HP500 Cam Help
02-12-2010, 09:31 PM
#12
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cam chioces......
like the others said, your lobe sep. is all wrong for a blown motor! I've built quite a few blown motors , both for cars, and
marine applications, and it really isn't feasible to run anything
less than a 112*. a good example is my current boat, a 25'
Ultimate Warlock SXT cat, with a bone stock 450hp 502 w/ a
2.3 whipplecharger/ intercooler setup. It would run 96mph
all day long (yes on gps) that factory cam is miniscule 480lift
but on a 115 lobe seperation! not the ideal cam by far, but it
makes 6-7 lbs boost, and is packing the cylinders pretty decently. your cam, while the lift and duration is pretty decent,
that 110* seperation angle is blowing alot of boost right out
your exaust! in other words, too much overlap! I'd say pull it out and have itreground, but that is the only thing that can't
be changed when you regrind a cam! my suggestion is to
look for somthing close to what you have, only on a 114*
LC! it would make a night and day difference, been there,
done that!
marine applications, and it really isn't feasible to run anything
less than a 112*. a good example is my current boat, a 25'
Ultimate Warlock SXT cat, with a bone stock 450hp 502 w/ a
2.3 whipplecharger/ intercooler setup. It would run 96mph
all day long (yes on gps) that factory cam is miniscule 480lift
but on a 115 lobe seperation! not the ideal cam by far, but it
makes 6-7 lbs boost, and is packing the cylinders pretty decently. your cam, while the lift and duration is pretty decent,
that 110* seperation angle is blowing alot of boost right out
your exaust! in other words, too much overlap! I'd say pull it out and have itreground, but that is the only thing that can't
be changed when you regrind a cam! my suggestion is to
look for somthing close to what you have, only on a 114*
LC! it would make a night and day difference, been there,
done that!
02-12-2010, 11:05 PM
#13
VIP Member
like the others said, your lobe sep. is all wrong for a blown motor! I've built quite a few blown motors , both for cars, and
marine applications, and it really isn't feasible to run anything
less than a 112*. a good example is my current boat, a 25'
Ultimate Warlock SXT cat, with a bone stock 450hp 502 w/ a
2.3 whipplecharger/ intercooler setup. It would run 96mph
all day long (yes on gps) that factory cam is miniscule 480lift
but on a 115 lobe separation! not the ideal cam by far, but it
makes 6-7 lbs boost, and is packing the cylinders pretty decently. your cam, while the lift and duration is pretty decent,
that 110* separation angle is blowing alot of boost right out
your exaust! in other words, too much overlap! I'd say pull it out and have itreground, but that is the only thing that can't
be changed when you regrind a cam! my suggestion is to
look for somthing close to what you have, only on a 114*
LC! it would make a night and day difference, been there,
done that!
marine applications, and it really isn't feasible to run anything
less than a 112*. a good example is my current boat, a 25'
Ultimate Warlock SXT cat, with a bone stock 450hp 502 w/ a
2.3 whipplecharger/ intercooler setup. It would run 96mph
all day long (yes on gps) that factory cam is miniscule 480lift
but on a 115 lobe separation! not the ideal cam by far, but it
makes 6-7 lbs boost, and is packing the cylinders pretty decently. your cam, while the lift and duration is pretty decent,
that 110* separation angle is blowing alot of boost right out
your exaust! in other words, too much overlap! I'd say pull it out and have itreground, but that is the only thing that can't
be changed when you regrind a cam! my suggestion is to
look for somthing close to what you have, only on a 114*
LC! it would make a night and day difference, been there,
done that!
The 741 is the same on my engine,also have low port velocity.Over lap is bad ,The factory 500efi cam they say is alot better with the blower.
rob
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
02-14-2010, 01:31 AM
#18
Charter Member # 55
Charter Member
The 525EFI was never available without a special grind order as far as I know. These are about the only 2 cams available off the shelf from Crane for Marine BBC since the company restarted. The 139011 is the old Crane 731. The 139651 will need to be spun faster to make its full potential power. I would spin it to around 5600rpms. Either one would be an improvement, but probably not as good as the 525EFI cam. Like was said earlier, you should contact Bob Mandera aka rmbuilder on this site. He can have a custom grind done to optimize your set up.
http://www.summitracing.com/search/P...yword=camshaft
http://www.summitracing.com/search/P...yword=camshaft
02-15-2010, 12:07 PM
#20
Charter Member # 55
Charter Member
I can't keep track of all the new part numbers any more. Both Jegs and Summit don't show all the cams available when you do a search, even though they have it in stock. Seems like unless you have the part number, you can't find what you need.
