TBI Crate Motor Recommendations

[dyeager535]

Any engine changes really will benefit most from a chip burn.

Will it work without a new chip burned to the current engines liking? Most likely yes. Will it have issues? Most likely yes.

Anything old like this without a wideband O2 sensor, has no way of adjusting the fueling under heavy throttle and when the system is open loop, like cold or at idle.

Best case, you do a swap, don't burn a chip, and you aren't making the power you should be. Worst case is that you don't burn the chip and the fueling and timing is off so far you melt pistons from running lean under heavy load. From a "small" change like headers, probably not going to get to the worst case scenario. But headers and cam? That's going to be pushing it. And IMO if you are doing modifications to make power, and leaving that power on the table because a chip burn wasn't done, seems counter-productive.

Increasing fuel pressure can sometimes help in these cases, but isn't the "right" way to do it.

 

[sweetk30]

Years ago i had a reman 350 with a small rv cam and the TBI did not like it .

 

[6872xtc]

I bought a '72 K5 that was running a Howell chip in the TBI on the original '72 350 that had been built with an Edelbrock cam. I worked very well.

I don't remember if @mrk5 bought an engine from ATK or who it was. He is in the middle of getting warranty work done on it now.

 

[dj31499]

I bought a '72 K5 that was running a Howell chip in the TBI on the original '72 350 that had been built with an Edelbrock cam. I worked very well.

I don't remember if @mrk5 bought an engine from ATK or who it was. He is in the middle of getting warranty work done on it now.

Alright that's good to hear about the Howell chip; emailed them yesterday, hope to hear back from them soon. If they can do it, I'd feel more comfortable moving forward with the L31 swap

 

[mrk5]

I bought a '72 K5 that was running a Howell chip in the TBI on the original '72 350 that had been built with an Edelbrock cam. I worked very well.

I don't remember if @mrk5 bought an engine from ATK or who it was. He is in the middle of getting warranty work done on it now.

Mine came from ATK Performance Engines which is technically a different operation from their standard ATK engines. Jury is still out on the warranty response.

 

[scouthead]

Also haven't seen any horror stories from Blue Print; just browsing their site I found this:

TBI Truck 1987-1995 - GM Small Block Compatible 350 c.i. Engine - Long Block

BluePrint Engines 350 c.i. TBI small block truck 1987 -1995 GM style crate engine - dressed longblock. Includes 30 month / 50,000 warranty & BPE Dyno Promise. Part #: BP350TBICT

blueprintengines.com

Seems like I'd be leaving some power on the table by going with it, but I'm starting to get lost in the weeds with a Vortec swap; seems like a lot of hassle without a lot of definitive answers or reputable sources in terms of tuning.

Bluepoint advertise 260 hp/342 torque, and the only thing different seems to be the cam; can you get those numbers just from a cam swap? If so, I might just run with it. Let me know what you think.
Again, thanks for all your input I really appreciate it.

I wonder if that crate motor is just a vortec long block with TBI heads bolted on?????


hmmmmmmmmm... the motor i built was/is .060 over @ 9.1 to one static compression, roller cam from a 4.3 lt1 (out of a b-body) with slightly higher ratio/ geometry rocker arms than factory (and they are roller tipped but no big deal there)... my cam specs should be VERY similar to a stock vortec 5.7 cam now.. maybe a lil bit higher total lift

i worked the heads a bit and knocked out some of the swirl bump in the heads...
bored throttle body.

noticeable power increase. not ridiculous, but very noticeable, and ran well without needing a tune- never failed to pass emissions testing over many years of abuse

 

[1-ton]

On my GM Goodwrench TBI 350 crate engine I installed a small RV cam, but it is a single pattern cam (adv. 262/262 duration and adv .476/.476 lift with .111 degree lobe separation) that limits vacuum fluctuation, which could drive the MAP sensor crazy on an OBDI/ECM. I also have a modified stock TBI that was bored out 1/8", which increases the CFM from 580 to 620 CFM. My TBI also has an adjustable fuel pressure regulator that is adjusted from the stock 9.5-PSI to 12- PSI. My saddle tanks also have fuel pumps from a Corvette or SS Camaro TPI engine, which are capable of 60-PSI max, instead of the TBI pumps that are only capable of 12-PSI max.

I am running the stock chip in my 7060 ECM/PCM which also controls 4L80E transmission. This combo runs OK, but it is not a world beater by any means. I also have TunerPro software that I have used to monitor my engines performance. I have set my BLM's by adjusting fuel pressure so my engine will not go too lean or rich in both the high and low RPM range. Adjusting my fuel pressure to 12-PSI seems to be the sweet spot.

I am running the timing a the stock 0-degrees. I have checked my ping counts with the TunerPro software, and as long as I run mid-grade gas my ping counts are well within normal range. Burning a custom tuned chip for my OBDI/PCM would be great, but I hesitate to do it because the 7060 OBDI/PCM for a 1991 V3500 Crew Cab is a very rare ECM to find anymore these days, and if something went wrong, and it was damaged I could be screwed in ever finding another one.

 

[dyeager535]

I wonder if that crate motor is just a vortec long block with TBI heads bolted on?????

I'd guess no based on the pics (if they are accurate) as the Vortecs didn't have fuel pump provisions, and that shows a blockoff. TBI blocks were hit and miss apparently.

 

[dyeager535]

noticeable power increase. not ridiculous, but very noticeable, and ran well without needing a tune- never failed to pass emissions testing over many years of abuse

The problem is, unless you are actually looking at what is going on while it's running, you don't know whether its optimized or not. Chances are it is not. Not berating, but as shown by 1-ton, enough modifications and it will start to run lean under hard use. And when that happens, whether you can hear it or not (and trust me, you won't always hear knock that the ECM sees) it retards timing. Just a couple of degrees is a noticeable loss of power under hard throttle, and the ECM will easily pull more than that if it needs to.

My L31 was exceptionally lean (and timing all wrong) compared to the L98 the ECM/PROM came from. It would run, but it makes a ton more power now that I have increased fuel where needed and changed timing to where it stays out of knock territory, on 87 Octane. After having witnessed this on a 454 with a "mild cam" and intake swap, and my own rig, until I've seen what the ECM sees, I don't trust that its running as well as it may feel like it is.

 

[scouthead]

fair enough- but on the other hand... after trying a few chips and finding out what a major pain it was going to be to invest the time in tuning (at least doing it to maximize performance AND keep it CA emissions compliant) i decided to run the truck and drive it. I was offered a chip burning machine and all the cabling, software, and about 100 free chips... but the guy told me he would be calling me when he needed chips burnt in the future. nahhhhhhhhhhh. I did log a lot of data in the early days of that engine, and found it very difficult to drive a stick and give any attention to a lap top at the same time! was rare I had a passenger who was willing to be the driver.

I got 65,000 miles of hard use out of it. spark plugs always looked ok, and i passed CA emissions on the dyno 3-4 times without any issues - I have all the reports in my file cabinet and the pollutant PPM did not change much over the years. about 1/2 of the first 30,000 was commuting- then all off-road abuse (with some commuting to and from the trails) somewhere in that first 30,000, I once drove a whole tank out of it on the freeway (optimal conditions) and got 14MPG -verified, on 35 inch tires without overdrive (manual trans though -SM465 and 3.73 gears)

that engine suffered a piston ring failure during a catastrophic event... is now on the stand torn down and everything inside looks new - except the cylinder wall where the rings broke- I drove the truck gently a few times to move it- put 300-400 miles on it before the engine got pulled. in that time, the blow by kept the oil off the cyl wall, and MOST of the cross hatching has been wiped away. no ridge at the top, and no scratches or cracks that I can see, but that bore is a lot shinier than the other 7, and the fragments of the rings show some "smearing" where the material was moving against the wall

anyway- there was a lot of time spent over on third gen.org when i built that motor, and i spoke to Brian @ tbi chips several times... after sending him a bunch of data, I moved some rare 68# injectors and a few other pieces from a cop car onto my motor, and he felt one of his chips he already had on the shelf was a good fit... changed the thermostat down about 30 degrees... and installed the chip. it ran like a RAPED APE- I mean like a completely different animal under the hood. impressive power gain, but it ran hot, and any sustained high rpm would get the coolant moving out of the radiator. I remember giving it hell on the freeway one time and the speedo wrapped around to where the numbers stopped... and my laptop was plugged in giving real time data... and I saw the digital speedo hit 110MPH, and it was still pulling really well- I remember thinking, "i don't know how high the lift is, I have no sway bars, the steering is twitchy... what are my tires rated for? -what happens if i have to hit the brakes? -this is the WRONG VEHICLE TO BE DOING THIS IN." Anyway, it would have needed a lot of tuning and many chips burned to get that dialed in, and not sure about passing CA emissions set up like that. I ended up going back to the stock 195 thermostat, chip and injectors.

talked to a few people @ comp cams and edlebrock also... and even though my machinist was a ford guy, he had a wealth of info and helped a lot. I was advised that cam selection could go very very wrong with a stock tbi management, and changing the valve size or freeing up the exhaust system too much could cause issues... and multiple big changes @ the same time seemed to be a guaranteed TBI headache. Comp Cams had a Torquer cam that was designed for the TBI and supposed to have some real seat of the pants feel to it... but was not roller lifter compatible, and I was hellbent on using them.

anyway- most of what I did was turd polishing... had a lot of elbow grease and time invested sourcing parts, but I traded some sign work for the machine work, and had less than 1500 bucks in the whole motor. Anyway, those days are gone, and I polished that turd as much as I could. it definitely could have performed better with a custom tune.

would have been fun to get the truck on a dyno with the stock chip and injectors just to see what the numbers actually ended up @

what was the stock LO5 rated @?

200-220HP and 300 torque?

 

[scouthead]

oh yeah- fuel pressure had to go up a couple pounds at some point during all the turd polishing and data logging. think the last time i checked it was running just a tad over 13


(thats with the stock #55 injectors back in there... and keep in mind @ 0.60 over on 8 cylinders, my 5.7 actually came out @ something closer to 5.9 liters- slightly different fuel appetite from the stock motor- looking back I'm amazed the thing ran so well given all the little changes)

 

[Joel Wilson]

Jasper Engines are not much better. BluePrint Engines seem to have a pretty decent history.

Just be careful about where those engines make their power. It might make 450hp from that 383, but at over 5 grand on the tach and that may or may not be what you want. Do your research to make sure you get what you want.

 

[1-ton]

oh yeah- fuel pressure had to go up a couple pounds at some point during all the turd polishing and data logging. think the last time i checked it was running just a tad over 13

I had my truck at 13-PSI, and the data logging showed my engine was running too rich under 2600 to 2700 RPM, but perfect above 2600 to 2700 RPM. When my truck was at 11-PSI it was the opposite...lean over 2600 to 2700 RPM, but perfect under that. I set my pressure to 12-PSI and the data logging showed it to be as good as it was going to get at both lower and higher RPM's.

 

[scouthead]

Stand alone wide band O2 kits have become very affordable since my days with my laptop running off the obd1 port... I have one now in the box waiting to be used on something. I have a buddy that bought the same one- made a quick weekend project out of rejetting his manx.

it could be a really useful tool if you need to start adjusting TBI injector pulse counts and widths after adjusting fuel pressure or changing the size of the injectors?

 

[dyeager535]

Yes, the old school tuning of OBD1 is definitely tedious. It's better now than long ago I'm sure, when I deal with it I just save the data log and export to excel so I can look at everything later, without trying to drive at the same time. Dialing it in takes a lot of time, and even after years (caveat: infrequent) mine still isn't what I'd consider perfect. Would be a lot easier sitting in the passenger seat doing it real time, but oh well. Like you, I don't have someone to drive for me most of the time. IMO the LS has pretty much killed the rationale for modifying gen 1 OBD stuff. Just swap an LS into it, as the support is there. Support for OBD1 is all but gone.

These injection systems burn clean if running even close to properly, and I've heard of them being retrofitted to older vehicles and passing the smog tests without a converter. Obviously in places that don't visual the converter.

 

[Chickntrk]

I'd guess no based on the pics (if they are accurate) as the Vortecs didn't have fuel pump provisions, and that shows a blockoff. TBI blocks were hit and miss apparently.

I have a 99 vortec engine and it had the fuel pump provision, I pulled it out of the Tahoe it came in from the factory too

 

[Big Ray]

I have a 2005 l31 sitting in the garage. No fuel pump provision.

Suppose to replace the tbi unit in my exs truck. Her motor was an 89, setup for roller cam but equipped with a dinky flat tappet unit.

My l31 is the old $1500 2 bolt main half ton engine. I believe GM dropped them. They sell the high $$ 4 bolt main engine now.

As for induction, I bought the Edelbrock 3505 Performer multi port conversion system. They never worked right with a tbi computer. Fwiw. I never installed mine, it's in the garage with the engine.

A lot has changed since then.

You can buy a motor in your desired power band ready to go. And as for controllers, the sky is the limit.

My new plan is working with Fockenheath to recam my l31, install the edelbrock kit with an after market controller.

Stick that in my daily driver 79 K5. Take the 400 from the K5, warm it up with the Proflo 1 I
bought and repower one of my burbs.

I think there's too many choices these days, which is a wonderful problem to have!

 

[TJ1978]

Blue print or west coast engines...

 

[dj31499]

I think there's too many choices these days, which is a wonderful problem to have!

Big Ray's a glass half full kind of guy, I respect it! You make a good point, there is a lot out there, think I've just gotten overwhelmed trying to rush this build together and haven't really taken the time to understand what's actually involved in making it work.

I sent Howell another email asking about this:

#HTBI670 – TBI UNIT: 670 CFM Holley 2-bbl with 80lb/hr Injector

Part # HTBI670 Holley 670 CFM adapted for use with Howell or GM wiring harness and ECM. Uses special Howell calibration PROM. Includes idle speed control by ECM. Suitable for high-RPM small block a…

howellefi.com

Similar to the TBI I had posted earlier for SPR, but it either comes with a prom or you can get one from them matched to the TBI. Worth a shot, we'll see if they decide to answer.

 

[scouthead]

so its the small block TB unit, with the big block injectors... and comes with a new chip for the ecm... could be cool, but if you expect it to bolt on and go, your motor better be set up with the same heads, intake, and cam as what they programmed it for.

edit-also ask them what fuel pressure it was calibrated at