cam degree and need HELP!!!!

[396_WAYS_TO_SPIT]

Ok I was trying to degree my cam tonight and I am lost. Here are my specs.
258 degrees @.050 int/ex
.615 lift in/ex
108 lobe seperation
.024 valve adj in/ex
in. opens @44
in. closes @80
ex. opens @80
ex. closes @44
based on 1.75 rockers. This is a clay smith cam. When we degreed it we came up with the intake opening @ 21 degrees. So that is where it threw me off. I am looking for 44 degrees like the cam card says. Whats going on here??? So I look at the tech articles and find this lil hand calculation.
"Calculating Timing Events:
Intake Opening
Duration/2 = Sum - Intake Centerline = Intake Opening
Intake Closing
(Intake Opening + Centerline) / 2 = Intake Closing
To figure exhaust, Opposite of Intake.
Overlap is IO + EC."
So I plug my numbers and get this........
duration"258"/2=129(sum)-108(intake centerline)=21(intake opening)
"intake closing"
21(intake opening+108(centerline)=129/2=64.5
21"intake opening"+64.5"exhaust closing"=85.5
So thats where I am lost :confused: :confused: I thought I would get the same numbers on my cam card. Something looks wrong here but I cant seem to see it! Please dont bash me as this is the first time I have ever done this. can someone please help me........
396

[396_WAYS_TO_SPIT]

bump

[Fiat48]

To start with..something wrong with specs you listed.
A cam that is 258 @ .050 cannot :
44 at >050
80 at .050
For that is 304 degrees duration at .050.
I suspect those specs are at .020 open or something.
Post picture of cam card. Will walk you through entire process.

[396_WAYS_TO_SPIT]

Fiat, you are right. The cam card says c-304-8-b and the cam is stamped 304 on it! Here are the pics. They are not the best but I got em...
Does that seat pressure look wrong to you?
http://www2.***boat.com/image_center/data/521/239cam4.jpg
http://www2.***boat.com/image_center/data/521/239cam1.jpg
http://www2.***boat.com/image_center/data/521/239cam2.jpg
http://www2.***boat.com/image_center/data/521/239cam3.jpg

[78Eliminator]

Jesus, are those blurry pics or am I drunk? :D

[Squirtin Thunder]

I wish I could read them !!!

[Squirtin Thunder]

Jesus, are those blurry pics or am I drunk? :D
Well are you ???
Sorry 396 had too !!! :D

[Fiat48]

I am quite sure the checking specs are at .020 lift and not at .050...although I don't see that notation on the cam card. So you are doing it right...degreeing it at .020.
Now try this:
Degree the cam again. Record the degrees at .050 lift.
Add 180 to those numbers and you should get 258.
Example:
Intake opens at .050 = 20 degrees BTDC
Intake closes at .050 = 56 dgrees ABDC
add 180 = 256 degrees.
Solid cam..yeah 140 lbs. Non roller flat tappet.

[396_WAYS_TO_SPIT]

Well are you ???
Sorry 396 had too !!! :D
No jim, I am mad and dissappointed. I have been busting my ass to get this boat in the water by this weekend. I have hit every roadblock possible :mad: Those pics were taken with my camera phone with as much light as possible. Some a$$hole stole my digital camera :mad: :mad:
The cam card says........
Grind c-304-8-b
in. opens 44 ex. opens 80
in. closes 80 ex. closes 44
duration at .050 258 degrees duration at .050 258 degrees
in. valve lift .615 ex valve lift .615
in. valve adj. .024 ex valve adj. .024
Based on 1.75 rockers
Set springs at 140 pounds seat pressure
Clay smith grind.......

[Squirtin Thunder]

I am quite sure the checking specs are at .020 lift and not at .050...although I don't see that notation on the cam card. So you are doing it right...degreeing it at .020.
Now try this:
Degree the cam again. Record the degrees at .050 lift.
Add 180 to those numbers and you should get 258.
Example:
Intake opens at .050 = 20 degrees BTDC
Intake closes at .050 = 56 dgrees ABDC
add 180 = 256 degrees.
Solid cam..yeah 140 lbs. Non roller flat tappet.
Micheal go with what Fiat say he will get you through this !!!

[Squirtin Thunder]

No jim, I am mad and dissappointed. I have been busting my ass to get this boat in the water by this weekend. I have hit every roadblock possible :mad: Those pics were taken with my camera phone with as much light as possible. Some a$$hole stole my digital camera :mad: :mad:
The cam card says........
Grind c-304-8-b
in. opens 44 ex. opens 80
in. closes 80 ex. closes 44
duration at .050 258 degrees duration at .050 258 degrees
in. valve lift .615 ex valve lift .615
in. valve adj. .024 ex valve adj. .024
Based on 1.75 rockers
Set springs at 140 pounds seat pressure
Clay smith grind.......
You have time just relax and it will get done !!! There is enough info here and people willing to help you will be fine !!!

[396_WAYS_TO_SPIT]

I am quite sure the checking specs are at .020 lift and not at .050...although I don't see that notation on the cam card. So you are doing it right...degreeing it at .020.
Now try this:
Degree the cam again. Record the degrees at .050 lift.
Add 180 to those numbers and you should get 258.
Example:
Intake opens at .050 = 20 degrees BTDC
Intake closes at .050 = 56 dgrees ABDC
add 180 = 256 degrees.
Solid cam..yeah 140 lbs. Non roller flat tappet.
So everything is ok fiat? Why didnt they state to check it at .020? So do I check it at .020 or at .050? Why does the intake open at 20 degrees BTDC? Is it the amount of duration and lift? So if i degree again I should come up with 76? Oh and one more thing......How and the hell did you know it was 304 duration and a solid cam???? All I know is that you are the man fiat;) You always pull through for me;) Thanks bud;) Now I can sleep;)
396

[Fiat48]

Somewhere in little tiny print it probably is supposed to say "Check at .020 lift."
But I guarantee you no cam can open 44 BTDC and close 80 ABDC @ .050....and have 256 degrees duration at .050.
A typical 284 degree cam at .050 =
Io 32
IC 72
add 180 =284.

[396_WAYS_TO_SPIT]

You have time just relax and it will get done !!! There is enough info here and people willing to help you will be fine !!!
I know jim. I just get stressed out when I get really lost. I will stab at it a million times until I get it right! Thats the one thing about me;) With the help of great people I think I will get through this. Big thanks to fiat for all his help. He even too the time to figure compression ratios with me a few months ago;) He always comes through plus he is always right on the money for some reason. I hope I can meet that man one day. I will buy him brew and even toss a few ladies at him if he doesnt mind;)
396

[Fiat48]

So everything is ok fiat? Why didnt they state to check it at .020? So do I check it at .020 or at .050? Why does the intake open at 20 degrees BTDC? Is it the amount of duration and lift? So if i degree again I should come up with 76? Oh and one more thing......How and the hell did you know it was 304 duration and a solid cam???? All I know is that you are the man fiat;) You always pull through for me;) Thanks bud;) Now I can sleep;)
396
Magic. I am Psychic. If I could only spell.
304 because 44 plus 80 plus 180 = 304
140 lbs..seat = solid lifter cam.

[396_WAYS_TO_SPIT]

Somewhere in little tiny print it probably is supposed to say "Check at .020 lift."
But I guarantee you no cam can open 44 BTDC and close 80 ABDC @ .050....and have 256 degrees duration at .050.
A typical 284 degree cam at .050 =
Io 32
IC 72
add 180 =284.
Aww now its making more sense to me;) Thanks again bob!!! You always pull me through. I am young and still learning this. I hope someday I can help people as much as you do!
Michael

[396_WAYS_TO_SPIT]

Magic. I am Psychic. If I could only spell.
304 because 44 plus 80 plus 180 = 304
140 lbs..seat = solid lifter cam.
LOL your crazy bob :cool: :cool:
396

[396_WAYS_TO_SPIT]

Magic. I am Psychic. If I could only spell.
304 because 44 plus 80 plus 180 = 304
140 lbs..seat = solid lifter cam.
Ok please explain why you just added them all up? So you check in/ex @ .020 and check the lift @ .050??
396

[Fiat48]

Think about what duration @ .050 (or .020 for that matter) is. The number of degrees the valve is off of the seat that much (.050 or .020) OR MORE.
.050 is kind of a standard measurement of duration because long ago it was determined that no real flow happened until the valve was .050 off of it's seat.
But some cam grinders argue...and some people are in love with big numbers. That's why big cams sell.
Some cam grinders list .020 numbers for checking...but almost always refer to the "standard" .050" number for duration.
Since big numbers sell cams....most manufacturers are still into the "total duration" number....and that number for your cam is 304. This is "bragging rights" so that you can tell your buddys you have a 304 duration cam.
Clay Smith has to list that cam as a "304"....because you might be comparing cams with another cam grinder who says you need his "304" duration cam.
Now..how did I know your cam was called a 304? I knew there was no way a 258 @ .050 camshaft can open at 44 and close at 80. No way. So these must be "just off the seat" measurements. And 44 plus 80 plus 180 = 304. "Advertised Duration." Marketing.
Disregard cam card at this point.
Find actual TDC.
Carefully open the Intake valve .020 off it's seat. Record that measurement. (Probably 44 degrees or close).
Now open the valve to .050 lift. Record that measurement. (Probably about 21 degrees).
Now write down your numbers.
Now...rotate the engine opening the valve to the highest point...while watching and counting the dial indicator. Total lobe lift should be about .352.
How did I get that? Because you said that your cam spec was .615 figured with a 1.75 rocker ratio (which seems wrong as it should be 1.7). .352 X 1.75 = .616.
Now check your closing times at .050 and at .020. When you get done:
Specs at .020 plus 180 will be 304. "Gross Duration".
Specs at .050 plus 180 will equal 258.

[Norseman]

No jim, I am mad and dissappointed. I have been busting my ass to get this boat in the water by this weekend. I have hit every roadblock possible :mad: Those pics were taken with my camera phone with as much light as possible. Some a$$hole stole my digital camera :mad: :mad:
The cam card says........
Grind c-304-8-b
in. opens 44 ex. opens 80
in. closes 80 ex. closes 44
duration at .050 258 degrees duration at .050 258 degrees
in. valve lift .615 ex valve lift .615
in. valve adj. .024 ex valve adj. .024
Based on 1.75 rockers
Set springs at 140 pounds seat pressure
Clay smith grind.......
Check with Clay Smith, but they used to measure the cams events at .006 lift, back in the day.

[Wicked Performance Boats]

C= chevy or cam, I'm not sure. 304 is gross duration. 8= 108 centerline. B= billet. Mechanical because there is a valve lash setting[.024] If you called George at Clay Smith Cans, he would probably tell you to put it in at 4 degrees advanced. Centerline @ 104. Just my opinion. Budlight :coffeycup