exhaust port to wide

[glen howell]

A loss in pressure has a great bearing on if you butterfly the exhaust port .Opening up the front of the exhaust won't lose very little in the pressurizing. And the vaccumizing of the transfers,Even raising the exhaust port to increase over rev. the only way tho to really prove this is if your porter eyebrows the exhaust over the transfer ports then you only have closing about 1/4" for the vaccumizing to load properly.If they don't have a flow bench to prove there work sometimes the porting only works on topend only.Some riders like some bottom end , and some mid range with the over/rev. opening the front and adding seperarated runners lets the pipe do it's work down low and in the mid range.And with the raisingof the exhaust port you still have a lot of over/rev.Most riders only know if it works or it don't work,A port job can either make you happy or very unhappy,So to end this dribble I suggust before having the port job have your porter check it on the flow bench before and after all the grinding is done.It might look super and still not work .

[glen howell]

About pistons Honda say's and only makes 3 stock pistons STD,1 over,2 over size, after that they say buy a new cylinder,after market pistons VERTEX, PRO-X,WOSSENER,In cast do make more o/size pistons but O.E.M. only makes 2 and only in cast .Exception if it's a factory werks bike it will most likley come with a art forged piston, But they only get tore down by PRO-TUNERS or HONDA and most people don't even know that ,Even the PRO-RIDER who rides it all he knows on a full factory ride is it goes real fast and it cost about $100.000 .

[gianni2takt]

About pistons Honda say's and only makes 3 stock pistons STD,1 over,2 over size, after that they say buy a new cylinder,after market pistons VERTEX, PRO-X,WOSSENER,In cast do make more o/size pistons but O.E.M. only makes 2 and only in cast .Exception if it's a factory werks bike it will most likley come with a art forged piston, But they only get tore down by PRO-TUNERS or HONDA and most people don't even know that ,Even the PRO-RIDER who rides it all he knows on a full factory ride is it goes real fast and it cost about $100.000 .

you are totaly right about that! i always use the newer wiseco pistons without the cutaways on the side , on the cilinders with or without portworks . the exaust will never freeports with this pistons

[thestuz]

89.5 prox(used)
89.25 wiseco new (new style)

the newer style wiseco has no cutouts and is heavier as a result compared to cast pistons of similar size.
the wiseco in this picture was about 20 grams heavier than the larger prox.
but the wisecp wrist pin was lighter, compensating some what.
there is also no reenforcing on the wiseco skirt, however forged pistons dont crack skirts so its prob not necessary.

[thestuz]

[100hp honda]

I suggust before having the port job have your porter check it on the flow bench before and after all the grinding is done.It might look super and still not work .

i remeber you said one of my cylinders didnt do well on your flow bench. funny thing is nobody beat that bike all weekend at glamis . took it also to some drags out near AP's house, spanked a ton of machines out there also.

[thestuz]

here we go again!

[fastkart]

must be that time of the month again...

[AlisoBob]

You'll make then drive to AP's to goof off, but not to attend HoonFEST??

Lame.

[glen howell]

100 I wish you still had that bike with that same engine,I would love for you to come and play vertacross side by side on the clock with this 72 year old man.With a CR-500 that has the right piston,and the right porting,and the right pipe to see the look on your face when you got your ass trimmed by a 72 year old man. Is a ton of bikes still 2000.Glen NAHA #42
[img][/img][/img]

[JBaze]

Hell Glen I'll come and play just to say I did it! That would be kick ass man!

[britincali]

when you got your ass trimmed by a 72 year old man.]

[glen howell]

Thank's Chris.

[glen howell]

JBAZE, Someone said thy built houses there at Kent under the hill on JOLLY RODGER.

[Roostius_Maximus]

the prox is the only 1 ive had a problem with, even the old RC pistons are perfect

[100hp honda]

You'll make then drive to AP's to goof off, but not to attend HoonFEST??

Lame.

i dont think i had anything to ride in '06, not real sure if i was even a member on the site yet because i didnt have a cr500 to join. '07 i had a bike but the constuction boom was going on and they had me working crazy long hours, worked so much i easily paid cash for the bike. about $3500 i think. not sure why i didnt go that year, probly working i guess. '08 hoon fest i had already moved away.

[JBaze]

Yeah Glen. Built houses all over the whole hillside!

[AlisoBob]

when you got your ass trimmed by a 72 year old man.]

Clyde getting "Tea-Bagged".....

[100hp honda]

[LOVEMYCR500]

so I just got my 500 porting done, one thing I didn't pay attention to and now I'm kicking myself a bit, got the exhaust port floor a bit too low trying to get the sleeve blended nicely to the floor of the exhaust port. I didn't make the ports wide so I don't have any issues with unloading the transfer port during the cylinder filling process (using a wiesco I got from Glen so it wasn't going to be a problem anyway) but at piston top dead center I have about .005 gap so it's going to free port a bit. At piston bottom dead center, the piston crown on the exhaust side hangs above the exhaust port about .20-.40 thousands. I know this isn't completely ideal, you want complete exhaust skirt coverage and you want the crown of the piston as unexposed as possible to exhaust gas but do you see ha huge problem with this hurting my performance is a huge way?

I have ported several 250r cylinders in the past with very good success (they are mocked up, degreed with a degree wheel, etc) but the angle of the exhaust tunnel I guess caught me a bit off guard it's steeper than the 250r. Live and learn I guess. Next time off the Glen. It's together and I will find out sooner than later if I screwed up or not.

[Roostius_Maximus]

that can be a big problem too, kills the pipe signal

[LOVEMYCR500]

I know it can but one side is probably .003 and the other I could barely get a .005 feeler guage under it so it's very small and it's going to be like that for a split second where it's at due to crank rotation at that point. i could see a gap around the side of the piston unloading the transfer port being a much bigger problem with the amount of area I'm talking with my problem.

[glen howell]

You should have called me now your only choice is to raise cylinder by adding base gaskets or getting one of my copper base gaskets and re-clearencing the top of the cylinder ,then lowering the transfers to match bottom dead center if you haven't put it togeather you could send in to me I can straghten it up .other wise you might have to get another cylinder. Glen

[south central hoon]

k, this wiseco (left) is better than the old style, prox (middle) and oe honda (right)

at .040 over

can you repost thephotos in this thread roosty?

[Roostius_Maximus]

somewhere i have more, seen one on ebay, its the one with the camera logo in the corner, i took some others i'll look for too