Re: An OHV guy finally gets it
 

I do a lot of reading, my posts are a compilation of reading. I was also raised in a drag racing/auto mechanic environment. I have worked in some GM assembly plants and talked to engineers, and have email buddies.
I refer to my notes fot the part numbers, to ensure accuracy, but a lot of te einfo comes from GM itself.

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Re: An OHV guy finally gets it
 

I do a lot of reading, my posts are a compilation of reading. I was also raised in a drag racing/auto mechanic environment. I have worked in some GM assembly plants and talked to engineers, and have email buddies.
I refer to my notes fot the part numbers, to ensure accuracy, a lot of the info comes from GM itself. Ive also done a few EFI retrofits. I was teh 1st Canadian, 2nd North American to install across ram MArine intake onto the 1996-1999 GMT-400 trucks. I passed the visual inspection and tail pipe dyno sniffer with this intake swap alkong with longtube headers. It was a project that a few guys collaborated with. The intakes came off of the 1997+ marine 350's that used the Vortec 8 intake bolt pattern. The issue with the stock intake/injectors is that the Central Sequential Fuel Injection(CSFI) thatw as used on teh 96-2000 Vortec 350/350 engines used poppet valves that didnt allow for larger units to be installed. We were stuck at 23 lb/hr of fuel. The most we got=out of a stock CSFI intake on a 383 engine with home ported Vortec heads, LT$ hotcam kit 218°/228° 0.525"/0.525" lfit with the LT4 hotcam kit's 1.6:1 roller rockers on a 112° LSA. The roller rockers are very similar to the rockers used on the 1996/97 LT4 engines.
With headers/exhaust it dynoed at 330rwhp/381 rwtq. ALong with a 3000rpm Vigilante torque converter from Precision Industries and 4.39 gears with 395/40 zr17 drag radials it ran a best of 13.2@ 102mph in an extended cab 2wd truck. No bad for a 4800 lb daily driver. But there was no more to be had, and if anyone went with a supercharger of turbo, you couldnt get above 250 at the crank withoiut additional fuel injectors. (such as using a Fueler like the early Callaway B2K turbos cars did with teh 2 extra injectors at the Rams horn intake)

Stock CSFI intake, look at all the injector debris inside the plenum
http://i1202.photobucket.com/albums/...ctordebris.jpg

Cross Ram Marine intake(inside with the upper plenum lifted off), compare to teh above stock intake. Much better
http://i1202.photobucket.com/albums/...orn/marine.jpg

MArine crossram intake left, stock truck intake, right
http://i1202.photobucket.com/albums/...idebyswide.jpg

Here is one atop a GM marine crate engine GM called this an IAFM Integrated Air Fuel Module. These were used atop Mercruiser 305,350, 383, 6.2 engine.
http://i1202.photobucket.com/albums/...rhorn/iamf.jpg

Same as above, but used and having the Mercruiser red paint on it
http://i1202.photobucket.com/albums/...intakeside.jpg

Other options we had was the Ramjet 350 intake as well.
http://i1202.photobucket.com/albums/...mjetintake.jpg

Or the BBK turtle intake, or any intake that held port fuel injectors and had the Vortec GEN 1-E's 8 vertical intake bolts, 2 at each corner of the intake, versus the older GEN 1 non-Vortec 12 angled intake bolts.

Using the cross ram intake, we are seeing 330rwhp with flat torque curves from 1800rpm-5000rpm with tiny 203° duration roller cams. Using the stock intake, it took LT4 hotcams and 383 cubes to get the same power.
Olus if you get any stock Vortec 305/350 K&N or similar air intake, or Whipple supercharger kit, or any other turbo or supercharger kit for the1996-1999 Vortec 305/350 van/truck/SUV the kit will bolt on 100% as the Marine intake's throttle body is on teh stock location. It actually uses the truck t-body because teh marine t-body has no attachment for the trucks cruise control.
I oersonally didnt need the extra fueling, I did it because I wanted to prove that it could be done, and done economically. There were a lot of naysayers. The advent of Tunercats OBD2 back in 2005 really opened up the possibilities for us GMT 400 Vortec V8 truck enthusiasts.
The marine intake lists for over $4000 for the upper and lower intake, fuel rails, 8 25 lb/hr stainless steel marine injector etc etc etc. I picked mine up used for $600 and did the complete retrofit for just under $1000 including the PCM tuning. You can get these intakes for $1800 from Michigan Motorz. I have seen the V6 versions for V8 Vortec heads go on Ebay BRAND NEW for $199. Great for the turbo V6 crowd.

Stock intake, to marine intake, with only the Injector Flow Rate(IFR) changed to compensate for the larger injectors, resulted in a big grin on my face. Even with the stock 191°/196° 0.412"/0.428 111°LSA cam ( cam also used in GEN 2 1994-96 Caprice with iron head LT1 260hp/330 lb/ft and GEN 2 iron head 4.3L V8 L99 caprice 200hp/240 lb/ft torque-and also in the1996-2003 vans/trucks/SUV), off idle torque was improved and instead of hitting a substantual horsepower wall at 5000rpm, power and revs continued up to the stock limiter of 5600rpm. There are now many of the conversions on the road today.

Sorry for another book.