Who ported this cylinder???

[Grande huevos]

Hey guys my buddy just picked up his first R and he got a steal with the condition and amount of aftermarket parts !! His cylinder has somthing etched into the side but I have never seen it, hopfully sombody can chime in!

[Bio86]

Haha I just picked one up too that has that same insignia on it!!  Have you checked the bore?  Mine had a big bore sleeve in it @ 72mm.

The porting itself looked nice, haven't degree'd it yet though.

[Grande huevos]

No we are going to look it over Friday night. I assume it's somthing good because the rest of the bike is loaded with nice aftermarket parts. That would be a sweet bonus if it had a 310 hiding in there!!

[C-Leigh Racing]

If it is a 310 sleeve, we can only guess & hope, who ever built the engine machined that OEM looking head gasket to fit the cylinder bore. It looks like they only used the thick center piece from a three piece metal head gasket.
Then again, all of that red high temp silicone you can see on the edge of the gasket, could be a clue that it could be a 310.
Something about that head just dont look right, like it might be a CR head.
Neil

[Bio86]

Did they make an OEM style head gasket to fit that larger bore?  I'm trying to find something now but having a hard time.  Just use a 3 layer MLS and shave the I.D. to size?

[Grande huevos]

If it is a 310 sleeve, we can only guess & hope, who ever built the engine machined that OEM looking head gasket to fit the cylinder bore. It looks like they only used the thick center piece from a three piece metal head gasket.
Then again, all of that red high temp silicone you can see on the edge of the gasket, could be a clue that it could be a 310.
Something about that head just dont look right, like it might be a CR head.
Neil

My buddy broke his reeds this last week so When we went to replace them We took a few pics just to see if some of the trained eyes out there could tell anything by looking at them?? It appears to be ported but that's about all we can tell.... Can you guys tell anything else just by looking without measurements?? Does it at least look like whoever was in there knew what they were doing??  Thanks in advance

[C-Leigh Racing]

Just from what I can see in those last two pics, you can tell the cylinder has been re-sleeve with the thick wall replacement sleeve, but I cant tell if it is a big bore 295 or a smaller bore. Those thick replacement sleeves like that, can have a bore anywhere from STD 66.00mm bore up to a 73.50mm.
Looking at the pic of the sleeve, it looks kind of thick, like maybe it is a smaller bore than a 295, but it could be the angles on the sleeve where the cylinder has been ported thats making it look real thick. A 310 sleeve would be quite a bit thinner than the one in the pics.
I would say the cylinder probably is ported, because if not, why would they go to the trouble of doing the work just in the reed & intake area. The work looks pretty good as well from what I can see.
Neil

[Bio86]

Are these cylinders possibly real old school ported from LRD ?  I have that same engraving on the side, I was looking at my LRD pipe and it has that same lightning bolt looking thing on the pipe tag.

[Grande huevos]

Just from what I can see in those last two pics, you can tell the cylinder has been re-sleeve with the thick wall replacement sleeve, but I cant tell if it is a big bore 295 or a smaller bore. Those thick replacement sleeves like that, can have a bore anywhere from STD 66.00mm bore up to a 73.50mm.
Looking at the pic of the sleeve, it looks kind of thick, like maybe it is a smaller bore than a 295, but it could be the angles on the sleeve where the cylinder has been ported thats making it look real thick. A 310 sleeve would be quite a bit thinner than the one in the pics.
I would say the cylinder probably is ported, because if not, why would they go to the trouble of doing the work just in the reed & intake area. The work looks pretty good as well from what I can see.
Neil

Ok cool thank you!! I had posted the same pictures on the other site and someone had said that the left port looks taller then the right side and it raises a flag?? I think it's just the angle of the camera being tilted and the lighting. In person it doesn't appear that way but we havnt had it apart any farther then what you see so we have not taken any measurements. Thanks for your time and opinions Neil

[C-Leigh Racing]

Ok cool thank you!! I had posted the same pictures on the other site and someone had said that the left port looks taller then the right side and it raises a flag?? I think it's just the angle of the camera being tilted and the lighting. In person it doesn't appear that way but we havnt had it apart any farther then what you see so we have not taken any measurements. Thanks for your time and opinions Neil

The pic looks like to me the left port is taller, just as stated, but understanding how the flow will enter the cylinder, the flow through the carb because of its angle tends to pack more into the right side of the engine, so when porting that area of the cylinder one would try to convert more flow to the left side.

You can see sometimes on the Pro-x & ESR cylinders, this to be true, because when those cylinders seize or loose the head gasket o rings, it will normally happen on the left front side of the cylinder from being leaner on that side of the engine instead of the right side.

Maybe Arlan or Jerry will comment on this idea. That is what I have on my mind when porting that area, in an attempt to level out the flow into the bottom end so it will be the same amount to flow up through the ports on both sides of the cylinder.
Neil

[Grande huevos]

The pic looks like to me the left port is taller, just as stated, but understanding how the flow will enter the cylinder, the flow through the carb because of its angle tends to pack more into the right side of the engine, so when porting that area of the cylinder one would try to convert more flow to the left side.

You can see sometimes on the Pro-x & ESR cylinders, this to be true, because when those cylinders seize or loose the head gasket o rings, it will normally happen on the left front side of the cylinder from being leaner on that side of the engine instead of the right side.

Maybe Arlan or Jerry will comment on this idea. That is what I have on my mind when porting that area, in an attempt to level out the flow into the bottom end so it will be the same amount to flow up through the ports on both sides of the cylinder.
Neil

Well That sounds like pretty good reasoning to me. That's awesome to know thanks

[udontknowme]

not sure if all honda engines are the same but the cr5 has the right boyesen taller than the left on virgin castings. normally i just grind them the same size. whether it makes a difference or not who knows. as fast as the air moves i think maybe the only way to put more air on the left side is with some kind of divider like the radvalve has. or possibly something else like what ktm tried, instead of having a 20* bend in the manifold like the cr5, you bend the cylinder intake 10* and bend the rubber manifold 10* so you have 2 gradual bends instead of 1 large one and this should allow the air to stay attached to the inner wall better around the turn

[udontknowme]

these are pretty similar in total amount of angle but the one on the right is divided into 2 smaller angles. im certain its like that for the reason neil said so it doesnt pile up on one side. should be much easier to go around the turn with 2 smaller angles