oil spray from the front of a new 502 motor custom built
09-12-2014, 12:01 PM
#52
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Okay guys so what a mess this is,
What they found is the cam on the street motor 502, the over lap on the exghust timing was sucking water back in through the silent choice we where domed from the start,
Block is ok thank god staying a 502
here is a list of the things that when bad
spun a bearing
three connecting rods
all the lifters
the cam
the oil pump
the crank
all the valve springs are rusted
the timing gear was loose bolt never tightened up
wrong spark plugs they never reached into the head
they installed a square port intake on an oval head
750 holly
So by this list you can see it was a mess, The new motor on the same block will have 502 at 525 hp heads are ok they will be looked over to make sure the valve job is okay new roller rockers are going in Rich at Rage power boats in Bridgeport ct was straight up with us. He pulled the motor out and broke it all down for us to see what happen so a word to the wise do not use a street 502 in a boat
Rage power boats is a full custom shop that can and will do it all from motors to interiors to paint and hull work they have a 20k sq indoor shop and build fast stuff they are power boat guys at heart and its show they have there own hulls and do full builds for poker runs and all out off shore glad we found these guys thanks to everyone for the help
Dino
What they found is the cam on the street motor 502, the over lap on the exghust timing was sucking water back in through the silent choice we where domed from the start,
Block is ok thank god staying a 502
here is a list of the things that when bad
spun a bearing
three connecting rods
all the lifters
the cam
the oil pump
the crank
all the valve springs are rusted
the timing gear was loose bolt never tightened up
wrong spark plugs they never reached into the head
they installed a square port intake on an oval head
750 holly
So by this list you can see it was a mess, The new motor on the same block will have 502 at 525 hp heads are ok they will be looked over to make sure the valve job is okay new roller rockers are going in Rich at Rage power boats in Bridgeport ct was straight up with us. He pulled the motor out and broke it all down for us to see what happen so a word to the wise do not use a street 502 in a boat
Rage power boats is a full custom shop that can and will do it all from motors to interiors to paint and hull work they have a 20k sq indoor shop and build fast stuff they are power boat guys at heart and its show they have there own hulls and do full builds for poker runs and all out off shore glad we found these guys thanks to everyone for the help
Dino
09-12-2014, 04:03 PM
#53
Sounds like someone bought a ZZ502 from GM Performance and just dropped it down in the boat with the stock exhaust. Hey, there's no real difference between a car motor and a boat motor, right? 
Now is the time to get your ducks in a row on this build heading into the winter. A phone call to Bob Madara will be very enlightening, and probably save you a ton of money and heartache in the long run. He can set you up with a formula to get a solid 625 - 650 HP from that 509 if you want to go that way. You may want to upgrade your exhaust, depending on what you already have. Bob knows what parts to put into this thing to make it live. He has some of the best pricing on his parts that I have found as well.
Short of that, you could probably build a pretty nice motor with a Crane "741" roller and a good set of aftermarket heads. You could get away from running a set of stock square port heads or even a set of the 041 oval castings with the 2.19 / 1.88 valves installed and some bowl work. Add a good single plane intake (Dart, Edelbrock), a Holley 800 DP from an HP500, and a decent set of performance exhaust manifolds with the longer risers, and you should end up in the 525 - 550 HP range, maybe a little better. The HP500 EFI cam would be a solid choice as well.
But give Bob a call. By the time it's all said and done, he could set you up with a custom hydraulic roller that is tailored to your application, for not much more money than an off-the-shelf cam would cost new.
Now is the time to get your ducks in a row on this build heading into the winter. A phone call to Bob Madara will be very enlightening, and probably save you a ton of money and heartache in the long run. He can set you up with a formula to get a solid 625 - 650 HP from that 509 if you want to go that way. You may want to upgrade your exhaust, depending on what you already have. Bob knows what parts to put into this thing to make it live. He has some of the best pricing on his parts that I have found as well.
Short of that, you could probably build a pretty nice motor with a Crane "741" roller and a good set of aftermarket heads. You could get away from running a set of stock square port heads or even a set of the 041 oval castings with the 2.19 / 1.88 valves installed and some bowl work. Add a good single plane intake (Dart, Edelbrock), a Holley 800 DP from an HP500, and a decent set of performance exhaust manifolds with the longer risers, and you should end up in the 525 - 550 HP range, maybe a little better. The HP500 EFI cam would be a solid choice as well.
But give Bob a call. By the time it's all said and done, he could set you up with a custom hydraulic roller that is tailored to your application, for not much more money than an off-the-shelf cam would cost new.
09-12-2014, 05:12 PM
#54
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the weak link is the drive its a volvo 290 we are staying at 525 hp on this build thanks for the help and yes we are using the mer hp 500 cam plus custom risers that will have a little water spray mixed at the tips for the most part dry
