Planet Minis

DC50

stevec

Whoever is doing the porting should have a flow bench. The proof is in the numbers. You should get a documented higher flow rate after the work is done. Anything else is just voodoo.

dood

wrong.
A flow bench doesn't tell anything about velocity or reversion. Just because you can flow big numbers doesn't mean that ported head will make hp.
Air moves both ways.
There is a sonic pulse that happens once the valve is open but there is an opposing wave once that valve is closed.
Cam timing can affect this also.
Anyone can make peak hp, but you also need accelleration.
Now where is my Voodoo doll and my magic dust.

dood

It's great that you care about your business, but you can't make everyone happy. I've learned that no matter how hard you try, you are going to piss someone off. It's just the nature of the business.
I've been building engines since the mid 80's. I'm 42 going on 24 ( ain't that right Nate )
Just do what you do and things will work out.

stevec

What you wrote is more than just sending a head and $100/$200 to someone with a die grinder. You're talking about the complete head assembly. Cam, port, valve sizing, etc which I think is beyond the scope of this thread.

If you die grind a passage for hopefully better flow then you need some way to quantify the results. I think flow rate is a reasonable measurement. Every respectable shop that does head work has a flow bench. It's not out of the ordinary to ask for before and after numbers.

If all you want is a pretty hole to look at then just send it out for extrude hone. It's relatively cheap and you get a nice looking shiny piece back.

Sometimes voodoo works better than hard numbers, but overall I trust hard numbers more.

On the other hand, there are lies, damn lies and statistics. So even hard numbers don't necessarily translate to real world performance.

76CR125ME

oops... shoulda read pages 2 and 3 before i posted...
sorry...

Lennart

I dont't know that much about porting but this is some porting first pic.

The other 2 pics are from my new ported Takegawa superhead + R KLX110, what you guys think of the porting?

lennart

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HACKMUNCH

short side radius son, thats where it's at.

moto234

how much do other people charge for porting? ahp charges 95, some other place i think pax had some thing for 150, what do others charge?

cyclerider57

For minibikes, most places charge 200-400 to do porting depending on the head.


someone such as myself... $100 an hour, minimum of 5 hours

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The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb

storminnorman07

so when you going to do one of my heads then jordan? i ain't scared to pay

Paxracing

It is the little things that take time and time is money,

cyclerider57

For respect to vendors, I won't discuss that on the boards. I only put up a cost estimate so people understand there is a difference in cost depending on who is doing it.

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The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb

storminnorman07

so ur saying is if i shot u and email you'll do it?

cyclerider57

I didn't say that either.

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The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb

moto234

so it can be pretty expensive to get a head ported then. is it worth the money?

moto234

cause 500 is alot of money. to me at least. a young guy with a ****ty job

cyclerider57

That's for the buyer to decide...

Different people look for different stuff from their equipment. For 99% of the backyard guys, it's not worth it. For 70% of the racers it's not. For national level racers, that's pennies.

moto234

true. i guess thats not alot to drop on a big bike, and not really alot for a mini either. but i dont know, i dont think i could justify it. im just not that good lol, and my motor isnt good enough for me to want to spend that much more on it lol. is ther a noticable difference between a 100 dollar port job and a 500 dollar port job? peformance and finish wise?

cyclerider57

Depends on who's doing each. Any bone head can charge you 500 to port a head but the money you dump in doesn't always equal the benefit you get out. It's in the person doing it over anything else.

__________________
The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb