Off the shelf cam options for marine engines
02-18-2016, 08:34 AM
#521
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So what was duration on the 680 lift cam? How log was it ran?
My buddy Rick has a 43 No-Tech that had EFI 598s in it build by Eddie before he went on his own. After a few years Rick rebuilt the motors lowering the compression and added 10-71 blowers. The boat responded well and ran 92 at about 5700 -5800 rpms. After 4 years of running that combo the motors came out. Rick worked with Marine
kinetics to update his cam from the original efi cam. Back into the water looking for 6000 rpms and 95 mph he went. Nope The boat went a best of 87 at 5600 rpms.
The boat was tuned right, both motors pulled the same - didn't make sense
Rick contacted Bob for guidance. Bob's response was Rick was running the wrong oil (50 wt). How could that make sense, The same oil had been in the boat for over 5 years. The old motors with the same lifters ran fine with the wrong oil.
We though maybe the exhaust needed to be better so. The next year Rick invested in new exhaust. Going from CMI E-tops with 1 7/8 runners to Stainless Marine Gen 3 with 5 inch tails. Result - exhaust temps dropped a little but no real speed change.
This year (out of frustration and friends making fun of his slow boat) the motors are out again for a cam change. Not with marine kinetics.
First cam that ran well was a Crane 651 with 1.8 rockers on the intake. Bobs cam was larger with 680 lift. Third cam - we will see how it runs. The 651 cams are on the shelf not for sale.
kinetics to update his cam from the original efi cam. Back into the water looking for 6000 rpms and 95 mph he went. Nope The boat went a best of 87 at 5600 rpms.
The boat was tuned right, both motors pulled the same - didn't make sense
Rick contacted Bob for guidance. Bob's response was Rick was running the wrong oil (50 wt). How could that make sense, The same oil had been in the boat for over 5 years. The old motors with the same lifters ran fine with the wrong oil.
We though maybe the exhaust needed to be better so. The next year Rick invested in new exhaust. Going from CMI E-tops with 1 7/8 runners to Stainless Marine Gen 3 with 5 inch tails. Result - exhaust temps dropped a little but no real speed change.
This year (out of frustration and friends making fun of his slow boat) the motors are out again for a cam change. Not with marine kinetics.
First cam that ran well was a Crane 651 with 1.8 rockers on the intake. Bobs cam was larger with 680 lift. Third cam - we will see how it runs. The 651 cams are on the shelf not for sale.
02-18-2016, 08:35 AM
#522
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Location: Olmsted Falls,Ohio Marblehead,Oh
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I do t have power steering, but I also meant crap as in if its gonna break things...
That's why I shared my results with you on F/B about changing my cam timing..
Who knows if the power steering pump or seawater pump starts taking exponentially more HP to turn once over a certain RPM....
We never ran it without the belts to check as it didn't matter, wasn't going in the boat without them.
We retarded the cam timing 4°, made more power on the top where I wanted it, and moved on..
Who knows if the power steering pump or seawater pump starts taking exponentially more HP to turn once over a certain RPM....
We never ran it without the belts to check as it didn't matter, wasn't going in the boat without them.
We retarded the cam timing 4°, made more power on the top where I wanted it, and moved on..
02-18-2016, 09:34 AM
#524
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My buddy Rick has a 43 No-Tech that had EFI 598s in it build by Eddie before he went on his own. After a few years Rick rebuilt the motors lowering the compression and added 10-71 blowers. The boat responded well and ran 92 at about 5700 -5800 rpms. After 4 years of running that combo the motors came out. Rick worked with Marine
kinetics to update his cam from the original efi cam. Back into the water looking for 6000 rpms and 95 mph he went. Nope The boat went a best of 87 at 5600 rpms.
The boat was tuned right, both motors pulled the same - didn't make sense
Rick contacted Bob for guidance. Bob's response was Rick was running the wrong oil (50 wt). How could that make sense, The same oil had been in the boat for over 5 years. The old motors with the same lifters ran fine with the wrong oil.
We though maybe the exhaust needed to be better so. The next year Rick invested in new exhaust. Going from CMI E-tops with 1 7/8 runners to Stainless Marine Gen 3 with 5 inch tails. Result - exhaust temps dropped a little but no real speed change.
This year (out of frustration and friends making fun of his slow boat) the motors are out again for a cam change. Not with marine kinetics.
First cam that ran well was a Crane 651 with 1.8 rockers on the intake. Bobs cam was larger with 680 lift. Third cam - we will see how it runs. The 651 cams are on the shelf not for sale.
kinetics to update his cam from the original efi cam. Back into the water looking for 6000 rpms and 95 mph he went. Nope The boat went a best of 87 at 5600 rpms.
The boat was tuned right, both motors pulled the same - didn't make sense
Rick contacted Bob for guidance. Bob's response was Rick was running the wrong oil (50 wt). How could that make sense, The same oil had been in the boat for over 5 years. The old motors with the same lifters ran fine with the wrong oil.
We though maybe the exhaust needed to be better so. The next year Rick invested in new exhaust. Going from CMI E-tops with 1 7/8 runners to Stainless Marine Gen 3 with 5 inch tails. Result - exhaust temps dropped a little but no real speed change.
This year (out of frustration and friends making fun of his slow boat) the motors are out again for a cam change. Not with marine kinetics.
First cam that ran well was a Crane 651 with 1.8 rockers on the intake. Bobs cam was larger with 680 lift. Third cam - we will see how it runs. The 651 cams are on the shelf not for sale.
02-18-2016, 09:42 AM
#525
Registered
i am not a cam expert but if the 651 cam made more power with the 1.8 rockers on the intake side the 651 is way wrong for the engine.all though i am a big fan of the 651 cam i believe it is not even remotely close to correct for a 598.
02-18-2016, 09:57 AM
#526
Registered
On the rebuild. Pistons, cams, pushrods, springs, 1.7 rockers, rings and bearings. Wasn't my doing but the 1.8 ratio went on after Eddie and before Bob,s cam. We still make fun of Rick for being so slow. But getting a condo with a diesel generator on board to 92 anytime he wanted to wasn't bad.
02-18-2016, 10:01 AM
#527
Registered
Mike,
The weird thing was the boost went up a little after the rebuild. Should have gone down if anything with cam change. So something funny went on with the airflow.
The weird thing was the boost went up a little after the rebuild. Should have gone down if anything with cam change. So something funny went on with the airflow.
02-18-2016, 11:12 AM
#528
Registered
We have seen that 651 cam make peak power in a 540 at 6400rpm with a roots blower. My gut tells me it was prob making its best power in ricks 598 around 5500ish. Prob why he was where he was. My guess is rick wanted to spin the engines faster, and make more power, hence a bigger cam. Just my guess though.
02-18-2016, 04:19 PM
#529
Has anyone else run one of these in a stock 454 mag,
Voodoo Hydraulic Flat Tappet Cam - Chevrolet Big Block 276/284
Product Description
Lunati's Voodoo series of Hydraulic camshafts deliver more area under the curve than any other series of Hydraulic camshafts. This means more throttle response, quicker acceleration, more vacuum, better efficiency, combined with maximum horsepower and torque!Hydraulic Flat Tappet. Hot street cam, likes 2800 converter, high-rise type dual plane intake with 850 CFM carb, headers, 10:1 compression and 3.73 gears. Likes up to 200HP nitrous.
•Advertised Duration (Int/Exh): 276/284
•Duration @ .050 (Int/Exh): 233/241
•Gross Valve Lift (Int/Exh): .554/.572
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 2200-6400
Voodoo Hydraulic Flat Tappet Cam - Chevrolet Big Block 276/284
Product Description
Lunati's Voodoo series of Hydraulic camshafts deliver more area under the curve than any other series of Hydraulic camshafts. This means more throttle response, quicker acceleration, more vacuum, better efficiency, combined with maximum horsepower and torque!Hydraulic Flat Tappet. Hot street cam, likes 2800 converter, high-rise type dual plane intake with 850 CFM carb, headers, 10:1 compression and 3.73 gears. Likes up to 200HP nitrous.
•Advertised Duration (Int/Exh): 276/284
•Duration @ .050 (Int/Exh): 233/241
•Gross Valve Lift (Int/Exh): .554/.572
•LSA/ICL: 110/106
•Valve Lash (Int/Exh): Hyd/Hyd
•RPM Range: 2200-6400
