3.4L fuel system selection

[esheffield]

I'm planning on building a Stalker V6 and am trying to decide on the best approach for the fuel delivery. I have a 3.4L from a 93 Camaro. The rest of the drivetrain is S-10. I plan on keeping the engine pretty much stock, probably changing only the cam and going to a distributor system, maybe with MSD or similar. I'm considering:

1) Edelbrock intake with Holley 390 carb (Most commonly used setup on Stalkers, but I see this intake isn't very popular around here.)

2) Use the TBI system from the S-10, but with either the 4.3 injectors or entire 4.3 throttle body and port matched. (Most interesting to me - lots of info out there on tuning the computer and something new for me to try.)

3) Offenhauser intake with Holley 390 carb (Tough to find and expensive when you do.)

4) Stock 2.8 carb intake with some porting and with Weber carb. (Weber carbs expensive and maybe fussy.)

5) Camaro SFI system as the engine originally had. (Have intakes and injectors, but that's all. Also found a guy who tried this for a 1 1/2 years on his stalker and finally just threw the Edelbrock/Holley combo on. Don't think I want to try this.)

I've seen lots of discussions about some of these options individually, but can't get a good feel for comparing them to each other.

Any help? Thanks!

[RacerX11]

RE: 3.4L fuel system selection

These are just my opinions, so take them with a grain of salt:

1. The 3.4/Edelbrock/390 setup has been done with great success in a lot of Fieros. With a good cam (H272 or similar) and headers/exhaust, you can see 220-230HP with an otherwise stock 3.4L. Most of the people around here have cars that were EFI stock, so that is what they tend to stick with, and thus the lack of carb discussions.

2. The TBI intake for the 2.8 does not flow very well, and is a dual plane design, so top-end HP is limited. See my option 6 below.

3. Good combo if you can find one. I would like to pick up an Offy manifold and make a custom top plate to convert it to a single-plane, possibly with TBI.

4. The intake isn't bad, but I am not a fan of the Webers. See option 6 below.

5. SFI system will offer great divability and torque, but I don't think it can match the carb-style intakes for ultimate power potential.

My Option #6. This is kind of a combination of #2 and #4 above. I am working on a setup for a 2.8 Fiero using a modified S-10 carb intake, with heavy porting, and an adapter plate to mount a TBI unit from a 4.3/5.0/5.7 (all the same bore size) using 5.0 injectors. This, along with ported iron heads, and a H272 cam. With a re-tuned computer, I think you can get about as much power as the 390 carb setup, but with the drivability/startability of EFI.

You may have sensed a theme here. I feel the stalker is best matched with a high-revving engine that makes great top-end power at the expense of low-end torque. I have driven light cars with torquey, low-revving engines, and they just aren't as rewarding to drive as the same car with a high revving engine with some top-end punch. The light weight will make up for the lack of torque down low.

Marty

[geoffinbc]

I hate carbs and do not recommend any. Maybe the weber since it is one of the best.

EFI offers better everything except maybe initial cost and for some people it plain freaks them out.

I have a Camaro 3.4L with a bored 2.8L manifold and a 4.3L TB. I love this combination and never have a problem with it. Plust it is more simple that any EFI system. The TBI intake is not really a dual plane intake. Each side is seperated (but it does have a crossover hole) but that is not what a dual plane intake means. The 2.8L intake is not restrictive by any means compared to teh heads and exhaust. There is also some meat avalible for cleanup and a small port job. Plus 614 is now selling superchargers for the TBI systems

The Camaro EFI system has the most potential I would think and it is the most up to date EFI system you can get for iron heads.

[BMC]

SFI better then carb, performance and appearance- full stop.

I prefer the SFI setup and don't think its worth going back to a carb. I have an L32 (Camaro 3.4L) in my 1982 S10 and in several MGBs that weigh more then your Stalker. BHP and Tq is great in both and you will love the SFI if you stay with it. We sell a completed wiring harness to use the 3.4L L32 series motor in aftermarket applications as well as aluminium flywheels that fit yur application as well as quite a number of other pieces. Hopefully I can get a ride in a Stalker some time... There is a guy not far from me that owns one that should be coming out to the autocrosses this year with his. He has a 2.8L with the carb if i remember correctly... We cant outrun his 0-60 times but we should have about 40 more MPH above what i understand a Stalker has for top speed.

Look at the price of the 4bbl intake, both the top and bottom half, the carburetor, distributor, wires, cap, rotor, linkages and all that and compare it to the price of SFI. Comparing apples to apples- new to new/ used to used, you will find that the price is not that far off and the SFI offers lots of Tq.

Hope the file comes through... This is a 100,000 mile motor with a larger bore TB, 1.52 roller tip rockers, and a few other small items, but basically stock internals.

-BMC.

[BMC]

Cant get the dyno chart to come through... To big of file (or numbers on the chart!) i guess.
-BMC.

[Kreb]

I've got a Stalker with 3.4 Offy and 390. I like the idea of putting in a 4bl TBI like the Holley commander on top, using megasquirt and Chevy sensors. Problem is I don't think that there's enough room under the scoop. As it is, the choke flapper barely clears, and Brunton recommends that you lob off the choke horn for better airflow. I'd like the driveability of EFI but am reluctant to tear down my strong performing manifold setup and go with port injection.

Any suggestions?

[BMC]

Kerb,

The 2.8L TBI with 4.3L injectors in it is a common conversion and supposed to work very well. The TBI manifold and TB units themselves are supposed to be much lower then the carb.
There is also a guy who builds the upper half to the edelbrock manifold with a 1" lower overall height if you need that 4bbl setup.

How about twin TBI setup on top of a dual side draught converter with your Offy manifold? That would keep it low and quite the look!

The lowest systems that I know of are the 3.4L Camaro L32 SFI manifold, but the aluminium heads were only 1/2" higher then the measurements we passed back and forth on another forum..

Also, there is a sort of upside-down bucket that you can place on a carb or TBI setup to place the air filter off to the side. I think this was designed for Jeeps going through the mud, but does a nice job of moving the air filter.
FWIW,
-BMC.

[Kreb]

How about twin TBI setup on top of a dual side draught converter with your Offy manifold? That would keep it low and quite the look!

I'm not sure what you mean. Could you point me to a pic?

My donor was a 94 Camaro (I think). The manifold looked pretty restrictive. Low profile though.

I like the upside-down bucket idea. I'm a sheet metal worker, so I should be able to fab up something quite nice.

[hamondale]

[quote="BMC"]How about twin TBI setup on top of a dual side draught converter with your Offy manifold? That would keep it low and quite the look!quote]

Just wondering since the Offy is a dual plane manifold, how would that factor in to this kind of a side draught setup?

Also, can anybody comment on the height of a suitable throttle body vs. the height of a Holley 390 that it could replace?

[tejohnson]

Sorry to be a bit off topic, but I was just looking over the "Options" at the Stalker site and noticed they have a Header Bend / Flange / Collector kit kit $195.00. If this were all 14 gauge, then it would be pretty sweet Looks like it only includes 10 45° and 2 90° bends tho... Looks like I might have something to do with the motor when I retire the GA

[BMC]

On one of the other V6 sites i am on, someone else pointed this out to me.

http://www.jameng.com/products/images/021000202.jpg

Looks like a good way to have GB shake hands with the USA in tech and appearance.

A car we had through the dyno shop with 100,000 miles on the motor with a little larger bored out TB, and a few external mods but nothing internal produced 192.6 RWTq at 3,800rpm and 153.4 RWBHP at 4800. The torque curve is not a curve but flat line so power is everywhere. Thats about 230 LbsTq and 185 BHP a the flywheel for an otherwise all stock 100,000 mile motor with the L32 3.4L SFI and DIS. This was after the installation of a haltech, which we think we picked up a little more on the low end, but lost power above 5000 rpm the way it is set up. Anyways, I feel that the SFI is the way to go. As far as how it flows, there are some people that say that it does not flow well, but other reports i have heard have stated that actual flow tests show that it is a better system then the old MPFI manifolds. I run the 3.4L SFI motor in a number of MGs and my 1982 S10 and love it for performance as well as hauling a load.
-BMC.

[Kreb]

Wow, that's a sexy link! Honey, can you loan me $1,000? What for? sexy carbs and adapter. Put down that lamp honey! Sure, Youll get that new couch someday!

On the EFI, those are pretty impressive numbers. I didn't think that was possible in such a mild state of tune.

[geoffinbc]

The 3.4L SFI manifold is the best flowing manifold avalible for the iron heads. It has long equal length runners and is a pretty low manifold aswell

There are pics of it in the gallery.

[Kreb]

Doh! My donor motor had that setup, and in a moment of passionate junk clearing I tossed it. Oh well, I'm sure that they're a cheap junkyard item if I decide to go that way.

[BMC]

Keep in mind, anything I say to do with 3.4L SFI is propaganda...
True but propaganda since I sell conversion parts for the L32. If anyone needs a copy of the dyno chart, I can email it in a .pdf format, just don't know how to post it here otherwise I would have.
Never throw the parts... People pay for those on eBay. We have had a guy with the 2.8/3.1L style manifold convert to a 3.4L manifold for his earlier motor due to the clearance it gives, not to mention the flow that the northerner above mentions.. (its not too often i can refer to someone as more NorT den miself. )
The serpintine system for the 93-95 L32 Camaro is also nice for alot of individuals since we have a conversion kit that removes the power steering and AC compressor and allows you to run the DIS and alternator in stock locations... Not great for Stalker guys since i understand that the alternator (according to one fellow) would not work there due to bonnet clearance but that setup is a cleaner setup with our kit then converting back to the v vbelts.. also we do have one fellow that builds serpintine kits that would work with the (probably) most common Stalker motor conversions and also crate motors for S10s.
To throw more stuff out there, one of these days i will list more out on the website that we sell, such as Aluminium flywheels that are direct replacements for the internal balance S10 and will fit any RWD block with the correct HTOB or clutch arm setup. (See, Propagana!!)

There is alot of pieces out there to upgrade these motors and even a few of us who fabricate specialty components to make the GM 60 degree better, or even fit larger things under the bonnet of a Stalker/Miata/MGB/Spitfire/S10/Jeep/Samuri/TR7/Midget/MGA/Alpine and Many others. Both FWD and RWD conversions!

FWIW,
-BMC.

p.s. I don't need no stinkin' 3-fitty to get power!