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Cam Shaft specs? What do they mean?

Started by billschroeder5842, December 18, 2011, 08:02:38 PM

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billschroeder5842

I was doing a bit of research on my '69. I've had the car for 7 years and bought it from the 2nd owner who had the car for 25 years.

I found that there was some engine work done in 1990 (still running strong!) Can anyone help me with deciphering these cam specs? I have no idea what these really mean or how it affects engine performance.

BTW, I have this cam, aluminum intake, 4bbl, electronic ignition and headers. I was told that my motor is a '72 400.

Intake
open 30 degrees BTC
close 78 Degrees ABC
288 total intake duration
.296 cam rise
.444 cam lift

Exhaust
open 74 degrees BBC
close 34 ATC
288 total exhaust duration
.2967 cam rise
.445 valve lift

This cam came from Melling Tool Company, Jackson, Michigan

Thanks!
Texas Proud!

Chryco Psycho

basically the duration & overlap are the most important specs , ad duration @ 288* which is relatively long duration & overlap of 64*  . these two specs control the way the engine runs , how it idles & what rpm it will make power up to , the longer duration combined with more overlap raise the rpm where the cam works . Lift is basically free , more lift will = more flow up to the point where the port flow stalls , typically around .500 lift on unported heads & up to .700 lift or more with good port work so generally more lift is better .
The cam you have is a stock cheater cam with longer duration but stock lift not the cam I would choose for street performance but it probably works ok .

billschroeder5842

Thanks for the info.

"stock cheater" so I guess I have something that is ever so slight "hotter" than stock?

I can get it to idle pretty well with only a slight "rump" bu it seem to have some vacuum issues; just not pulling enough.

thanks!
Texas Proud!

Chryco Psycho

the longer duration will reduce the vacuum & give it the lope

mchlharp

i would like to say i knew what all that meant but id be lying. i am restoreing a 69 charger r/t with a 440 4bbl 727 trans the engine only has 19000 miles on the original block numbers matching i want to put a bigger cam in it but i have absolutly no clue what size brand specs im looking for would u school me on everything cam i know how they work but all the numbers throw me off
Michael W. Harp

Chryco Psycho


mchlharp

ok i want to get a little more hp out of my 440 what cam do u suggest i get without having to change stock heads and headers ect i want stock look but just more power not over kill if i can just go with a little better cam thats what i would like to do
sorry this is my first restore i know basics mechanics never rebuilt an engine before
Michael W. Harp

Chryco Psycho

the stock manifolds have very little scavenging effect so you want to stay with less overlap around 112* CL , the duration will control where the powerband is & get as much lift as possible .
Most cam companies have Tech lines you can cal & see hwta they suggest for your application . The Lunati VooDoo cams are designed to do this , get the duration so the powerband is where you want it & maximum lift , you may have to custom order the cam with the 112* CL to work with the manifolds

Challenger340

The simple math from the specs you posted, is that you ALREADY have a 112 degree CL (lsa) Camshaft,
that,
if installed "straight up" with no advance, has an Installed Centerline of 114* ATDC.

The easiest "cure" for your old " Wolverine/Blue Racer" grind as they are called now, and has ALWAYS been ther cure for those Cams, would be to advance the current Camshaft 4* with Manifolds for 2 reasons...
1.) build more Cylinder Pressure by closing the intake earlier and increase Torque
2.) Open the exhaust sooner to promote a hotter burn(higher Pressure) out the exhaust manifolds to enhance "whatever" scavenging when the Intake does open later.

I have tested this on the Engine Dyno countless times with smaller the Hydraulics which you have...with manifolds on 440-6pack engines
Comparable "modern" Camshafts, with the SAME duration @ .050,  from ANYWHERE...CompCams, Lunati, Crane, etc., etc., on the same 112lsa,  will provide approx 5-15 hp
thats it...thats ALL !
IMO,
NOT worth it unless you are contemplating a BIGGER grind(designed FOR Manifolds), at which point, DO NOT request a move of more than 2 degree's LSA from ANY Cam design profile.
Far MORE going on with Camshaft design for anybody on the internet to claim "expert" status on any site, including me, unless they wish to post their SAE Tickets in Cam Dynamics for all to see.
Long story short....
PHONE....and Let the Camshaft Companies Technical Staff make a LSA(CL)Reccomendation on a Cam, WITHOUT you "requesting" something you heard about LSA on the Internet, from anybody, which tends to slant them, to tell YOU, what they "think" you wanna hear.

Just my opinion.
Only wimps wear Bowties !