SLORYDER Posted April 16, 2010 Report Share Posted April 16, 2010 Ok I will be running PT Hi-revs, 34mm PJ's, +7 timing advance, about a 126 transfer duration, and I will bring my exhaust up to about 194... My intakes have been raised some and my head is stock which I plan on machining...Sea Level So I need some advice on fine tuning her before I slap hetr together.. 1. How much should I mill on my stock head to get it to a goood compression but still run pump gas? 2. How much more should I raise my intakes for that exhaust duration and if you have any tips on how to shape it to get a little bit broader range? 3. Any other tips you might have while I still have the top end off as far as the porting goes. Like do you see anything wrong with my durations? I can raise the transfer timing a bit but not much since it will be coming off the piston crown. Thanks, Marcus Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 16, 2010 Author Report Share Posted April 16, 2010 BTW I ride mostly sand,, not really any trails so.. And how about adding boost ports.. Thanks Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 16, 2010 Author Report Share Posted April 16, 2010 Why the heck can't I edit my post? Anyways also if you have had luck with staggering the transfers I would appreciate any info on that Quote Link to comment Share on other sites More sharing options...
AKheathen Posted April 17, 2010 Report Share Posted April 17, 2010 well, you do have the books to give you the numbers.......start with your desired exhaust time/are to match the pipes, then raise the transfers to the desired blowdown, and shape to port time/area again, and keep them perfectly symetrical from right-left, and anlyize where and when the flow from every port is going to converge in the trapped area to get the right shape. open the intake enough to match the flow of everything else, but not exceed it or the piston windows..........putting the wormholes in yourself are a bad idea, it is real tricky/precise, and requires welding half the time. Quote Link to comment Share on other sites More sharing options...
firebanshee Posted April 17, 2010 Report Share Posted April 17, 2010 Paul Turner high rev pipes would not be my choice of pipe for drag racing and hillshooting in the sand. I have never ran a set but i also have never been out ran by a set either. I think T-5s will out run high revs, not to mention the cpi,shearer,rockets,fat bastards, a little off topic but it sounds like you are trying to get all you can out of your bike after seeing all your other posts.IMO Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 19, 2010 Author Report Share Posted April 19, 2010 Well my problem is I can't make up my mind half of the time. I am cerain now, however that I am going to work with what I've got and spend my money elsewhere. I've read bell and jennings' books and I id gather a lot of good info... Does .035 sound like a good amount to mill and still be on pump gas? My transfer timing is not 126 like I thought more like 122..Will that work with a 195 exhaust or will I need to bump it up a little? And when opening the transfers up, I was going to attempt to widen them instead of messing with the inside and outside radii...How much can I safely widen them Thanks Quote Link to comment Share on other sites More sharing options...
blowit Posted April 19, 2010 Report Share Posted April 19, 2010 Well my problem is I can't make up my mind half of the time. I am cerain now, however that I am going to work with what I've got and spend my money elsewhere. I've read bell and jennings' books and I id gather a lot of good info... Does .035 sound like a good amount to mill and still be on pump gas? My transfer timing is not 126 like I thought more like 122..Will that work with a 195 exhaust or will I need to bump it up a little? And when opening the transfers up, I was going to attempt to widen them instead of messing with the inside and outside radii...How much can I safely widen them Thanks Wait, I thought you were going to add a spacer and chop off the cylinders. I is all confused now... Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 19, 2010 Author Report Share Posted April 19, 2010 Wait, I thought you were going to add a spacer and chop off the cylinders. I is all confused now... Can you mod my head if I add the spacer and don't tough the deck? Quote Link to comment Share on other sites More sharing options...
blowit Posted April 19, 2010 Report Share Posted April 19, 2010 Can you mod my head if I add the spacer and don't tough the deck? You want to add the spacer and have us "add" clearance as well? I suppose setting up a head to "drop in the hole" a bit could be done if that is what you are asking but would certainly be a special design and I don't think we would have the time to do something like that. I think your best option is to bite down on that bullet (real hard) and port those cylinders like they should be. Take your time, make small adjustments, and plan to take them off and adjust things a few times. Brandon Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted April 19, 2010 Report Share Posted April 19, 2010 The proper way to do it would be to install the top end. Measuer the squish then go from there instead of blindly cutting .035 of the head. Measure first, cut second. Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 19, 2010 Author Report Share Posted April 19, 2010 The proper way to do it would be to install the top end. Measuer the squish then go from there instead of blindly cutting .035 of the head. Measure first, cut second. Thanks man. I just don't want to set my squish just right and then be too high on my compression.. What would you recommend for the squish ? Firebanshee- Not to start anything here, but I've heard the hi-revs will make more hp than the T-5... And blowit..I'd pretty much gave up on the idea of using a spacer. I figure I can probably get away with making the small changes to my transfer durations by cutting the piston crown...I thought I had 126 degrees of transfer duration but it looks like it's onlt like 122-123. I've read the books and from what I've read it is a little low, however like I said I don't feel comfortable touching the transfer roofs. This is why I am trying to come up with ways to increase it w/o doing so. I am curious as to how much is safe to cut off the crown and what is a good number on the low side to set my transfers with 195 exhaust...? Quote Link to comment Share on other sites More sharing options...
Profilact Posted April 20, 2010 Report Share Posted April 20, 2010 F those PT P.O.S. pipes. I just rode and then outran a 421 cub with those pipes on it. What a dog. My little FAST ported stock cyl stoker walked all over it. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted April 20, 2010 Report Share Posted April 20, 2010 you dummy. just about every week you come up with a stupid shortcut to get around biting the bullet and just doin it right. you realize how important the squish band is, and how much scalloping a piston anywhere effects it? just bite the bullet, and find a way to cut your transfers right, or have someone do it. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted April 20, 2010 Report Share Posted April 20, 2010 Most people shoot for .040 and absolutly no tigher than .035 Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted April 20, 2010 Author Report Share Posted April 20, 2010 you dummy. just about every week you come up with a stupid shortcut to get around biting the bullet and just doin it right. you realize how important the squish band is, and how much scalloping a piston anywhere effects it? just bite the bullet, and find a way to cut your transfers right, or have someone do it. Actually my friend I am far from a dummy. I can't just come out and ask a question on here because I can never seem to get a straight answer if it pertains to porting. So I just now actually bought a subscription on Macdizzy so I might actually learn something and not have to deal with moody little pricks. And btw what you call a stupid shortcut is the exact method recommended in the book YOU told me to read. Thanks to those who actually tried to help. Quote Link to comment Share on other sites More sharing options...
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