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tbi intake on lt1 engine

 
bo1500
V-6 Camaros rule!
Posts: 81
Joined: 06/04
Posted: 08/10/04 12:10 PM

Hey everyone i wanted to know if it is possible to mount a tbi intake on a lt1 engine witht the aluminum  heads the engine is a 95 and the intake is off of a 94 tbi both are 350's. I was told if i notched the intake it would work i am in a bind any info i s appreciated.  

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oldbogie
I mow my lawn and find Chevys
Posts: 1195
Joined: 08/03
Posted: 08/10/04 03:33 PM

The 95 LT1 is a rather different animal from whence your 94 TBI intake comes from. The TBI manifold will neither match the LT1 ports nor fit the bolt locations.


The TBI manifold could be modifed, I haven't done this, but I'm gussing that the manifold to head flange could be built up with weld and milled for a gasketable fit. Or some adapter plates made to fit the manifold ports to those of the heads and either or both the heads and intake milled to accomodate the thickness of the adapter plates. There's still the bolt arraingement to be worked. It's possible to drill and tap the heads to match the manifold bolt pattern. But some of the manifold bolts come close to the existing bolt holes in the head to where these holes would have to be welded shut in order to redrill and tap the manifold bolt pattern. This is a lot of work and there's no assurance that the new holes in the head are located in enough material to accept the bolt torque and heating cooling cycle loads imposed upon them. The LT1 has no water return provision where the TBI manifold does. What the LT1 head does have in that location is an open hole to the oily inside of the engine. This means that the coolant return of the TBI will have to be very clean and a seal made to close this off from the atmosphere.


An alternative to put TBI on a reverse coolant flow LT1 would require a GMPP LT1 carburetor intake like 24502592 as a starting point. You will need a 4 barrel to TBI adapter plate, Holley used to make these but more likley than not you'll have to fab one. The manifold or the adapter plate will have to be modified to provide an EGR hook up if your running on the street and subject to SMOG inspections/tests. You'll also have to fab an EGR adapter and all the plumbing as there's nothing commercially made for this. You could adapt some Edlebrock and GM parts to plumb the EGR. Edlebrock used to catalog a tube P/N 2899 if your using headers or the GM part 10220275 if your using cast iron manifolds. But none of this is bolt on, all will take fabrication and fudging to get it to work.  Of the two choices, this one is the way I'd go. But either way will require fabrication talent.


Don't forget the computer will never deal with this without a chip.


http://www.fastchip.com/


http://www.hypertech-inc.com/


http://www.superchips.com/


http://www.kcspeed.com/


http://www.jetchip.com/


Of course in either of these situations you have to remove the LT1 oil pump drive to make way for the distributor's conventional oil pump drive, not a big deal but you have to remember to do it or the distributor will not fit and you'll have to pull the intake off to get at the drive mechanism.


If your LT1 has the original injection system, it just might prove simpler to get an LT1 engine wire harness and computer (OK and fuel pump) and redo, what I expect is a pick up, to run the complete LT1 system and engine. This is probably the least expensive and least difficult alternative.


Bogie


 

 

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bo1500
V-6 Camaros rule!
Posts: 81
Joined: 06/04
Posted: 08/10/04 04:31 PM

Hey Bogie i dont know if you remember or not i am the one you responded to when i asked about a lt1 swap into a 94 tbi pick up i tried calling the guys at JTR but i got no answer i wanted to know if the book they sold would show me how to use the factory wiring harness. I have tried a few places and they want to do it but they want me to purchase the "painless wiring harness" that an extra 700 bucks and i am 1300$ in this lt1 so do you know if the book they offer would cover that? The harness is uncut all pugins are intacked. I am at the point where i want to remove the lt1 but i am hearing about all the performance gains i will be giving up.


I am simply trying to figure out the which is going to be the simplest way to go is the re-wiring of my truck going to be real radical or is it just a little tweeking? I am tryin to get it over with and of course i have all these fly by night mechanics say Blushh i know SOMEONE that can do that no  problem, but like always they want the painless harness. So Bogie please i am on my last foot any insight would help me out. Just incase i havent said it in the past thanx for the info.

 

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oldbogie
I mow my lawn and find Chevys
Posts: 1195
Joined: 08/03
Posted: 08/11/04 11:55 AM

I remember the discussion but not the detail anymore. You have a 95 LT1 with aluminum heads thus Camaro or 'vette in origin transplanted into 94  full size pickup which had a TBI 350, am I correct?


The questions I need re-answered are related to how much of the LT1 do you have:


1. It's transmission? And what is it auto/manual?


2. LT1 Wire harness(es) consisting of the engine harness, transmission, engine compartment, body/chassis?


3. Do you have the LT1s fuel injection and computer?


4. The LT1 sensors including anti-knock, O2?


5. LT1 fuel tank and pump; just the pump?


6. Is the truck 2 or 4 wheel drive?


Bogie

 

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bo1500
V-6 Camaros rule!
Posts: 81
Joined: 06/04
Posted: 08/11/04 10:19 PM

Hey Bogie to answer your question(s)?


1.I dont have the 460le tranny i have the 700r4 from my truck.


2. I have the complete harness out of the car not cut anywhere.


3. I have the injection system out of the car along with comp.


4. The sensors i am not sure of i dont know if they are on the block or seperate if you give me a idea i might be able to find out.


5. I dont have the fuel tank or the pump but i am sure i can get it if i need to.


6. The truck is  a 94 2WD.


I can get anything you think i am going to need all i need is a list of them and i will make it happen i am fired up abd ready to go. If you think the book will bring me through i will get that also. Thanks in advance.


 

 

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oldbogie
I mow my lawn and find Chevys
Posts: 1195
Joined: 08/03
Posted: 08/12/04 04:31 PM

What about emissions, do you live in California or a state that uses California emissions regulation? IE are you subject to inspection and test or just a tail pipe test or no inspection and no test?


I'll have to admit that an LT1 against a 700R4 in a full size truck is one I haven't done. The 700R4 doesn't need the computer to shift but does require a mechanical control from the engine which the FI on the LT1 has no provision for. I've got to look at a couple things here; 1) what to do with the unsued 4L60E commands from the computer, this may need a load to keep from smoking the computer, this could be a 4L60E transmission replacing your 700R4 or perhaps some resistors and or coils to simulate the electrical load of the 4L60E's solenoids. Second is whether it's practical to or possible to run a throttle linkage from the LT1 throttle back down to the 700R4. Lastly whether you want the lockup converter to operate and if so how, this could come from the LT1 computer, a stand alone computer GM makes for 700R4s in older vehicles, for-go the lockup feature.


To tell you the truth at this point I rather think that either pulling the LT1 out or converting it to TBI will prove to be the shortest, least expensive distance to a running truck. The LT1 is actually 2 generations ahead of your truck, its systems are more similar to the new Gen III 346 than they are to your old Gen I 350 or the Vortecs.


But anyway, let me cogitate on this for a few days and get back to me with your emissions status.

 

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bo1500
V-6 Camaros rule!
Posts: 81
Joined: 06/04
Posted: 08/12/04 07:00 PM

Hey Bogie i figured as much about this project. Everyone was telling me that "oh thats easy" but, as i am seeing it is more complex than i thought. To answer your question i am in Florida and emissions has been cancelled.  I am looking into trying to buy a motor but, i having a hard time selling  the lt1. I am going to wait to see what you come up with but, i am going to keep looking thanx in advance.  

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oldbogie
I mow my lawn and find Chevys
Posts: 1195
Joined: 08/03
Posted: 08/13/04 10:20 AM

If emissions are not an issue the simplest, quickest and least cost solution is to put the GMPP intake 24502592 on the engine with a Holley 650 to 750 carb and a HEI distributor. You'll need a carb style pressure regulator to reduce the TBI pump pressure down to 3-4 psi.


Bogie 


 

 

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bo1500
V-6 Camaros rule!
Posts: 81
Joined: 06/04
Posted: 08/13/04 06:13 PM

Hey bogie now if i go with the carb and intake what would i be losing or gaining? Is the fi better performance or is the carb better?  I just want to make sure that i am getting all i can out  of the motor.  Did you come up with anything using the lt1 injection? The truck has been dormant for 2 years now but, if you think this is the best and easiest  way to go i trust you. Tell me what can i expect with the carb on this motor?  Do you think i should up the cam or anything to make it really work tell me what you think. What would you do?



Edited 8/13/2004 6:17 pm by bo1500  

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