77amc

Good morning.
Just to start by saying I've been working on vehicles/machinery for almost 30yrs but have ventured into uncharted territory 'so to say' by trying to adapt a LT1 into a BMW 328i convertible. (and FI systems for that matter..)
The LS swaps would be just tooo expensive for me and picked up two Lt1's and a Fleetwood 4l60e,complete harness for under 500.!!

What I would like to is build a test stand to get it running BEFORE I install and wrack my brain combining the LT1 and the BMW cluster (to say the least..)
I've spent months reading and building up a pile of parts.
I'd also like to strip down the Fleetwood harness from what is NOT needed so it would be easier to adapt.
(What would be better ECU.. The stock caddy or the 411 OBD-II..? ) Or would that just complicate things more?

BUT, What about the over-flow, cooling tanks that are usually behind the pass side headlight on the GM's. Are they ABSOLUTELY NEEDED? or can one run JUST a conventional type of cooling system?

And if you feel it necessary to flame this thread.. WHY? ..Haters..


And if this works out pretty well, I have a source for a 4.3 LT1 in a Little mighty max truck.

E

Injuneer

You need a recirculated fuel supply (43.5psi), a recirculating coolant supply (has to have a radiator to remove heat), a 12V power supply. Not as simple as it sounds.

This is an LT1 on an engine dyno - but same concept. Fuel supplied and returned by the braided S/S lines, coolant supplied and returned via the rubber hoses in the lower left. The engine test cell has all those systems built in.

96capricemgr

Once you strip down the harness you will find very few wires need to be hooked up, that will make things a lot clearer for you.
I would use the 95pcm cheap and easy to tune.

Far as cooling you can run a surge tank system.

The 411pcm I believe needs much more expensive tuning software. Like more expensive than the engines and tranny. The 95 LT1 pcm there is actually free programs though I would instead buy Tunercat, TTS Datamaster and a cable for a total of around $250.

ACE1252

Be sure of what you are getting. I think they made a 4.8 LT1, but not a 4.3.... the 4.3 will be a V6.

Injuneer

The "Baby LT1" is the L99, 265ci = 4.3L

lt1-xjs

Some people are quite capable of reworking the fi harness, I was not. I used Speartech, they eliminate what you don't need, reprogram the computer and you have 4 or 5 wires to hookup and run. It made my install a piece of cake.

Injuneer

Your 93 will have less wires - no MAF, 2 injector wires rather than 8, single wire O2 sensors, etc.

77amc

Injuneer: So, which harness would be better?

'94 Fleetwood harness (the one that I have already, but burnt apart where the goofy EGR pipe runs in back, and would need to be spliced back together)

'93 Camaro Harness? (the other engine that's only 70K mi) but non-vented opti.. (actually don't have this one, just the engine. BUT would I need a specific harness to a certain year engine?)


I'm all ok with the fuel, cooling, yadda yadda. I just needed to know if one HAS TO have that goofy overflow tank?
A couple of years ago I helped out a bud who needed money, bought his '96 Z28 that was overheating and had a TERRIBLE time getting that thing to run without overheating.
Ended up selling because of that.. NEVER could get it to bleed right.

I really hate wiring in the first place, and would just love for someone who has gone down this road to chime in and say.. "Hey, Here's a color coded schematic of what I did to get mine running.. What? OH, you are gonna need the routing for the cooling lines too! HERE.. I got that also!!"

E

Injuneer

I don't know anything about the B-Body harness or PCM, so I can't respond on that at all. I'd start with the aluminum head F-Body engine to save weight, but that's not a popular opinion with the B-Body owners, who will challenge my assertion.

As far as an F-Body harness, its got to match the PCM you plan to run. 93 is set up for speed-density and batch-fire injectors. The IAC connector is different as well. O2 sensors are single wire, unheated. All other years are mass air, full sequential, same IAC connector, 4-wire heated O2 sensors. 94/95 will be OBD-I - cheap tuning, less invasive emissions diagnostics; 96/97 will be OBD-II - cheap scanning, more expensive tuning and more invasive emissions diagnostics (which can be "programmed out". If you strip enough of the superfluous emissions diagnostics out of the 96/97 PCM and harness, the 94-97 harnesses would become interchangeable for a transplant to a non-F-Body chassis.

There's a minor glitch at the coil (double connector 94/95, single connector 96/97), minor glitch on the Opti connector (short connector 94, long connector 95-97 - but the short Opti harness extension is replaceable).

77amc

Looks like I'll just use the B harness, ECU etc.. BUT i'll have to pull the iron heads on the Caddy motor to see what kind of mileage the bores look like. and then use the ported z heads of course.
Then you scared me by reminding me that sometimes I don't know what the heck I'm doing messing with fuel injection.. NOW I WON'T BE ABLE TO SLEEP!!

AAARRRggghh!!

E

96capricemgr

The weight difference on the heads is about 45lbs, people like to make a big deal out of it but we are talking the weight of 7-8gallons of gas. Do you keep your hotrod low on fuel to keep the weight down? Probably not as this is not that big a deal.

Ported aluminums should be a big upgrade over the iron heads though so if you have PORTED heads do it. I would not bolt as cast aluminum heads on though. If that was the option I would save the aluminums for later porting with no downtime.
Bores on these don't show wear unless run badly overfueled or something. 200K and you should still see crosshatch.

Far as the cooling, just so long as you route the steam tube back into a circulating part of the system you are good and do not need the circulating pressurized tank.

Injuneer

As predicted.

I would think 45# on the front end of a BMW would have a significant impact, but I suspect the OP knows the front suspension capabilities better than either of us.

77amc

Thanks for the responses guys.
I really wasn't thinking of the weight at all.. More of heat dissipation since the radiator isn't HUGE, just med size.
With the advantage of no dizzy in back, It may afford me to put the engine back further than even the stock engine was.. Thereby helping any weight issues. ALthough probably minor considering the mani's, mounts, and all the other stuff on the front of the LT will add up. BUT hey.. I think it will be more fun to watch Biffy or Scooters face when I dust them off Just won't be that often with 5.00/gal gas

I have read in several areas that the iron heads flowed better compared stock=stock.
BUT, the alloy heads had sodium filled valves and I took these heads apart probably over a year ago, ported them and they got a little flash rust on the rocker studs. DANG.. Gotta find that box of valves! (kinda 'hid them' on myself)

Again, thanks.

E

Injuneer

Only the LT4 has sodium filled valves.

77amc

OK, got another Q. Found a used Hypertech Power programmer for sale and it was for a '96 impala.
Of course it connects to the OBD port, but isn't that port usually UNDER the dash instead of in the engine compartment?

I mean, if I'll try and make a harness to run on a test stand, and the OBD connector is under the dash, Is there any other wiring that HAS TO contain wiring from the dash?
Because if I use either the Programmer or Laptop, they would BOTH need to connect there correct?

In other words, If I pay out for a UN-CUT engine harness, is that enough or would I have to pay extra for the port connector, and wire that in also?

Thanks E