how do I make my 454/502 mag boat "faster" ????
10-05-2021, 03:35 PM
#31
Registered
iTrader: (1)
Originally Posted by SB
Found a 502 with max power 5600rpm I had run into pipemax:
@ 5800 RPM
- Induction System Tuned Lengths = ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 35.485' (usually this Length is never used)
2nd Harmonic= 20.140' (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 14.061' (ProStock or Comp SheetMetal Intake)
4th Harmonic= 11.067' (Single-plane Intakes , less Torque)
5th Harmonic= 8.979' (Torque is reduced, even though Tuned Length)
6th Harmonic= 7.554' (Torque is reduced, even though Tuned Length)
7th Harmonic= 6.520' (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 5.734' (Torque is greatly reduced, even though Tuned Length)
Note> 2nd and 3rd Harmonics typically create the most Peak Torque
4th Harmonic is used to package Induction System underneath Hood
Plenum Runner Minimum Recommended Entry Area = 2.865 to 3.223 Sq.Inch
Plenum Runner Average Recommended Entry Area = 3.294 Sq.Inch
Plenum Runner Maximum Recommended Entry Area = 3.365to 3.981 Sq.Inch
Minimum Plenum Volume CC = 1113.7 [typically for Single-Plane Intakes]
Minimum Plenum Volume CID= 68.0 [typically forSingle-Plane Intakes]
Maximum Plenum Volume CC = 8229.2 [typically for Tunnel Ram Intakes]
Maximum Plenum Volume CID= 502.2 [typically forTunnel Ram Intakes]
@ 5800 RPM
- Induction System Tuned Lengths = ( Cylinder Head Port + Manifold Runner )
1st Harmonic= 35.485' (usually this Length is never used)
2nd Harmonic= 20.140' (some Sprint Engines and Factory OEM's w/Injectors)
3rd Harmonic= 14.061' (ProStock or Comp SheetMetal Intake)
4th Harmonic= 11.067' (Single-plane Intakes , less Torque)
5th Harmonic= 8.979' (Torque is reduced, even though Tuned Length)
6th Harmonic= 7.554' (Torque is reduced, even though Tuned Length)
7th Harmonic= 6.520' (Torque is greatly reduced, even though Tuned Length)
8th Harmonic= 5.734' (Torque is greatly reduced, even though Tuned Length)
Note> 2nd and 3rd Harmonics typically create the most Peak Torque
4th Harmonic is used to package Induction System underneath Hood
Plenum Runner Minimum Recommended Entry Area = 2.865 to 3.223 Sq.Inch
Plenum Runner Average Recommended Entry Area = 3.294 Sq.Inch
Plenum Runner Maximum Recommended Entry Area = 3.365to 3.981 Sq.Inch
Minimum Plenum Volume CC = 1113.7 [typically for Single-Plane Intakes]
Minimum Plenum Volume CID= 68.0 [typically forSingle-Plane Intakes]
Maximum Plenum Volume CC = 8229.2 [typically for Tunnel Ram Intakes]
Maximum Plenum Volume CID= 502.2 [typically forTunnel Ram Intakes]
10-05-2021, 11:24 PM
#32
Platinum Member
Originally Posted by liquidlounge
Lots of choices here, but can we come up with a preferred runner length say for 500HP, 550, or 600HP? From what I have read here its runner length, throttle body, tuning if you want to up the cam. Well, the tuning and throttle body are probably best done by someone in that niche, but the manifold could be cut down locally by anyone with a mill. Knowing how much to cut the runners down would be a great addition to this highly informative thread..
Rough mill pic is one partially completed, I angle mill and cut taper on divider and all openings so there less hand grinding. Second pic is first MPI intake I ever modded, Ive since cut dividers much more BUT I made over 650 HP with THAT intake NA and well over a 1000 blown years ago
10-05-2021, 11:28 PM
#33
Originally Posted by CarreraHector
Hey Smitty do you have a shop? Sounds like you know your 502 MPI's like the back of your hands my friend. I'm looking for someone to rebuild both of mine and are more power as they have 600+ hours on them.
10-05-2021, 11:32 PM
#34
Originally Posted by snapmorgan
I toasted a 454 mag mpi in one of my boats and decided to build a mild 540 for it. After tuning, it made 565hp with the stock intake. I got one of the extrude honed intakes from ASM and had the throttle body bored out, made over 600 with no changes. I know that i left 30hp on the table by using the MPI setup, but it is what I had at the time and it worked great. I was also able to find a slightly larger oil cooler that fit in the stock location that had 1/2"npt fittings. Made all new oil lines with -8 hose. Worked out well.
