Would like to make 600hp out of a HP500
#11
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Re: Would like to make 600hp out of a HP500
Originally Posted by axapowell
Ok...Alot to process. Sounds like a great combo, but don't I already have most of that in my HP500?
Victor Jr= Dart intake+porting
Demon 850 cfm Carb= Holley 850
Crane cam in HP500 Intake .576 lift 222 degrees duration at .050
Exhaust .598 lift 230degrees duration at .050
110 center
Your grind: Intake .594 lift 228 degrees duration at .050
Exhaust .600 lift 232.7 degrees duration at .050
112.2 center
JE pistons, 118 cc chamber, 2.10 intake valves, 1.88 exhaust, crane gold roller rockers.
So, if I got this right, I can go to a GM Signature Series Rect. Port Aluminum head (GM PN#12363400) with the bigger intake valve (2.25/1.88E) change the exhaust valves to Manley Inconel and a bigger cam similar to yours, keep the stock bore(if I can) port my intake manifold to match the gasket and heads, change the module in the distributor and add a rev limiter with a box(MSD or such) that should do it? A few less cubes, all good bottom end, and balance the rotating assembly...This should be around 600 hp at 5600-5800 rpms.
Hmmmm....has anyone else had a winning combo?
Thanks so far for the responses!! BIG HELP
Dave
Victor Jr= Dart intake+porting
Demon 850 cfm Carb= Holley 850
Crane cam in HP500 Intake .576 lift 222 degrees duration at .050
Exhaust .598 lift 230degrees duration at .050
110 center
Your grind: Intake .594 lift 228 degrees duration at .050
Exhaust .600 lift 232.7 degrees duration at .050
112.2 center
JE pistons, 118 cc chamber, 2.10 intake valves, 1.88 exhaust, crane gold roller rockers.
So, if I got this right, I can go to a GM Signature Series Rect. Port Aluminum head (GM PN#12363400) with the bigger intake valve (2.25/1.88E) change the exhaust valves to Manley Inconel and a bigger cam similar to yours, keep the stock bore(if I can) port my intake manifold to match the gasket and heads, change the module in the distributor and add a rev limiter with a box(MSD or such) that should do it? A few less cubes, all good bottom end, and balance the rotating assembly...This should be around 600 hp at 5600-5800 rpms.
Hmmmm....has anyone else had a winning combo?
Thanks so far for the responses!! BIG HELP
Dave
I started with a lowly 502 mag EFI
Please keep in mind that my cam was custom ground and matched to my head flow, my engine, and my boat specs...
Your particular combination may require something a little different... P.M. RMBUILDER on this site and he can set you up PROPERLY!!
Doug
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Re: Would like to make 600hp out of a HP500
All ideas above sound like good engine results. Your HP 500 only made 470HP by Mercury's dyno correction factors, fully dressed with that exhaust. Keep in mind Merc used 5400RPM as a reading on HP. All dyno numbers are right but the key is what are you compairing them to? The Merc correction factors are close but not the same as a auto engine. A little change can make a big difference on the Dyno. What you have to look at is what is the HP at 5400RPM. Winding up a engine to 6000RPM can get you that number but it has no more usable torque in that RPM range.
A low compression engine, say under 9/1 will not make 600 by Mercs dyno results. Not saying it wont pick up well, I just believe that 550HP is tops. With higher compression, say 9.75/1 I belive you can get 580-590 HP. I think you would need 10.25/1 to get 600hp. The main reason i say this is compression equals torque. More torque = more HP. Remember that HP & Torque cross at 5250. Also remember that once the torque falls off, the boat stops accelerating. A boat does not coast like a car. A NA engine makes peak torque about 4200RPM so you are on a slight decline from then on. After 5250 Torque really begines to drop.
Take an engine, one guy will spin it 5400 with marine setup and call it a 550HP. The next guy will use dyno exhaust, dry, spin it to 5900 and call it a 600HP. That engine will do the same in a boat but can be rated both ways.
The key is to match Compression to cam to heads to intake to carb to get the best result. A 502 with a 741 cam and 8.75cr, huge heads, will not fall out of a tree. A 502 wth 10.2cr stock heads wont work well eithier.
I did a thread in the Nordic section on my 500EFI increase you can look at. Marine dyno numbers 572HP, 605ft torque. I also did a 500HP with 9.75cr ported heads, 741 cam new carb that worked well as mine did. The higher compression makes it pull much harder on accelaration.
Good luck, I wish I did a 540 now.
A low compression engine, say under 9/1 will not make 600 by Mercs dyno results. Not saying it wont pick up well, I just believe that 550HP is tops. With higher compression, say 9.75/1 I belive you can get 580-590 HP. I think you would need 10.25/1 to get 600hp. The main reason i say this is compression equals torque. More torque = more HP. Remember that HP & Torque cross at 5250. Also remember that once the torque falls off, the boat stops accelerating. A boat does not coast like a car. A NA engine makes peak torque about 4200RPM so you are on a slight decline from then on. After 5250 Torque really begines to drop.
Take an engine, one guy will spin it 5400 with marine setup and call it a 550HP. The next guy will use dyno exhaust, dry, spin it to 5900 and call it a 600HP. That engine will do the same in a boat but can be rated both ways.
The key is to match Compression to cam to heads to intake to carb to get the best result. A 502 with a 741 cam and 8.75cr, huge heads, will not fall out of a tree. A 502 wth 10.2cr stock heads wont work well eithier.
I did a thread in the Nordic section on my 500EFI increase you can look at. Marine dyno numbers 572HP, 605ft torque. I also did a 500HP with 9.75cr ported heads, 741 cam new carb that worked well as mine did. The higher compression makes it pull much harder on accelaration.
Good luck, I wish I did a 540 now.
Last edited by Linster; 10-10-2005 at 08:03 PM.
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Re: Would like to make 600hp out of a HP500
Just to give and idea of what it takes to pull 600hp out of an 8.2L
http://www.sdpc2000.com/catalog/1579...ies-Engine.htm
http://www.sdpc2000.com/catalog/1579...ies-Engine.htm
Last edited by Back4More; 10-10-2005 at 11:39 PM.
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Re: Would like to make 600hp out of a HP500
[QUOTE=Linster] Your HP 500 only made 470HP by Mercury's dyno correction factors, QUOTE]
I believed the 470 hp rating was at the prop? the engine did make 500 hp at the crank.
I believed the 470 hp rating was at the prop? the engine did make 500 hp at the crank.
#15
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Re: Would like to make 600hp out of a HP500
If you're going to buy new heads, get Canfields or AFRs. The Canfields are less expensive and less waiting time. It'll take a Crane 741 or equiv. cam to reach your goal. The specs are the same as that cam in the Scoggin Dickey ad above. Good chance you'll see reversion with that cam requiring longer or dry tailpipes. It'll take 56-5800 rpms to make that hp. Use the valvesprings that Crane recommends but shim them to 150-160 lbs of seat pressure for extra insurance against valve float.
#16
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Re: Would like to make 600hp out of a HP500
Originally Posted by Linster
Good luck, I wish I did a 540 now.
#17
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Re: Would like to make 600hp out of a HP500
buy my 540 only 22hrs of running time to date. made 625hp at 5750 on the dyno with a gm steel head. carb to pan for 6k no exhaust or access.