Hey guys,
I got my hands on a nos lt250r small reed cylinder, I'm looking at having it sent out for porting, just curious on who to send it to these days. A buddy of mine just built a 310 yz250 powered blaster and he eats me alive so I'm looking to build some power.
Carl (Bartlett Racing) out of NY.....
if only porting only the cylinder then the only thing you can do is change the exhaust port and outlet---- or get a different cylinder.
when you port the exhaust it will need a bigger carb to match the larger flowing exhaust port and outlet. hence the need for 38mm-40mm carb.
- just a chainsaw file will be enough to port the cylinder like CT or any other race company.
- u just need to know the width and height of the exhaust port to shoot for.
- it sounds like the rm250 top end might be a good way to go but im afraid the stock yz250 will still win as a guess. he got nearly a complete factory 250 with a tuned stock carb thats big enough.
there is much more to porting then raising exhaust timing, thats a redneck port job, yes u will most likely gain some power, but there is more to it then that, especially if u want a real runner. u cant go wrong with carl
Subluncay I don't think u know what your talking about half the time.
Get ahold of Carl bud aka iceracer.
My cylinder is heavily ported and the stock 34mm carb was just fine man.
Carl is good, Pete at Hybrid Engineering is good, Jerry Hall at Hall's Precision Racing, Arlen at Led Performance. Any of these will do great work good luck, what kind of riding are you doing?
I've already have a hall built motor in my 89 Lt500r and I love the power . I always planned on having my cylinder for the 250 done at flotek but I believe he's shut down. Just looking for options, I still need to contact Matt and see what a pipes going to cost me here up in Canada. Thanks for the Imput guys. My 250 is a trail bagger.
I've already have a hall built motor in my 89 Lt500r and I love the power . I always planned on having my cylinder for the 250 done at flotek but I believe he's shut down. Just looking for options, I still need to contact Matt and see what a pipes going to cost me here up in Canada. Thanks for the Imput guys. My 250 is a trail bagger.
Where abouts in Canada are you located?May want to talk to Carl about pipes before contacting Shearer if you plan on sending him your cylinder.
carl barlett racing
aka ice man
Subluncay I don't think u know what your talking about half the time.
Get ahold of Carl bud aka iceracer.
My cylinder is heavily ported and the stock 34mm carb was just fine man.
your missing out on some power maybe. raising the exhaust port makes the pipe peak earlier because of increased blowdown. widening the exhaust port makes a bit more torque and optimises for larger carbs to make torque.
porting the transfers gets tricky because it could lower the primary compression wich would lower the torque and increase the blowdown
milling the head to get a good squish and compression is as responsible for a modern running engine as the ports.
Subluncay I don't think u know what your talking about half the time.
Get ahold of Carl bud aka iceracer.
My cylinder is heavily ported and the stock 34mm carb was just fine man.
your missing out on some power maybe. raising the exhaust port makes the pipe peak earlier because of increased blowdown. widening the exhaust port makes a bit more torque and optimises for larger carbs to make torque.
porting the transfers gets tricky because it could lower the primary compression wich would lower the torque and increase the blowdown
milling the head to get a good squish and compression is as responsible for a modern running engine as the ports.
Raising the exhaust port does increase the blowdown time/area but in the majority of the case makes the pipe peak later or at a higher RPM not earlier or at a lower RPM.
Transfer port modifications are tricky. There is not a particular modification that works best on every engine. The only way we learn about any of these modifications is to try it, then run the engine in the field and or on the dyno to evaluate whether the modification was beneficial. Real port development usually requires some cylinders to take one for the team and end up in the scrap pipe
If the transfer port modification involves raising the transfers, it decreases the blowdown time/area of the exhaust port. It does not increase the blowdown.
I've dealt with Carl the B man before. Just give him a call and he can answer any questions you may have. He's a nice guy who takes time to talk to you about what your wanting and figure out where to go from there. The dude is extremely knowledgeable. I'm sticking with him for any work I need done. I've never heard a single complaint about him. 5 STAR Triple AAA+.
Subluncay I don't think u know what your talking about half the time.
Get ahold of Carl bud aka iceracer.
My cylinder is heavily ported and the stock 34mm carb was just fine man.
your missing out on some power maybe. raising the exhaust port makes the pipe peak earlier because of increased blowdown. widening the exhaust port makes a bit more torque and optimises for larger carbs to make torque.
porting the transfers gets tricky because it could lower the primary compression wich would lower the torque and increase the blowdown
milling the head to get a good squish and compression is as responsible for a modern running engine as the ports.
Raising the exhaust port does increase the blowdown time/area but in the majority of the case makes the pipe peak later or at a higher RPM not earlier or at a lower RPM.
Transfer port modifications are tricky. There is not a particular modification that works best on every engine. The only way we learn about any of these modifications is to try it, then run the engine in the field and or on the dyno to evaluate whether the modification was beneficial. Real port development usually requires some cylinders to take one for the team and end up in the scrap pipe
If the transfer port modification involves raising the transfers, it decreases the blowdown time/area of the exhaust port. It does not increase the blowdown.
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SUBLUNACY REPLY-
no. the pipe would peak earlier and have more over rev.
no. if the transfers are raised the primary compression lowers period.
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nobody is making more torque on any build unless the pipe acts like a torque pipe on the cylinder.
sublunacy, you really should stop.
You have no clue what you are talking.
I think motorgeek already told you how you are stupid.
From your new post.
1) Raising just the exhaust port will make an engine more peaky, not come on sooner.
2) Raising the transfers has little to zero effect on static compression, the exhaust port is higher.
3) You can make more torque from just porting, it just might be higher in the RPM curve.
Again, please stop talking.
ZillaFreak you sound like an 8 year old child. im sure your bike would be filled with other peoples parts and tuning but your still a wannabee
Bwahahahahaaa! You guys are hilarious... New here, pardon me, excuse me...just passing through.
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