Difference between these two MPI/EFI intakes?
#1
Registered
Thread Starter
Join Date: Aug 2006
Location: IAD/FLL
Posts: 2,090
Likes: 0
Received 0 Likes
on
0 Posts
Difference between these two MPI/EFI intakes?
Just poking around for fuel injection intakes since I occassionally entertain the idea of a carb to EFI conversion.
Came across these on ebay and noticed the ASM is different from what I normally see as a Merc MPI intake.
Can anybody shed any light on the different applications?
Thanks,
Michael
Came across these on ebay and noticed the ASM is different from what I normally see as a Merc MPI intake.
Can anybody shed any light on the different applications?
Thanks,
Michael
#2
Registered
Re: Difference between these two MPI/EFI intakes?
Originally Posted by handfulz28
Just poking around for fuel injection intakes since I occassionally entertain the idea of a carb to EFI conversion.
Came across these on ebay and noticed the ASM is different from what I normally see as a Merc MPI intake.
Can anybody shed any light on the different applications?
Thanks,
Michael
Came across these on ebay and noticed the ASM is different from what I normally see as a Merc MPI intake.
Can anybody shed any light on the different applications?
Thanks,
Michael
Bryan
#3
VIP Member
VIP Member
Re: Difference between these two MPI/EFI intakes?
The AZ Speed Intake was used on Volvo Penta 7.4GSi (454Mag) and 8.2GSi (502Mag) marine engines. Merc Racing also used them on the 500EFI and still uses them on 525EFI engines.
The Merc Intake was used on their 454MagMPI and 502MagMPI engines.
The intake manifolds are not vary different but the intake plenums are. The AZ Speed plenum has less volume and the TB is in the front vs on the side like the Merc.
From what I've read and been told, either works vary well up to 500HP. The AZ Speed works better then the Merc on higher power engines.
The Merc Intake was used on their 454MagMPI and 502MagMPI engines.
The intake manifolds are not vary different but the intake plenums are. The AZ Speed plenum has less volume and the TB is in the front vs on the side like the Merc.
From what I've read and been told, either works vary well up to 500HP. The AZ Speed works better then the Merc on higher power engines.
__________________
Patrick
Patrick
#4
Registered
Thread Starter
Join Date: Aug 2006
Location: IAD/FLL
Posts: 2,090
Likes: 0
Received 0 Likes
on
0 Posts
Re: Difference between these two MPI/EFI intakes?
Thanks guys. And I think I just learned a little more technical terminology: intake "manifold" versus "plenum".
It looks like the big difference is the "mating area"? Essentially a long- vs short- runner?
So the Merc manifold definitely needs the Merc plenum, but I wonder if the AZ intake would accept the Merc plenum? Just a thought.
Merc plenums are probably a lot easier to come by than the AZ setup I bet; probably best to find a 500EFI setup complete if that's what I wanted?
Thanks,
Michael
It looks like the big difference is the "mating area"? Essentially a long- vs short- runner?
So the Merc manifold definitely needs the Merc plenum, but I wonder if the AZ intake would accept the Merc plenum? Just a thought.
Merc plenums are probably a lot easier to come by than the AZ setup I bet; probably best to find a 500EFI setup complete if that's what I wanted?
Thanks,
Michael
#5
VIP Member
VIP Member
Re: Difference between these two MPI/EFI intakes?
The Merc 454/502Mag fuel injection systems do seem to be a little easier to come by and they are less $$ for sure. Like I said earlier, they are great for under 500HP. There are modification that can be done to the Merc manifold to shorten the runners but I'm not sure the $$ are worth it.
I would say that the Merc Racing/AZ Speed setup would be the way to go for 500HP+ application. That's if you can find a unit for reasonable $$. Merc Racing didn't use there own on 500+HP for a reason.
As for swapping the plenum, a Merc plenum is not going to work on the AZ Speed intake. You could probably modify the Merc intake to except an AZ Speed plenum, but...
I would say that the Merc Racing/AZ Speed setup would be the way to go for 500HP+ application. That's if you can find a unit for reasonable $$. Merc Racing didn't use there own on 500+HP for a reason.
As for swapping the plenum, a Merc plenum is not going to work on the AZ Speed intake. You could probably modify the Merc intake to except an AZ Speed plenum, but...
__________________
Patrick
Patrick
#6
Registered
Re: Difference between these two MPI/EFI intakes?
The AZ plenum has shortened runners and is extrude honed. You can shorten and port a merc plenum yourself . I did mine.
#7
Registered
Thread Starter
Join Date: Aug 2006
Location: IAD/FLL
Posts: 2,090
Likes: 0
Received 0 Likes
on
0 Posts
Re: Difference between these two MPI/EFI intakes?
OK, so let's say I can get over not having the blue paint and EFI500 placard. Will the MPI manifold bolt to Mark IV 454 MAG heads? I've been doing a lot of reading, and somewhere I saw there's a difference in port size between the manifold(s) and the heads.
Am I crazy/stupid to consider just bolting on an MPI setup to an old carb'd MAG?
Thanks,
Michael
Am I crazy/stupid to consider just bolting on an MPI setup to an old carb'd MAG?
Thanks,
Michael
#9
Registered
Join Date: Mar 2001
Location: Arkösund / Sweden
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Re: Difference between these two MPI/EFI intakes?
Originally Posted by handfulz28
OK, so let's say I can get over not having the blue paint and EFI500 placard. Will the MPI manifold bolt to Mark IV 454 MAG heads? I've been doing a lot of reading, and somewhere I saw there's a difference in port size between the manifold(s) and the heads.
Am I crazy/stupid to consider just bolting on an MPI setup to an old carb'd MAG?
Thanks,
Michael
Am I crazy/stupid to consider just bolting on an MPI setup to an old carb'd MAG?
Thanks,
Michael
I do believe that the Magnum EFI intake/Plenum requires less space in front of engine than the 500EFI so you have to check if you have the space needed in you engine bay if you decide to go Blue 500EFI intake/Plenum.
The Carb to EFI conversion will be a very interesting challenge and upskilling experience for you. It will cost you more than the benefits of EFI is really worth for one engine but I believe that your new knowledge will pay of in the future.
I´m in the process myself to swap from MagnumEFI intake to Blue 500EFI intake on my 502(515) I will buy a Holley commander ECU to be able to tune it myself.
#10
VIP Member
VIP Member
Re: Difference between these two MPI/EFI intakes?
Originally Posted by engine
I´m in the process myself to swap from MagnumEFI intake to Blue 500EFI intake on my 502(515) I will buy a Holley commander ECU to be able to tune it myself.
AZ Speed & Marine is now offering packages of software, ecu, and harness as well...
__________________
Patrick
Patrick
Thread
Thread Starter
Forum
Replies
Last Post
tcm07
General Boating Discussion
20
10-03-2008 02:00 PM
ls1nova
General Boating Discussion
10
12-02-2007 05:11 PM