Vortec L31 MARINE MANIFOLD project! Q&A

Performance modifications, tips & tricks

Moderators: flyingpolarbear, Dev, James B.

VortecBlazer
Posts: 100
Joined: Mon Nov 19, 2007 9:36 pm
Location: FL, '87 S-10 Blazer w/'97 L31 350, 0411 PCM,1.6RR,918 vavle springs, XR270HR cam, Marine intake

Post by VortecBlazer »

According to PSWired post in this thread
http://www.pacificp.com/forum/viewtopic ... light=evap

I'll basiclly just get some fuel smell without the evap solenoids

Hog
Posts: 5025
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

VortecBlazer wrote:Thanks Hog, I figured while I was swapping cams and had the intake off why not get the marine intake. Then cost to benifit comes into play. You think the stock intake will support the cam or starve it?
Here is teh full reply I got from teh gentleman who did the swap and dynoed before and after.
"Wish I knew what the intake alone made for power. I gained 35 RWHP at peak and closer to 50 RWHP toward redline with the marine intake, e-fans, and my custom mandrel bent 3.5" CAI setup however that was including the additional loss of the 4L80E over the 4L60E. The 80E is probably eating a minimum of 6-8% more power than the 60E"

peace
Hog

mnewman949
Posts: 2
Joined: Fri Feb 07, 2014 11:13 am
Location: Dana Point, CA

Post by mnewman949 »

Hello --

New forum member here and I wanted to thank you all in advance for this great article/thread. I hope you don't mind I have brought this topic back from 2005!

I just picked up the MPI setup and plan on putting it in to my 99 Tahoe. I have recently built a 383 stroker with the same Camshaft specs as the GMPerfrmance's HTE383e stroker, Summit Vortec 64cc heads and 1.6 roller rockers. From my calculations I should be just at 10:1 compression. I have the motor running in the truck now with NO engine light, really good torque but not all that impressed with HP overall. I am sure its due to the limiting fuel system/tune -- Enter the MPI conversion! I have not dyno'd the truck yet so not sure what I am pushing but on paper its somewhere close to 300-350 hp and 350-400 ft lbs of torque.

Any suggestions, or additional insight for the conversation process would be greatly appreciated. I picked up the Upper/Lower plenum, and fuel rails for under 500.00 and according to the MPI writeup I should not have to spend too much more.

Can anyone help with suggested Injector lb?

Mike

Robert B.
Posts: 11
Joined: Sun May 19, 2013 8:33 am
Location: Houston, Tx

Post by Robert B. »

Does anyone have pics of the thermostat bypass looking down from where the thermostat would sit? I think I have an idea of how far to drill but would like a visual.
I was able to pic one up yesterday.

Image

Whipped383
Posts: 2104
Joined: Mon Mar 01, 2010 9:12 pm
Location: Salt Lake, 97K1500,ECSB, 383,Whipple,0411,Marine, 03K2500,CCSB,8.1&Allison, Whipple in progress

Post by Whipped383 »


Robert B.
Posts: 11
Joined: Sun May 19, 2013 8:33 am
Location: Houston, Tx

Post by Robert B. »

Thanks Whipped!
So it needs to travel straight through that little hump into the center ring without breaking through the humped part?
What size bit did you wind up using?

Whipped383
Posts: 2104
Joined: Mon Mar 01, 2010 9:12 pm
Location: Salt Lake, 97K1500,ECSB, 383,Whipple,0411,Marine, 03K2500,CCSB,8.1&Allison, Whipple in progress

Post by Whipped383 »

I cant remember now I used a 3/8 pipe tap so whatever size that is I think 9/16. Iv done 3 of these intakes but its been a while since Iv done one.

Robert B.
Posts: 11
Joined: Sun May 19, 2013 8:33 am
Location: Houston, Tx

Post by Robert B. »

I was thinking it was a 3/8 fitting.
Am I right on this part? "So it needs to travel straight through that little hump into the center ring without breaking through the humped part?"

Whipped383
Posts: 2104
Joined: Mon Mar 01, 2010 9:12 pm
Location: Salt Lake, 97K1500,ECSB, 383,Whipple,0411,Marine, 03K2500,CCSB,8.1&Allison, Whipple in progress

Post by Whipped383 »

Yup and yup. Its a 3/8 pipe thread fitting, Pipe thread is bigger

Robert B.
Posts: 11
Joined: Sun May 19, 2013 8:33 am
Location: Houston, Tx

Post by Robert B. »

Add another one to the list. Got my truck running on the marine intake yesterday now I just need a tune.

johnsr
Posts: 2
Joined: Thu May 29, 2014 2:53 pm
Location: lafayette, in

Post by johnsr »

I am new to this forum and would like to start out saying HI...
I a planing a build using the marine intake on my '92 k1500, as I really hate the stock TBIâ„¢ setup. I already have the block and crank at the getting cleaned and freshened up for this. Has any on condensed the hole thread down to just the relevant how to, like a manual? Also are there any tips, pointers that you guys have for me.

Whipped383
Posts: 2104
Joined: Mon Mar 01, 2010 9:12 pm
Location: Salt Lake, 97K1500,ECSB, 383,Whipple,0411,Marine, 03K2500,CCSB,8.1&Allison, Whipple in progress

Post by Whipped383 »

You will need vortec heads to start with, TBIâ„¢ heads no worky with the marine.

johnsr
Posts: 2
Joined: Thu May 29, 2014 2:53 pm
Location: lafayette, in

Post by johnsr »

I was looking at these heads from summit racing NAL-12558060 Vortec Cylinder Heads, with this cam CCA-08-409-8 and this Throttle Bodie BBK-1710. I also will be running a 4l80e in place of that stock 700r4 in there now.

mnewman949
Posts: 2
Joined: Fri Feb 07, 2014 11:13 am
Location: Dana Point, CA

Marine Vortec Intake, Plenum and Fuel Rail for sale

Post by mnewman949 »

Hello --

I recently bought the Marine intake setup and started my build. I have decided to scratch my project. My loss is someone else's gain. I wanted to give the forum members here first dibbs before it goes back on EBAY. Lower intake has some surface rust and the Fuel Injector Ports needs to be reamed. (Pictures will be provided soon)

Here is what I have

Lower Intake
Upper Plenum
Stainless Steel Fuel Rail
New #32 Bosch Injectors
Complete AN fittings to complete Fuel Lines

$800.00 OBO, I will entertain reasonable Offers.

Mike

hit626387
Posts: 5
Joined: Mon Sep 22, 2014 9:22 am
Location: Maryland

Post by hit626387 »

Hello new member officially but have been stalking the forum for quite some time now and have learned much. I've had a marine intake for awhile now and finally have some time to work on it. The only question I have is related to the coolant bypass hose. Has anyone tried to use a waterneck riser tapped with the correct npt barb fitting rather then drilling into the manifold itself? Seems like a quick and straight forward alternative. Don't bash me if it's already been asked but I did search the topic with no results.

98Whitey
Posts: 2
Joined: Sun Feb 15, 2015 3:50 am
Location: *manassas*

Post by 98Whitey »

I'm sorry that I didn't read threw all the pages, but I've been reading back and forth on this. And wanting to do it for the past two years now. I found an intake on ebay, but it is without a harness, injectors, or fuel rail. Can anyone help me out with a place to buy them? Or should I continue to look.


Thanks,


Anthony

VortecBlazer
Posts: 100
Joined: Mon Nov 19, 2007 9:36 pm
Location: FL, '87 S-10 Blazer w/'97 L31 350, 0411 PCM,1.6RR,918 vavle springs, XR270HR cam, Marine intake

Post by VortecBlazer »

Find the rail on ebay or CL also. The injectors you can get from a corvette or camaro guy that has upgraged from their stock 28lb (I had a buddy who gave me his), and the harness you can buy new injector plugs or find some at a local junkyard. If you go the junkyard route like I did you could grab the injectors with the plugs.

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

Post by 97VortecChevy »

So can you use the Volvo intake ? I seen that someone said it is diff .... I need a marine intake !!

ORION OFF ROAD
Posts: 83
Joined: Fri Jan 30, 2015 8:13 pm
Location: *Salt Lake*

Post by ORION OFF ROAD »

Regardless of Volvo, or Merc. There are some that have a different tb set up. Specifically a 4-bolt tb, instead of a 3 bolt tb. I've had my hands on both Volvo, and Mercruiser ones that are correct. And even a "marine power" one that is correct as well. It was neither the Volvo red, nor Mercruiser black. It wad a weird grayish/green color

Toclcl
Posts: 7
Joined: Sun Jan 25, 2015 6:46 pm
Location: *alberta*

Post by Toclcl »

Anyone have a current supplier on the west coast for the intakes..?

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