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CVO Technical => Twin Cam => Topic started by: gremlush on December 24, 2008, 03:21:02 PM
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I have been porting H-D heads since 1978 {sold biz last year} anyway , I always liked to use 89-90 % valve to seat ratio . The H-D 110" heads have a 93 % ratio on the intake !!!!!!! YOU WANT POWER ,CHEAP ? Put in a 2.125 intake valve { H-D # 18190-08} $15.50 ea. } that will get you a 90.5 % ratio and do a 4 angle seat cut , 'mill' the heads .030-.040 and use a Cometic .030 head gasket and a cam. Dewey
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Interesting thanks for the info.
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Hey Dewey, thanks for the great tip. You got a good name after 30 years -- that's sayin' a lot right there. How's everything going on the other side of retirement?
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Retirement is 24/7 , thinking about going back to work to rest. Gotta run now ,Gunsmoke is on. Dewey
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Hmmmm, thats interesting. I own a '07 FXDSE, with the SE110 motor. I have been sorta going through my mind about mods to get more power out of the motor. Wanting in the neighborhood of 100-110hp without to much work. I was figuring on new pistons and cam, with some head work. So you say open up the intake even more? I thought it was 2" already? But put in larger valve with work, mild port, cut head, thin gasket and cam will get me there? What kind of comp are you talking about, around 10:1? That would be cool, with a cam in the 590 lift, 246 dur. int. close of 40-44 should make it work?
BigMo
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I have been porting H-D heads since 1978 {sold biz last year} anyway , I always liked to use 89-90 % valve to seat ratio . The H-D 110" heads have a 93 % ratio on the intake !!!!!!! YOU WANT POWER ,CHEAP ? Put in a 2.125 intake valve { H-D # 18190-08} $15.50 ea. } that will get you a 90.5 % ratio and do a 4 angle seat cut , 'mill' the heads .030-.040 and use a Cometic .030 head gasket and a cam. Dewey
Perfect Set Up For The SE 251 grind :2vrolijk_21:
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I would think that using a larger valve and sinking it deeper into the seat would limit your ability to do future head rebuilds and would require you to be replacing seats on a rebuild instead of recutting them. And instead of machine work on the heads, you can use 10-10.5:1 pistons to get the CR up. And wouldn't the extra power you get from doing this mod, come at the top at the expense of the bottom/mid? Just throwing out some thoughts and questions out there Dewey, not questioning your findings. Thanks. Merry XMas! ;)
Hoist! 8)
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let me 'spain' a little. When you have 93% seat to valve {1.930 dia.} with a 2.080 valve ,you need to look HARD to see the 45 degree cut and forget about the 60 degree ! You have nothin but a big hole. Nothing to cut your angles on ,right ? By going with a bigger valve {.045 bigger} you can do a 30-45-60-70 cuts. YES ? THE STOCK VALVES ARE 'BACK CUT' 30 DEGREE. its all about making the Y , with the back cut on the valve and the cuts on the seat. Look at a Y , bigger on the top and then narrows down ,yes. Just remember 1 thing , 80% of your air flow is controlled by the valve and the seat. The only other way is to weld up the ports. The stock 110" heads flow BAD. once you 'fix' the valve and the seat {cuts} they do fine. Whatever ,been doing this stuff for over 30 years,not trying to sell ANYTHING. Dewey Merry XMAS and GOD BLESS.
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let me 'spain' a little. When you have 93% seat to valve {1.930 dia.} with a 2.080 valve ,you need to look HARD to see the 45 degree cut and forget about the 60 degree ! You have nothin but a big hole. Nothing to cut your angles on ,right ? By going with a bigger valve {.045 bigger} you can do a 30-45-60-70 cuts. YES ? THE STOCK VALVES ARE 'BACK CUT' 30 DEGREE. its all about making the Y , with the back cut on the valve and the cuts on the seat. Look at a Y , bigger on the top and then narrows down ,yes. Just remember 1 thing , 80% of your air flow is controlled by the valve and the seat. The only other way is to weld up the ports. The stock 110" heads flow BAD. once you 'fix' the valve and the seat {cuts} they do fine. Whatever ,been doing this stuff for over 30 years,not trying to sell ANYTHING. Dewey Merry XMAS and GOD BLESS.
What I hear you saying is that the poor flow characteristics of the stock SE 110 heads is a result of the stock intake valves and seat cut. Is that correct?
And... a Very Merry Christmas to you! Thanks for the info.
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let me 'spain' a little. When you have 93% seat to valve {1.930 dia.} with a 2.080 valve ,you need to look HARD to see the 45 degree cut and forget about the 60 degree ! You have nothin but a big hole. Nothing to cut your angles on ,right ? By going with a bigger valve {.045 bigger} you can do a 30-45-60-70 cuts. YES ? THE STOCK VALVES ARE 'BACK CUT' 30 DEGREE. its all about making the Y , with the back cut on the valve and the cuts on the seat. Look at a Y , bigger on the top and then narrows down ,yes. Just remember 1 thing , 80% of your air flow is controlled by the valve and the seat. The only other way is to weld up the ports. The stock 110" heads flow BAD. once you 'fix' the valve and the seat {cuts} they do fine. Whatever ,been doing this stuff for over 30 years,not trying to sell ANYTHING. Dewey Merry XMAS and GOD BLESS.
Wasn't about buying or selling, just trying to learn from those who are knowledgeable. Thank you for that explanation Dewey! :2vrolijk_21:
Hoist! 8)
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Just remember ,you can't hold whats NOT in your hand.
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you da man dewey...thanks for a simple solution
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Ok Dewey. sounds like a plan but who we going to get to do that for us . how many porter so you feel would do this for those of us that would by chance want to do i it ?? you ??
i have a spare set of the 110" heads i am looking to do something with, and may be interested in trying your bigger valve suggestion~ thanks
Happyman
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I am sure the guy I sold my biz too would do it,he name is Don. Good man. Look on my web site and then 'click' on his. www.deweyspegs.com or you can do it yourself. know someone with a 'NEWAY' seat cutter {carbide} and a mill to 'flycut' your heads. I would but GUNSMOKE is on. Sorry Dewey
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you are talking about increasing the intake valve size??
Thanks again
happy
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I am sure the guy I sold my biz too would do it,he name is Don. Good man. Look on my web site and then 'click' on his. www.deweyspegs.com or you can do it yourself. know someone with a 'NEWAY' seat cutter {carbide} and a mill to 'flycut' your heads. I would but GUNSMOKE is on. Sorry Dewey
gremlush sorry but I have to call BS on this one. We all know you are out on a doughnut run.
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I only eat the 'hole'. ya da mans....
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And in addition to what Dewey said all the 110 heads are not created equal. Some of the early releases had a correct throat %. The late CVO and HTCC heads I have done have a raised 45° seat that plays hell with flow. Just a correct valve job 4 angle and 3 on the valves corrects that. The Harley valve corrects the later oversized throat heads.
Quoted from Engine Builder RE: head porting, Joe Mondello interviewed by Larry Carley
“A few weeks ago, we had three engineers from Harley-Davidson Screaming Eagle Division here for a technical session. They just designed a new 103 head and a 110 head and were quite proud of how well it flowed. We took their head, and in three days time we improved the airflow 52 cfm over their initial design. Out of the 53 cfm that we picked up, 25 cfm was due to changes we made in the valve seat angles alone. That shows you how critical valve seat angles are for maximizing airflow and power,” says Mondello.
Just a tidbit I thought I would share not an endorsement of Mondello just interesting how much difference proper seat and valve preparation makes.
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Let me use my years as a head porter (1974 to present) to expand on.What Dewey has said.The radius below the seat(Some porters call it the choke)it's location and diameter As well as seat angles port shape,volume and length all effect how the port works.The raito of 89 to 90% is a good measure.I have gone down as low as 86% to obtain better low lift flow.When you look at the seat remember there is a valve stuck in there.The relationship between the valve and the seat changes constantly as the valve opens and closes.All the angles effect the air flow differently.At different lifts some angles work better others.Same for the choke a larger radius improves the approach angle of the air to the seat at low lift.Conversely at higher lift the same choke(larger radius) becomes a restriction.So we are forced to choose a comprimise for the appliaction for which we are using the engine.Dewey is quite correct in that over 90% you loose most of your bottom angles this tends to annoy the fuel and air as it trys to make the sharp turn at the seat and valve.One key factor not to forget is that you want sharp edges were seat angles meet.These sharp edges grab the air and help turn it around the seat.(not true for the exhaust) That is why the newer guide and seat machines (sunnen,serdi,newen) are so popular With stable carbide pilots and carbide cutters A truer and sharper seat can be obtained than with stones or hand held cutters.I do not use the single bladed(multi angle) cutters on my intake seats as they cannot generate a sharp enough union between angles.Depending upon appliaction I may use 38-48-60-72 seat angle combo and 88 to 89 % valve dia. choke for a higher lift cam. Nothing is cast in stone. There tons of other factors that go into total port design.We can see how EZ it is to mess up a port.The factory did! So be carefull out there.All the trick fuel injection programing and port work in the world. won't fix a screw up in the basics.
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:vrolijk_11:
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I was told by a local HD machine shop the 110 SE heads cannot be milled do to the location of the compression releases.
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“A few weeks ago, we had three engineers from Harley-Davidson Screaming Eagle Division here for a technical session. They just designed a new 103 head and a 110 head and were quite proud of how well it flowed. We took their head, and in three days time we improved the airflow 52 cfm over their initial design. Out of the 53 cfm that we picked up, 25 cfm was due to changes we made in the valve seat angles alone. That shows you how critical valve seat angles are for maximizing airflow and power,” says Mondello.
This is the part that blows my mind. I thought CVO to Harley was what AMG is to Mercedes.
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Thats funny right there... :D
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I was told by a local HD machine shop the 110 SE heads cannot be milled do to the location of the compression releases.
that is razzle dazzle!!
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Big AL is right about % {valve-seat} and MOST of the dyno's on my web site were 87-88 % intake ,ex. were different. He is also right about sharp angles on the intake seat ,ex. different. If you want to know what these 'stock' 110" heads flow ,ask DON deweysheads, I am sure he will tell you. BIG HOLE - NO FLO !!!!! In my opion , these are good heads ,they just need a 'little' valve-seat work, and when you 'mill' {flycut} .050- .060 off of them,you make the combustion chamber smaller and pretty good. You can 'machine .040 off the heads with no problem. More than that ,make a alum. washer the put under the comp. release to raise it up. Dewey ps. got my 30 tooth front pulley today ,yahoo.
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I'm surely not an expert...I have owned 2 xls, 1 victory, 1 flh, and 2 fxds...and I DARE say my '08 cvo is the best bike ever...so you can stick your internet myths up your...well, you know
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I'm surely not an expert...
Duly noted!
:2vrolijk_21:
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do I know you???!!!???
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I'm surely not an expert...I have owned 2 xls, 1 victory, 1 flh, and 2 fxds...and I DARE say my '08 cvo is the best bike ever...so you can stick your internet myths up your...well, you know
ahhhhhhhhhhhah well said .
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with all do respect, first a statement and a Q. i agree with valve agle(s), valve size,and seat radius etc, that been said
what would be gained in a street power doing all those mods. not trying to be an a-hole, just your opinion-on track vs
street. thank you. axil
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This is the part that blows my mind. I thought CVO to Harley was what AMG is to Mercedes.
Perhaps if Harley was 1/10th as competent as M-B they could make CVO into something other than a styling exercise. If you take a good look at any CVO going back through time, it has never been about performance. A CVO is a styling exercise using parts out of the accessory catalog. There are no ride or handling improvements, and the engine output increase from the added displacement (95 versus 88, then 103 versus 88, now 110 versus 96) is pathetic when compared to what AMG does.
CVO reminds me of the days when Ford, GM, and Chrysler put racing stripes and spoilers on their 6 cylinder models and called them GT's, etc.
Jerry
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Perhaps if Harley was 1/10th as competent as M-B they could make CVO into something other than a styling exercise. If you take a good look at any CVO going back through time, it has never been about performance. A CVO is a styling exercise using parts out of the accessory catalog. There are no ride or handling improvements, and the engine output increase from the added displacement (95 versus 88, then 103 versus 88, now 110 versus 96) is pathetic when compared to what AMG does.
CVO reminds me of the days when Ford, GM, and Chrysler put racing stripes and spoilers on their 6 cylinder models and called them GT's, etc.
Jerry
ya they need to take the lest costly models and put in great motors and great brakes and suspension and leave alll the heavy excess chrome off these things and then we have the sleepers that just could have some good performance instead of al the razzle dazzle that has no real function. pretty don't make um run good.
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the "performance" bikes that HD makes are water cooled.
to
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They're not gonna give you "legal performance"! Too expensive to do it that way, especially when they can sell it to everyone afterwards, and not care about the legalities! STF!!! ;)
Hoist! 8)
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Perfromance= $$$$, always been thatway...but these heads flowed crummy...My pea sized brain could tell when I pulled the plugs on my 07 and saw a plug with two sided colors...tan/whits on one side...blackgray on the other...Go figger...Hemi's... ;D
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with all do respect, first a statement and a Q. i agree with valve agle(s), valve size,and seat radius etc, that been said
what would be gained in a street power doing all those mods. not trying to be an a-hole, just your opinion-on track vs
street. thank you. axil
Here is an example of how the street performance of a 110 w/SE255 cams, 50mm TB, and slip-on mufflers is improved with the addition of better flowing heads.
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Here is an example of how the street performance of a 110 w/SE255 cams, 50mm TB, and slip-on mufflers is improved with the addition of better flowing heads.
I thought that looked familiar, that is my bike, Mike Stegman at Latus Motors spent a lot of time with it. You can see my last name "Gaddis" on the chart.
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Rooster,
What head work was done to improve flow?
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Rooster,
What head work was done to improve flow?
Baisley ProStreet Heads.
Perhaps Rooster will share more about it since this is his build. I would imagine that it is a great driver based on that torque curve. I wonder how the temps are with the short duration 255 cams.
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The bike runs real well up to a little over 4k rpm. Gas mileage has been about 42. It pulls my tent trailer well also. The temps are good unless sitting in traffic on a hot day. First time out was 251 cams, and domed pistons with comp 10-5-1. Ran very hot, no low end power, all on the top, and pinged like crazy, no fun to ride on a hot day. The only thing better than the way it is now would maybe be a bit better cam and a better pipe. Still thinking about those Yuill Bros pipes to get the heat off both of our right legs better. I don't have the specs of the heads but Dan Baisley at Baisley Performance is a super nice guy to talk to. I had an issue with the seals deciding to leak and he went through them and gave them back to me NO CHARGE. Great service, I highly recomend them.
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The bike runs real well up to a little over 4k rpm. Gas mileage has been about 42. It pulls my tent trailer well also. The temps are good unless sitting in traffic on a hot day. First time out was 251 cams, and domed pistons with comp 10-5-1. Ran very hot, no low end power, all on the top, and pinged like crazy, no fun to ride on a hot day. The only thing better than the way it is now would maybe be a bit better cam and a better pipe. Still thinking about those Yuill Bros pipes to get the heat off both of our right legs better. I don't have the specs of the heads but Dan Baisley at Baisley Performance is a super nice guy to talk to. I had an issue with the seals deciding to leak and he went through them and gave them back to me NO CHARGE. Great service, I highly recomend them.
Rooster,
Are you using stock flat top pistons or the Latus 9.6:1 product?