I am going to put a stroker motor in my car with plans on a blower in the future. I am just curious to see which way most of you would go. It is going to be a street/strip car, so tuning is going to be a factor.
I need ideas!!!!!!

 

carbs are so much easier to deal with, its almost a no brainer. HOWEVER there are stand alone FI set ups that look good. what do you want to spend time and money on?

 

Yeah, I gotta put in a vote for carb due to simplicity.

 

I miss EFI all the time. Carbs are quirky and annoying. Ignition modules can still fail. Floats can get stuck. The car wasnt designed for a carb, so retrofitting a carb system will always require a few workarounds. I have a problem my fuel boiling in my feed line because it goes over the radiator hose. Just a lot of annoying crap. I got stranded a few weeks ago over a fuel pump circuit problem, so just because there's a carb doesnt mean it's reliable. This is ignoring the other annoying crap like figuring out the TV cable and speedometer and TCC lockup...

Carbs are tempting, but I suggest you find a way to retain the EFI setup if you can. The cost differences may make carb the only practical way to do it, but at least with EFI you can fit everything under a stock hood, and there's soemthing really cool about a very fast car with a factory hood.

 

For a reason .
Most are too lazy to learn about EFI and the benefits it gives over a carb on a street
Read
http://www.hotrod.com/techarticles/e...install/engine

FWIW
I have a carb where it works best ; @ WOT on my race engine

 

I went with Carb for my 86.

Reason One, My car was already equipped with a carb.

Two, I already had most of what is required to go non-ECM already in my garage = CHEAP!!

Three, I didn't want to spend the money to upgrade to an EFI ECM or better ECM and buy a laptop for tuning at the time. (12 years ago) $$$$

I've actually been considering getting a 5.3L GenIII motor for my 70 Z28 and keeping it EFI lately but I also like the old school look in an older car like that. I still have the factory Muncie 4-speed and 4.10 posi rear under it. Just don't have the original engine block.

Unless it came equipped with an LG4 or L69 (CARB). Main difference is the fuel rails are routed on the passenger side versus (EFI) driver side.

 

That does make it easier, though. And you dont have to worry about fuel pressure regulators and completely rerouting all your fuel lines. Like I said, due to my fuel line routing my fuel likes to boil in my feed line. Causes me all sorts of headaches but there's not really a way to avoid it. I wonder if I moved my FPR to the intake manifold if it would cure it. It would keep the fuel line over the radiator hose pressurized... It's not going to boil if it remains pressurized. But tehse kinds of things happen when you're trying to homebrew engineer things and dont have GM's R&D budget.

 

After going the efi route, tuning, emulators and all.... I say go carbs.

Dealing w used chips means 50% of your chips just don't work, an additional 20% verify and take a flash but won't work when installed.... Leaving 30% that work.

New chips (that were obsolete in 1994) are hard to come by.

 

I'm guessing you have a Holley dual feed carb correct?

Have you hooking the fuel line to the rear instead of the front?

http://www.summitracing.com/parts/sum-220104/overview/

Just install it with the feed facing towards the rear.

 

That means running fuel lines all the way down the frame rail and up the firewall, around the distributor and back to the engine. But there's not much room to snake it through the engine in front of the dist, and around the back... I always thought there were rules about running fuel lines on the firewall? Doesnt seem all that practical to me. I've heard you run into problems when you have too much fuel line past the FPR also. But it would probably work...

 

I am planning on doing away with the factory computer on the car so I would basically be starting from scratch. I plan on street and strip use so tuning is a big factor.

 

Even more reason to go with the carb. When done right they can be just as reliable as an efi system. and tuning is quite simple as well.

 

Yea, per NHRA you are not suppose to run the fuel line from the firewall to the motor. This is encase the flywheel/flexplate decides to explode you won't cut the fuel line with it.

I was actually thinking you would run it from the fender over the rocker cover, between the carb and dist to the fuel line. If your headers are coated or wrapped you shouldn't get too hot going over them that way. Not the prettiest method but better than laying across the thermostat housing/radiator hose.

 

What kind of line are you using? I've attached a pic of my routing, I don't have boiling issues.

 

Tuning is even more simple with an aftermarket EFI system. Just plug in a cord and in a snap you can change fuel ratios, timing, timing curve, ext.

To change the A/F ratio on a carb you have to drain the bowl, remove parts and then swap the jets and put everything back together. To change the timing curve you have to change weights and springs in the distributor..... and so on.

I'm not arguing for him to go EFI but just showing that tuning is quite easy and not as messy with an EFI system as compared to carbs. I've worked on motors with carbs since 1983 and have raced a 67 Camaro with a carb'd motor since 91. To me it's all down to $$$ and ¢¢¢ and what I already have in my garage versus what I will have to buy.

For me I'd rather have a carb over a stock ECM TPI system for some things and I'd rather have a LSx type system over a carb for other applications.

 

You're coming from the passenger side. He's coming from the driver side across the front of the motor over the radiator hose/thermostat.

 

Most people don't. Some people do. They try phenolic spacers and all sorts of thing, rarely with any positive results. I've read accounts all over the internet of people dealing with this and never really finding a solution.

In my case Im pretty sure it's just fuel percolating in the feed line because of various things Im able to infer and check on my own.

I used to run a push-loc hose. I tried wrapping it with heat insulating tape near where it was getting warm. Didn't help. I then moved to braided hose. Didn't help. Then I rerouted the braided hose in front of the radiator and it didnt do it anymore. But I was worried about safety in an accident, so I pulled it back to where it used to be, and all the problems came back. I've put electrical wiring conduit around it in an attempt to insulate it recently, with the intention of wrapping THAT in heater hose, but it hasnt helped at all either so im not sure that strategy is worth it. But if you search here you find a small subset of people who have hte problem and none of them have ever cured it. I found out that if i route my fuel line away from heat, it goes away, but I havent come up with a practical, safe, and elegant way of doing that yet, so I've been trying to make do with what I've got somehow.

But the point is, there's no OEM way to do this, so you're just throwing things together on your own. GM spent the money and R&D time to figure this stuff out and built cars like that that just worked instead of me having to buy tons of fittings and regulators and braided line and torque converter lockup kits and fan switches and fuel pump relays etc.... Which all come into play when you swap to carb. If you've got the money and time an AN fittings it's not a big deal to sit around and play with this stuff, but carb is by no means the "easy way" most people think it is (my opinion). It's just cheaper.

Maybe I'm naive, but I feel like an EFI system would be much less prone to this type of quirkiness. It'd be more consistent from season to season too.

Im actually planning on raising the FPR by changing the mount, and maybe the extra height will help the feed line get over the engine without touching it so much.

 

Why
here are 500Hp engines out there on re programmed stock ECM's

Wrong way for starters.
You buy an adapter and use nice new modern EEPROMS ;instantly re- programable

You can get the 27SF512 chips for a $1.50 ea



http://www.ebay.com/itm/10pcs-SST27SF512-70-3C-PG-SST-27SF512-EEPROM-DIP-28-/180955520912?pt=LH_DefaultDomain_0&hash=item2a21ca1f90

 

Wow, I didn't know that the newer cars had it on the driver's side like that, what a pain. I see the dilemma

 

Both will get the job done equally well, the question really is:

How much do you want to spend up front?

if cost is no object then have at it with EFI, BUT after all the time, money, frustration and similar performance as a carb you will arrive at the same conclusion and you will have lighter wallet for it.

IMHO the best EFI systems come from: GM, FORD, CHRYSLER, TOYOTA, etc.
Why? because they have invested thousands of hours and MILLIONS of dollars developing, testing, and manufacturing them.

These systems work excellent for the vehicles they are built for and provide the perfect balance of performance, daily reliability, fuel economy, and emissions.

by that same token the OEM 3RD gen EFI system was the best for it's time given the criteria they had to work with.

Once you deviate from the OEM you can toss all that in trash if you don't know what you are doing with an aftermarket or Custom fuel system be is EFI or CARB ( IMHO ALOT of what I see in most all of these "tech" posts is just that, poorly executed and thought out work based on lack of experience )

 

1) A properly plumbed carb system needs to be fed from the passenger side.

2) The fuel pressure regulator you can mount on the carb with regulator bracket.
3) The fuel line is routed along the front of the block to a mechanical pump and or then towards the passenger side sub-frame, from there if goes back to the fuel tank.

4) A return line is recommended since this will prevent vapor lock.

All factory 3rd gen (carb or otherwise) use a return line for this reason.

the OEM did it this way, a high-performance system is no different in principle except that the lines, pump, carb are larger to meet the fuel demands of the engine.

#5) the OEM fuel lines are undersized for any high performance use past OEM levels with a carb in particular because a carb depends on fuel volume to keep the float bowls full of fuel.

Pressure is simply the force at which the fuel is delivered is has nothing to do with volume. that being said most carbs need 8 PSI or less fuel pressure typically just 7 and on a run it can dip down to 4-6... but like I said pressure is not volume..

MOST PROBLEMS with Carb is fuel delivery stemming from an undersized / restricted fuel system. the next issue is the carb is typically oversized for the application. lastly is a bad calibration (too rich or too lean). Get these things right and all of these problems somehow magically disappear.

A simple carb fuel line system that will meet most people on this site's needs is: -8AN (1/2 line) from the tank all the way to the regulator, from the regulator you run -6 (3/8 line) to the carb bowls. of course you need the fuel filter regulator, pump, but you get the idea. also be sure to replace the stock pick-up tube in the tank.

For more information on how to size and plumb fuel systems correctly visit Aeroquip's, Magnafuel's, or even Holley's website.

In summary a well-built fuel system in not inexpensive but it is critical for the proper operation of the engine.

The key is to size it accordingly for the intended application.

 

Hey FRMULA88 What is mounted to the fuel pump location on the block. I don't recognize what's on there. Doesn't look like the typical Holley/Edel mechanical pump.

 

I am using a piston style mechanical fuel pump, so far I am very happy.
The pump will flow as much fuel as I need and should be the only unit I ever need to use, even if I decide to add a pro-charger in a few years.
I plumbed the system with -10 main line so it can support up to 1,500 HP.

http://racepumps.com/

There is a lot of information on the site about the pump and how to plumb fuel systems in general. I spoke to Mr. Stewart a few times he is a great person to know.

 

I've heard of the piston pumps (build specs) but never seen one installed. Very Cool