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TBI 383 questions

dyeager535 gives me a lot of credit but all his advice is sound! :waytogo:
He's a better engine builder then me too! I just tune them when done! Can't tune out something that motor was not built correctly for...

Cop Car injectors are rare and when found expensive.

But you do need more fuel, so take your pick?
1. Adjustable regulator, you already need a pump so that is not a added cost. Get one for 1990 TPI motor or 96-97 Vortec motor, if you use a CK5 gas tank it will bolt in place. Even a good stock TBI pump will usually get the 15 PSI your going to need, but why buy it for same cost of others?

2. BB 74 lb/hr injectors at stock pressure. You won't need the 80 lb/hr BB injectors. I can tune down but can't tune up when the fuel is not there.

3. Cop Car injectors if found at reasonable price.. stock pressure.

If injectors are used then have them cleaned/serviced, if there's no one near you then look for Mr Injector. He does all mine. Service is cheap and replaces all screens and O rings, I've seen injector flow change from 2 to 11 % with service. He sends all gaskets and O rings needed to replace them in TBI unit, add on a new spring and regulator diaphram while doing this as he has them in stock. Just money well spent.
 
I would not consider the BBC injector. Everyone I have talked too says hard to tune. Do the Diy porting and turn up the pressure then forget it. I had a stock 350 TBI that rock with a little timing, ported TBI and police car injectors. The 383 will be for a budget build.
 
80' 427 said:
I would not consider the BBC injector. Everyone I have talked too says hard to tune. Do the Diy porting and turn up the pressure then forget it. I had a stock 350 TBI that rock with a little timing, ported TBI and police car injectors. The 383 will be for a budget build.
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The only thing that made my BBC injectors hard to tune was the poor advice I got from TBICHIPS about fuel pressure. Once I got the fuel pressure set the tune was pretty easy.
 
Pretty sure the heads will limit it more than the tbi
 
80' 427 said:
I would not consider the BBC injector. Everyone I have talked too says hard to tune.
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You've never talked to me about it? :dunno:

I use them all the time on built 350-383 engines, either 74 or 80 lb/hr. Pressures are lower and way easier to tune then trying to get same amount of fuel out of a 61 lb/hr 5.7L injector. As pressure rises it's harder for the injector to open and close! Opening is easy tune adjustment "Injector Bias" But there's no parameter for the close

Seen lots of issues when guys get BB injectors from 95 trucks that run twice the fuel pressure on half the injector... these are like 4.3L injector flow with lots of pressure. But injector dynamics are different and meant for that high pressure.

He's in a strange place where he could do either, raise pressure or BB injectors.

I've never had issues with tuning pressure up to about 18 PSI, then it get's a little harder.

There are ways to tune down fueling if the injector flows enough. Can't tune in more fuel then what it is capable of putting out.

Fuel pressure and injector size is not a guess. It is calculated for HP of engine. 1991 K5 engine was 210HP@4000RPM and just barely has enough injector flow at 12 psi.
 
n4xplay said:
so for a shopping list,I need :
- 454 TBI base
-should I go with the 65Lb, cop injectors
-adjustable fuel pressure set up

Mark once I get it installed I will be in touch for the tune

thank you all again

(62 fat guy I'm not being a smartass...you are the first person I ever heard of who felt that way about those heads...)
im not knocking what you posted as i have read it and i dident take you as a smart A$$ but i dont blindly follow with out doing my homework yes its up on a web page but there is no stated reasoning to why the heads are junk , my view is there is always tradoffs its like talking to some one about there AT tires, your told ya there great in the snow but suck in mud.../ the head doesnt flow and makes crap HP ... wheres the traid off... my point is everything is good at somthing or was good at somthing and untill you run the AT tires and find out for yourself what there limits are its just passed on information and can be jaded or biased :popcorn: wich is still good but you get my point.
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all good :waytogo:

I'm going to subscribe, I am really interested in making the TBI heads work. I have a used set in the garage, I'm willing to "experiment" on them. I planned on using them to practice porting.
 
just finished watching this guys videos...this is his work on the TBI heads...:eek1:

says he built them for TORQUE when you see what they look like stock you'll see why everyone says they suck

[YOUTUBE]G654y5nj-H4[/YOUTUBE]
 
So if you have an extra couple hundred hours they become great.
 
for a first timer maybe...:haha:

I'd love to have a talent like that, he does purty work...I shot him an e-mail about the price on something like that...

most likely it'll be cheaper to buy Vortecs...:rolleyes:
 
The piston rings are clearanced and the pistions are in there respective cylinders, the cam is in, but working cam walk clearance and saving for head rebuild 4 month old child and Xmas presents from the wife slowed things down. It's still in the works just an extra slow build,juggling finances, family time and work schedule. My friend did however get some 3/4 ton axles the only catch is they are 3.42 geared with some chips on the spiders. My wife however decided,to purchase the better half of a 60 gallon compressor for my Xmas present, but my garage is not wired for 220, so I had to drop a power plug from the breaker box and plumb the reg and air lines in, good stuff and will help in the long run but not helping funds avalibility for heads and other movement on the engine or fuel system
 
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I have a 383 I built for my 89 TBI Jimmy. I built it totally stock with minor work like gasket matching the heads and manifold. I run the stock TBI and everything. I have never had a problem with it. The added cubes gives me the grunt I need and my cam (the most mild cam I could find) gives me 18mpg with 35's and a dana60/14bff combo. Like I said, everything else is stock on the motor.
Someday I will add flow matched injectors, 350 injectors not the 7.4's. The 7.4's are a waste of money in my opinion. But I will also add an externally regulated fuel pressure pump and gauge as well as port and polish my TBI. After that maybe vortec heads and intake.
But for now, 85k miles, it has been completely stock with a 383 and it works great.
 
I am running stock heads on my 89 TBI with a 383 I built. I am getting 9.5 compression and run 87 regularly through it. I don't have any problems with detonation in it.
 
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