:

 

[XP_Slinger]

Oops...sorry about the double post fellas