Transplanting EFI V6 into 71 Lemans [Archive] - PY Online Forums

Mike S

10-08-2004, 02:07 PM

I have a 71 Lemans with a straight 6. What I would like to do is transplant a EFI V6 from a late model car into it. My goal is to have a nice cross country driver that is good on gas and passes modern smog tests. What would be a good donor car? I was thinking of a impala or something like that. Has anyone delt with changing over the engine managment wireing? How hard? I am just trying to decide on how I should go with this next project. I already have a 67 GTO 10 sec race car and a 72 Lemans 12 sec street car.
Mike S

Mike S

10-08-2004, 02:07 PM

PMDRACER

10-08-2004, 03:40 PM

Just rattling off what's off the top of my head - some obviuos, but what the heck.

1. Why a V6 and not an V8?
2. The job would be much easier with a RWD engine and trans combo. The entire drivetrain is then kept inline with what the ECU is expecting.
3. Get the engine, trans, and everything you can with it.
4. In lieu of #3, you can buy aftermarket stand-alone ECUs for certain applications.
5. With stock ECUs, they rely on catalytic convertors with O2 sensors on the inlet and outlet sides. I cannot remember if it is California State or US Federal, but it is illegal to put catalytic convertors on a vehicle that was not originally equipped with them for reasons of fire hazard. - No Joke!
6. You present speedo is mechanical, most new stuff is electronic. You will need an adaptor, convertor, or a new guage.
7. If you are staying stock you can have your tank modified to take the stock EFI in-tank pump from the donor car.
8. Run a new line up front for fuel feed, and the stock 3/8 line in the car now for return.

shotgun

11-01-2004, 04:52 PM

I thought of doing the same thing.Too many ideas,not enough money and time,mostly money though.
Find a Firebird with a 3.8 automatic overdrive.Trans plant everything.
With the right gear,no cat and true duel exhaust would make a great runner.
Car would also handle better due to lower weight of drivetrain and the fact the v6 sits further back in the chassis.

NaOH

11-05-2004, 10:00 PM

That would be an interesting swap. I'd love to see a s/c 3.8 from a GTP, but admittedly it would be somewhat problematic. Of course, there's a developing aftermarket for the N/A 3.8 as well...

matrix

11-11-2004, 04:35 PM

Get a LT1 from a Impala/Caprice or Camaro, etc. With the matching 4spd overdrive trans. My 96 Impala SS ran low 14s and got 27 mpg on the highway with just catback exhaust, Cold air intake, and 3.42 gears in place of the stock 3.08

Quadrajet

11-14-2004, 08:11 AM

Have you considered a Chevy 4.3L? They are cheap and plentiful, rear drive in C1500 trucks and G10 Vans, and still rated at 200 HP. The Z code motor's would probably be easier to swap in than the more complex W motors, but you still get TBI and very basic computer controlled emmisions.

Not really a screamer, but good torque and great reliability. My company uses vans equipped with these engines, one of which has 180,000 hard miles on it with no rebuilds, no knocks, pings, smoking, etc.

Ogre

11-15-2004, 05:19 PM

Quadrajet,

More info PULEASE!! I am considering a similar project. Why is the Z code best? From the info I've gathered so far, the Z was on 1988-93, then the W came out in 94-95, and then the X came out in 96 and 97.

What are the major differences and the pros and cons to swapping them. I understand that the Z was originally TBI, and then it became CPFI and Turbo (I bought one of the original 1991 Syclones -- great fun).

Please educate me on the differences.

Thanks,
Ogre

Quadrajet

11-15-2004, 07:26 PM

The biggest difference between the two is the fuel injection setup. There is no huge advantage to running a Z over a W and I am not aware of any major internal differences between the two, I just think it would be an easier swap since most W's are going to utilize the more complex OBD2 computers. The Z motor's fuel injection setup is much more basic and ...well...cheaper overall. I work for an auto parts distributor and I am selling EFI parts and fuel pumps for W motors on a daily basis and these parts do add up. That is not to say they are failure prone, it could just be that there are so many of them out there that it is reflected in the demand.

I've never attempted a swap like this, so I am no expert by any stretch. Being that it is super common on rear drive vehicles and it has very large displacement (for a V6), I just felt that any 4.3 would be a great way to go. I always thought it would be cool to have a resto mod, but the cost and complexity of the whole thing always made me go back to the cheap, proven, emissions lite, carburated option. Since Mike S already has two vehicles like this already, I can see why someone would want to try it.

If I can think of anything else that might be helpful, (or if you need part numbers) I'll be happy to let you know.

Ogre

11-16-2004, 07:29 AM

Thanks Q-Jet,

As I said the little Syclone Turbo V-6 at 285 hp with 360 ft-lbs was a lot of fun stop light-to-stop light. It's amazing how you can go through four big tires that size in just 15,000 miles. I also had a carbureted 4.3 on a ski boat and while it wasn't great it did a good job.

The best I can tell it's just six of the small block 350 cylinders, and with a little tweaking should be able to get 225+ which is just a little under the 250 hp the '72 400 ci poncho was rated at with a LOT less weight.

It defnitely won't be a drag racer, but could be peppy while maintaining a decent mpg.

My game plan is to find an early ('88-'92) GMC Jimmy and strip everything including 700R4 tranny (wiring, computer, etc.) for a total tranplant. I still have a lot of studying to do before I try it, but theoretically if you've got the entire package, it should work. We all know how far theories go ...

Anyway, I appreciate your input on staying away from the later W and X codes. And any other input from anyone who's had this bright idea and dicarded it would be helpful also.

Thanks,
Ogre

Bill Eveland

11-17-2004, 02:19 PM

I agree to use a z engine with a throttle body. These engine only take 12-13 psi to run on . The newer engines take 55 psi to run and when they drop below 45-50 psi wont run. Iv'e replace a bunch of those pumps.
You may want to pay attention to your doner as well for what gear ratio/tire size for the vss calibration/vehicle speed.

disc0monkey

11-18-2004, 04:37 PM

if i were you i would find a blazer or s10 with a 4.3L. more stroke than a 3.8 so its got more torque. A 4.3L V6 is basically a 5.7L 350 with the back cylinders taken off. More than enough power in my '99 4.3 vortec 4x4 blazer. 200hp 270ft/lbs of torque and it weights over 4500lbs. No problems with the motor or fuel/injection system and mine a CSFI (sequential fuel injection), if you really wanted to put a torque cam in it from Comp Cams, and it will fly! easy swap dont have to change the lifter because they are roller http://forums.performanceyears.com/groupee_common/emoticons/icon_smile.gif

sorry didn't read the last posts

disc0monkey

11-18-2004, 04:40 PM

sorry i see someone already suggested it, my bad...guess im not the only one that is happy with these motors, and they get good mpg and take a **** kickin

Turbo Indian

01-02-2005, 05:10 PM

why not do a Buick Grand National engine?, 3.8 turbo, with 42.5# inj, stock apearing 61 mm turbo, 200r4 trans with lock up convertor I went 11.20's in a 3658# car @ 26mpg. I then switched to 55# inj went 10.96 @ 125.9 & still got 22 mpg!!
I have thought about doing this to a 67 gto. I have already done this swap to my 67 firebird, it is priamary a race car, it will see the street only to cruzins.

Engine-Ear

01-07-2005, 08:14 AM

thanks for sharing the info, everyone!

I am planning an engine swap in my '89 GMC pickemup truck...it's got a v6 (5 speed standard tranny) that goes thru a LOT of oil right now.

Stay Tuned!!

pontiac_fanatic

01-10-2005, 10:16 PM

I am just adding my 0.02 here but IMO, the 4.3L Chevy V6 is junk. It's a pickup engine and will run out of breath real fast. TBI--at least from GM--sucks too. I think you'd be very disapointed.

Get a 3800 Series 2. Be faster and better on gas.

Whatever you do--get an engine from a RWD car not a FWD one. There are differences in the block. So a Impala (FWD) won't work easily.

67Vert428

01-18-2005, 10:46 PM

Well, for ease of installation and similarity in drivetrain have you considered a complete powertrain swap of a 5.7l Roadmaster TBI? The TBI was GM's simplest setup. The ECM's can be easily recalibrated with a custom chip, and the VSS's aren't in the dash but the trans -- which is overdrive. This, I think, would make an excellent swap. Vintage would be '91 or '92. The transmissions are not electronic yet and OBDII didn't start till '96 - no converter monitoring, which means effectively you don't have to run one; the computer doesn't care.

tininjun67

01-27-2005, 02:22 AM

you can run a converter in your car without fear of starting it on fire. that law was in place when leaded fuel was still available. if you put an injected motor in, it would only make the car more emissions friendly.
good luck with the project whatever path you choose. Virtually any new electronic controls can be converted into stand alone set ups for installation into an older car. Don't let that scare you. The tbi stuff from GM is ok, easy to install, but don't expect a lot of performance from them. They are the workhorse of the efi world. Aftermarket controls tuneable with a laptop would be ideal, then harness mods, chip burning or pcm flashing would not be an issue. however, price, the need of a laptop, and tuning ability come into play. If you're just going to bolt in a stocker, the stock program should be fine. An older 700r4/4l60 (94 or older) is still cable driven on the speedo, so that problem could be avoided.

Quadrajet

02-19-2005, 05:03 AM

Originally posted by pontiac_fanatic:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I am just adding my 0.02 here but IMO, the 4.3L Chevy V6 is junk. It's a pickup engine and will run out of breath real fast. TBI--at least from GM--sucks too. I think you'd be very disapointed.

Get a 3800 Series 2. Be faster and better on gas.Whatever you do--get an engine from a RWD car not a FWD one. There are differences in the block. So a Impala (FWD) won't work easily. </div></BLOCKQUOTE>

I agree from a performance standpoint the 3.8 "K" motor is probably a better choice than a 4.3 IF you want to deal with retrofitting OBD 2 electronics. You are only going to find a RWD one from a 96-02 F body. Boneyards aren't exactly littered with them. Theoretically, I suppose you could even add on a supercharger from a VIN "1" 3.8, which again means more screwing with electronics.

Calling the 4.3 a piece of junk is a little unfair. It is a much simpler swap and a much easier piece to find. They are torque monsters (for a V6) and would provide happy driveability in a midsize muscle car.

My opinion is that most people who think about doing this type of swap end up scrapping the whole plan. I once considered it, but when you add up the cost of getting a fuel injected v6 to work in an older application, it costs considerably more than dropping in a carbureted emissions free, computer free V8 that will decidedly outperform it.

Imaginative, yes. Cost effective, no.

TinInjun

02-22-2005, 04:40 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Quadrajet:
I suppose you could even add on a supercharger from a VIN "1" 3.8, which again means more screwing with electronics. </div></BLOCKQUOTE>

Nope as you stated at the end of your post, "Cost effective, no" The Vin 1 motor has it's own cylinder head, so you would have to buy the heads with the supercharger. The difference being the injector is mounted in the head on the Vin 1 motor because of supercharger clearance problems. Also the Vin 1 superchargers intake is on the back side. This would cause intake routing problems with the firewall. The Syclone or turbo 3.8 motor would be the easiest and more cost effective way to go. If your not looking for big time power, the 4.3 is a great way to go. It can also be built to make good power.

Quadrajet

02-23-2005, 05:48 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TinInjun:
Nope as you stated at the end of your post, "Cost effective, no" The Vin 1 motor has it's own cylinder head, so you would have to buy the heads with the supercharger... </div></BLOCKQUOTE>

Just one more example of why I don't think I'd ever do this personally. How long would it take for the nominal gain in fuel economy to offset the extra cost of this type of swap? (rhetorical question). In my opinion, if it costs $5000 (as an example) to get a moderately performing V6 into a nice pre-emissions vehicle, I would just go out and buy a nice moderately performing post-emissions vehicle for $6000

disc0monkey

02-23-2005, 05:16 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by pontiac_fanatic:
I am just adding my 0.02 here but IMO, the 4.3L Chevy V6 is junk. It's a pickup engine and will run out of breath real fast. TBI--at least from GM--sucks too. I think you'd be very disapointed.

Get a 3800 Series 2. Be faster and better on gas.

Whatever you do--get an engine from a RWD car not a FWD one. There are differences in the block. So a Impala (FWD) won't work easily. </div></BLOCKQUOTE>

I think the 4.3 will out run a 3.8 anyday, its a nice long stroke v6 mine is SFI but with a intake, cam, and converter its really stout, stock they are very torquey which is good for his car. second the sy/tys were nasty with the turbo setup as were the TTAs and GNs, looking at dyno charts 4.3Ts have better power bands.

pontiac_fanatic

02-23-2005, 05:47 PM

okay I revise my statement a bit....junk is a bit harsh--but I wouldn't be putting it on Wards 10 best engine list.

Certainly the 4.3L SFI or I think they are CPI--central port injection is better the the TBI

(its not 270lbs-ft though...260 was the highest it was ever rated and it was dropped a bit down rom there i think)

but I have driven the SFI (CPI) ones and I was very unimpressed. Kind of rough and unrefined, I think. Probably durable though.

A 4.2L I6 would be a killer swap (pricey though)--put the OHC badges on and have some fun

Turbo Indian

02-23-2005, 06:05 PM

[/QUOTE]
the sy/tys were nasty with the turbo setup as were the TTAs and GNs[/QUOTE]

Turbo Indian

02-23-2005, 06:12 PM

the sy/tys were nasty with the turbo setup as were the TTAs and GNsQUOTE]
I have 2 friends that have syclones, well actually now one because 1 sold it because his dads Buick T type would allways kick his ass. the syclones have poor head design, & it takes mega $ to get these trucks to run decent #'s. I'm not saying these are not cool trucks, but when it costs 3 times the amount of the $ to get these trucks run, it's not worth it.

Quadrajet

02-24-2005, 05:06 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by pontiac_fanatic:
Certainly the 4.3L SFI or I think they are CPI--central port injection is better the the TBI
... I have driven the SFI (CPI) ones and I was very unimpressed. Kind of rough and unrefined, I think. Probably durable though.

A 4.2L I6 would be a killer swap (pricey though)--put the OHC badges on and have some fun </div></BLOCKQUOTE>

The W motors are CPI, and like the fuel pumps I sell a lot of those pieces too.

If you want an Overhead cam inline 6, I've got a '68 OHC-6 pontiac sitting around. Swap that in and you'll still be all pontiac and avoid getting ragged on for putting a chevy between your fenders. http://forums.performanceyears.com/groupee_common/emoticons/icon_biggrin.gif

mike nixon

02-24-2005, 10:50 PM

if you were closer i'd be able to hook you up with a 3.4 drivetrain /harness ect from a 95 bird.

actually a mostly complete 95 bird less nose/int and the big dent in the right side.

the tbi 4.3's weren't bad engines as stated before the don't turn a lot of rpms and the mileage isn't as good as other choices.

no way in hell would i transplant a cpi 4.3 into anything. parts are expensive and once they get some miles on them the use a lot of parts.

for the guy who mentioned oil consumption in a 4.3 i'll bet the oil rings have rotated around and lined up with each other. in the early 4.3 engines this was common.

mike