Cam and valvetrain longevity....??? low duration high lift...
10-07-2016, 09:50 AM
#1351
I am not so sure about that small of runner head on a 540+CI marine engine. My 548s have Dart 360s speced by Teague and made great numbers. Bob recommended AFR 305s for my 502ci 575sci, I thought that was small as well, or was it just what he had on the shelf? As far as my cams they are Crane Hydraulic Roller 254/262 680/680. 982 and 984 a side at 8psi
10-07-2016, 09:51 AM
#1352
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I am not so sure about that small of runner head on a 540+CI marine engine. My 548s have Dart 360s speced by Teague and made great numbers. Bob recommended AFR 305s for my 502ci 575sci, I thought that was small as well, or was it just what he had on the shelf? As far as my cams they are Crane Hydraulic Roller 254/262 680/680. 982 and 984 a side at 8psi
That is a big port, prob wouldnt go that route for an NA 540 marine build, the 320 darts would prob work better. But with that roots up top, low end shouldn't be an issue. Im sure yours made plenty of torque.
10-07-2016, 09:54 AM
#1353
Nice to see someone finally put some cam in an engine. These. 240* 540s are a dime a dozen .
That is a big port, prob wouldnt go that route for an NA 540 marine build, the 320 darts would prob work better. But with that roots up top, low end shouldn't be an issue. Im sure yours made plenty of torque.
That is a big port, prob wouldnt go that route for an NA 540 marine build, the 320 darts would prob work better. But with that roots up top, low end shouldn't be an issue. Im sure yours made plenty of torque.
10-07-2016, 11:14 AM
#1354
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A buddy talked to kip today at cam motion said they have not had issues with harness, he wants cams to check, I plan to have frock style check them local also and compare results, I have 4 guys that wanna check them, so hard to have many involved... He did also say he's not a fan of small duration high lift but had to give Bob what he asks a for, also said I am a solid 10 degrees duration away form good power... I will be calling him myself personally later and let you guys know how my convo goes.
10-07-2016, 02:44 PM
#1355
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I see that MK was spec'ing high lift short duration for pretty much everything. So what is the theororetical value of such relative short duration? I'm flipping through a comp cams catalog and all of their cams for marine use ~.550 lift but about +20* on the duration. These seem flat and wide compared to the MK cams.
10-07-2016, 04:05 PM
#1357
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It seems like that tight of a duration would give you a peaky spread of more power. Which makes sense as folks were having to prop down to let the engines get to that power, and then it would fly. Please correct me if that's wrong.
10-07-2016, 04:19 PM
#1358
Charter Member#568
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I know Tim's cams had more lift than mine but mine still are outside of the norm I guess. I don't know that my power curve was particularly peaky. Perhaps I'm mistaken though not being exposed to as many combinations as some here
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10-07-2016, 04:26 PM
#1359
Charter Member#568
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This was the peakiest pull with the 2 in spacer. I went with the 1 inch spacer because it was broader than this one and higher in torque. I don't have that graph in the phone to upload here
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