Thread: Raider Porting
12-18-2006, 09:20 PM #1
Here's some pics of my first attempt at porting.
I raised the exhaust port to 35.5mm from top of the cylinder deck and widened it to 51.8mm. There is a curved opening cut into the bottom of the skirt on the intake side. The transfer ports were raised to 53.8mm from top of the cylinder the deck and the sides of the sleeve and case were cut to match. The tranfer ports are cut a little deeper into the cylinder and the roofs were cut flat. This has been the hardest part, it's very challanging to get in there and try and smooth out the cut marks. The Exhaust ports have been polished and I'm working on the matching the exhaust manifold to the cylinder and polishing the inside of it as well.
12-18-2006, 10:08 PM #2
Is this the tool of choice.
Last edited by Flying Scotsman; 12-18-2006 at 10:14 PM.
12-18-2006, 10:25 PM #3
I used a dremel tool with a 90 degree adaptor and every bit I had in my kit. I used a couple different carbide bits that look like that bit just smaller, the dremel bits are 1/8 inch shanks. Most of the bits I found for porting have 1/4 inch shanks. The compressor I have at home just doesn't put ot enough cfms for air tools so the dremel is the best that I could do.
12-18-2006, 10:44 PM #4
Dremel tools are nice but the extra rpm from air is a smoother finish.
I have a dremel but I have been thinking about air tools for a while.
When I get back my 2 sets of cylinders from up North I might just give at least one of them a tweak or two.
Thanks for the measurements what is a stock cylinder height 4.686"
I havent converted to mm yet sorry.
12-18-2006, 10:56 PM #5
I use a digital caliper that converts from sae to metric with the push of a button. It works great, you can get one off ebay for around 20 bucks.
12-18-2006, 11:04 PM #6
It was easy to do the skirt and the exhaust port but the transfer ports are truly a challenge. I think some air tools would have made the job much easier. Also there is a much better selection of porting bits and sanding drums for the air tools.
12-18-2006, 11:17 PM #7
You guys have to stop this!!! I am so tempted to tear apart my perfect running ski to try some of this stuff
Keep up the good work- and keep us posted
12-18-2006, 11:31 PM #8
Not sure why you decked them was it to bring in your port specs or to bump the compression.
Looks like you did a nice job.
12-18-2006, 11:33 PM #9
I know how you feel, my raider was running fine. I just thought it was time to do some of the things that other people are doing on here. For me it's great to do things that take more time than money. This is what I love to do on my day off, it's very relaxing for me.
12-18-2006, 11:50 PM #10
I did not deck the cylinders, that's just the measurement from the top of the ports to the top of the cylinder. I raised the port opening to get this measurement. My compression will go down because the exhaust port is higher now. I have been running a R and D head at 150 psi and that is what I'm going to use when I put the engine back together. After break in I will check to see were the compression is at. I think it's going to be lower than what I want so I will probable send my stock yamaha head out to someone to modify and then sell my R and D head. Also I'm having the cylinder bored up to 82mm so it will probable help to adjust the head for this as well.
Last edited by oldmanraider; 12-18-2006 at 11:53 PM.
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