what rpms should i run??? 540ci NA.....
12-10-2010, 07:15 AM
#41
Registered
iTrader: (4)
Could you explain this to me? I see that your valves will be closer to the piston but the lift and rocker ratio is still the same. The mechanics that lift the valve are the same.
Last edited by Rookie; 12-10-2010 at 07:23 AM.
12-10-2010, 07:29 AM
#42
Registered
Those cams are awful. They have less duration and lift than a 415hp 502 efi. Most rv cams have more lift and duration. A good cam for stock rectangular port heads is the Crane 651. It is 244 int. / 256ex. duration @ .050, .630 / .630 lift. this cam will make 575-600 hp and rev to 5400-5600. For any more hp, you will need aftermarket heads.
Last edited by PatriYacht; 12-10-2010 at 07:33 AM.
12-10-2010, 07:31 AM
#43
Registered
iTrader: (4)
You will appreciate the new castings. This will be the Marine/Street Strip head that he has wanted to cast for years. He has a couple heads out there on some boats and a couple on some weekend drag cars. He finally got some poured a few weeks back, they are at Dart getting the machine work finished now. Hopefully he will get them back before Christmas and I will post some pics and info.
12-10-2010, 09:13 AM
#44
Registered
Platinum Member
You are correct, what I meant was that he will loose the ability to put in a higher lifting cam because there will not be as much clearance.
12-10-2010, 11:32 AM
#46
Registered
The piston to valve clearence with those pistons is quite large. Easily enough for any cam you would want in a marine engine. To answer the original question, I bet the hp peak would be 4600 using the parts specified. And I would guess that it makes about 450 hp but about 700 ft.lbs. of torque.
12-10-2010, 11:35 AM
#47
Registered
Thread Starter
The piston to valve clearence with those pistons is quite large. Easily enough for any cam you would want in a marine engine. To answer the original question, I bet the hp peak would be 4600 using the parts specified. And I would guess that it makes about 450 hp but about 700 ft.lbs. of torque.
12-10-2010, 11:38 AM
#48
Charter Member # 55
Charter Member
Those cams are awful. They have less duration and lift than a 415hp 502 efi. Most rv cams have more lift and duration. A good cam for stock rectangular port heads is the Crane 651. It is 244 int. / 256ex. duration @ .050, .630 / .630 lift. this cam will make 575-600 hp and rev to 5400-5600. For any more hp, you will need aftermarket heads.
12-10-2010, 11:44 AM
#50
Registered
Platinum Member
The piston to valve clearence with those pistons is quite large. Easily enough for any cam you would want in a marine engine. To answer the original question, I bet the hp peak would be 4600 using the parts specified. And I would guess that it makes about 450 hp but about 700 ft.lbs. of torque.
