Porting knowledge

FGR01
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FGR01 10/30/2014 12:06pm
10/30/2014 12:06pm
I've ridden multiple 2-strokes that had the absolute best, no cost spared motor work done by the big name company. On most of them I would describe the powerband as "useless for anything other than flat track racing", "worse than stock", or "ruined".
rocketsocks26 10/30/2014 3:42pm
10/30/2014 3:42pm
I had my 06 yz250 done by pro circuit, and was so excited to get it done from them when i got it back and was looking at it i thought their work looked like shit!it was no fire breather either lol talk about dissapointment! I had micky kessler port cylinders for me that looked like a work of art, im guessing one of the mexicans did my cylinder
Cygnus
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Cygnus 10/30/2014 5:53pm
10/30/2014 5:53pm Edited Date/Time 10/30/2014 5:55pm
Flow benches can be a huge advantage in slowly working on a cylinder or head. I would never pay for porting without a flow chart to go with it. Before and after.

I did pay for this service from a performance place out of Tampa back in the day for my Cosworth FZR 600 superbike.

The Shop

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GuyB
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GuyB 10/30/2014 6:02pm
10/30/2014 6:02pm
2 Stroke Beast wrote:
Does anyone know the basic knowledge of what to do to the transfer ports to change the power curve I tried to look it up and...
Does anyone know the basic knowledge of what to do to the transfer ports to change the power curve I tried to look it up and got nothing any help Thanks danny
Have someone who knows what they're doing do it.
MR. X
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MR. X 10/30/2014 6:25pm
10/30/2014 6:25pm
Im confused how the port height changes the power band, this guy clearly shows how the power bands are supposed to be changed.

https://youtu.be/P-jX9mJfbps
PTshox
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PTshox 10/30/2014 11:30pm
10/30/2014 11:30pm
A couple years ago i was talking to pr2 about porting a 250sx cylinder, his price was crazy around $575, and his reason being was he ported from the inside of the cyclinder, which was difficult cause it can chip the cylinder walls, it didnt make sence to me is this common? And he also slammed other companys cause he said mexicans wherent porting his cylinders lol

I had a chat with that guy that runs PR2's engine department. He wanted around $900 to do a valve job on a CRF250R head... The head already had his porting done to it. I about fell out of my chair. Then I sent his ported CRF head to a well know engine tuner that has done work for me. It was put on a flow bench and tested. Flowed right around the stock numbers.. As I recall it was actually down a little bit from stock. I wouldn't send this guy a hamster to baby sit.

Jrewing
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Jrewing 10/31/2014 3:55am
10/31/2014 3:55am
Learn to jet for conditions. Nothing like a well jetted 2 banger.
rcannon
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rcannon 10/31/2014 7:11am
10/31/2014 7:11am
There are small things you can do that will help.

Just look at the parts, and some issues will be obvious. My 1998 yz 250 was a perfect example. I had to replace its powervalve and noticed the new oen was slightly different. You could see the valve split in half, and neither side matched the other. Also, the entire valve blocked the exhaust port, just slightly, when it was supposed to be fully open.

Just matching that up offered a lot more top end.



Joko
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Joko 10/31/2014 6:32pm
10/31/2014 6:32pm
Ok, so we are down to Varner, Tom Morgan, HP bikes, Chatt Watts.,,,,,?
2 Stroke Beast 10/31/2014 6:37pm
10/31/2014 6:37pm
Joko wrote:
Ok, so we are down to Varner, Tom Morgan, HP bikes, Chatt Watts.,,,,,?
yep now we need to see who has best prices
slipdog
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slipdog 10/31/2014 7:06pm
10/31/2014 7:06pm
Joko wrote:
Ok, so we are down to Varner, Tom Morgan, HP bikes, Chatt Watts.,,,,,?
What's HP bikes?
GIwasB4
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GIwasB4 10/31/2014 7:19pm
10/31/2014 7:19pm
GuyB wrote:
Have someone who knows what they're doing do it.
DG knew what they were doing. Too bad they don't offer it anymore. Anyone know who the master cutter at DG was?

NOS cylinder



1980 DG ported cylinder





slipdog
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slipdog 10/31/2014 7:26pm
10/31/2014 7:26pm
^^^Sweet addition of Boyesen ports
slipdog
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slipdog 10/31/2014 7:46pm
10/31/2014 7:46pm
newmann wrote:
I spent $500.00 12 years ago getting my 74 CR250 ported. Of course that included polishing and matching the carb to a billet intake manifold, manifold...
I spent $500.00 12 years ago getting my 74 CR250 ported. Of course that included polishing and matching the carb to a billet intake manifold, manifold to cylinder, cases opened and port matched to transfers, exhaust port and manifold matched and polished as well as cutting and reshaping the head. Had to have a pipe built to match the engine mods for another chunk of change. She's a fire breather though. Smile

Bummer that the guy turned out to be a bit of a flake and has yet to return some other pieces I sent him ten years ago....

I sure wish there was someone out there who could do something similar on a 74/75 CR125 engine for me. Slippy???
I missed this comment yesterday and I think we PM'd about it a while back, but I wouldn't be against a project like that even though '90's and newer are my specialty.
Joko
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Joko 10/31/2014 7:46pm
10/31/2014 7:46pm
Hpbikes.com
Waiting on return of my YZ144 cylinder, will report soon
madmaxperformance 10/31/2014 7:53pm
10/31/2014 7:53pm
I had a mod business, specializing in yamaha sled engines, sent them all over the world. Built a big bore kit for Cat 800/900 twins, and modded 50cc bike engines, 60s, etc, some 250s and 125s.

My yamaha sled engines I will say were some of the best in the world. You absolutely can port nicasil or any plated cylinder without compromising the plating.

It's not the time you are paying for, it's the technology. And, the tools. Porting tools are the cheap part. Milling machines, lathes, etc for cutting cylinders, carbs, heads, etc is where the cost is.

If you know what you are doing, you can improve pretty well ANY two stroke. A degree wheel, and good measuring tools, to calculate port timing and port area, and flow characteristics. Dyno time helps a ton as well.

It is VERY difficult to improve a stock race bike cylinder by just grinding and polishing. In fact, 95% of the time, it will likely be slower, unless it's a horrible casting. You have to be looking at port timing, and overall pipe/cylinder design.

For most guys... fresh top end, great jetting, jack up compression a little bit, and run good fuel, with a reputable pipe brand... and it will be the best money spent. Then, from there, it's a ton more work, and often is best to have the whole engine to degree it, case port, cylinder port, and head rechamber, as well as ignition timing.. A well built 250 is amazingly fast, and usable.
GIwasB4
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GIwasB4 10/31/2014 8:17pm
10/31/2014 8:17pm
So would you porting aficionado's recommend smoothing out and polishing this original DG port job?


Pit Row

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madmaxperformance 10/31/2014 8:21pm
10/31/2014 8:21pm
Not much nope. Have to see all the transfers, exhaust port, etc. A bit here and there, but that's not where the power is.
stillwelding
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stillwelding 10/31/2014 8:42pm
10/31/2014 8:42pm
GuyB wrote:
Have someone who knows what they're doing do it.
GIwasB4 wrote:
DG knew what they were doing. Too bad they don't offer it anymore. Anyone know who the master cutter at DG was? NOS cylinder [img]https://p.vitalmx.com/photos/forums/2014/10/31/69239/s1200_nos_1980_yz125_cylinder.jpg[/img] 1980...
DG knew what they were doing. Too bad they don't offer it anymore. Anyone know who the master cutter at DG was?

NOS cylinder



1980 DG ported cylinder





I'm pretty sure it was Harry Klemm. I remember the sarcastic jingle, "Do you have a Hairy Klemm?"
slipdog
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slipdog 10/31/2014 8:55pm
10/31/2014 8:55pm
I agree with Madmax, not much you could do that could change anything other than aesthetics. The big increase is already there with the addition of the sub intakes(Boyesen ports) and most everything else is in the port windows.
GIwasB4
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GIwasB4 10/31/2014 9:37pm
10/31/2014 9:37pm
GuyB wrote:
Have someone who knows what they're doing do it.
GIwasB4 wrote:
DG knew what they were doing. Too bad they don't offer it anymore. Anyone know who the master cutter at DG was? NOS cylinder [img]https://p.vitalmx.com/photos/forums/2014/10/31/69239/s1200_nos_1980_yz125_cylinder.jpg[/img] 1980...
DG knew what they were doing. Too bad they don't offer it anymore. Anyone know who the master cutter at DG was?

NOS cylinder



1980 DG ported cylinder





stillwelding wrote:
I'm pretty sure it was Harry Klemm. I remember the sarcastic jingle, "Do you have a Hairy Klemm?"
It was Harry Klemm. The guy was a genius.
So would you smooth out and polish this cylinder, or leave original?
PTshox
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PTshox 11/1/2014 12:44am
11/1/2014 12:44am
Yep... it was Harry Klemm... he's still around doing stuff. Try him or Eric Gorr for 2 strokes. Varner can also do some good work on 2 strokes. Ron Hamp is very, very good for 4 strokes.
lumpy790
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lumpy790 11/3/2014 6:15am
11/3/2014 6:15am
Chad Watts Watts Perfections and Barr's Competition are local for me.
Jakes Dad
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Jakes Dad 11/3/2014 7:45am
11/3/2014 7:45am
Increasing intake flow is one thing knowing where to put it is another. Reshaping the transfer to keep the intake charge at the center of chamber and not blowing out the exhaust is the key. 2 strokes are tricky with that invisible wall created by the pipe. You can over power that wall with a stronger intake charge and it's then just wasted. This is where my guy will re-weld or epoxy where needed. Dyno results show torque curve coming in 1000 to 2000 rpm sooner than stock.

He's not taking any work until after Mini O's though.

www.tdc2strokeperformance.com
hvaughn88
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hvaughn88 11/3/2014 8:03am
11/3/2014 8:03am
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work done by the big guys (not naming names) and it being a cluster, it makes me wonder how these companies are doing as much work as they are. Is it a situation where they started out small and did great work, and then the quality diminished as they grew? Or is situations where a customer like myself, who doesn't know much, just assumes that what they are getting done is really what they need?
O___o
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O___o 11/3/2014 8:16am
11/3/2014 8:16am
Jakes Dad wrote:
Increasing intake flow is one thing knowing where to put it is another. Reshaping the transfer to keep the intake charge at the center of chamber...
Increasing intake flow is one thing knowing where to put it is another. Reshaping the transfer to keep the intake charge at the center of chamber and not blowing out the exhaust is the key. 2 strokes are tricky with that invisible wall created by the pipe. You can over power that wall with a stronger intake charge and it's then just wasted. This is where my guy will re-weld or epoxy where needed. Dyno results show torque curve coming in 1000 to 2000 rpm sooner than stock.

He's not taking any work until after Mini O's though.

www.tdc2strokeperformance.com
Hey, you are in the area and probably old enough to remember "SNR" Stormin' Norman. He still around?
reded
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reded 11/3/2014 8:21am
11/3/2014 8:21am Edited Date/Time 11/3/2014 8:24am
hvaughn88 wrote:
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work...
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work done by the big guys (not naming names) and it being a cluster, it makes me wonder how these companies are doing as much work as they are. Is it a situation where they started out small and did great work, and then the quality diminished as they grew? Or is situations where a customer like myself, who doesn't know much, just assumes that what they are getting done is really what they need?
One guy does the work and gathers the numbers. They then send his port job to the magazines for tests and it comes back with rave reviews and the orders start rolling in. Then they hire 4 flunkies to grind out the customers cylinders using the numbers provided. When the flunkies get done it looks like they attacked it with a hatchet and a hacksaw.

Having said that, I had a '95 KX250 cylinder ported by FMF back when and it couldn't have been any more beautiful. Ran like a scalded dog too!
O___o
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O___o 11/3/2014 8:28am
11/3/2014 8:28am
hvaughn88 wrote:
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work...
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work done by the big guys (not naming names) and it being a cluster, it makes me wonder how these companies are doing as much work as they are. Is it a situation where they started out small and did great work, and then the quality diminished as they grew? Or is situations where a customer like myself, who doesn't know much, just assumes that what they are getting done is really what they need?
reded wrote:
One guy does the work and gathers the numbers. They then send his port job to the magazines for tests and it comes back with rave...
One guy does the work and gathers the numbers. They then send his port job to the magazines for tests and it comes back with rave reviews and the orders start rolling in. Then they hire 4 flunkies to grind out the customers cylinders using the numbers provided. When the flunkies get done it looks like they attacked it with a hatchet and a hacksaw.

Having said that, I had a '95 KX250 cylinder ported by FMF back when and it couldn't have been any more beautiful. Ran like a scalded dog too!
Not 100% sure but I think that's when Varner was an FMF employee.
slipdog
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slipdog 11/3/2014 8:55am
11/3/2014 8:55am Edited Date/Time 11/3/2014 8:56am
hvaughn88 wrote:
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work...
I know next to nothing about porting, etc. Let me put that out there first. My question, though, is after hearing some people mention getting work done by the big guys (not naming names) and it being a cluster, it makes me wonder how these companies are doing as much work as they are. Is it a situation where they started out small and did great work, and then the quality diminished as they grew? Or is situations where a customer like myself, who doesn't know much, just assumes that what they are getting done is really what they need?
reded wrote:
One guy does the work and gathers the numbers. They then send his port job to the magazines for tests and it comes back with rave...
One guy does the work and gathers the numbers. They then send his port job to the magazines for tests and it comes back with rave reviews and the orders start rolling in. Then they hire 4 flunkies to grind out the customers cylinders using the numbers provided. When the flunkies get done it looks like they attacked it with a hatchet and a hacksaw.

Having said that, I had a '95 KX250 cylinder ported by FMF back when and it couldn't have been any more beautiful. Ran like a scalded dog too!
O___o wrote:
Not 100% sure but I think that's when Varner was an FMF employee.
100% it was Varner...

Not sure when he became an employee, '95-'96ish, but they sub'd the porting to him for years before just bringing him in house.

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