I borrowed a few pictures around the net a will let them speak for themself. The Marine intake uses external injectors that can be upgraded. The spider type sits in the plenum of the intake and is limited in flow. My mildly cammed engine was close to maxing out the stock injectors at 85% DC. Then notice how much less trash the air has to flow around in the marine intake without the spider in the way.Originally Posted by JeepsAndGuns
The stock Vortec 5.7 has the injectors under the upper plenum. People call them the poppit or spider style injectors. Not only are they not upgradeable, they create a pretty big restriction in airflow. they are right in the intake runner paths on a few runners.
The marine one is open on the inside, since it uses normal style injectors mounted on the outside with normal fuel rails.
Oh wow, I see now. No wonder you and other people wanted that intake. I have never seen the inside of the stock intakes, and I must say, that is not the best design I have seen.
79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
Vortec heads were actually used in Marine applications before the trucks. The first application I'm aware of is around '92 IIRC. Although many people want the truck style intake to keep the engine looking stock-ish and minimize the amount of changes to the truck, there are other marine intakes that can be found.
I picked these up years ago but there are other options today right out of aftermarket manufacturer's catalogs. Good thing, too. Anything that looks like a marine manifold usually fetches top dollar these days.
Got the Tahoe fans all wired up to discover I had a bad relay and a wrong relay. I will be picking up a better set of relays today. Already swapped in the massive 34" x 18" x 2 3/16"core radiator into place to match the fans. Everything is soldered, heatshrunk and fused. I will throw the loom on it once I get the relays swapped. Somehow I obtained a SPST relay with dual outputs rather than a SPDT with switched outputs. As soon as it activated for high fan it would short power to ground and blow the fuse.
Last edited by Fast355; 10-21-2013 at 04:22 PM.
Vortec heads were actually used in Marine applications before the trucks. The first application I'm aware of is around '92 IIRC. Although many people want the truck style intake to keep the engine looking stock-ish and minimize the amount of changes to the truck, there are other marine intakes that can be found.
I picked these up years ago but there are other options today right out of aftermarket manufacturer's catalogs. Good thing, too. Anything that looks like a marine manifold usually fetches top dollar these days.
That is the intake I am running!
Last edited by lwrs10; 10-21-2013 at 04:53 PM.
http://www.youtube.com/watch?v=hdzYKsGIpC4
Fan wiring is loomed and fans installed. Still cannot get the PCM to activate the fans with the a/c but altered settings on the low speed for the present time to run anytime the engine is warmer than 30°F and less than 40 mph. I will add in a dioded circuit to the compressor relay or run my old method of an auxiliary fan control on the pcm and temp switch in the head for high speed.
The voltage does not even quiver with my 220a alternator although I do need to tweak the idle air volume for the fans some.
Last edited by Fast355; 10-23-2013 at 03:59 AM.
you either have to activate the AC fan control in raw hex in the system segment(best way), or swap in a camaro system segment. None of these can you do in HP tuners.
Lots of options in EFI Live and looks the same in TunerCat? Or am I missing something?
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
I can control low speed just fine. High speed just clicks the relays. Considering just hooking back up the temperature switch in the head.Lots of options in EFI Live and looks the same in TunerCat? Or am I missing something?
Cylinder head mounted fan switch method is now being used and the setup is cooling well. I have only heard high fans activate once after a stopping in traffic right after a taking a heavy beating at prolonged WOT!
What year 4L80e are you using Fast?
89 K1500 Scottsdale 5.7L 5spd 3:42 RamJet cam Dart iron TBI heads 427 PCM swap
95 C2500 Cheyenne 6.5L turbo diesel 4L80e 4:10 DB2-4911 Manual pump conversion 0411 PCM trans control 2Bar COS
05 Outback XT 2.5L turbo gas auto
2002
Someone got ambitious and datalogged after adding 2° of timing across the board under load and 2° more in the heavy load, lowest rpm area. Still massaging a lean spot caused by the intake but this thing pulls harder now than ever. The only time I am seeing any knock retard is at the lowest speed the converter stays locked in overdrive while aggressively opening the throttle. No timing was added in the trouble area but I am considering adding a little more burst knock back in and around that area to prevent it from doing it. I have also considered slightly raising the lockup mph to keep the engine from seeing that load.
Last edited by Fast355; 11-05-2013 at 04:10 PM.
I raised the TCC lockup to 60 mph and the lockup induced lugging and spark knock is no more. I am able to run a 13.4:1 air/fuel ratio and 28* total timing from 3,500 rpm though 5,500 rpm in 1st and 2nd gear. I found through testing the CCOT logic is actually very accurate. I have the EGT limit set to start brining in the CCOT at about 1,400* and have the AFR timing compensation map setup to pull up to 8* of timing as the CCOT air/fuel ratios increase. The maximum enrichement is set for 1,650*F estimated EGT and the actual EGTs run about 1,600 on prolonged WOT and actually start to drop as the air/fuel mixture richens to its maximum of 10.8:1 at about 85 mph. With the timing retard I am not seeing knock going into 3rd gear either. So basically its working as intended now.
Also managed to get a piece of 3.5" aluminum tubing mandral bent in the shape of my PVC intake and wrapped with a heat insulator. We tig welded on a couple of aluminum tabs to hold the intake on the fan shroud. I am seeing 98 KPA on a 101 KPA baro reading now and spikes over 250 gms/sec airflow.
Someone is also well over 300 RWHP now with his L31/4L80E/9.5" 14-bolt driveline. This person also gained 40 ft/lbs of torque at 1000 rpm at the wheels by adjusting the timing map in that area using a locked 3rd gear pull on a dyno. Talk about a throttle response boost. Someone drifted his Express around a 90* right hand corner afterwords without intending to.
Last edited by Fast355; 02-04-2014 at 09:54 PM.
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