Camshafts.....

malibu795

malibu795

misspeelleerr
Apr 28, 2007
7,848
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Haven't see a good camshaft thread in a while if at all...

Anyone have the specs on the current OEM camshafts?
Duration @.006", @.050" lift, LSA, intake centline
Lb7, LLY, LBZ, LMM, LML?

Going from a LMM .040 17.5:1 long block to bone stock LBZ long block.
The LBZ block spools faster, runs cleaner, and RPM power band is 3-400rpm lower.. With 8ci less displacement, lower compression. In sure some of the difference is piston bowl related... Piston bowl design does not move rpm band around.... Camshafts depict rpm range. And everything else plays off that, heads, turbo, etc
It's "supposed" to be same at the LMM yet it doesn't perform the same even when it had stock pistons...


I see alot of LSA in the 109° range Hamilton/comp/crane. Socal won't release their specs.. Is TTS still making camshafts?

While narrow LSA are beneficial to increase efficency in upper rpm usage mainly because one can use savaging to help pull more air into a cylinder... Mainly noticeable on SC/NA engines..

My basic understanding of LSA
Narrow LSA of 106-110° kill efficiency in lower rpms and excell at higher rpm where as LSA of 112-116° or wide LSA increase efficiency in lower rpm and run out of steam at higher rpm..
Educated deductive reasoning. Turbo charged engine would be hurt from narrow LSA due to exhaust back pressures seriously reduce scavenging.. When one Looks up turbo spec'd camshaft and compare them to a SC/NA Camshaft of same rpm range the turbo charge camshaft have a wider LSA
I'd degree my LMM but I don't have a 1piece crankshaft:eek:
 
moparkxracer

moparkxracer

Well-known member
Jun 25, 2010
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Would be nice to know what they are as well, I have a SoCal one in mine. It will more then likely be pulled and swapped out. Just don't like having something that you don't know what it is.
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
7,848
281
83
42
in the buckeye state
I can deal with operating ranges. But building something on a crap shoot in dark based off some ones opinion with no reference point. Is a bunch of BS imo..

800.00 camshaft is a big bill
 
moparkxracer

moparkxracer

Well-known member
Jun 25, 2010
2,309
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Out and about
Mine is an AF it's abt double that. It did spool a gtx4202r/5541 very easily. Just would like to know what it is, I inderstand why some don't give specs but for what I've spent on engines would be nice to know.
 
S

S Phinney

Active member
Aug 15, 2008
4,011
18
28
Quncy, Fl
malibu795 said:
Haven't see a good camshaft thread in a while if at all...

Anyone have the specs on the current OEM camshafts?
Duration @.006", @.050" lift, LSA, intake centline
Lb7, LLY, LBZ, LMM, LML?

Going from a LMM .040 17.5:1 long block to bone stock LBZ long block.
The LBZ block spools faster, runs cleaner, and RPM power band is 3-400rpm lower.. With 8ci less displacement, lower compression. In sure some of the difference is piston bowl related... Piston bowl design does not move rpm band around.... Camshafts depict rpm range. And everything else plays off that, heads, turbo, etc
It's "supposed" to be same at the LMM yet it doesn't perform the same even when it had stock pistons...


I see alot of LSA in the 109° range Hamilton/comp/crane. Socal won't release their specs.. Is TTS still making camshafts?

While narrow LSA are beneficial to increase efficency in upper rpm usage mainly because one can use savaging to help pull more air into a cylinder... Mainly noticeable on SC/NA engines..

My basic understanding of LSA
Narrow LSA of 106-110° kill efficiency in lower rpms and excell at higher rpm where as LSA of 112-116° or wide LSA increase efficiency in lower rpm and run out of steam at higher rpm..
Educated deductive reasoning. Turbo charged engine would be hurt from narrow LSA due to exhaust back pressures seriously reduce scavenging.. When one Looks up turbo spec'd camshaft and compare them to a SC/NA Camshaft of same rpm range the turbo charge camshaft have a wider LSA
I'd degree my LMM but I don't have a 1piece crankshaft:eek:
Click to expand...

There is more to it than just the lobe separation for sure. It takes the whole profile to determine if its acceptable for the application. Diesels are low rpm engines in the realm of discussing rpm play in cam selection. You wont to pick a camshaft that will promote airflow on intake and exhaust with just the right amount of lobe separation as to not bleed off drive pressures in a turbo charged diesel. The combination of duration and separation along with the valve timing event determine how efficient that cam will be with the specific engine that its being used on. Purpose of the vehicle including final drive ratios are the most helpful things to consider when picking the camshaft. I really good example of what I am talking about is that I ran the 9100 AF camshaft with my CCSB triple turbo 200 over injector truck. The previous camshaft had the same LSA, a small amount more exhaust lift, a small amount less intake lift and about ten degress less timing than the 9100 has. Daily driving was much better with the previous cam, drive pressure was about 15 psi higher, I had boost when driving it down the road and top end power did not suffer. With the 9100 smoke levels where much greater, power under the curve was less, power was way up in the rpm range. It really wanted to run when you were ready to stop running it. Overall performance suffered with the 9100 Camshaft. It was simply the wrong camshaft for my application. Bigger is not better. You ave to keep in mine that these two cams are not a day and night difference in specs either. Parts that compliment each other is where it is at. Mark at Danville has dyno tested a bunch of cams and he can attest to the importance of not being too aggressive on camshaft selection for your application.
 
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