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CVO Technical => Twin Cam => Topic started by: SHRADER on April 24, 2005, 09:58:25 PM

Title: SE-253 cam specs
Post by: SHRADER on April 24, 2005, 09:58:25 PM
Many times on this site I have seen reference to the mystery cam specs of the SE-253 cam that comes stock in 103's.

Here are the specs for the cam as posted in little known  2003 technical forum that has long since been deleted from H-D's dealer only site.

Intake    .530 lift      237 duration  open 9 BTDC close 51 ABDC
Exhaust  .530 lift     252 duration  open 62 BBDC close 17 ATDC

Just for everyones info.
REGARDS
SHRADER
Title: Re: SE-253 cam specs
Post by: Defender on April 24, 2005, 11:53:48 PM
Thanks for the info.... [smiley=biggthumpup.gif]
Title: Re: SE-253 cam specs
Post by: ReynoldsS on April 27, 2005, 06:32:44 PM
I had my local shop call today and they said 237/239 on the duration, Now its got me wondering. [smiley=confused5.gif]
Title: Re: SE-253 cam specs
Post by: Fatboy on April 27, 2005, 06:38:26 PM
OK......I'll admit I'm a novice on cams so here's my question for the wrenches out there.

What is the ideal cam for a 103 to be riden mostly in the 2000 - 4500 rpm range? And are gear driven cams really better? [smiley=nixweiss.gif]
Title: Re: SE-253 cam specs
Post by: ReynoldsS on April 27, 2005, 07:55:23 PM
Hey Scrader, My Bad. Your post is correct on the duration. And Fatbot I think this cam would work very good in that rpm range, and I would say gear driven cams are better. alittle freeer turning and no shoes to wear out. But for now i'll just check mine ever 20,000 [smiley=xyxthumbs.gif]
Title: Re: SE-253 cam specs
Post by: kng103 on April 27, 2005, 08:33:31 PM
Quote
OK......I'll admit I'm a novice on cams so here's my question for the wrenches out there.

What is the ideal cam for a 103 to be riden mostly in the 2000 - 4500 rpm range? And are gear driven cams really better? [smiley=nixweiss.gif]


this has been discussed and argued here before.
my oppinion is that the cams are the one biggest change you can make with the best results for the least amount of money. assuming you already did the stage1 and pipes.
Title: Re: SE-253 cam specs
Post by: Fatboy on April 27, 2005, 08:43:46 PM
KNG103,

Here's what I think I'm going to do once the bike "gets here" next week: Hooker True Duals, Zippers 50mm throttle body, high flow air cleaner kit and their new Thundermax ECM. The cams may be an option I would consider if I better understood the cost/benefit/results for my application.

I'd like to stay under $2500 in parts to make this bike run better. I don't beat up my toys but I do want it to move out when I punch it up a little when out with the boys.........

Thank you for your input and advice.
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 28, 2005, 07:26:25 AM
Fatboy I sent you a PM.

Shrader thanks for the info on our STOCK CAMS!

After doing the basic mods the next thing I would do is remove the stock Harley cams and chains. The cam has a decent profile  for a stock 103 but the chains must go. This has been a problem the motor company refuses to address. I have seen to much wear and damage because of the tensioners not to mention the slack in the chains and cam timing problems at warp speed.

I am going to make some changes when I return from Myrtle as I have stated in the past.

Harley makes some good high performance items that I am going to use but when you want to make good numbers the aftermarket is all over them. I have a set of Bob Wood cams with gear drive. The heads will be Zippers, the pistons right now are going to be harley. The throttle body and ECM are also going to be zippers. I am going to keep this bike looking as stock as posible and at 103.

Title: Re: SE-253 cam specs
Post by: kng103 on April 28, 2005, 08:09:34 AM
Quote
KNG103,

 Here's what I think I'm going to do once the bike "gets here" next week: Hooker True Duals, Zippers 50mm throttle body, high flow air cleaner kit and their new Thundermax ECM. The cams may be an option I would consider if I better understood the cost/benefit/results for my application.

 I'd like to stay under $2500 in parts to make this bike run better. I don't beat up my toys but I do want it to move out when I punch it up a little when out with the boys.........

 Thank you for your input and advice.


if you are going to change over to a 50mm throtle body.
you should definitley do some head work, intake work, and change out the cams.
now your talking some serious loot.
like old hubbard say's " speed cost money"
if you are doing head and cam work, the stock throttle body is fine.
Title: Re: SE-253 cam specs
Post by: mr_magoo on April 28, 2005, 08:25:49 AM
The sign in the old shop read SPEED COSTS HOW FAST CAN YOU AFFORD TO GO?
Title: Re: SE-253 cam specs
Post by: Fatboy on April 28, 2005, 09:03:01 AM
Bottomline is: Opee will look best chasing my taillight!

He will be setting the local benchmark when he gets his bike back and then gets it dyno tuned later on.
Title: Re: SE-253 cam specs
Post by: hd2003-se2005 on April 28, 2005, 09:33:45 AM
Quote

if you are going to change over to a 50mm throtle body.
you should definitley do some head work, intake work, and change out the cams.
now your talking some seriuos loot.
like old hubbard say's " speed cost money"
if you are doing head and cam work, the stock throttle body is fine.



Kng is right in his post above.
If you did the Freedom package at $1,400 that would leave $1,100 for cams and tuning and stay in your budget.
I believe that would be a great combination.
[smiley=xyxthumbs.gif]

Hey Kng
What's this about Hubbard being "OLD" [smiley=nixweiss.gif]
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 28, 2005, 09:35:37 AM
Magoo you said it best. Thats exactally what the sign reads in the speed shops around here.

King I have to disagree with you on the 50mm throttle body. I personally think the 103 is starved for air. If I do (and I am) head work compression change and a radical cam I am going with Zippers 54mm throttle body. They have done a lot of testing with the stock 103 and the 50mm and thier ECM. I have it but I also put in a 6 speed at the same time and I have to go back into the clutch and find out why it won't release. So I have not road tested the unit as of yet. The guys on the York tour will get to see it first hand if I get it ironed out by sunday. The bike ran  good with a thunder header,screamin eagle air cleaner and power commander so I have a base line for comparrsion.

The more air and fuel you can cram into these motors the more power you will make(volumeritic efficency). If the 45mm throttle body is ok why does the motor company use it on the 88 as well? Just a thought. With the mods you have done to your bike I think you would benefit from a larger throttle body as well. Stay safe

THE DAWG
Title: Re: SE-253 cam specs
Post by: kng103 on April 28, 2005, 10:19:04 AM
Quote
Magoo you said it best. Thats exactally what the sign reads in the speed shops around here.

King I have to disagree with you on the 50mm throttle body. I personally think the 103 is starved for air. If I do (and I am) head work compression change and a radical cam I am going with Zippers 54mm throttle body. They have done a lot of testing with the stock 103 and the 50mm and thier ECM. I have it but I also put in a 6 speed at the same time and I have to go back into the clutch and find out why it won't release. So I have not road tested the unit as of yet. The guys on the York tour will get to see it first hand if I get it ironed out by sunday. The bike ran
Title: Re: SE-253 cam specs
Post by: the O`Fender on April 28, 2005, 12:51:03 PM
What are you looking for more torque or more HP? obviously we all want more of both but the answer to that question dictates what to do with the heads and what cam to use and weather or not to enlarge the throttle body. The hot rod guys I have been discussing this with (many) the majority feel the 45mm TB will flow more than enough air for 125+HP however the injectors are questionable. The reason I am posting this is I believe that the Zippers TB reuses your stock injectors. A questionable solution to the issue of HP.  
Title: Re: SE-253 cam specs
Post by: Fatboy on April 28, 2005, 01:15:36 PM
O'

Things that make me go.......hmmm. I guess from a number's standpoint I'd like get to 105hp & 110tq +/-

And do it for the least expense possible while maintaining reliability. Low end 1800-4500 rpm range is where I live most of the time.........

Thanks for your input!
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 28, 2005, 06:57:18 PM
Quote
What are you looking for more torque or more HP? obviously we all want more of both but the answer to that question dictates what to do with the heads and what cam to use and weather or not to enlarge the throttle body. The hot rod guys I have been discussing this with (many) the majority feel the 45mm TB will flow more than enough air for 125+HP however the injectors are questionable. The reason I am posting this is I believe that the Zippers TB reuses your stock injectors. A questionable solution to the issue of HP.
Title: Re: SE-253 cam specs
Post by: B767capt on April 29, 2005, 08:05:44 AM
I had mine dynoed after the build with the stock TB and then with a 53mmTB.  The numbers or curves were the same until 3500 rpm, then the 53mm TB jumped up on both TQ and HP.  They were concerned that 53 might have been too large and loose velocity which means low TQ, but it matched the stock TB.
Title: Re: SE-253 cam specs
Post by: kng103 on April 29, 2005, 01:17:30 PM
Quote
I had mine dynoed after the build with the stock TB and then with a 53mmTB.
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 29, 2005, 08:02:43 PM
Good deal Capt. I might hava thought that a 50mm would have been just about right. I installed my 50mm last night. I really need to measure the stock throttle body. 5mm sure is a big difference. I am going to try to ride it sunday. Stay safe.

THE DAWG
Title: Re: SE-253 cam specs
Post by: B767capt on April 30, 2005, 11:15:55 AM
KNG103 I emailed you the dyno sheet.  I tried here, but it said the file was too large.  If you know how to get it on here please do.  
Thanks, Bill
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 30, 2005, 03:50:04 PM
Capt what were the numbers?????
Title: Re: SE-253 cam specs
Post by: kng103 on April 30, 2005, 04:42:21 PM
Quote
KNG103 I emailed you the dyno sheet.
Title: Re: SE-253 cam specs
Post by: kng103 on April 30, 2005, 04:43:47 PM
Quote

here goes nothing

Title: Re: SE-253 cam specs
Post by: B767capt on April 30, 2005, 05:09:15 PM
Thanks you saved me from redoing it.  I appreciate it.  Bill
Title: Re: SE-253 cam specs
Post by: kng103 on April 30, 2005, 05:33:12 PM
Quote
Thanks you saved me from redoing it.
Title: Re: SE-253 cam specs
Post by: bubbarosa on April 30, 2005, 07:03:42 PM
Hey B767cpt... are you using the "stock" se103 heads or the se103+ heads with those 103+ pistons?  alot of places i look says that ain't going to work with stock  and some people say it works great.   I like those numbers either way though!
Title: Re: SE-253 cam specs
Post by: B767capt on April 30, 2005, 07:41:05 PM
Yes I am very happy with the build.  Bob Wood did the math and Colin at Underground did the head work.  The valves are stock too.  This is what I got with the CVO 103 heads.  We wanted to keep them on there to keep the value of the bike.  They were only decked to make them square.  Bob did not want to butcher the heads.  All the compression is from the pistons and the .030 head gasket.   It's about 10.7 or 10.8.  We put .005 over on piston size.  The dyno was done in very humid and hot conditions and we figure with good air it would have pumped out 128-129 on TQ and 118-119 on HP.  The best thing is the valve train is quiet.  It had a tick before when hot.  Not now.  I was lucky as my crank run out was perfect so no gear noise.  The bike runs much smoother than when stock from the factory.  It ain't lean.
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on April 30, 2005, 08:02:27 PM
CAPT those are good numbers for a fuelie. You get some good air and the numbers will only get better. How does the bike ride? Stay safe.


THE DAWG
Title: Re: SE-253 cam specs
Post by: B767capt on April 30, 2005, 08:23:48 PM
Dawg the thing is scarry fast.  I mean your at 90mph at a blink of an eye.  It pulls real hard.  i just hope it lasts.  Still getting original mileage.  At 180 miles I put 4.5 gallon in.
Bill
Title: Re: SE-253 cam specs
Post by: SHRADER on May 01, 2005, 08:36:16 PM
I was looking through some stuff and found contradictory information. A tech tip dated from January of this year lists the following different specs for the cvo 253 cam.

Intake    .536 lift   239 duration   open 7BTDC close 52 ABDC
Exhaust  .537 lift   256 duration   open 59BBDC  close 17 ATDC

Don't know which one is correct?

REGARDS
SHRADER
Title: Re: SE-253 cam specs
Post by: DCFIREMANN on May 01, 2005, 09:02:26 PM
Shrader have you ever installed a screamin eagle 103 kit? The catalog says the kit comes with the 253 cams. Just wondering if they send a timing card with the kit? If I get a chance this week I'll try to get a card on the cams if in fact they are even available. I really don't know why this is such a secret.

To me it doesn't matter I want to take the chains out of the motor. But to some of the other owners it might come in handy at some time or another. Stay safe.

THE DAWG
Title: Re: SE-253 cam specs
Post by: kng103 on May 02, 2005, 08:01:33 AM
Quote
I was looking through some stuff and found contradictory information. A tech tip dated from January of this year lists the following different specs for the cvo 253 cam.

Intake
Title: Re: SE-253 cam specs
Post by: the O`Fender on May 02, 2005, 11:59:09 AM
Quote

either way the duration is way to long.


Too long for what? oodles of torque@low rpm's!!!!
Title: Re: SE-253 cam specs
Post by: spydglide on May 02, 2005, 12:42:13 PM
Quote

Too long for what? oodles of torque@low rpm's!!!!

"Oodles of Torque at low RPM's"...........now, THAT'S for me!  [smiley=huepfenlol2.gif]
Title: Re: SE-253 cam specs
Post by: shovelhead71 on May 02, 2005, 02:50:04 PM
was looking seriously at changing cams sat - trying to identify the 103 cylinder heads as to what they are - are they already ported for good air flow ? look up part numbers and what the talon parts sytem shows is not what is shown in the hd catalog ? also these have cast pistons in the stock 103's and not very confident on having these in a higher rpm engine - would just as soon go with forged PRO pistons for any larger cam than a .253 - also forged pro's better compression builders. so sat just switched out with the rineharts full exhaust with the high performance baffles - major change in performance right now.
anyone seen the new HD poster with the big knots in the exhaust piped kicking the epa?
Title: Re: SE-253 cam specs
Post by: osmacat on May 03, 2005, 09:23:30 AM
Hey Shovelhead, How do you like the Rineharts with the performance baffle? What is the difference in the baffle? An earlier thread said that the guys at Rinehart thought these baffles were to small for the 103. What do you think?
Title: Re: SE-253 cam specs
Post by: Tony - www.1700cc.co.uk on May 08, 2005, 04:54:23 PM
Quote
I will probably go with the zippers 50mm, if i don't send mine to bc gerolmy to be reworked.


Kng,

BC Gerolamy will have an exchange unit soon for the SEEG2 as I am upgrading to their 50 mm twin throat and they are buying my stock one of me. They will be bringing the unit back to California after having come over here to tune my bike in late May 2005.

I hope this helps.
Title: Re: SE-253 cam specs
Post by: Jordan1200 on January 06, 2019, 07:24:06 AM
Many times on this site I have seen reference to the mystery cam specs of the SE-253 cam that comes stock in 103's.

Here are the specs for the cam as posted in little known  2003 technical forum that has long since been deleted from H-D's dealer only site.

Intake    .530 lift      237 duration  open 9 BTDC close 51 ABDC
Exhaust  .530 lift     252 duration  open 62 BBDC close 17 ATDC

Just for everyones info.
REGARDS
SHRADER
Dunno where you got these numbers but this is an old post so doubt there will be a response.
This is straight from the harley docs on the stock and 103 and others
(https://uploads.tapatalk-cdn.com/20190106/725476fbad79cef163a98dec712a7329.jpg)

Sent from my SM-G930W8 using Tapatalk

Title: Re: SE-253 cam specs
Post by: Jordan1200 on January 06, 2019, 07:32:18 AM
Dunno where you got these numbers but this is an old post so doubt there will be a response.
This is straight from the harley docs on the stock and 103 and others
(https://uploads.tapatalk-cdn.com/20190106/725476fbad79cef163a98dec712a7329.jpg)

Sent from my SM-G930W8 using Tapatalk
I see these are specs for older bikes
253 cam specs listed in it from MoCohttp://cloud.tapatalk.com/s/5c31f53c249cc/older%20HarleyCamSpecs.pdf (http://cloud.tapatalk.com/s/5c31f53c249cc/older%20HarleyCamSpecs.pdf)

Sent from my SM-G930W8 using Tapatalk