INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

LSA comparo in the new Engine Masters Mag

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Old 11-13-2005 | 03:50 PM
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Originally Posted by Sport Side
i cant find the damn mag.
is it on news stands?
heard the tight LSA kicked some ***... who would of figured???
what was the setup?
in this N/A application 112 was the worst
Old 11-13-2005 | 04:06 PM
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But you have to realise this was on a small block too. They tested 106or108 through 114 or 116. I got the mag, just dont remember. The sb cams have slightly different numbers than the LS based motors. Id like to see a LS1 with a 4speed auto idle with a 108 or even 110 LSA cam. It was a very interesting article though.
Old 11-13-2005 | 07:42 PM
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Originally Posted by white1
But you have to realise this was on a small block too. They tested 106or108 through 114 or 116. I got the mag, just dont remember. The sb cams have slightly different numbers than the LS based motors. Id like to see a LS1 with a 4speed auto idle with a 108 or even 110 LSA cam. It was a very interesting article though.
LSA has NOTHING to do with how a motor idles. It's the lobes and LSA combined that create a given amount of overlap. Overlap is what people fight when they are trying to get their profile to idle correctly.
For example, a 215/215 108LSA will idle slightly better than a TR224-112 depeding on the profile/ramp rates.
Old 11-15-2005 | 10:04 PM
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just wonder if I will have any problems with the 230/236 on a 110 in my 6.0?
Old 11-15-2005 | 10:31 PM
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Originally Posted by Dark Halo
just wonder if I will have any problems with the 230/236 on a 110 in my 6.0?
That cam should work good with your 6L. I'm building a 408 for the Wood Hauler's truck and Comp suggested a 232/238 with 112 LSA for his but the 112 LSA was due to the fact that he is running Nitrous, but thats close to the same size as yours. I think your cam is gonna perform great though.
Old 11-16-2005 | 09:25 AM
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Originally Posted by Sport Side
LSA has NOTHING to do with how a motor idles. It's the lobes and LSA combined that create a given amount of overlap. Overlap is what people fight when they are trying to get their profile to idle correctly.
For example, a 215/215 108LSA will idle slightly better than a TR224-112 depeding on the profile/ramp rates.


True, however they compared the same grind on different LSA. A TR224 on a 114 will idle better thatn a TR224 on a 112.
Old 11-16-2005 | 01:20 PM
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So if I had a cam with say duration of 210/210 lift of .500/.500 and 1 cam had a LSA of 112 and the other was 118.5.

What would be the difference in characteristics. Which 1 would make the most lowend torque, high rpm hp, idle characteristics. This is the last part of cam specs which I dont understand.

Can anyone please clear this up for me, and probably others also.

thanks a bunch

Hog
Old 11-16-2005 | 01:42 PM
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Originally Posted by hog
So if I had a cam with say duration of 210/210 lift of .500/.500 and 1 cam had a LSA of 112 and the other was 118.5.

What would be the difference in characteristics. Which 1 would make the most lowend torque, high rpm hp, idle characteristics. This is the last part of cam specs which I dont understand.

Can anyone please clear this up for me, and probably others also.

thanks a bunch

Hog

The tighter LSA will have more torque down lower. The wider LSA will perfer top end. The tighter LSA will have more "lope" to it, and the wider LSA will idle smoother.

I love the way my 112 idles and runs, it just has some tuning issues such as surging at red lights, and dying when I pull into the driveway, or back out of some parking places.
Old 11-18-2005 | 12:51 AM
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Perhaps this is the same issue of Engine Masters that has an article that I contributed to. In the article we refreshed a pair of Brodix 18º heads for a 395cid Chevy. We helped tune them up (and down in some places of the exhaust lift curve). The before and after results netted approximately 20 flywheel horsepower and 20 ft/lbs of torque accross the useable rpm range. The only other component that was changed was the lobe center of the cam. I believe that the lobe center change contributed more to the torque and hp increase than the head work given the useable lift curve of the hyd. roller cam. Whatever the case, the target objective of 600flhp was reached.
I had the good fortune of working with an Engine Masters finalist in the first two events (Nelson Racing Engines). I can tell you with certainty that the camshaft choice was most critical to the overall power curve of those engines. All the entrants had a variety of different cam, head, intake and exhasut combos, but they were all really stout with torque across the useable rev range. It became clear that the valve event is paramount. We found that choosing the ideal valve opening and closing positions are more important than overall lift the cam offers. The lobe center positions were very important to performance.
Great topic Grippy. One that I wish I had another lifetime to explore.............

Richard
Old 11-18-2005 | 11:04 AM
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Originally Posted by Richard@WCCH
Perhaps this is the same issue of Engine Masters that has an article that I contributed to. In the article we refreshed a pair of Brodix 18º heads for a 395cid Chevy. We helped tune them up (and down in some places of the exhaust lift curve). The before and after results netted approximately 20 flywheel horsepower and 20 ft/lbs of torque accross the useable rpm range. The only other component that was changed was the lobe center of the cam. I believe that the lobe center change contributed more to the torque and hp increase than the head work given the useable lift curve of the hyd. roller cam. Whatever the case, the target objective of 600flhp was reached.
I had the good fortune of working with an Engine Masters finalist in the first two events (Nelson Racing Engines). I can tell you with certainty that the camshaft choice was most critical to the overall power curve of those engines. All the entrants had a variety of different cam, head, intake and exhasut combos, but they were all really stout with torque across the useable rev range. It became clear that the valve event is paramount. We found that choosing the ideal valve opening and closing positions are more important than overall lift the cam offers. The lobe center positions were very important to performance.
Great topic Grippy. One that I wish I had another lifetime to explore.............

Richard
I'll have to re-read the Mag to catch that article

I've been running various Engine/Cam combinations through "Dyno Sim" Software, but more importantly, my combination and so far it is looking very good with HP peaking at 6000rpm and TQ peaking at 2000rpm
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