#4-#7 lobe swap cam
Thread Starter
Racer
Joined: Sep 2004
Posts: 495
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From: berwick pennsylvania
#4-#7 lobe swap cam
was reading about comp cams 4-7 lobe swap cam.
my question is what would have to done computer wise to make this swap in my 85 l98? claims to have some real benifits like smoother torque curve,less crank deflection and more hp.
my question is what would have to done computer wise to make this swap in my 85 l98? claims to have some real benifits like smoother torque curve,less crank deflection and more hp.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by 85blkrose
was reading about comp cams 4-7 lobe swap cam.
my question is what would have to done computer wise to make this swap in my 85 l98? claims to have some real benifits like smoother torque curve,less crank deflection and more hp.
my question is what would have to done computer wise to make this swap in my 85 l98? claims to have some real benifits like smoother torque curve,less crank deflection and more hp.
You won't have to do anything. Your old system is what they call batch fire. It fires one bank and then the other. If it was a sequentially fired injection like what is used on the later LT1 cars or LS1 cars then you woudl have to rewire the injectors. Did you read that article in I think CHP or maybe Hot Rod magazines about the 4-7 swap? Their extensive testing was inconclusive. In fact in one of the last tests on the engine dyno the original firing order actually made a tad more power.
Race Director
Joined: Jun 1999
Posts: 14,924
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From: Merritt Ils Fl
Chevy Hi Po did a series of dyno pulls with the same mule with only the cam changed. Their conclusion was there was not a significant difference. Not worth the effort. It is,however an interesting idea.
Drifting
Joined: Nov 2003
Posts: 1,637
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From: Honeoye Ny
Im not as interested in the hp advantage as I am in the deflection in the crankshaft. it's more about trying not to break stuff. But I too would like to see further data about engine harmonics. say check two different cams same duration but one with the revised order on the same motor in a dynamic engine balancing fixture. such as the ones used in mass production
Thread Starter
Racer
Joined: Sep 2004
Posts: 495
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From: berwick pennsylvania
strength
Originally Posted by Baldturbofreak
Im not as interested in the hp advantage as I am in the deflection in the crankshaft. it's more about trying not to break stuff. But I too would like to see further data about engine harmonics. say check two different cams same duration but one with the revised order on the same motor in a dynamic engine balancing fixture. such as the ones used in mass production
