Race Logic Porting Kit

[SANDSTAR]

Good idea on getting your suspension in order.

[95prerunner]

ok I'll port then bore, I should get the templates some time this week. I'll post anymore guestions I have thanks.

[erbilabuc]

if any of you want to see some pictures hit me up on msn messenger

 

cubanmikey@hotmail.com

 

 

 

I have a few pictures to clear things up

[zman22]

Anybody have a set of templates they want to sell?

[superveiw]

I did my Banshee and SRX (they have them for snowmobiles and watercraft too) with the race logic templates and they are both WICKED fast. Paid $89.00 for each set (cheap). Easy to do and a very good manual. I heard they have them on e-bay sometimes, but not sure how much $$.

[bpreuss]

what kind of template bore would be good for mx? more of a low end to mid range port, is there any templates like that?

[erbilabuc]

what kind of template bore would be good for mx? more of a low end to mid range port, is there any templates like that?

they only have one template

[FORMULASPEED]

Racelogic on ebayPORTING

Since the kit doesnt come with transfere templates. You can clean them up.

Here is some info.

(Im not telling anybody to do this. Im just passing Info that I got. Take it however you want to. If any of the BIG DOGS on this site see something that isnt right Please post a response. Im not held respnsible)

 

The best thing you can do with a stock cylinder is to clean up unmatched ports to the cylinder sleeve and smooth out rough intake edges.

If you look at the intake on the stock cylinder, you will see an aluminum wall. You can cut the wall angle down with out cutting into the sleeve. This will help increase the intake velocity and cut down on some unwanted turbulence.

If you look at the upper portion of the stock cylinder intake photo, you will notice an aluminum wall. We want to reduce and blend the angle to cut down on turbulence and increase velocity. When the air\fuel mixture hits the aluminum wall inside the intake port, it creates turbulence. When we cut the angle down, it will increase flow, velocity, and cut down on unwanted turbulence.

 

If you look at the center of the stock cylinder intake you will see another aluminum wall. We can shave this wall as well without cutting the sleeve. We DO NOT want to remove the centerpiece of aluminum/steel. This aluminum/steel piece gives piston support; when removed, will cause the piston to rock and possibly crack the skirt of the piston, increase the chance to hang a ring and reduce the life of the cylinder bore. Just by changing just these two items will greatly improve your engines performance.

 

 

When porting the intake or transfer ports, never polish them. Leave a mild amount of roughness to help mix or atomize the air\fuel mixture. Only polish the inside of the exhaust port.By opening up the size of the intake port, you allow more air/fuel mixture to enter the lower part of the cylinder more efficiently. At the same time we are increasing the amount of volume in the area where the air/fuel mixture will be compressed before transferred. This lowers the amount of pressure or compression of the fresh air/fuel mixture under the piston, lessening the velocity of the transfer. That is why with a stock configuration, I suggest you only match port the cylinder and modify the areas that will restrict flow or create unwanted turbulence. With a stock motor you can open up this area a little and gain some power, but keep it to a minimum. Match porting and cleaning up casting flaws will do more than you think. If you are increasing your bore by more than 3 to 4 piston sizes, you can open this area up more. If you are increasing the stroke you can open it up more again. The larger the piston the larger the suction when the piston is traveling upward. The larger the piston the more area it is compressing. The longer the stroke, the more volume of air/fuel mixture will enter the lower part of the cylinder while the piston is traveling upward. The longer the stroke, the higher the air/fuel mixture will compress as the piston travels downward, before the transfer ports open. So with more stoke you can increase the volume area as much as the extra volume the longer stroke will consume.

 

Now the lower transfer ports need to be matched to the cases and gaskets. This will help a lot.

 

Then lets clean up the area between the lower transfer area and the upper transfer ports. With a stock motor, clean up the painted areas without removing too much material. There are a few areas that you will still see paint in some creases, that's ok. This area is also trapped under the piston before the transfer ports open. The same theory is used here as well as the intake area. That is as if a larger piston or a longer stroke is concerned. With a larger piston (3-4 sizes min.) and or a longer stroke you can open these areas up more as you increase the piston size or the length of the stroke. Make sure that everything blends well and turbulence is reduced and flow is increased. Refer to the ported cylinder photos.

 

The next item is the upper transfer ports. Read this carefully, it might be confusing. With the stock motor, the upper transfer ports at the bottom of the port should be even with the top of the piston at BDC. Rotate the crank until the piston is at BDC. With the piston at BDC, take a thin marker and place it at the edge of the piston. Draw a line along the cylinder wall by the transfer and exhaust ports. Then move the piston up to the top of highest transfer port. Again draw a line around the cylinder to locate the top of the highest transfer port. The top of the exhaust port will be much higher, so don't worry about it. In this case we are not worried about the top of the exhaust port, just the bottom. When you pull the cylinder off, you will see the marks, indicating where the bottom of the transfer ports are, where the top of the highest transfer port and the bottom of the exhaust port should be. This line is a guide to use when widening the transfer ports and to make sure the port is all the way down. Don't cut the transfer ports any lower than the top of the piston at BDC. It will do you no good and might cause some unwanted turbulence. The bottom of all the transfer ports should be even with the piston at BDC and all of the transfer ports should be even, or the same at the top of the transfer ports. With a stock motor, matching the castings will widen the ports a little. You can widen them more. Don't widen them in the very front going towards the exhaust. You can widen the transfer port in the front just not the end of the front port towards the exhaust.

If you raise the top of the port you will be changing the port timing. The higher you raise the transfer port the later the port closes as the piston travels upward. The higher you raise the transfer port the sooner the port opens on the power stroke. It is a good idea not to raise the top of the transfer port more than 1/8 of an inch with stock stroke. As you increase the length of the stroke I suggest that you don't raise the top of the transfer port at all. You need to lower the transfer port to match the height of the piston edge at BDC. This will increase the size of the transfer port. I believe that you should widen the transfer port, rather than raising it. Widening the transfer port instead of raising it will keep the compression of the fresh air/fuel mixture the same and give you plenty of flow and good velocity transfer when the port opens. If you raise the transfer port it will not compress the fuel as much because the transfer port will open sooner and start to transfer the mixture.

 

Catch 22. If you raise the top of the transfer port, it does not compress the mixture under the piston as much because the transfer port opens sooner than before, releasing the mixture into the cylinder. This means less pressure resisting the downward motion of the piston. End result is less transfer velocity but a faster revolution and less torque.

Widening the transfer port, rather then raising it will compress the mixture under the piston more, creates a higher transfer velocity and a higher compression. This forces more mixture into the upper part of the cylinder. This compresses more of the mixture between the piston and head and forces more of the burnt fuel out of the cylinder. End result is more torque because you are getting more fresh mixture into the cylinder, but this will slow the revs down from the extra compression on top of the piston and more compression of the fresh fuel under the piston.

Bottom line is; to raise it slightly for faster revs or widen for more torque. There is a happy medium by widening and slightly raising the port. I think you get the picture.

 

 

The next issue is the exhaust port. The exhaust port is similar as the transfer ports. I suggest widening the port rather than raising it. Make sure the bottom of the port is even with the piston at BDC. You should have a line there that you drew earlier. If you raise the exhaust port, it will allow the motor to rev. faster but will reduce the amount of torque because the compression area is reduced. The compression area is reduced because the exhaust port is closing later when the piston is traveling upward. This reduces the amount of mixture being compressed. The duration of pressure from the detonation of fuel will be reduced because the charge will be released faster with the raised exhaust port. Raising the exhaust port slightly is ok. Remember a 20 thousands of an inch cut will make a difference. With a stroked motor you will be lowering the exhaust port to match the location of the piston at BDC. The wider you make the exhaust port, the more torque you will gain. You don't want to go too wide or you get too close to the transfer ports and worse increase the chance of hanging a ring.

[Nighty]

WOW! awesome stuff formulaspeed!

 

Thanks for shareing!

 

I dont see any pictures yet though.

 

Can you mail them to me? Nighty@nighty.servebeer.com

 

thanks!

[superveiw]

formulaspeed My Banshee porting kit came with an application sheet witn insturctions and pictures about blending the reed area and transfers. It also had a spec for raising the transfers. I did the template mods and blending (reed & trans.), I didn't do the transfer spec. The differance was amazing, VERY VERY FAST.