Fast355

iTrader: (2)

This post is for the guys that are looking to build a BUDGET oriented TBI 350 to go into their 305 powered Camaro or Firebird or whatever it is. Properly setup, with proper gearing, chassis prep, driving, and rubber, I see no reason low 13s and even high 12s are not possible in a full weight car. Another KEY factor is placed on driveability, emissions, and fuel economy. Some of this is pretty basic, other parts tend to get plenty complicated. I am not trying to teach you how to build an engine, but rather build one that is affordable and can be operated on a TBI setup. The end goal is 340 FWHP and 25 MPG highway at sane speeds. I am not covering the actual prom tuning that it would take to run it because we have a DIY-prom board for that. I may cover it at a later date. I am going to divide this into several basic sections.

1. Long Block Parts Selection
2. Other engine parts and selection
3. Fuel Delivery

A.) Part selection

Since this is to be a budget build, I am centering the build around a 1996-2002 L31 350 Vortec engine. They seem to be extremely plentiful around here and can be bought in complete long-block form without accessories, intake, and exhaust manifolds, for $500.00 at most yards. The basic budget will need to include a Vortec specific intake manifold as well. Selection here is key. Look hard for a 1997 up L31 in a truck above 8,600 lbs GVW but NOT natural gas or propane, the 1997 up without gaseous fuels will ensure the normal Vortec head and not the hardened exhaust seat model. The 8,600 lbs gross vehicle weight (GVW) will give you 4 bolt mains as standard equipment. Fortunately in the Vortec years the compression ratio remained the same (9.4:1) between HD and LD trucks, unlike the TBI years. There are also multiple other reasons for the Vortec block use.

1. More advanced metallurgy for stronger, longer lasting bores
2. Powdered Metal rods that are stronger than the old GM PINK rods
3. Nodular Iron crank that is almost as tough as the old forged one
4. Factory Roller cam equipped (not always the case with a TBI truck engine)
5. You get the great flowing Vortec heads with their Fast Burn chambers

You might end up having to buy a fully dressed engine in order to get it, just depends on the yard. Don’t fret over it too much though, as many of the components command stiff prices if sold on Ebay or the like. The intake manifold with its poppet injectors is typically worth better than $100.00. Exhaust manifolds $50.00. Serpentine belt setups go for $100-200 in most cases.


Out with the old


Make sure that you get a written guaranty that the engine is re-buildable and the major components are guarantied to be useable. If you can find one out of a wrecked, running truck, that would be even better.


For the first time Small Block builder, once you get it back home, this is the step where you buy the book “How to Rebuild the SMALL-BLOCK CHEVROLET” ISBN 1-884089-95-X (Autozone carries in with their Haynes manuals) and read it cover to cover. It is a great book covering Small Block basics from tear-down through installation.

Now it is time to take care of the Vortec engines Achilles heels. They are easily fixed with some careful parts selection though.

1. Tiny factory cam ( Hyd Roller with 191/196 @ .050, .418/.430 lift, 111* LSA)
2. Heads that will not accept more than .450” lift without modification
3. Factory composite plastic timing cover with crank sensor provision
   
   
   
4. Factory timing chain setup for crank sensor

The fix is relatively simple though.

1. Production GM LT4 cam (P# 12551142, $182.58 gmpartsdirect.com)2551142
   Duration @ .006 - 282/277
   Duration @ .050 - 203/210
   Lift w/1.5 rocker -.446/.449
   LSA 115*
   
   
   
2. GM makes a spring and retainer combo for their LT4 engine that allows up to 0.490” lift out of otherwise stock Vortec heads.
3. GM makes a plastic timing cover without the sensor hole for Mercury Marine
4. Cloyes markets a double roller timing chain for factory roller cam equipped small blocks.

Fast355

iTrader: (2)

B.) Other components

1. [*]

2.) Exhaling- You might often hear me say to replace the exhaust on a L03 car from the heads back. That is not a joke, it is that bad out of the factory.

1. Headers- Any car that originally had a L03 should have its cast iron exhaust manifolds used for boat anchors. They are super restrictive and have a tiny opening to them. A logical upgrade is a set of headers. AVOID anything that is marked as a direct replacement for the LG4/L03 as they will be forced to breathe through the stock Y-pipe. The good headers were designed for the L98 TPI engine. (Hooker 2460s work great)
   
   
   
2. Y-Pipe- As if the exhaust manifolds were not poorly flowing enough, the engineers at GM had to give the L03 a dinky little Y-pipe that is a restriction on the stock 170 FWHP 305 (the proof is trucks make a full 10 HP/20 ft/lbs more)
   
3. Catalytic Converter- Once again the little 2 ¼” catalytic converter is too small for decent performance on a stock L03, much less a 340 FWHP 350. A dual cat setup would be a great upgrade for this, but they are getting very hard to find.
   
4. Cat-Back-Make sure that you go with a good muffler, that will support the needed flow, without causing excess back pressure on the system.
   
5. The ideal setup will be 1 5/8 x 2 ½-3” mid-length headers, 2 ½” pre-y pipes, Dual 2 ½” cats, Flowmaster 2 ½” to 3.5” Y, 3.5” single inlet muffler out a single 3.5” pipe. That is not always possible. 3” is more commonly available, cheaper, and works fairly well when substituted. Be warned however, the cross-flow muffler is not known to be a good flowing muffler style. It often restricts HP.

3.) Drivetrain- You will need to make sure that your drivetrain is up to the power increase.

1. 700r4- At the very least a Corvette Servo, Transgo Shift Correction kit, properly setup and adjusted TV cable, fresh fluid and filter (I like Royal Purple ATF). It would be a great time to install the GM 5,000 rpm governor (P#24202117, $26.21 gmpartsdirect.com). A converter for a 1995 CPI L35 4.3 S10 will stall around 2,600 rpm behind a 350 and is available from GM still. A Corvette TV sleeve and plunger will give WOT 3-4 shifts.
   
   
   
2. T-5-A strong clutch is a must. Power shifts must be avoided for the unit to last. Make sure it has fresh fluid in it before abusing it. A T-56 swap along with 3.73s with an Eaton differential would really wake up a T-5/3.08 open combo.
3. 7.5” 10-bolt- there are a lot of parts made for this unit to strengthen it. But at some point it is going to blow. Strange has some really nice 8.5” 10-bolts and 12 bolts to put into its place. Royal purple comes to mind both here and in a T-5.

C.)Proper fueling

Fuel Injector requirement- To mathematically calculate the injector size you will need to have to make your HP is pretty simple. Lets say our engine is capable of 340 FWHP. How much fuel will it need? Simple. Take 340 HP divide it by .85(Max Safe Injector Duty Cycle for TBI), then divide by 4 (easier than saying number of injectors and BSFC). On a TBI engine with two injectors it will always be 4 (.50 lb/hr/HP and 2 injectors) That gives you 100 lbs/hr per injector. Oops, GM only ever made a 90 lb/hr injector in the US, and I have 2 68# injectors, what do we do. Well we take the stock GM fuel pressure of 12 PSI and raise it. How much though. Well this simple equation will help a lot. New flow rate = Old flow rate x SQRT (New Pressure/Old pressure) Lets switch this equation around. We know the old flow rate and the old pressure and the necessary flow rate. Just solve for the new pressure.

100= (Injector size(68)) x SQRT (X/12)
100=SQRT(X/12)x 68
100/68=SQRT(X/12)
1.471=SQRT(X/12)
1.471 squared=(X/12)
2.163=(X/12)
2.163 x 12 = X
X=25.956 PSI

The closest production regulator to this is the GM 30 PSI unit used on the later 454 trucks/vans/suburbans. It is GM P# 17113079, $64.74 gmpartsdirect.com. Using the 30 psi regulator will give you 108 lbs/hr using 68 lb/hr injectors.



You might wonder why you need more than 100 lbs/hr. It has to do with a little routine called Acceleration Enrichment (AE). Lets say you are accelerating at 3,500 and 1/2 throttle. Suddenly a Honda comes along begging to be destroyed. You mash the gas, the manifold goes dry because you just sucked the fuel out of it. The engine bogs and backfires. One kill for the Honda. Lets just say not having enough fuel to cover AE is not fun.

This is a chart of approximate flow and what 30 PSI will do to it.

Engine---12 PSI----30 PSI
2.8/3.1-----33---------52
4.3---------45---------71
5.0---------55---------87
5.7---------61---------96
5.7HF------65---------103
5.7HF------68---------108
5.7 96 Van 72--------114

Just to give you an idea 10 lbs/hr is roughly 20 HP per each injector. For each 10 lb/hr for the pair is 40 HP more potential.

Keep in mind the factory pump is overwhelmed in most cases by a mild 305. I would definitely upgrade to at the minimum a factory replacement TPI pump, with a Walbro 190 being good and a Walbro 255 being better.

Here is the finished product. Stole it from CHPs Mission 305.

ShiftyCapone

iTrader: (7)

Excellent thread Fast. We just need you to swap one of these combo's into a 3rd gen! Is that in your future by chance, hint hint, ??

Fast355

iTrader: (2)

I am thinking BM needs to build one for his Monte Carlo SS. He is without an engine in it right now.

Possibly in my future, although not right now.

PS-the tuning side is coming later on tonight or in the morning.

dimented24x7

iTrader: (2)

I essentially have this combo in my car. The performer flat tappet that I have is very close to the LT4 cam, except it has slightly less lift, a touch more duration @ .05 and .006 and a tighter LSA. While it wont run 11's or anything like that, its definatly a fun setup for the street, works very well with the factory 2.73 gearing and stock stall, and still gets good fuel economy.

Fast355

iTrader: (2)

Part two of the TBI 350 Vortec build. Now that it is built and installed, it is time to tune the beast. You have several choices on how to control it.

A.)The stock PCM is the hardest to work with. It is however already in the car. All of the TBI F-cars short of the 1988 models, used the “8746” running the $61 code. It still has the slow 160 baud rate, that gives updates every 1.2 seconds. A good quarter mile pass only gives 8-10 updates of data. Very slow datalogging makes for a time consuming tuning process. The 8746 also lags in processor speed and resolution. The VE tables for instance are very basic and rely on an RPM adder for high RPM operation. The spark tables are the same way. The code lacks many features to adequately run a high performance engine and powertrain.

By far the most common datalogger is WinALDL, although I am working on definition files for the new ScannerPro software. ScannerPro is something new from the creator of TunerProRT (Can log data from the stock ECM)

WinALDL


ScannerPro


B.)The EBL is a special board that is fitted into a stock ECM. What this provides is dramatically faster data output, faster even than the 8192 baud rate PCMs. The end result is much more data, at much a much higher frequency. The EBL board typically sends out 17 updates of data per second. A good quarter mile pass will give over 200 updates now. That is what we call a lot more data. This data includes much more information than the stock ALDL output could ever give. The second benefit is a performance based code, that is tailored to everything from a stock engine to a forced induction, nitrous snorting monster. It will work well on anything from a stock LB4 4.3 TBI V6 through a 572 cubic inch 4 bbl TBI or MPFI monster. RBob really did a fine job on this product.

DynamicEFI

RBob’s EBL comes with its own Datalogging software, which also offers VE self correction based on either Wideband readings or BLM output.


I don't know if RBob and Jon still include the original stuff with it, but I actually like how I can change the readings on the various gauges (for example 0-85 speedo instead of the fixed 120). I wish he would work on this a little more and re-release it.



C.) The P4 PCM came in all of the 1993-1995 GM TBI trucks with automatic transmissions. It is a much faster running PCM than the stock 8746 PCM and offers an 8192 ALDL baud rate. It offers many of the features provided by the EBL, gives electronic transmission control capability, but does not have provisions to read positive manifold pressure, nitrous control, etc. The P4 ECM is a great step up for people who cannot afford the EBL, or would like to upgrade to a 4L60E transmission. I love my 4L60E transmission, it is just so darn easy to change shift-points, shift feel, clutch holding power, etc. This route requires repining the wiring harness to the newer truck PCM “RED” & “BLUE” connectors. Not to difficult, but rather time consuming. Don’t forget that Dimented24/7 has a MAF setup running on the $0D code used in the TBI P4 PCM.

https://www.thirdgen.org/forums/atta...-x-over-01.gif

I know of two dataloggers for the $OD PCMs





I am working on a ScannerPro definition file for the $OD equipped PCM vehicles

Now that we have selected the appropriate ECM/PCM to do the job we move on to how to set it up to properly run your engine. I recommend that you visit the DIY prom board and do A LOT of research. Then take a stroll over at Moates.net for TBI programming options. I settled on a Moates Burn1 after converting the ECM to use Flash Chips. It’s a somewhat simple procedure involving about 1 hour of time, basic hand tools, and a soldering iron. The whole procedure is on Moates.net. If you use the EBL, the chip slot is already prepared for the flash chip. For the P4 PCM, Moates.net carries a Memcal that has the appropriate flash chip holder already on it, no soldering required.

Links : Moates.Net

Fast355

iTrader: (2)

Now that you have picked out your ECM/PCM of choice it is time to set it up. It is pretty easy to set-up a base bin that will allow your engine to start and run, IF you do your research. Keep in mind that it doesn’t have to be perfect from the start. It will improve as you go along and make the necessary changes. I prefer TunerProRT over all the other tuning programs out there. There is just so much more available out there to use with it. It is used by A LOT of us TGO guys and most common questions can be readily answered on the DIY Prom board. Once you have your burner, your ECM, you can obtain your .ECU and .BIN files. The .ECU is a set of instructions showing what each hexdecimal means in the ECM. The .BIN is a calibration based on hexdecimals. Thankfully you don’t have to calculate anything with hexdecimals or even work with them when using TunerProRT. This wasn’t the case when I first started with EFI tuning back in 1999 or so.

All of these screenshots come from the P4 truck PCM with $0D coding, but the others are very similar.

I typically start with the Base Pulse Width Constant(BPWC). The BPWC is used by the ECM to correlate injector size to cylinder volume. The higher the number the longer the injector is held open. Most stock GM TBI .BINs are in the 125-150s range. This gives them more than enough pulsewidth for a smooth idle and sufficient time to fire the injectors to about 4,500 rpm (redline on a stock TBI). However we are not stock. If you read further up about injector sizing, you will be delivering a lot more fuel than stock. I have personally used BPWCs in the 80 range with success. Your BPWC needs to match your engine size and fuel delivery. It is pretty easy to calculate out. I even happen to know a website with a calculator. Just don’t go by their injector size table. Take my numbers and convert them over to GMS/SEC from LBS/HR.

http://www.fortunecity.com/rivendell...24/gm_inj.html

(IF it doesn't come up, check back after a short period of time, it goes down alot)

In the P4 PCM, it is just injector flow and cylinder volume, NO BPWC calculations needed.




Next it is time to setup the timing table. For a mildy cammed engine I typically setup the distributor at 6* advance and set the corresponding initial timing setting in the ECM at 6*. This allows for quicker starting with a cold engine but does not put excessive drag on the starter at other times. The initial timing on the distributor and in the PROM MUST match or it will mess with the whole timing advance curve.

I then like to 0 out the PE tables, for simplicity.



I then take and setup the timing table. You have to be careful here as there are often BIASES applied to the tables. The ECM will not work with negative numbers as the hexdecimal setup will not permit it. Some OEM timing tables will actually go into negative advance at WOT and very low RPMs. To do this they apply a 9.81* (10*)bias to the timing. Then they will put 5* in the table perhaps. The end result is a spark reading of 5*-10 or -5* timing.

This timing table is not displayed with any biases (corrected for in the .ECU file) and is indicative of my Dart headed 355. It is actually an Iron Head LT1 map with slight changes due to the weight of the van.



When the timing map is complete we will work with the fuel map. Chances are the cam change has made the engine run very poorly, possibly even not run. The problem is in the fuel MAP. A stock L03/L05 idles at around 40 KPA or atleast 18 in/hg of vacuum. A cammed engine will idle at 50-70 MAP or roughly 14-16 in/hg. The loss of engine vacuum will give a rise in the MAP reading. The higher MAP reading is then sent onto the lookup table, where the ECM calculates the fuel injected off of the now incorrect cell. The ECM will be using numbers that would be indicative of a stock engine under load, while the modified engine is trying to idle. The result is much increased fuel delivery. At the same time the low-speed volumetric efficiency of the engine is killed off somewhat. This further richens the calibration. Then throw in the poor burn caused by the overly rich air/fuel mixture and things go down hill fast. The more duration, the bigger the problem, and the longer it takes to correct. Luckily the LT4 cam makes LOTS of vacuum at idle and should need only slight tweaks in idle fueling.



At this point I would set the PE/WOT Air/Fuel (A/F) ratio to around 12.5:1, this will ensure things are plenty rich, even if you make some mistakes in the VE tables.



I would change the Throttle Position (TPS) for Power Enrichment (PE spark/fuel mode) up to around 65-70% from whatever it is stock. This will allow you to see what is going on at higher loads and RPMs. I would not do this for long periods of time or hold the throttle right on the ragged edge of PE for too long though.



As you work with the calibration make gradual changes, this will allow you to see what is going on.

Some other tables of interest are the

Idles Speed vs. Coolant-this controls the idle speed the ECM will attempt to run the engine at. It will need to visited when you cam a TBI engine. The stock TBI engines are happy at 500 RPM. Most cammed engines like 650-750 rpm for idle. I have also found that 700 RPM on stockish engines helps A/C operation on the hottest days (especially with a belt driven clutch fan), engine cooling, flat-tappet camshaft lubrication, and idle smoothness. Keep in mind that there are likely multiple entries for this. Idle in Park/Neutral. Idle in Drive/Reverse. Idle adders for A/C and the like.



Transmission Torque Converter Clutch parameters, properly setup they give a huge difference in driveability to even stock engines. The stock GM TCC strategy is all about Corporate Average Fuel Economy (CAFÉ). It SUCKS compared to what you can do on your own. Shift strategies on TBI trucks with the 4L60E are just as bad. Come on 3,800 RPM WOT shifts, I don’t know what GM was thinking???



Definitely avoid the temptation to go WOT until you have the fuel and timing sorted out and are confident that everything is plenty rich to be safe. Too rich and you buy plugs and maybe an oil change. Too lean and you buy internal engine parts.

Another good thing to do at this point is adjust the minimum idle air rate screw on the front driverside of the TBI. You should set this so that you Idle Air Count (IAC on a datalog) is about 5-10 steps on a fully warmed up engine in park/neutral with the A/C off. Too much IAC opening is actually bad, as it is an ECM controlled vacuum leak.

Now for the fun part!!! If you have a chance to get a 4L60E transmission with the 305/350 Vortec engine, it works awesome when used with the $0D code. I absolutely love my 4L60E. Here is why, consistent and controllable shift points all day long. (6,100 RPM @ WOT 1-2, 2-3)

DM91RS

Chris is there any reason for choosing the LT4 cam over a similar LT1 cam?

I am also assuming that you are leaving out cams similar in price such as the ZZ4 because of the cost of machining the heads for the higher lift of the exhaust.

FreeLoader

I'm stuck here wondering why you'd change out the intake setup? or switch the pcm setup to ecm?

honestly that setup looks good to me straight from the junkyard(though admittedly I would change the cam) why would you take a less efficient tbi setup and put it on yours, and junk the better one?

if i'm reading this right, and I think I am, the pcm already compensates for the shortcomings of our ecm, the 8 injector setup not only has a much better aftermarket, but leaves us open for a higher power potential due to the higher injector capacity.

basically, if you CAN get a fully dressed engine, why would you go with an older design? i'm not arguing that the tbi isn't a "good" system, i'm basically wondering why you wouldn't go with what at least appears to be a "better" design if it essentially came free with the engine?

Fast355

iTrader: (2)

There are very limited programing options for the Vortec PCM. Everything I have seen is $$$$. The newer Vortec PCM is flash based without a chip of any type. It is OBDII with much more wiring. The vortec would also take many fuel system mods to install with the factory intake. You would have to install 4 oxygen sensors, 2 before the cats, 2 after, then install many other solenoids, sensors, and relays.

Actually the Vortecs poppet design sucks. The TBI setup has more potential to it. The vortec intake/injector setup is non-upgradeable. There is very little aftermarket for it. The TBI market is better established than the vortec. I already have a 350 vortec with the production LT4 cam in it. It is in my Express. The poppet setup is a nightmare waiting to happen. I had to replace the original poppet spider rail with the GM MFI conversion. That smoothed things out, but it is already at the ragged edge of running out of fuel. The poppets run at 60 PSI, but are rated at 19 lbs/hr at 43.5 psi. They are 24 lbs/hr at 60 psi and 330 HP is about all that you can get out of the system without a supercharger or additional injectors. The other problem is all of that garbage gets in the way of air/flow. The only intake that is available for upgraded EXTERNAL injectors is the Mercury Marine piece. It lacks and EGR valve. The Vortec TBI setup has atleast a chance to be legal.

I attached pictures of the stock intake setup. Firs is the stock injector poppet. Second is the upgrade MFI injector. Last is the upgrade MFI setup sitting ontop of the manifold, in the middle of the plenum.

TierAngst

.

Fast355

iTrader: (2)

I don't know what Jake was trying to post, but he he actually got to hear the idle of the LT4 cammed 350 Vortec out at Impalafest a few weeks ago. I didn't get to stay very long, or I might have lined it up against an Impala. I probably would have lost, but thats 6,200 lbs of Express vs. a 4,300 lbs car. Maybe he will comment on how mild the engine sounds or something.

FreeLoader

wow, i apologize, I assumed they were standard injectors.

would there be any way to perhaps drill out bigger holes and modify the wiring for standard injectors(by that i essentially mean the tpi type)?

it seems like a system worth looking into, several companies use at least something similar to it, ironically fuel seems to be the only limiter(wheras I thought it would actually be the advantage).

as for the pcm, it wouldn't be any different than the poeple on here who install an lt1 or ls1, it's the same basic modification on any obdII. as for the 4 oxygen sensors, the rear two could be removed easily, many people do it. and the a bung could simply be installed on the other side for the second oxygen sensor.

again, i apologize, i realize that this is intended to be a budget build, and that it's probably meant to lean more towards the more tradtional ecm tbi people on here, I guess i'm just stating that at least as far as the pcm goes(and it wouldn't exactly cost an arm and a leg more if you could get the full dress setup), I'd keep it if i could, especially with the 4l60e.

as you just said, the stock intake setup can be pumped up to 60 psi to emulate 24 lb injectors(with more atomization no less), which would more than likely be plenty for my personal use. I guess I'm wondering if you could actually get away with doing LESS modification and making the same, if not 1-2 more, hp.

I own a 97 z28 along with my 88 camaro, which in this case means it might actually be a bit easier for me to go that route anyway, as I'll only have to be setup for obdII tuning on both cars if I were to make the switch.

so do you think that route might be a good budget idea for anyone in my position on the forums? or is there something I'm missing here?

Fast355

iTrader: (2)

The stock poppet setup already runs at 60 psi.

Airflow is actually very limited through the stock plenum. If you think that the TBI intake is a flow blocker, take a look at this piece up closer. The vortec intake setup is very restrictive, especially over 4,000 rpm. That is where my express starts getting a noticeable HP loss and it continues the higher it is reved. I know some shorty headers would help with it some. I built essentially the same engine that is in my Express, but used Dart Iron eagles, a Performer 3704 Intake bored to 2" and a BBC TBI unit. The Dart 180 engine out-powered the vortec by a full 38 RWHP @ 5,600 with torque gains from idle. The Vortec 350 PCM also only gives a 5,800 rpm limit and is not removeable.

The poppet setup is pretty unique. I doubt that a person could drill some things out to installl standard injectors. You can't look to the 454 for help either. It used standard old injectors on the outside of the plenum.

I know you could use the PCM from the vortec, along with the wiring, sensors, etc, but to work out all the problems will take some time and a good chunk of change.

Here is a stock vortec dyno. 199 RWHP/265RWTQ That is about 242 FWHP/300 FWTQ.

http://www.hypertech-inc.com/get_dyn...1358603&tp=pdf

FreeLoader

alright, fair enough.

I have some other questions that I would ask, but they just pull further and further away from the general idea of a 350 tbi setup, not to mention cost increasingly larger amounts of money.

this seems to be one of the best ways to get a damned good build on a fairly cheap setup.

Fast355

iTrader: (2)

The PM function works well. Send away.

Fast355

iTrader: (2)

The LT4 cam has a narrower lobe seperation angle and more duration.

Cost of machining the guides is why I picked that cam.

TierAngst

While it did sound very mild, I'm going to bet that a large part of that was due to your engine breathing through straws :-P
Even still, there wasn't a lot of noise coming from the engine bay itself so the exhaust I don't think is the entire cause of mild noise.

As for the previous post, I don't know how to delete that so I just edited it. I was going to say something involving why you would ditch the newer style intake but as I was typing it you posted so when I realized that I just erased everything.

RBob

iTrader: (1)

Fast, great write up, you put the info down for all have available.

The EBL is provided with the What's Up Display (WUD), as shown above. The speedo can be made adjustable, along with the tach. If you have other items you would like to see, please PM/email a wish list. The currrent version does have an adjustable red line for the tach.

RBob.

seanof30306

iTrader: (4)

That L31 short block is what PHR used in their 447 hp "Budget Sledgehammer" buildup in the November, 2006 issue. They assert that most L31s you'll find will be in pretty good condition, as the overdrive transmissions they came with means they turned less rpms over their lifetimes than in the past. Makes sense to me.

sdpc2000.com offers a new L31 shortblock for 1229.75. 350 / L31 4-Bolt Main GM Performance Parts Short Block Engine Assembly :: 12556121 - SDPC

Unless you can do all the work yourself and need no machine work, that's a hard price to beat. They sell a balanced and blueprinted L31 short block for 2159.95. L31 350 SB Chevrolet Balanced & Blueprinted Short Block :: 12556121BP - SDPC

You can get the complete long block for 2875.92. This has the windage tray they talked about in PHR, as well as the oil pump, lifters, pushrods, etc., and has a 36 month, 100,000 mile warranty. You could easily get 250.00+ for the heads and cam to defray the cost a bit. 1996-02 Chevrolet, GMC C, K, & G (L31) :: 12530282 - SDPC


http://www.jegs.com/webapp/wcs/store...00367_-1_10763

alvanwie

Excellent write up Fast355. Having recently completed a similar budget build I know this information would have saved me a lot of time and searching for the right combination.

Your target hp range makes a lot of sense to keep the budget in line from my experience. I targeted the 375-400hp range and there is definitely some added expense and complexity associated with that.

I started with a rebuilt vortec long block from City Motor Supply in Texas. They are an extremely high volume rebuilder that I believe wholesales to other rebuilder. The guy I worked with was John Deere who was in charge of their internet sales (good guy, easy to work with). I believe the basic long block was about $1400. For an added $45 they put in hypereutectic flat top pistons (10:1 compression ratio). I sent them the cam I wanted along with the valve springs and retainers and they installed them at no extra charge ( they did get to keep the stock parts). In less than a week my long block was delivered to my home. Since they ship in high volume they get very good shipping rates, I think it was about $100 to ship.

To get around the valve lift problem I used Crane Valve Spring Retainer Kit – P/N 10309-1. This is good for around .525" of lift without machining the heads.

I used a GMPP 4bbl intake (with EGR) along with a used 454 tbi and 454 adapter. This was to help support my increased hp target.
- GM 454 Throttle Body Injection – P/N 17087021
- GM TBI to Quadrajet Adaptor Spacer – 1.75 inch - P/N 10045799
- GM Vortec aluminum intake manifold P/N 12496820

One other tip. The vortec block does not have a coolant bypass port in the block. So, you need to provide an external bypass from the water pump to the intake. In my case I reused the old 305 pump which did not provide a bypass. To remedy this simply drill a couple of 1/4" hole in the edge of the thermostat and let it bypass through there.

Tuning of my combination was difficult, at least for a first timer. I think the combo that Fast355 presented would be quite a bit easier. I will not go into detail here, but with experience you do pick up little things that shorten the process and the guys here on the TBI board where very helpful with info to get me through some of the problem areas. And yes, this combo did past the smog test although it was very close on hydrocarbons. I believe here also that the combo that Fast presented would be much easier to tune for smog test if that is a requirement.

With the added hp, the stock (freshly rebuilt) 700r4 trans was very erractic and would barely complete a 1-2 shift at WOT. Installing the corvette servo and a .500" TV boost valve and sleeve seems to have solved this problem.

The engine has less than 1000 miles on it, but at this point I am very happy with the results. Very streetable and runs strong. Sorry, no dyno test yet to verify if I reached my hp goals.

Al

Thought I would include a picture and the Dyno2000 sim of the engine showing 399fwhp@5500rpm and 443ft.lb torque@4000rpm.

Fast355

iTrader: (2)

I've never seen a Vortec 305/350 block without the bypass hole. Even the GM Goodwrench Crate engine that I installed had one.

I use 4 x 3/16" holes in the sides of a 180* thermostat. Works very well on my builds.

City Motor Supply is VERY local to me. They did the machining when I built my 312.

vorgath

Hate to bring it up, but what about smog legal ? Granted one can hopefully pass it off as a 305 TBI, but what if the smog check place 1) really know engines, and 2) decide to be complete @$$holes ? Isn't there some rule that one can't put a truck engine into a car ?

And what about smog legal headers ? Of course can drill some holes and custom make the AIR fittings, but what if some places require the CARB number for the headers ? (I've read on the forum that this happened to some people, headers had AIR fitting etc, but the smog place did indeed require the actual CARB numer, talk about real @$$holes)

92green3RdGen

Excellent Thread Fast!!! This really cleared things up about the questions i had about what i should do....also my goal was around 300 rwhp so this fits it perfectly thanks again!

seanof30306

iTrader: (4)

You either can or you can't, dude. Virtually every car mag in publication is based in California, and they discuss this issue all the time. If you need headers with a CARB sticker, then, only buy headers with a carb sticker. If you run across an inspector who is a stickler, try another, and keep trying others till you find one who isn't. Ask other hot rodders in your area how they got their cars to pass. Do some research of your own, in your area.

When transplanting an engine from a newer car into an older one, I believe you have to have smog equipment and meet the emissions requirements for the engine, and not the car (I could be wrong on this). That information, though, is readily available on the internet. When I lived in Georgia, the state had a website explaining all that, I'd guess California has one, too.

Just look.

edit: I just looked at your sig, you're already smog-illegal, as well as downright illegal. No inspection station in the country is going to (legally) pass a car with turndowns ahead of the rear axle. Just go back to wherever you got your last inspection.

alvanwie

RE: Vortec Coolant Bypass

The info I gave above was based on research I did at the time when I was investigating using the Vortec engine for my build. That was quite some time ago, but here is what I recall (right or wrong?).

Gen I Small blocks 1996 and later (Vortecs) do not have the coolant bypass in the block. The Vortec engines used a special thermostat which actually controlled the bypass port located in the manifold. It would close the bypass when the thermostat was open to force all of the coolant through the radiator.

Therefore when using a 1996 or later block (if it does not have a bypass port in the block) you need to provide an external bypass of some sort. Otherwise when the thermostat is closed there is no coolant circulation through the engine. This will cause hot spots in the engine and since the thermostat is not located at one of the hot spots it will probably not open. Many times you will not even see much of a rise on the temp gauge either and unless you here the coolant boiling in your heads you will probably have no idea why your shiney new motor cooked.

superbee

Nice thread. Im currently running everything already except the vortec heads and conversion intake, and tuning equipment, which im waiting till next summer for.


Would a complete newbie to engine tuning be able to tune a vortec engine like you did with only a winter's time experience? Im going to read up on the stickeys and start playing with it on my cammed 355 untill the summer... Thanks.

alvanwie

Superbee, The Vortec heads will not make tuning any more difficult. I believe the biggest factor in making tuning more difficult is overlap in the cam which results in less and unstable vacuum. Cams similar to what Fast355 recommended along with the info on this board should get you there with no problem.

superbee

Great, thats a relief. My cam is 204 int and 214 exh, and .421 and .444 at .50 so i was going to get 1.6 rockers to put it up to 470 ish lift, lift isnt near big as tuning factor as duration correct?

alvanwie

Superbee, yes that is correct. Lift does not have near as much effect on tuning difficulty as duration and LSA, both effect overlap. With the duration of your cam it should not be very difficult.

vorgath

I asked in general regarding smog/emission issues, nothing to do with my own setup (setup for the smog check now, all legal). I believe it's a valid question though, how to make it pass completely through smog.

Can one tune it down so far that it would pass smog ? i.e. pass smog as a stock 305 ? I know it CAN be done uhmmm loosening a few bolts here and there, leaking cough exhaust cough cough i.e. less reading at the pipe.

But would it be able to be tuned down to pass right off ?


Oh believe me I'm reading this one, since in a few months I may very well go and get me a 350, seems it's much MUCH cheaper to get pistons etc for standard 4 inch bore, and hey if I can get Vortec heads, vortec block, why not

After all, this is THE cheapest buildup I've EVER seen.

Fast355

iTrader: (2)

A 305/350 will blow practically the same emissions readings. Everything is in parts per million. With a good tune in the ECM, the readings should practically be zero.

This is without EGR, 75 lb/hr worth of injectors, EBL, custom tuning. I have headers and dual cats.

vorgath

Awesome

weberflorida

iTrader: (2)

Cmon man!! Let's put one in your car!! can you say trip to the junkyard!!

Fast355

iTrader: (2)

I am just adding a link to the PCM conversion.

This will also eventually show the MAF conversion and possibly a Vortec head/Vortec MPFI intake swap using the TBI PCM with MAF and linear EGR valve.

https://www.thirdgen.org/forums/tbi/...ml#post3122342

92ss wagon

Great write up Fast. I am going to do one of these build ups finally..:-) I was thinking of taking 1 step further. Has anyone read this article?Any thoughts?Thanks again for all the help!
http://www.popularhotrodding.com/eng...ock/index.html

DJ

rocko350

having had a terrible time tuning a tbi motor with that tight of a lobe seperation id say good luck. seriously consider a wider lsa (lt4 hot cam with 1.5 rockers on purpose)and possibly less compression or be prepared for a lot of chip burns. my full roller 11.2:1 355 was at the 250 chip mark and still had a lot of power and fuel economy on the table. not saying that dialing any engine in won't take a lot of work ,but that motor would be hell to tune for tbi. maybe with Fasts maf/tbi hybrid it might be a little easier. combination selection for intended use is what really makes the difference.

Fast355

iTrader: (2)

Its not my MAF/TBI Hybrid setup. It is Dimented24x7s. He deserves the credit on the initial setup and the ECM code. Don't get me wrong it still takes alot of work to do something of this magnitude even having the ECM code.

92ss wagon

I was going off that because of the 450HP. That is what I'd like to have in my car since it's 4400LB's I'll be honest, I'm not very good with any of this motor stuff but I love it! I figured they had all the details and part numbers to do the motor so I'd just have a machine shop do what it says and have it work. make sense? I also thought of running a carb since I dont yet have the knowledge to burn chips and change comps out. Someday I hope to have alittle knowledge but I still have more to read.

DJ

92ss wagon

Well I started my project today I went and bought a 1998 Vortec 350, 880 casting just like is posted. Now I'm reading as much as I can and would like to build 450-500hp Alot for a newbie like me.(lol)

DJ

Fast355

iTrader: (2)

You will need to have the distributer opening in the intake you choose enlarged to fit your distributer. The round body B/D body cars have a larger diameter opening so the distributer can be stabbed into the engine with the engine in the car. Any competent machine shop can do this for you.

92ss wagon

thanks Fast. I appreciate your input. Do you think that HP is feasable with a TBI unit? Or should I go carb? Have you ever read the article I posted above on the 475HP Vortec motor? Thanks alot for your time and posts!!!

DJ

Fast355

iTrader: (2)

It will be very tough with TBI, but I think with the EBL modded to drive dual TBI's and two TBI units with 4 injectors it would be possible. IIRC, Edelbrock is making a nice new high rise style dual 4 manifold for Vortec heads as well.
----------
The dual quad vortec style performer RPM intake is part number 7526 from Edelbrock. In the latest JEGs catalog it is $289.99.

http://store.summitracing.com/partde...5&autoview=sku

I think with the Performer style dual quad intake, 2 center mounted TBI adapters, 2 standard 350 TBIs, 4 350 injectors with an external regulator (Vacuum assist) and good tuning with the EBL, 500 HP is definately possible.

rocko350

sorry dimented24x7 and fast355. didn't mean to misdirect credit in the wrong dirction. i think that the ebl has a lot of potential. i'm considering the dual tbi's on my 509with l29's and fabbed intake in my caprice.

Pelle

Hi,

What modifications is needed to the stock TBI fuel lines (and fittings) when raising fuel pressure?

Thanks,

//Per

Fast355

iTrader: (2)

The fuel line fittings are Power Steering style fittings. The rubber hoses are probably good to 100+ PSI provided they are in good shape. The only problem that I had was in the tank. The factory TBI fuel pump/sending unit used pinch style clamps to secure the little piece of rubber hose that went between the sending unit and the pump. I re-used these when I put the TPI pump in my tank. Despite the fact that the TPI pump came with gear drive type clamps. An oversite on my part that ended up with me pulling the tank again. The first time I took the pressure up, it got to about 26 psi and blew the pump off the sending unit assembly.

I recently changed to AN lines on the pressure side from my sending unit to the metal line and from the metal line to the TBI assembly. I also plumbed in an external regulator at the same time. Eliminating my stock regulator at the same time.

I used this page to do this.
http://members.shaw.ca/betterthanyou/regulator.htm

Fast355

iTrader: (2)

Thats cool, that Vortec 509 with dual TBIs should run like a raped ape in that heavy caprice.

JohnBlazeLTZ

Thats cool, that Vortec 509 with dual TBIs should run like a raped ape in that heavy caprice.

[/QUOTE]

I don't know if you guys have ever been accused of being mind readers...but your reading my mind right now!!! I have been debating a 383 dual TBI build up for a while now....

At one point I bought a TBI Vortech blower kit hoping to reach into the 400hp zone...and after visiting Turbo City's website and laying my eyes on this




Here's a nice litle read...(Sorry...they mention the MS EFI System....Booo Booo...)

http://www.jalopyjournal.com/forum/s...905&&showall=1

....Anyway...this is getting in peoples heads now with the advent of all these up and coming EFI systems...I do general searchs for the Dual TBI Set up and all the sudden...they start coming up more and more often. This is a feesible plan...and as the article above mentions...it could be the biggest bang for your buck engine ever.

I am serious as a heart attack on this one. A short block that can handle up to 500hp can be built buy using ALMOST all OEM parts...and the manifold would only cost 250 and TBI'S can be had for almost free...all that is needed after that is the EBL set up and ...were looking at a very realistic 450 hp and...on a 383...at least 500 or more of TQ...which in my mind...like Fast said...would be perfect for a big body Caprice. I think it would move that mass of steel quite nicely.

Sometimes a loss sleep at night thinking of the shock and awe fcto on this set up. I would probably go to a cowl hood set up and have it suck in the air off the windshield. For us Caprice guys...this could be an all around the town *****/ Ford smasher. Seriously...everytime I think about what it would be like to pop the hood on my LTZ to reveal an engine like that in the engine bay...my mouth starts to water.

92ss wagon

Hey John,
I read alot of your posts and projects on the 9c1 forums. I am buidling a 383 system right now with 450-500HP for the wagon I've been reading the info on here for over a month now(lol) I too am leaning towards the dual tbi combo with the EBL. Rrob is a great help along with FAST, DIMENTED and Kdrolt I wished I knew more on the programming thats my only fear on this build up. Keeep me posted on which way you go maybe we could help each other since the cars are similar.

DJ

JohnBlazeLTZ

Hey man...good to hear you are on the same idea I am. Email anytime. Hopefully we can share information. I won't go back to the othern forums anymore. I think a lot of people there are really cool...but then there are the jerks that make the whole experience unenjoyable by treating each iother rather poorly. The whole scene has changed since I first posted there and its kind of a waste of time now. Those LT1 guys are suffer from a God Complex so often that it makes me sick. Keep in touch...alot of guys still email me frequently. Talk to you agian soon.