Lets build a 502
#1
Registered
Thread Starter
Lets build a 502
Well its cold as hell, a plan for a 502 should fill some time and be fun... and help me figure out what to do. So the motor has a manufactured for GM tag on the side part # 12568778, it has heads with casting #12562934 and brass freeze out plugs. I dont know if its a marine or not. Their is a set of tube style headers that are dry to the tip.
Price point of say $6000. Durability takes trump over performance. I would like to get around 500 hours out of the top end if that's possible. With that said I would like to get as much performance as possible also.
Price point of say $6000. Durability takes trump over performance. I would like to get around 500 hours out of the top end if that's possible. With that said I would like to get as much performance as possible also.
#2
Platinum Member
Platinum Member
Well its cold as hell, a plan for a 502 should fill some time and be fun... and help me figure out what to do. So the motor has a manufactured for GM tag on the side part # 12568778, it has heads with casting #12562934 and brass freeze out plugs. I dont know if its a marine or not. Their is a set of tube style headers that are dry to the tip.
Price point of say $6000. Durability takes trump over performance. I would like to get around 500 hours out of the top end if that's possible. With that said I would like to get as much performance as possible also.
Price point of say $6000. Durability takes trump over performance. I would like to get around 500 hours out of the top end if that's possible. With that said I would like to get as much performance as possible also.
- Part Number: 12568778
- Engine Type: Chevy Big-Block V-8
- Displacement (cu. in.): 502
- Bore x Stroke (in.): 4.470 x 4.000
- Block (P/N 19170540): Cast-iron with four-bolt main caps
- Crankshaft (P/N 10183723): Forged steel
- Connecting Rods (P/N 19170198): Forged steel, shot peened
- Pistons (P/N 12533507): Forged aluminum
- Camshaft Type (P/N 24502611): Hydraulic roller
- Camshaft Lift (in.): .510 intake / .540 exhaust
- Camshaft Duration (@.050 in.): 211° intake / 230° exhaust
- Cylinder Heads (P/N 12562920): Iron rectangular port; 118-cc chambers
- Valve Size (in.): 2.190 intake / 1.880 exhaust
- Compression Ratio: 8.75:1
- Rocker Arms (P/N 12523976): Stamped steel
- Rocker Arm Ratio: 1.7:1
- Water Pump (P/N 19168606): Cast-iron, long-style
- Flexplate (P/N 10185034): 14"
- Recommended Fuel: Regular Pump
- Ignition Timing: 32° Total @ 4,000 rpm
- Maximum Recommended rpm: 5500
- Balanced: External
Last edited by BenPerfected; 12-29-2017 at 08:25 PM.
#3
Registered
Thread Starter
The motor is what I already have with the headers. I dont know weather to just freshen the motor up (probably the smart thing) or try to get as much power as possible with some new heads and/or cam (what will prob end up happening because i never stick to my plan of doing things cheap or easy. lol )
#4
Platinum Member
Platinum Member
Speed Calculator
This is a good place to estimate your max speed using weight, hull efficiency and HP. The one thing that will lose weight the quickest will be your wallet.
This is a good place to estimate your max speed using weight, hull efficiency and HP. The one thing that will lose weight the quickest will be your wallet.
#5
Charter Member # 55
Charter Member
No way you will get 500hrs out of valve springs with any decent sized cam.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
#6
Registered
No way you will get 500hrs out of valve springs with any decent sized cam.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
Jeff
#7
Registered
Thread Starter
No way you will get 500hrs out of valve springs with any decent sized cam.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
#8
Registered
Thread Starter
No way you will get 500hrs out of valve springs with any decent sized cam.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
With what you have now and your budget, swap out the cam for a Crane 168731.
Cam, lifters, roller rockers, springs, etc will run about 2k + valve job and some head work for prob around 1k.
It would be a very close build to an HP500.
Bottom end cost will depend a lot on what is needed.
#9
Platinum Member
Platinum Member
iTrader: (6)
200-250 hrs ^^^^^^^^^
#10
Registered
Join Date: Nov 2013
Location: Port Clinton ohio
Posts: 31
Likes: 0
Received 0 Likes
on
0 Posts
I think you will want at least 500 hp in that boat? 90 percent of the time it's plenty on the lake... On the bay,more would be nice. Those damn jet skis are fast these days and it sucks when they creep by ya. Lol