At the moment, I can get 350TBI from '88 Van and actually don't know anything about this engine: gas mileage, performance, allowing to mods etc. If anyone knows something about this type of engines or can give me some advice, please reply. I want to swap my V6. Thanks.

 

Be careful with van/turck motors. there are some motors that are "detuned" with lower compression and camming to give better long-term life in certain HD models. Other than that, you should be ok. The PROM will be mellow as well as the cam/ehaust system, anyways, compared to a car but those can be taken care of quite cheaply.

Oh, SOME of the van TBI harneses are VERY long becasue they locate the ECU behind the front seat in a compartment so make sure if the harness is the long version, you can live with it.

 

swap no prob. you would want to rebuild i bet, and swap lots a parts so that its not a van engine. ask the dealer what the engine specs are and give them the vin so they can tell you. if its not the original you will never know without doing a full rebuild. i know somebody who just got a 350 out of a 80k truck, cost was 600$. thats junk yard cost. so if you are cheaper. go for it.

 

OK, thank you! I want to ask another two things.

1) How can i determine, that engine is "detuned". Dealer shop can tell me CR and HP for that engine, if I show them VIN. What is CR, hp-rating of "detuned" engine? Can I check something else, to example, valve diameter or something else? This engine is in the Van at the moment.

2) maybe should I go with carb. (I must change that staff anyway) and change intake and cam, buy carb and full exhaust. I that case, how big is the loose in gas mileage and how big is the win in performance?

Thanks!

 

If I were swapping in a new engine, the intake would be carb or TPI. The only reason I'm running TBI is 'cause thats whats in the RS. I've asked, but no one has ever convinced me that TBI is a viable performance intake. Get a cheap 350 long block and get a real intake and you'll be happy.

 

The OEM TBI equipment can prive you 300hp pretty easily out of a 350cid motor with 9.0CR and a pretty mellow cam along with fuel pressure changes and a custom PROM. I am quite new to GM TBI systems but have more dyno work on them now than most do here, if they have any at all. IMO, keep the TBI...

Not sure how to find out the motor is detuned. Have to ask someone who knows at a dealer, I guess. Pretty sure 3/4ton vans and above have the mellow motor but I am not sure. same with pickups, I believe.

I am presently working on drive-tuning a 350TBI with a COMP XE250 cam. Running VERY strong right now!!! Gotta be 300hp...

I tried the LT4 Hot Cam for a couple days but too much change from the previous cam for me to change the PROM effectively. will post dyno results in a month or so when I get the PROM tuned right. Wish I had simple "BLM learning" software to help me make PROM changes in 1 hour instead of 2 weeks... Help, CRAIG!?!?!

 

Thats great except for the fact that it isn't that difficult to get 350hp from a carbed 350sbc. Once again, why go with TBI over carb or TPI?

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'68 Camaro - Vortec 350
'91 Camaro RS - 305 TBI

 

I'm not gonna get into this one. Go with a carb if that is what you are comfortable with. have fun. CARB board can help you...

And it's not THAT difficult to get better throttle response, mileage, emmissions and overall power out of the TBI. What IS difficult is taking the time and spending a little money, and I do mean little... I have been trying to lend a hand to people here (some have helped me IMMENSELY) but noone seems interested in my work or dyno results. I am VERY close to ending my days on this site for I feel I am not a true part of it.

IMO, the GM TBI system doesn't need tweaking all the time. Yeah, I LOVE carbs, too, but man, this TBI I got running now is about as nice as it gets... No joke, man.

If you want simple, stay with carb. If you want complex but done right, go with TBI. Wires were meant to carry current... Might as well use them.

[This message has been edited by FastBroker (edited March 23, 2001).]

 

FastBroker I think others would be interested in dyno results, I know I would. I have a vortec 350 on the stand preping it for an April-May install and plan to keep the TBI. People need to be more open minded about making TBI work

 

I'm interested in your TBI work too! Not so much for my camaro, which is TPI, but for my Bravada. They only offer TBI or CPI for the 4.3, and I've heard nothing but bad things about CPI so I want to keep the TBI setup on mine. Seems very similar to the V8 version, so hopefully some of what you share will apply!

 

FastBroker, plese e-mail me:
camabird@usa.com

I'm very interested in your work with TBI. I probably go with that engine and with TBI, so your help is very needed. Thanks.

 

Just post in the TBI Forum, preferrably starting another post for us. That's what this site is for, isn't it. I'll be glad to help, if I can, as will others.

 

OK, you're right. First, which mods are necessary to make 300hp from 350TBI engine (what have you done to your engine)? Maybe have some homepage or something, where I can find some information. I also interested in dyno sheets. How big is your engines gas mileage?

[This message has been edited by max87Camaro (edited March 27, 2001).]

 

let me finish this configuration/PROM como and see if I am at 300hp with the 1-11/16" TBI unit. I will make a tech article if I am. Won't be done 'til md April unless someone can help me get the Craig moates software working for 7747 data acqusition...

 

Ok, I did this swap a while ago, and wrote a letter to chevy hi-po about what changes had to be done. Physically you don't have to do any mechanical swaps to the engine or the equipment mounted to it but you do have to change:
1. you have to switch to truck injectors (i think that they are #65 injectors)

2.have to change the knock sensor

3.have to change the Knock module (ESC module)

Thats all that they told me about it. It will be a good idea to get a custom chip made, but it shouldn't be totally necessary. You can also order a chip from GM with something that is close, but its hard with the engine rebuilt and bored out.

The reason I kept my TBI is because of the emissions restrictions in MA. Also, you have to go through a lot more work to switch over to carb and its a lot more expensive. Although I may try to switch over this summer....

lata,
Mike

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1989 RS.. Newly installed 350,bored out 30 over, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, rapidfire plugs, chevy caprice 350 chip, 200* fan switch.

 

Fastbroker,

Where did you get your prom tuning/programming stuff at? And where can I get the stuff cheap? I need to make a custom chip especially with some of the mods I'm planning for the summer

Thanks,
Mike

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1989 RS.. Newly installed 350,bored out 30 over, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, rapidfire plugs, chevy caprice 350 chip, 200* fan switch.

 

I bought a SnapOn diag tool a while back and have a buddy of mine at a LARGE preformance aftermarket company burn/erase/help me with the rest.

No cheap way around it, I guess.

 

I have an '88 silverado with a tbi 350. When it was stock, it had 210hp @ 300ft/lbs of torque. My current 350 should have a little more than 300hp. The most restictive things on that engine are the heads and cam. The heads would be the worst of the two.