Go Back  Offshoreonly.com > Technical > General Q & A
Good, honest advice wanted. >

Good, honest advice wanted.

Notices

Good, honest advice wanted.

Old 11-03-2002, 09:58 PM
  #1  
DonMan
Guest
 
Posts: n/a
Lightbulb Good, honest advice wanted.

Over the winter, I would like to perform a few modifications to my 7.4 MPI (310hp). Last winter I installed Stainless Marine exhaust, K&N arrestor and an adjustable fuel psi regulator from Vortec. I did not gain any rpm or speed whatsoever. A couple experts have advised I am tapped out with the MPI set-up.
I would like to scrap the fuel-injection ( I have a buyer for it) and install the following pieces:

Edelbrock 750 cfm Marine Carb
Edelbrock Performer RPM intake
Holley 110 gph electric fuel pump
GM ZZ502 (502/502) camshaft
.527"/.544" 224*/234*
GM ZZ502 valvesprings
Mercruiser Delco distributor (from carb engine)

My Questions:
Do you think I`m crazy for walking away from the injection?
Will I gain any rpm or speed from these mods?
Would you do anything different with what I have to work with?
...Please don`t tell me to sell the 7.4 and buy a 502. I want to work with this engine before I swap power.

As always, any comments good, bad or other are always appreciated!!!!
 
Old 11-03-2002, 10:10 PM
  #2  
Registered
 
Join Date: Apr 2002
Location: LOTO, MO
Posts: 241
Likes: 0
Received 0 Likes on 0 Posts
Default

I would use a Merlin manifold, it has the brass inserts in the water passages. As for the rest, not sure.
88 MACH 1 is offline  
Old 11-03-2002, 10:23 PM
  #3  
VIP Member
iTrader: (1)
 
Smitty's Avatar
 
Join Date: Apr 2001
Location: Chicago il
Posts: 4,213
Received 0 Likes on 0 Posts
Default

DO NOT USE THAT CAMSHAFT!!!!! Get a cam that is for a marine application!!! Call Teague marine or someone that builds marine H.P. engines. If you go with that cam you will be sorry.

Also I recommend going with the Edelbrock Air Gap manifold. Makes better power at the mid and top end.You also might want to look at doing some port work on the heads as well.
Smitty is offline  
Old 11-04-2002, 06:07 AM
  #4  
Registered
 
Join Date: Jun 2001
Location: Michigan
Posts: 3,345
Likes: 0
Received 0 Likes on 0 Posts
Default

leave this engine stock...well i guess if would rather spend more time working on it than using it????
audacity is offline  
Old 11-04-2002, 06:23 AM
  #5  
Offshore Addiction
Guest
 
Posts: n/a
Default

i think your going to run into problems somewhere between the heads on the motor and that cam your trying to install.but i do know that you dont have much farther to go with the original setup....already been through that.........
 
Old 11-04-2002, 06:28 AM
  #6  
Charter Member #655
Charter Member
 
dyno's Avatar
 
Join Date: Dec 2000
Location: Holland, Michigan
Posts: 4,939
Likes: 0
Received 1 Like on 1 Post
Default

one word ........Pro charger!
__________________
If your boat has a sail do you ride a horse to the ramp?
dyno is offline  
Old 11-04-2002, 07:30 AM
  #7  
DonMan
Guest
 
Posts: n/a
Default

Originally posted by 88 MACH 1
I would use a Merlin manifold, it has the brass inserts in the water passages. As for the rest, not sure.
Isn`t the Merlin manifold an open plenum? Would this really be a good idea? I always run in fresh water, no salt ever. Do I really need those brass inserts?
 
Old 11-04-2002, 07:33 AM
  #8  
DonMan
Guest
 
Posts: n/a
Default

Originally posted by Bigwavz
DO NOT USE THAT CAMSHAFT!!!!! Get a cam that is for a marine application!!! Call Teague marine or someone that builds marine H.P. engines. If you go with that cam you will be sorry.

Also I recommend going with the Edelbrock Air Gap manifold. Makes better power at the mid and top end.You also might want to look at doing some port work on the heads as well.
The ZZ502 cam was actually recommended by a expert who frequents this forum.

As for the Air-Gap intake, just read a dyno report on one. I think I will go that route, looks like a great manifold!
 
Old 11-04-2002, 07:45 AM
  #9  
DonMan
Guest
 
Posts: n/a
Default

Originally posted by Offshore Addiction
i think your going to run into problems somewhere between the heads on the motor and that cam your trying to install.but i do know that you dont have much farther to go with the original setup....already been through that.........
I have spoke with a reputable performance engine builder, they say it will work just fine. I can even retain my factory non-adjustable valvetrain.
 
Old 11-04-2002, 07:46 AM
  #10  
DonMan
Guest
 
Posts: n/a
Default

Originally posted by dyno
one word ........Pro charger!
FOUR WORDS......

I CANNOT AFFORD ONE!
 

Quick Reply: Good, honest advice wanted.


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.