Vortec L31 MARINE MANIFOLD project! Q&A

Performance modifications, tips & tricks

Moderators: flyingpolarbear, Eric@PPE, VicC, James B.

97VortecChevy
Posts: 38
Joined: Wed Feb 11, 2015 7:47 pm
Location: Groves

Post by 97VortecChevy »

Speeder wrote:That's been tried, but the demand wasn't there. Folks now are looking at putting LS engines in their Vortec trucks.
Yea, that's right... hell i'm even thinking on a 5.3 or 6.0 install

bronc3buster842001
Posts: 7
Joined: Mon Oct 04, 2010 1:15 pm
Location: Missouri

Post by bronc3buster842001 »

Got my intake a few weeks ago.. The injectors in it were Bosch 280158165.. Found one site that says they flow 26.8@3 bar.. Yet no one can confirm this

z71gmc06
Posts: 1015
Joined: Tue May 08, 2007 12:45 pm
Location: Michigan

Post by z71gmc06 »

Maybe this will help. Are you sure the middle number isn't 150?

http://www.fuelinjector.citymaker.com/F ... Rates.html


Here's another good one.

www.usrallyteam.com/content/products/in ... r_data.xls

bronc3buster842001
Posts: 7
Joined: Mon Oct 04, 2010 1:15 pm
Location: Missouri

Post by bronc3buster842001 »

Found the info here....

http://users.erols.com/srweiss/tableifc.htm#BOSCH

https://www.injectorrx.com/bosch-fuel-injectors/

Just wanting to confirm these numbers are right.. Both say the same.. But seems most of the charts out there are just copy and paste..

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

The ones on my truck flow 25 lb/hr @ 3 BAR/43.5 psi. That's actually measured and from the injector flow report. They were the stock marine injectors. Delphi EV6 units with USCAR connectors, IIRC they are rated at 24 lb/hr from the factory, but all mine flowed 25 lb/hr after cleaning and refurb.

peace
Hog

bronc3buster842001
Posts: 7
Joined: Mon Oct 04, 2010 1:15 pm
Location: Missouri

Post by bronc3buster842001 »

What number was on your injectors.. Ive found 2 differnt part numbers. Ones for a pre-2007 and 2008 up

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

bronc3buster842001 wrote:What number was on your injectors.. Ive found 2 differnt part numbers. Ones for a pre-2007 and 2008 up
They would be for pre 2007 as my project was completed before 2007.

peace
Hog

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

Cross Interchange Parts


Factory Number

GM 12567905
BOSCH 0 280 156 082
CHEVROLET 12 567 905
BOSCH 0 280 156 081

from some of the resources found here.
http://www.pacificp.com/forum/viewtopic ... +injectors

I'll try and take a peak for the exact number from my injectors.

peace
Hog

bai78
Posts: 187
Joined: Mon Jun 22, 2009 7:56 pm
Location: Dallas, TX: '99 ProCharged Tahoe, '02 Denali XL LQ4, AWD, mp112

Tahoe lives, but still not 100%

Post by bai78 »

Unbelievable, it's been 5 1/2 years since I got my marine intake and now it is finally on my truck.

I know I'm like a decade late to the party since quite a few have sold their setups, trucks, or simply swapped in a 6.0 or better motor.

It was a realy pain to swap and even more of a headache routing all the piping for the blower back on.

I got the obvious codes like p0405 and p1345. The EGR I'll deal with either with a divorced setup or just a delete and block off plate all together. The p1345 was fun. I hooked up and saw 56° for timing but this was with a brand new billet distributor. After a few adjustments I got her to .5° and figured I'll leave it at that.

The irritating one was p0200. I had cylinder misfire up on the scanner and didn't see any current ones while monitoring. I was gonna check history so I could track it down a bit but decided to call it a day. Also, when I try to give it some gas my truck stumbles and then increases in rpm. This could be related but also thought of my TB blade that I had modded when the truck was down.

Lastly, I got some dripping below the truck and guess it is a fuel line. I'm not sure if it's the feed, return, or both.

Aksl
Posts: 2
Joined: Thu Jun 30, 2016 2:32 am
Location: Moscow

Question

Post by Aksl »

Hi everyone,

Have a question to all, why not to just install manifold from earlier Pontiac firebird or impala, the engines are L31, manifold should bolt right on, and less changes to make then with the marine intake...?

Thanks in advance, and sorry if the question is dumb..

It is not that i have something against, it`s the opposite, I have a k1500 Chevy Silverado 5.7, with vortec heads installed and CSFI (spider injectors), and right now I`m in the middle of decision making, what to install on my truck..

Therefore, any suggestions and reasons why would be appreciated!

Thank you.

CrazyHoe
Posts: 6228
Joined: Tue Feb 19, 2008 8:30 am
Location: Mtl; '98 2dr4x4 Tahoe, L31,Hookers Long T, 0411,EFIlive, 4L80-E,dual 3",marine int+inj

Post by CrazyHoe »

As far as I understand it, the marine intake was to keep the oem look (important for some states) and to provide for injector upgrade and move away from the crapy CSFI injector system.

Are you talking about the LT1 intake? I don't think those have a hole for the distributor and are reverse coolant flow, so the thermostat system should be different.

Bushwacker
Posts: 106
Joined: Wed Jul 04, 2012 4:05 pm

Post by Bushwacker »

I think he's talking about the old tune port intake, they make a vortec lower, you have several options today,ram jet , edelbrock pro flow, weiand stealth ram & I'm sure probably more , if you have emissions the marine is probably the only way to go!

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

3 bolt t-body on an upper plenum that has 4 bolts

Post by Hog »

This $22 4 bolt upper plenum t-body to 3 bolt throttle body(which our Vortec 305/350 L30/31 trucks/vans/SUVs) use stock from the factory.
https://www.summitracing.com/int/parts/ ... /overview/

As per "issue to Overcome" #25 in James B first post of this thread, you must space the throttlebody upwards in order to prevent the t-body arm from contacting the end of the passenger side fuel rail.

Image

And here is the Throttle Body Adapter installed on the front of a GEN III intake manifold
Image

And another picture of the t-body bolt pattern adapter on its own along with its supplied fastening hardware.
Image

I am not 100% sure that this adapter alone will provide sufficient clearance between the throttle body arm and the front portion of the fuel rail on the passenger side. Regardless a spacer could be used along with this adapter to provide both enough clearance AND the change in bolt pattern.

There seems to be more and more Penta/Volvo and other upper plenums from the crossram L31 truck style that come with 4 bolt 75mm t-bodies. This adapter will allow these 4 bolt t-body uppers to be used along with stock L30/L31 3 bolt t-bodies found in our 1996+ vehicles.

There are some 4 bolt cross ram style upper plenums for sale on their own on EBay. These adapters shold really help out us GMT-400 style vehicle owners looking to do the Marine Intake retrofit. I cant belive its been 12 years around this time where a concerted effort from certain folks here at PPE made this Marine Intake swap a reality.

peace
Hog

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Re: Tahoe lives, but still not 100%

Post by Hog »

bai78 wrote:Unbelievable, it's been 5 1/2 years since I got my marine intake and now it is finally on my truck.

I know I'm like a decade late to the party since quite a few have sold their setups, trucks, or simply swapped in a 6.0 or better motor.

It was a realy pain to swap and even more of a headache routing all the piping for the blower back on.

I got the obvious codes like p0405 and p1345. The EGR I'll deal with either with a divorced setup or just a delete and block off plate all together. The p1345 was fun. I hooked up and saw 56° for timing but this was with a brand new billet distributor. After a few adjustments I got her to .5° and figured I'll leave it at that.

The irritating one was p0200. I had cylinder misfire up on the scanner and didn't see any current ones while monitoring. I was gonna check history so I could track it down a bit but decided to call it a day. Also, when I try to give it some gas my truck stumbles and then increases in rpm. This could be related but also thought of my TB blade that I had modded when the truck was down.

Lastly, I got some dripping below the truck and guess it is a fuel line. I'm not sure if it's the feed, return, or both.
Hey man, its been a few months now. How is she holding up? Did you get all your finishing touches completed?

peace
Hog

Zq8 blazer
Posts: 1
Joined: Sat Apr 22, 2017 10:54 pm

Post by Zq8 blazer »

So other than using larger injectors what is the purpose of this? Hp gains?

gotahoe01
Posts: 2
Joined: Tue Nov 28, 2017 1:04 pm
Location: WI

Indmar MCX Marine Intake

Post by gotahoe01 »

Would a marine intake from a Mastercraft Indmar motor work on a L31? The throttle body attaches at the front of the upper vs. the top. Not sure what other differences there are.

James B.
Moderator
Posts: 2823
Joined: Thu Apr 03, 1997 4:00 pm
Location: '98GMT400, '98GMT410, '99GMT420, '00GMT420

Re: Indmar MCX Marine Intake

Post by James B. »

gotahoe01 wrote:Would a marine intake from a Mastercraft Indmar motor work on a L31? The throttle body attaches at the front of the upper vs. the top. Not sure what other differences there are.
The short answer is "yes" it can work, but there are a bunch of other issues that will need to be overcome. The Vortec truck thermostat incorporates a radiator bypass function that allows coolant to continue to circulate and equalize temperatures throughout the block and heads without running it trough the radiator. The Vortec cooling system is "parallel" where coolant flows through the heads gasket into the heads equally between all cylinders rather than a series circuit where coolant primarily flows around the cylinders in through the front of the block, then up through the passage at the back where it returns forward through the heads and into the intake manifold. The point of the whole system is to have fewer hot spots and make everything more even - and critical to that is fluid constantly moving.
Far as sensors, use the truck throttle body with idle air control and throttle position. May need to adapt the manifold absolute pressure sensor. There will not be any possible provision for EGR far as I know, so plan on blocking that off at the manifold/header. You'll need to improvise a throttle cable and cruise too. Last sensor involved will be the coolant temp. (there are 2 on these motors, one for the PCM in the manifold and one for the instruments in the driver side head)
The Vortec crab distributor fits fine with these intakes - these motors ship that way.
Not sure about fuel fittings but you can use the parts listed on page one to adapt the stock lines.
The belt path appears to be a potential problem, plan on eliminating the stock idler pulley location and relocating with some custom brackets.
All in all, that intake would be a better performing solution easily. The marine adaptation is intended for those who wish to retain OEM component compatibility, emissions, and even aftermarket part compatibility but also have standard fuel injectors. There are *much* better performing solutions available for Vortec heads.

Edit:
Want to also mention a Vortec 454 (L29) throttle body will work better for this because the cable is oriented to come from the bottom direction rather than the side.

davkenrem
Posts: 16
Joined: Sun Aug 13, 2006 7:55 pm

Re: Indmar MCX Marine Intake

Post by davkenrem »

James B. wrote:
gotahoe01 wrote:Would a marine intake from a Mastercraft Indmar motor work on a L31? The throttle body attaches at the front of the upper vs. the top. Not sure what other differences there are.
The short answer is "yes" it can work, but there are a bunch of other issues that will need to be overcome. The Vortec truck thermostat incorporates a radiator bypass function that allows coolant to continue to circulate and equalize temperatures throughout the block and heads without running it trough the radiator. The Vortec cooling system is "parallel" where coolant flows through the heads gasket into the heads equally between all cylinders rather than a series circuit where coolant primarily flows around the cylinders in through the front of the block, then up through the passage at the back where it returns forward through the heads and into the intake manifold. The point of the whole system is to have fewer hot spots and make everything more even - and critical to that is fluid constantly moving.
Far as sensors, use the truck throttle body with idle air control and throttle position. May need to adapt the manifold absolute pressure sensor. There will not be any possible provision for EGR far as I know, so plan on blocking that off at the manifold/header. You'll need to improvise a throttle cable and cruise too. Last sensor involved will be the coolant temp. (there are 2 on these motors, one for the PCM in the manifold and one for the instruments in the driver side head)
The Vortec crab distributor fits fine with these intakes - these motors ship that way.
Not sure about fuel fittings but you can use the parts listed on page one to adapt the stock lines.
The belt path appears to be a potential problem, plan on eliminating the stock idler pulley location and relocating with some custom brackets.
All in all, that intake would be a better performing solution easily. The marine adaptation is intended for those who wish to retain OEM component compatibility, emissions, and even aftermarket part compatibility but also have standard fuel injectors. There are *much* better performing solutions available for Vortec heads.

Edit:
Want to also mention a Vortec 454 (L29) throttle body will work better for this because the cable is oriented to come from the bottom direction rather than the side.

I am currently aquiring parts to go this direction. I will keep this thread posted to my progress.

bronc3buster842001
Posts: 7
Joined: Mon Oct 04, 2010 1:15 pm
Location: Missouri

Post by bronc3buster842001 »

Im selling my intake. Time to go to an LS.

Formyboat
Posts: 1
Joined: Sun Jun 17, 2018 5:43 am
Location: Australia

Post by Formyboat »

Could somebody tell me the part number of this marine manifold preferably the lower section or where to get one and what term to use I have had no luck at all new or 2 nd hand
Thanks James

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