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Cam choice?

speedfreak2030

speedfreak2030

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Engines: BBC tall deck, 4in strokeX4.62 bore, Dart pro1 365's untouched, 7.2 CR, 671 blowers @4psi, superchillers, 30' Velocity with TRS. Running old school Lunati #30207 hydrolic cams. Specs: int..572 ex..572, 244/244 duration@.050, advertised duration is 308/308, with a 110 lobe seperation. These cams are 100+hrs old but work well, any other cam profiles on proven engines worth trying?
 
Give Bob Madera from Marine Kinetics a call. Great guy and every conversation is an education. He's RMBuilder on the boat sites.
 
speedfreak2030 said:
Engines: BBC tall deck, 4in strokeX4.62 bore, Dart pro1 365's untouched, 7.2 CR, 671 blowers @4psi, superchillers, 30' Velocity with TRS. Running old school Lunati #30207 hydrolic cams. Specs: int..572 ex..572, 244/244 duration@.050, advertised duration is 308/308, with a 110 lobe seperation. These cams are 100+hrs old but work well, any other cam profiles on proven engines worth trying?
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Please excuse me for saying but your engine combination seems a bit mismatched. Why a tall deck but only a 4.00 stroke? That block can easily house up to a 4.500 stroke. Why a 7.2 CR and a chiller but only 4 lbs of boost? Is the quality of fuel where you are really that bad? It seems to me that 7-8 lbs. would be safe even on 89 octane and 10 lbs.+ on 93. Your heads are very large for that size engine although the blowers are probably helping. There are a lot of good cams for supercharger use. They seem to like wide lobe seperation like 112-115 and generally have more duration on the exhaust side. Lift has gone up to the .630-.650 area. For instance the Crane 651 would be a good choice if you want big hp and can tolerate a rough idle. It is 244 int. / 256 ex. duration @.050 lift, 114 lsa, .630/630 lift. A smaller cam is the Crane 741 at 236 int. / 248 ex. @.050, 112 lsa. .598/.630 lift.
 
Leave well enough alone. These are in a 30 Velocity. Any more and it would be faster than Miss Geico.
;)
 
Wow, I didn't realize it was that small. That boat must be a rocket with those engines. How do you fit tall decks back there? Aren't they on like 32 in. centers?
 
When I bought the boat it had the engine combo already installed. I had to reblock the engines due to freezing and split blocks. All original parts where reused as internals showed no ware. This is my second season coming up and have a few bucks to spend. The engines are out as it only takes me 3-4hrs to pull them almost as long to winterize. As for the the boost, I think that the gauges may not be reading acurate boost pressure because of the small1/8 O.D tubing I used, so boost maybe higher. The tubing is something I am changing also. I had a problem with CompCam lifters I used so a recam is necessary. Would the crane 651 be too big, idle isn't a concern. Next year I am going with 4 1/4 or 4 1/2 stroke but for now I need new cams. Lots of room to work on the engines after the hatch is removed. :sifone:
 

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If you are going larger, the 651 would be an ideal cam. A friend had them in a pair of supercharged 588's and they ran very well. The small tubing is common and should have no effect on the gauges performance unless it is kinked. You might want to verify the gauges accuracy, however, with another gauge. Mistakes with boost can get really expensive.
 
Chris said:
Leave well enough alone. These are in a 30 Velocity. Any more and it would be faster than Miss Geico.
;)
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Never mind Chris, doesn't everyone want to be faster than the stinking salamanders, seperated sibling spinster sister, Samantha? surely! Can't believe I wasted 10 min of my life trying to be witty, what a tool! off to the bar:sifone:
 
Every cam should be made specific for your setup. If you get cams now then get stroker cranks next year, you will need another set of cams. Just seems like you will be doing things over again. If you want to get 100% out of the engine I would really give Bob a call. He will give you a education and you will never buy a cam from anyone else again. My setup in not anything like yours but I gained 5 MPH from about 2k in valvetrain parts (on a single). Bob likes the Moral lifters, Isky springs and rollmaster chains to make a matched set. Since the upgrade the boat idles better, plains quicker and runs faster.
 
Called Bob, super nice guy and quite a knowledge basis. After talking to him I am going back to the Lunati cams. Good results for my application. Next year when I stroke the engines(more $$$) and have my end goal in sight (cu/in wise), he will talior grind me a set of bump sticks for my ride.
 
speedfreak2030 said:
Called Bob, super nice guy and quite a knowledge basis. After talking to him I am going back to the Lunati cams. Good results for my application. Next year when I stroke the engines(more $$$) and have my end goal in sight (cu/in wise), he will talior grind me a set of bump sticks for my ride.
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Sounds like a good idea, give him a call back next year. You may need new pistons and rods also, not sure since you have a tall deck. I have a 489 stroker with the GM block, 4.25 stroke, stock length rods with offset pistons.
 
I think you're on the right track! For now I'd put my money into drives so when you stroke it next year and drop a 651 in it, you'll really be flying!
 
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