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vortech to tbi?

T

Txchevy18

1/2 ton status
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Im looking at purchasing a used marine 350, full roller, from what I can tell vortech heads, unkown cam and about 100hrs on it. It has a blown head gasket that was replaced by the warrany now they dont want to pay for the shipping to send it back.

I know ill need a new intake to make the tbi work as well as a new chip. I found teh gm performance intake for 350 and started to look for alternatives.. Can i use a intake used to run vortec heads with a carb and then throw a tbi adapter on top of that with out any ill effects or signifigant power loss?
 
Get an Edelbrock intake, ethier Performer or RPM for a Vortec, and then get the Holley adaptor 17-45. Don't get the GMPP Vortec intake inless this is a stock motor....they don't flow very well....
 
I think if you use the Vortec manifolds, or somewhere I saw a remote style EGR. If you don't need the EGR you can get a chip burned to run without.....
 
ok well, I dont have any emmission stuff on the truck as of now so Im not sure if I need it or not. I also have shorty headers w/o air tubes. I know that egr is exhaust gas recirculation, but what does it contorl? Im guess it gives the comp more data to set the timing and fuel curves appropriately?
 
I'm not sure what it does. I have a set of Vortecs that I might use, went to get rid of the EGR, but since haven't gotten that far, not sure what to do....only had couple sips of coffee, so don't really know what I'm typing.....lol
 
If you will need to install the emissions stuff later for testing then the EGR will give you problems using the vortec heads as they don't have any exhaust crossover in them which is needed for the EGR, you will need to pull exhaust off the passenger side manifold. There is a kit somewhere for doing this but your swap is getting expensive quickly.
 
Well I would like to attempt to keep this emmission legal. But I recived it with out any of the smog stuff so I may already be past that point. I also ordered a new set of ceramic coated shorty headers w/o A.I.R. right before I found out about the vortec that I have now. I would like to try and maintain the egr for mileage reasons but if it cant be done then it cant be done.
I figure If i can come out under 1500 including cost of the motor then I did alright. I already know im goin to have to upgrade the fuel system considerably since the marine tbi ran at 28 psi. with a set of 45 lb\hr injectors from a 4.3 to beable support the 315hp reliably.
Tommrow Im ordering:
arp head studs
arp intake bolts
arp carb stud kit
felpro head gaskets,
w/e intake I need, as well as an tbi adapter/spacer
Im also considering an autoprom usb pack from moates.com

I want to do this right the first time and not take any short cuts so im willing to spend the money if need be.
 
just my opinion but it sounds like your going to be partin and piecing this tbi together untill you get it right if I am reading this right you will be playing a guessing game which costs alot trust me I did it wth my tpi unless your really dead set on get the tbi to work just carb it. Vortec heads with a good carb IMO is a great set up that what I will probably put in my s-10 unless I can come across a complete vortec motor. Just my 2 cents:dunno:
 
update

Jimmy thanx for input. I have to considered and been told by many locals to just carb and be done with it. The problem is that a carb is in all reality a 20yr old technology and a step backward IMO. I atcually hate having to adjust the freaking things every week since the weather is so odd around here. There will also be a lil wow factor. How many 88 era vehicles can communicate with there computers in realtime via a laptop? I also enjoy messing with computers and tinkering in general. Plus if I can pull a few mpg out of it and still pass emmission then I will have achieved my goal. That and the emmisions guy wouldnt pass it if he looked under the hood and saw a carb.. and it sticks out way to much for the sticker to be anything but legit.. not that id ever do that sorta thing...

Well Ive been reading everything I can find on the subjuct lately and have started to compile a a parts list and begin ordering.

I have a few questions
Can anyone back up the post of the gmpp intake being restrictive to flow?
Should I run a walbro 190 or 255?

Am I off my rocker to think I can coax 340-350 out of this motor with the addition of my prostreet ignition sytem, billet distributor, dual flexalite fans, a set of shorty headers , free flowing exhaust and a performance focused tune?


Motor stuff
arp head studs
arp intake bolts
felpro gaskets

Tbi stuff
from extremefi.com
50mm bored and rebult tbi
injector spacer
8-40 psi AFPR
AN inlne fuel pressure test port

Dynamic efi
Ebl flash.. thig thing looks so sweet!

Misc
68# caprice cop injectors
walbro 190 or 255 fuel pump
an intake combo of som sort

Thanx for the response guys this website sparked my intrest in efi and the tuning it can do. I cant wait to get it all set up.

txchevy

And just to be a pic here what its all goin in..
SSPX0022.jpg

This is mid swap I need to get an updated pic.. 35's rear 38's front
SSPX0441.jpg
 
The votec motor with tbi will run good I did it in my 89 sub with no problems. With headers you will have to weld in an egr tube for the egr to work.

bigred81
 
*Apparently* the GMPP intake is a production piece. Some sort of van was Vortec-headed but still TBI. So doesn't surprise me that it wasn't a high-RPM piece. Not going to say I have flow numbers, but even the heads aren't high RPM champions, no reason the intake needed to be.

I think your big intake issue is going to be EGR. If you want to run EGR with TBI and Vortec heads, I don't believe you have any choice other than the GMPP piece. Maybe with a TON of work and weird routing of pipes you could use a carb intake setup for EGR, but I can't imagine how ugly exhaust gas piped to an adapter on the intake would look. I believe the GMPP intake has the port towards the rear of the intake, pretty much out of sight. The TPI Vortec base does.

If you don't want to run EGR, I see no reason to just make life simple and run a Vortec to carb intake with a TBI adapter. And if I was going that route, I'd probably start with a 454 throttle body and the stock 4 barrel adapter...I've heard a couple problems with the bored out throttle bodies, but not sure which brand they were.
 
That was kinda what I was thinking as well. Ya I belive the van( 96 or 97 astro) used a 74# injector with the vortech heads but, they seem to be almost non existent from what the guys at the junkyard have said. Im not looking for crazy high rpms but, I figured that if the gmpp one did in fact flow better then i would be able to justify its higher cost.

Since ill be running the ultimate tbi code with the ebl flash I can can just go in and disable out the start up egr test and zero out the fuel and spark tables associated with it.

I decided to go with a bored out tbi unit instead of the 454ss unit for a few reason. They are getting harder to find, the internals most often have hard wear after 100,000+ miles of use, the throttle linkage would require further modification to make it work and the tps sender would require an extra adapter and some proggraming get everything on a even playing field.

I have read a few of the problems that have been associted with the bored unit and hope that the overall performance is worth the risk. I see myself spending countless hours tuning this thing up to its full potential, but thats half the fun..
 
Re: Fuel pump. 190LPH will easly support the HP numbers you want. But you might as well go with a 255 LPH they are the standard replacement for a performance V8 build. They are only a few dollars more than the 190. And who knows? You might want to mod the engine more later.

I have a bored 46mm (590cfm) TB from Extreme FI on my K5 with a mild 350. It works well and have had no problems with it. Just had to play around with the fuel pressure a bit to get it running the way I like. It definatly gave me more power over the stock (480cfm) 42mm TB.
 
thunder: Thats kinda what I had thought and its only $10 more for the 255lp hig pressure version. I dont see myself ever building more hp into it unless I hit the lottery.. Im already 1300 into this swap..and I still dont have a new head gasket..

I wouldnt think so considering it is just allowing more air into the intake. Tho Im not exactly for sure.. it may infact hinder it by a millisecond o so due to the need to use a bigger throttle plate(butterfly).. ie: wind resitance.. Since its fuel injection Im hoping Ill be able to take up the slack and make this a very responsive motor.. maybe someone thats done more with this system can give a second opinon.
 
I do not notice much diference in off idle responce. At cruise it responds better. But You do need an adjustable FPR to fine tune it. Its also nice to have a real time scanner so you can monitor BLM, integrator, knock counts, after you make changes in pressure and or timing. I run mine at 13 PSI and +2 degrees timing for the best combo of performance and MPG. My 350 is a very mild build with all the usual bolt ons and TB mods

Re fuel pump: You really dont need the high pressure pump. The regular 225 has more than enough pressure for TBI
 
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