Engine Compression/Parts Questions

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Redtruck-VA

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Hemi-5.7, 5.9 12v & 24v diesel
Yeah the cam, I will almost definately get from Inertia. They do custome grinds, and have a couple supercharger cams.

Trup, can you share the spec on those cams?
 
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Trupiano

Trupiano

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Hometown : Puyallup,WA Stationed : Little Rock,
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2010 Ram 2500 6.7L CTD Crew Cab
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6.7L CTD
Blown Spartan

$490 SHIPPED
  • 2xx/2xx Duration Camshaft
  • Designed for use with forced induction systems (superchargers, turbo systems)
  • Our Performance Heads Recommended
  • Custom Tuning Required
  • Our Custom Forged Pushrods Recommended
Ive heard the Spartan is good, but Blown Spartan is best. No specs on blown spartan... 2xx/2xx for duration on they're website, and cant find anything anywhere else, but Ive heard it has a longer exhaust duration. I'd have to call them and tell them what I plan to do and have them custom grind one for the specs. That will be a while's away...
 

Redtruck-VA

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Yes, maybe talk to them. I find it great fun looking at the specs trying to figure the key points. I really liked the Crazy Spartan (Danny's cam) on 114 lsa. But can't help thinking about a Spartan on 115 lsa. I like lift, but not the overlap. Story time: Had a 70 chevelle with a 427 BB ran the oval port heads with a really high lift cam but with wide lobe centers, 4:11 gear, 3000 TC. That sucker was an animal on the street. Springtime is going to be fun...
 
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Trupiano

Trupiano

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Yeah I'll have to do alot of research into a good cam grind. I don't really know what duration, LSA, and lift are, let alone what's best for me. I think duration is how long the intake and exhaust valves are open?
 

Redtruck-VA

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Yeah I'll have to do alot of research into a good cam grind. I don't really know what duration, LSA, and lift are, let alone what's best for me. I think duration is how long the intake and exhaust valves are open?

Try this out,

APE - Cam terminology
 

Redtruck-VA

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Mostly I agree with what they have. But like the cheater cam. This might be generation gape thing, but a cheater cam was a custom hot cam that was reground to have no more lift than the OEM cam ran in stock class drags. We didn't directly refer to lsa but used the term overlap. Tighter lsa meant more lope (overlap) at idle with power moved up the rpm range. Erratic vacum at idle tied in with reduced relative cylinder pressure (compression). Wider lsa smooths out the idle and vacum reading and increases relative cylinder pressure (compression). This is easier understood by saying a engine with the valves closed is harder to turn over than an engine that allows some of the air to escape. This also might explain the high success rate of the 260 cam in that it optimises our engines CR and general engine flow characteristics. Cam selection takes serious MoJo as everyone make subtle changes to their engines that requires a little different characteristic from the cam to maxiumize output. There is no cam that does it all unfortunately. How about stock cr using a Spartan on 115 lsa with BV heads and spray? Or stock block 5.7 with 6.1 custom BV heads with a 10.25 cr and a Spartan on 114 lsa? Get my drift? Unfortunately I don't have the money to try them all and will end up compromising so I don't have to do another cam change later. Great fun......
 
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