I recently instaled a GM Performance 350 base HO in my 89 'bird in place of the LO3. I've tried the stock TBI and Holley 670 cfm TBI, but niether seems quite right. The stock 305 TBI, even with increased fuel preasure, seems a tad too small and with the Holley I get low RPM bog. Can I get a custom chip? After 400 miles I've thrown no codes and like the exrta ?150+? horsepower.[list=1][*]GM 350 HO w/ Vortec heads[*]Heddman heders and Ypipe (no cat)[*]TCI torque converter w/ 2000 stall speed[*]ThermoMaster chip, Accel 300+ ignition[*]Minnus all A.I.R. and smog[/list=1]:hail:

 

are you running 350 injectors in the stock TBI? youll definetly need that and definetly a chip. Id say try the holley 670 and a custom chip.

 

I'm using a Turbo City ported throttle body, 350 truck injectors,
a Crane Compucam 2030 (hydraulic roller) and a custom chip from Ed Wright at Fastchip.com with my TBI 350.
It's a good combination. It's no firebreather, but it's putting out over 300 HP at the flywheel and it passes smog in CA as a 305.
The throttle body seems like it's sized right for the motor and I'm at about 18PSI fuel pressure. Motor pulls strong to over 5000 RPM and this is with the smaller (1-5/8") SLP headers and somewhat restrictive Edelbrock Performer TBI intake.
Are you using the GM Vortec TBI intake, or a 4-bbl intake with adapter?
-Rich-

 

I'm using the GM Vortec intake (I don't like it as much as the Edelbrock Performer). With the Holley 670 it runs a little erratic, especialy down low under 1500 RPM, but up top it's great! Just sucks too much fuel (8 MPG). I increased the fuel presure with the stock TBI (a constant 11 PSI) but at idle their is a waver and occasional stumble. I had to turn up the manual idle screw. So, where can I get a custom PROM to run the Holley? Also, I used to have neck-breaking gear changes with the kick-down adjusted and now it wont hold first gear no matter what I adjust the kickdown to.

 

I'm sure Ed Wright can burn a chip for you, but if you have the extra time, use the money you would spend on the chip and buy your own chip burning equipment, and learn to do it yourself, because even as good as the Ed Wright chip may be, there is almost no way it can be perfect on the first try.
Also, 11psi sounds a little low assuming your using the stock 305 injectors. The L03 came stock 9-12psi fuel pressure.

 

GM Vortec TBI intake??

 

I'm an old fart too I guess! Hey where can I get anaftermarket throttle body ***'y something chrome or anodized? I just spent 3G's rebuilding a 350 for my 89 convertible and I don't think stock fuel delivery is gonna cut it.

 

Here's the thing, is your 670 TBI for the 350 or the 305? The injectors are different on the two as well as the settings. Low rpm bog may be too much or too little fuel. I'd say do a quick tuneup, adjust timing, fuel pressure, ensure wires, plugs, cap and ignition system up to the task of handling increased fuel. Remember, if a 305 stock needs 12 psi, a 350 will definitly need a good amount more espcially if flow rates are increased via vortech heads and intake manifold. Then finally if nothing is solved ensure chip isn't holding you back. A 305 chip will definitly not hold well to a 350 upgrade of that magnitude.

 

YUP

Right here......



http://www.sdpc2000.com/cart.asp?act...d=738&pid=8154

AJ

 

Now the $5 question: Has anyone run headers w/ the external EGR of this GM Vortec TBI intake??? I wouldn't want to run L31 manifolds after all that work.

 

Since you guys are on this subject...I am also planing on a 350 and I think I am going to go with the ported TBI. My question is...with this setup and the right chip will I be able to get the full 330 hp out of the 350 vortec crate motor???

 

That's what it's all about.
The GM 350 HO is a powerhouse; in fact driving the commute is less fun with so much extra power (over my old LO3). The traffic justs kreeps at 85 MPH.

I'm looking at Ed Wright's Custom Chip order and see that there are way too many variables to consider. At $350 bucks a pop I only want to do this once. Also, I run the same 11 PSI with the Holley TBI and the stock TBI. What gives?

I figure 500 miles is enough to break my new motor in, any thoughts on that?
(First 500 miles: No WOT; Vary RPM; No long periods of idle; Generaly take it easy and keep it arround 2000 RPM.)

 

Here's a good way to break it in.. go to some place 500 miles far away, make a day of it. Or make it a 250 mile away and the return trip 250 miles so there's your oil change at the end of it. Also 500 miles seems good for a break in period, justt keep the good things in mind.. no wot, long idle easy rpm 2-2.5k rpm is good...

 

id make sure it was in tune and running perfect before i took a 500 mile trip with a brand new motor i didnt know yet.

 

DONT take a 500 mile trip with it! Engines to not break in properly with highway miles. Youll want to use the car for around 500 miles of bs trips around town to the grocery store, bank, etc. Let the engine see varying loads and rpm speeds so it breaks in properly. Basically drive it normally. Uneven wear will result from steady state operation.

 

Now can I flog it?

OK, I've got 500 miles of varied RPM use on my new motor. After an oil change can I get on it or should I gradualy increase to full-blown launches? Is there a guide line after the first 500 miles?

 

i suppose since its technically "broken in" you could. But beating on a motor is never good for it. A little spirited driving wont hurt, though

 

I thought I'd give you guys a visual on my project, heres the old engine.

 

Heres the new one ready for the umpteen sensors and wires and stuff. I also have to put the headers on still.

 

You can't expect Ed Wright to be able to tune your car via the Internet. It's like dialing in a carb. Look into getting a cheap laptop and cable to use as a scantool, and then you can get into the PROM burning stuff.

 

Check this set up out.

91rsramair.tripos.com

 

I did the same 305 to 350 swap. You definately need the bigger injectors from the 350, along with the knock sensor and module, and a new chip (advice from Rich92RS....and I took it, and glad I did). While I cant argue with the idea of burning your own, I have no experience there, and had Ed Wright burn one for me. From the few miles I put on it driving from the shop down to get painted, the motor feels good. I ran Dyno2000 on the combo..now I wouldnt swear to its accuracy, but it shows 300HP/350ftLbs at the flywheel, which is right about what I was hoping. Certainly 5 miles is hardly a fair evaluation, but so far, so good! I'm going nuts here though....we started this in April, and the first coat of red only went on yesterday. At this rate, I'll get the convertible back just in time for winter storage Good luck with the swap!

 

Sounds like you're saying that the 305 and 350 use different knock sensors. Please clarify. With 700 miles on my new motor all is good.

 

They do use different ones. Different sensors and ESC Modules.
They're Tuned to different frequencies.
-Rich-

 

OK, no problem on getting the 350 knock sensor... but what's an ESC module and where is it located?

When I think of electronic spark control I think of late '70's Chryslers with "computers" mounted on the air cleaner. Anyone else get my drift?

 

i just replaced my sensor, which detects the knock, with a borg-warner one. I never replaced the electronic spark control module, which sends a signal to teh ecm when spark knock is detected. The ecm in turn retards the timing untill knock is gone. So far all seems well with jsut a new sensor.

 

It's a little flat plastic box, with a four-pin connector, mounted on the bracket that holds the fan and fuel pump relays, between the master cylinder and fender, on the driver's side of the firewall.
They are designed to be used as a matched set. The part#'s are different for 305/ 350.
350 sensor: AC/Delco # 10456288
350 module: AC/Delco # 16128261
-Rich-

 

thanx, rich. Ill guess i probably should get another module. BTW, what does one of those modules run $ wise?

(Lol... 666th post)

 

I got the knock sensor and module($95 @ dealer) no problem. I see the sensor goes into the water jacket in the block, but what is the sensor above it on the head? They both have the same squeez connectors. I confused the two connectors when I did the swap and I think the knock sensor has a white(natural) wire.

 

That would be the fan switch?
-Rich-