Hi all!

I have finally begun the work on improving my 4-stroke Jammin' X2CRT project again (with the modified OS FS.56 Alpha). The latest improvement i've made was to smooth out the flow through the intake manifold and the intake port in the cylinder head.
As the intake manifold I use was round and the intake in the cylinder head is oval I have smoothed out the difference between these, so the intake, where the carb sits still is round but it transitions smoothly to an oval shape that fits the cylinder head. This also means that the diameter is bigger close to the carb and slightly smaller in the cylinder head, so it's kind of tapered/conical shaped. I hope this results in the air/fuel mixture to be compressed more through the intake port and also increase the speed of the air/fuel mixture on it's way to the combustion chamber.
And in the process I have also slightly increased the diameter (area) of the intake port. So hopefully i'll be able get more air/fuel through to the combustion chamber. Now I just hope, that the intake valve is big enough to handle it.

I'm also planning to reduce the rotational inertia in the driveline slightly by using a smaller spur gear (44 vs 48 tooth spur) and using a smaller clutch bell, thus also being able to mount the engine closer to the centerline of the car. I just need to calculate which size of clutch bell I need? I'm using a 20 tooth bell with the 48 tooth spur now. So i'm guessing something like an 18 tooth bell should work fine with the 44 tooth spur? Hopefully these modifications will help the engine rev up faster and create a better balance in the car.

I'm also considering increasing the passive cooling of the engine with coolingfins from a computer (like the coolingfins from the processor in a computer). It seems like the ventilator driven by the crank shaft just isn't sufficient to really keep temps down.

So far I have been running with an OS muffler from the FS .91 engine (the F-4020 muffler). But it seems that this is restricting the engine, so 'ill try running it without the muffler next time. I'm thinking of making a longer header pipe keeping the same diameter "all the way", so I can route the exhaust tip outside of the bodyshell. This might get louder, but if it works, i'll figure out a muffler for it later. I have found a company specialised in making flexible steel tubes with different types of thread and nuts in the ends, so I can fit it directly to the header pipe or maybe the cylinder head. Hope they will help me out.

I'm also considering increasing the exhaust port diameter also. What do you guys think?

Have any of you guys tried to raise the compression on a 4-stroke? I measured the head gasket and it was 0,2mm and it made me wondering if I can get a 0,1mm head gasket?

So far I have been running with the pressure pipe from the muffler to the tank, but reading the first pages of this thread I realised this is not so good? So, i'll try running it without pressure to the tank next time.
Finally i'm also getting the Perry VP30 fuel pump, so I hope this will help in creating a constant and reliable fuel pressure.

Long post, sorry, but I just wanted to share the progress of my project and my ideas with you guys to get your opinions and experiences.

I have attached a before and after picture of my intake-work.