RaceLogic Porting

[plumbjet]

Hi All

Got my template this week and made a start on the porting template is not the same as the one on the Tech FaQ Posts its the superstock freestyle new one

Tell me what you think ,am i on the right track is my taper to long, should i cut more out, the template is for a superjet 701cc but my one is being bored out to 760

Please tell me if you think i need to anything, any help would be good.

 

[plumbjet]

This is the template shape

 

[romack991]

I've haven't done many port jobs so I can't give you much comparison but I used the original sport port and used a long taper and really focused on making it as smooth as possible. What I found to work best after the die grinder was to use a rounded file to make sure the surface wasn't wavy. It could catch small dips that I didn't notice at first. I really like how my motor runs.

Edit. Including a snap shot of my taper.

 

[QJS]

You have a very agressive taper in the sleeve, remember when you bore this to 760 a lot of this will cut away.
Chris.

 

[plumbjet]

Hi Chris got the parts today thank you very much, chris do you mean i should take more off ,so when bored i will still have the same size opening

 

[oxnard111]

Hi Chris got the parts today thank you very much, chris do you mean i should take more off ,so when bored i will still have the same size opening

what did you order?

 

[WaveDemon]

that transfer should be a lot longer and then chamfer it. it looks like you used the template as the outside of a chamfer.

 

[QJS]

Hi Chris got the parts today thank you very much, chris do you mean i should take more off ,so when bored i will still have the same size opening

Catch 22 this one, given that the exhaust port width is calculated as a percentage of the cylinder diameter then you should really work from the final size, this is what I do, bore first then work out port width. The downside is that for someone who is not doing this all the time there is always a chance of damaging the sleeve and if your up to 760 you don't have much to play with.
Whatever way you choose to do it you really need to take your current size further back into the port tunnel.
Chris.

 

[plumbjet]

chris i think i understand what you are tell me, i was a little bit concerned about how much i could take off near the sleeve end thats why i taped it so much fort i would cut in to the water jacket.

 

[Mouthfulloflake]

YES

that newer sport port template is WIDE... I used it on my 760 cylinder and I was worried about the water jacket too...

its VERY thin in there im pretty sure.

Ive considered some epoxy or JB weld inside the cavity...

 

[plumbjet]

Your right there Wider thought i had the wronge template did you finsh your portiing with the template did you get any pic,s that would help a lot

 

[D-Roc]

from the pics it looks alot like the way mine turned out but i am only running it as a 82mm bore. not sure how it will look once you bore it out to 84mm, you will probably loose a bunch of the port size which should be even bigger anyways for the bigger bore.

 

[plumbjet]

Had a good bash at it today and think i have got it right this time would not like to have to take any more out. Think i must be MM from the water jacket but have made the taper a lot small then before. Going to send them up to ATP first thing for boreing to 760 i hope chris will tell me if i need to do sum more work on them. will post a picture or two a little later.

 

[#ZERO]

If you look into the exhaust port opening on the cylinder side you'll notice the sleeve appears thicker at the edge where you did you porting.

This is because you did most of the porting at a sharp angle and did very little porting of the aluminum casting.

Try to make the sleeve thickness even all the way around the exhaust port without exceeding the template guide.

Make the inside of the exhaust port wider with an even taper to the outer window and it will look great.

 

[davidescu_radu]

Well,this was my mistake too