I went to the dealer today and he informed me that he does all types of porting and machining. He says he has built up a lot of motors and even has a dyno to test the mods on.

The question is this: Is porting and other machining easy to do (for the dealer/mechanic) or does it take years of experience to get it just right? My dealer said he could do the trail porting with the machined head and a better carb for my Scram400 but I heard so many of the guys here say to only go with HPD or RCR. But for me they are in the states and that means big $$'s and a month or so of "no riding"... Can a reputable dealer with the experience do a good job that would match my HPD pipe, clutch work and Aaen roller?

Any suggestions or tips?

Thanks a lot!

 

Xplor
I believe the real good port jobs come from guys with a lot of experience and a flow bench. This is not to say your dealer will give you a bad port job but on a dyno or a flow bench a difference could probably be seen. I would think since they advertise they can do it they have some knowledge and most likely won`t ruin it.

I`m not sure if you could get the info being "sacred tribal knowledge" at some companies but you could try calling reputable companies that port and get some info on their procedures. This way you could ask your dealer some educated guestions and make a decision based on his answeres. HTH

98 Scrambler 500
00 Trailblazer 250

 

My dealer does porting, also. I kind of doubt he does as many to have the experience of HPD or RCR, but he does have one advantage. He does all the work, and warranties the whole thing. Don't get me wrong, I'm sure RCR & the rest stand behind their work. What I am saying is that if you have porting done, and it throws a rod soon after, my dealer will fix it. He inspects the engine and warrants the whole thing to run. Without sending in the whole engine, there is no way RCR would know the condition of the rest of it. On the other hand, a knowlegable mechanic shoud do it right. It is just that with our dealer there isn't any hunting around who to get to fix it. I would ask what kind of guarantee they give on an engine they work on.

 

Thanks guys...
by the way, what exactly is a flow bench?

 

I'll still be ahead.

Trust them. I would.

 

Xplor
A flow bench is not really a bench. It is a test stand that they put your head or cylinder on that measures the amount of air that flows through it in CFM (cubic feet per minute). They get a baseline reading of what your part flows. Then when they are done with the port job they can see how much more it flows. Not sure if it tells where (in the rpm`s)it flows better.

Where the experience comes in is where to remove material to flow best for your mods and riding style ie... race or trail. Idon`t know too much about 2 strokes but I think what they do is make the port wider then for better top end they remove from the top of the port and low end they remove from the bottom and mid range is a little of both or vise versa but you get the picture.

On a 4 stroke just matching everything, cleaning up the flashing from the casting and polishing helps it flow better. Matching the parts (in your case cylinder to reed cage & such) is usually part of any port job.

Thats about the exstent of my knowledge. I`m sure theres 2 stroke guys who have more info. HTH

98 Scrambler 500
00 Trailblazer 250

 

Wait until the snow flies zorro. I got a good tow rope for tour 2x4.

 

EasterEgg,

Do you think with a porting, machined head and better carb my Scram could get more top speed(10 mph??) along with some low end and mid? What kind of power increase are we talking about exactly? What power ranges?

I ask this because I drag raced my buddy Zorro again and after the first 50 feet he slowly got a great distance in advance...gotta catch up one of these days!

Thanks

 

Xplor, I had Rick Ritter do the porting and head modifications on my Scrambler in July. I specified mid range porting, without giving up much low end, and to be run on 92 Octane pump gas. I put it all back together and this thing flies. I haven't tuned the carb yet, as I was breaking in a Wiseco Piston, and wanted to keep the engine rich ( And running pre-mix ). I put the quad up for the fall and winter hunting seasons, and will be tuning come spring.

 

Xplor
I`m a 4 stroke guy, built many a V8 Chevy used to race mud boggs with trucks until it got too expensive.

Before I had the Scrambler I had a Warrior that I did extensive mods to bore & stroke to 435cc, 12 to 1 piston, White Bros race cam, titanium retainers with hd valve springs and ported polished head. When I raced it everyone was amazed at how fast my Warrior was. I ported & polished the head myself with the help of a friend who raced motorcycles flat track.

A lot of what I know can be used toward 2 strokes and have some knowledge of them but I have never modified one. I guess it`s the long way to tell you I don`t really know or an accurate guess either. If I were to guess I would say you will definately gain power but will it be enough I don`t know least you get some of my back ground.

One thing to consider is the shaft drive in order to gain more mph you need to increase engine rpm because they are directly related. HTH

P.S. One day I will be asking if I can come play with you guy`s. Possibly doing Hatfield-McCoy in April and I`m only allowed 1 trip a year but some day.

98 Scrambler 500
00 Trailblazer 250