Hello everyone I been building 250r for a few years now and just got back into the blasters. What I'm looking for is some port timing numbers with squish clearances . Just a rough just where to start for low and high rev bikes. Thanks for the help in adavance
port timings
- Thread starter 265r sleeper
- Start date
Come on any one . Does nobody know any port timings for a blaster. How bout for a dt200 . Just looking for a starter point. I built this blaster motor just looking for some numbers now. I don't want to buy someone's port to have to copy it. Id rather find some numbers and build from there I have 4 blaster cylinders with heads some preported by like a 5 year old some stock all heads are stock. I port match for my stroker just never raised my port timings. Now looking for some numbers to go off of. Like start at 182 degrees then ill play with my timings to find what's what.
If i knew any i would help ya out but the guys who do this stuff for a living don't really like to give it out. and the ones who pay for it don't like cutting out the guy that spent his time and energy learing it
The Thread is on compairing a swapped 250cc mx motor/ stock blaster/ dt200 blaster.
BUT if you scroll down abit on the first page Best states the port specs of a dt200.... hope yamaha dosnt mind.....
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You have 4 cylinders. Start small and work your way up. Instead of "buying" someone else's port and copying, put in the hard work and learn what changes what and why. It'll take you longer, sure but you'll have a more firm grasp on what does what when you're done.
Thanks but this isn't my first time porting. I've ported many cylinders from shee to 250r , dirt bikes , jetski . Just have done a blaster right . I had one over 9 years ago but didn't know what I was doing all I did was open up the ports never port timings. Now I have more time and knowledge on porting just like stated just not on a blaster.
If you've ported a 250R and banshee and have time and knowledge about porting then you should a REALLY good starting point to apply to a blaster.
Why would you come on here and ask for details about port layouts and timing knowing that anyone who makes money off their time and energy spent developing their own knowledge base isn't going to give out their paycheck?
Just because porting isn't magic doesn't mean anyone is going to hand out information for free.
Why would you come on here and ask for details about port layouts and timing knowing that anyone who makes money off their time and energy spent developing their own knowledge base isn't going to give out their paycheck?
Just because porting isn't magic doesn't mean anyone is going to hand out information for free.
Well they have all these DIY porting and head work along with other stuff to help you build your motor but no one wants to give out port numbers but will tell you if your porting sucks or even guide you through every step on building a motor . Even if you have numbers if you can't port or a unclean motor builder than you only as good as the work you produce. Who knows I may suck at porting may not know how to set up a timing wheel or even check cc of the head . But a lil help would be nice.
It's nearly impossible to give out anything other than "basic" help (without numbers) because every single number is dependent on other factors.
You should rechamber your head to 18cc's. But wait, if you have a 182° of exhaust port duration that's a race gas head. If you have 200° of exhaust port duration, that's not even back to stock compression. Every "number" is dependent on so many factors.
Before I got into actually building engines and figuring out WHY (instead of just that) things were the way they were, I used to think it was simple. If you had the "perfect number" you would make a killer engine but it's not so. Make an engine with 200° of exhaust duration and run a stock head on it. It's going to completely blow to ride. It's going to have much less than stock bottom end and barely better than stock top end.... well WHY is a drag ported engine and head so vastly different than stock? Because drag racers ONLY value the power between the shift points with a given set of gearing. Basically, everything below 7k rpm doesn't matter at all.
I haven't even mentioned fuel choices, pipe choices, jetting, air inlet method.... see how a "simple" answer isn't truly possible?
If you had experience building "shee to 250r , dirt bikes , jetski" engines you should understand the paradox already. Do you see now, why I suggested building 4 different engines to test out the particular setups?
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