Punchline: I successfully did it

A lot of people didn't think it could be done, but using a Series I L67 from a '95 SSEi, I was able to transfer the */C specific parts onto my '89 LN3. I will say now that it'* not in a Bonneville, but in my Buick Reatta. I've posted heavily on the Reatta.net board about my project, but thought you guys would like the info and photos. I find Bonnevilles to be pretty cool anyway. I've got 40+ photos with narration. Really, it took like 2 months for me to get it done, but I don't drive it during the winter so it wasn't bad. There'* a lot of info and details that I'm going to forget to say here, so feel free to ask away. Most photos were taken with my Canon Powershot A80, but sometimes I slacked and used my Palm Treo 600.

Who am I? My name is Philip. I live in Dimondale, Michigan. I'm 18. I love working on my Reatta and my 2 Ford Explorers. I've got over 2k posts on the Reatta board and 1500+ on the Explorer4x4.com forum. I do all my own maintenance and most repairs. Most I've probably taken on was either this project or changing the tranny in my '92 XL. I'm not a ricer boy, spoiled, etc.



My ECM, sans memcal. Ryan of GMtuners did my ECM program.



The engine I bought. Good running (or so they say) with like 155k miles. Not really an issue. I found that the tensioners and idlers were recently replaced and, I don't know much about these */C units yet, but it felt okay when I spun it. Didn't get to hear it run, but oh well.



Crankshaft end of the motor I bought. It'* pretty clean.



Top view. Got the injectors and fuel rail off already.

Injectors, fuel rail, and tensioner assembly. It'* much bigger than the LN3'*. A tight fit, but it did indeed bolt up.



Throttle body off of the L67. It'* considerably bigger than the LN3'*



Supercharger off of the intake manifold. It may have been better to keep it on cuz I had some issues with getting the gasket and O rings to seal, but mostly because of my lack knowledge in internal engine work. Learned a lot, quick, though.



You guys may be familiar with this view, but the bottom of my */C. I did let the oil drain out for a few days (and rolled it around) and replaced with genuine GM */C oil.



Manifold off of the L67. Not much to see here. I did not use the L67 heads.

Why did I take this approach? After much research, I figured that the engine internals (pistons, crankshaft, etc) of the LN3 weren't weak or anything and could tolerate boost. Swapping out the entire motor would also be a PITA. Didn't want to go Series II because it'* expensive and challenging to get like a '98 PCM to interface with the Reatta'* IPC and ECC (touch screen console).

copy and paste the thread on here or post it up here in a new topic....ppl here are interested and ALL the details

Left is the L67 throttle body and LN3'* on the right. I'm using the L67'* IAC and MAF but the LN3'* TPS.



This is an LN3 intake manifold gasket up to the L67'* manifold. Notice the round PCV port, but that everything else will match up just fine.



On top of my dad'* Reatta convert. spoiler, is the L67 gasket on the bottom and LN3 on the top. I bought both sets for comparison but didnt use the LN3 stuff.



Under the hood of my Reatta (like my Teves ABS?). Throttle body off.



On my LN3 again. Notice the throttle body heater lines.



Injectors and fuel rail off. We are not using EGR anymore.

Intake manifold off. Notice that the LN3'* alternator and power steering pump are on top. The alternator will later be about where the P/* pump is, and the pump will be like "down and back" I guess. Also notice that the pressured fuel line goes to the front of the motor (L67 fuel rail ports are on the back)



L67 intake gasket on my LN3 cylinder heads. The PCV port will just kind of dead end there. No big deal. I will later explain how I made my PCV system.



Bottoms of the manifolds. Coolant and intake ports are the same.



The line in yellow normally connects to the throttle body for PCV. Valve sucks through the intake manifold. The L67 manifold doesn't provide for this, so, I ran this line to the Fernco I used with my new cone air filter. I had access to another junker LN3, so I stole the front valve cover from that (with the PCV line). So, its rigged up so I have two front valve covers . The rear line is connected to vacuum that would normally be used for the power brake booster. So, I have a pretty good loop of clean air. I asked some smart people on the Reatta board and we concluded that PCV is important.



Harmonic balancers. L67 left, LN3 right. They're really the same. The L67 balancer is supposedly tapered and needs a puller/pusher and the LN3 pretty much falls off without the center bolt. There was an odd ridge in the L67 balancer which we had to get rid of to get it to fit, but it'* otherwise perfect. The interruptor rings for the CPS are slightly larger in diameter compared with the LN3, so I used the L67 CPS. Signals and connector are the same.



The L67 balancer is not so much bigger, just uses the space it already has I guess you could say. The one I got with the engine seemed to be in good shape. I suppose one could swap the interruptor rings and use the LN3 CPS, but the LN3 used some weird propriety hardware that looked like it took Torx sockets but doesn't.



Not much to see here.

Intake manifold, coolant tubes, and tensioners fitted. No issues with them bolting up, though tensioner was difficult to deal with due to the lack of a lot of space. Notice the P/* pump. I did have problems with the intake manifold gaskets leaking, due to my improper torquing, but I later got it figured out and it'* doing fine.



The LN3 P/* pump has a resevoir attached to it which wouldn't work here, so I removed it and rigged up this. BTW, we're a family of plumbers :P



Harmonic balancer fitted. The LN3 uses a tiny shock absorber in front of the balancer. Was not an issue with it fitting though. I replaced my water pump last summer. To make it short, I got p!ssed with it and just used RTV. Hasn't leaked though.



Postdated photo. Notice my sexy second valve cover. I should have painted it, but oh well. Something else I'll have to do eventually.



Some chopping on the tensioner assembly we had to do to clear what I think is the oil pressure sensor. The L67 uses a different oil filter setup, which was going to be a PITA to swap. Didn't do enough to hurt the structural integrity of the assembly.



Work so far. Took like 2 months do to it all. Finally got to drive it yesterday.



The big boomin M62. You can see my plumbing for the heater core.



Me looking cool.



Throttle body region. I later switched back to the LN3 throttle cable "plate". Doesn't quite fit right, but good enough, because the L67'* doesn't have a provision for the transmission cable.



God rid of my stock airbox and got this sexy APC filter. K&Ns cost too much. Radiator hose is stock Reatta, but with an inch or two cut off each end.



The MAFs have the same basic part numbers, but the l67 has this goofy thing around the wires. I asked Ryan which to use, and he said the L67'*, because he programmed my memcal to work with it. I guess from how I understand it, the LN3 ECMs have a limit as to how much airflow they can recognize, but he did a pretty good job.

That'* about it. As I said, there'* lots of details and minor problems we had to create solutions for. I don't yet have a "done" picture, but will get one. Not a problem if you want details on something or special photos.

Ryan'* first memcal burn was dumping in too much fuel, so he sent me a socketed setup. But we also found out we had an issue with the harmonic balancer not fitting on the keyway, throwing off timing. Actually couldn't get it started until we figured it out. Not a problem once we figured out what happened though.

Fine tuning needs to be done, but it'* running pretty good. Idle was high, like around 2300 rpm at first, but after a bit of driving, is back to below 1k. I haven't driven it much this weekend (just on our street, rural) cuz its not insured yet, but will take care of that tomorrow and start driving it.

So far, we're at least to stock Reatta performance. I haven't driven it in a few months, so not always easy to tell, but I think it'* helping. Can make decent takeoffs without much throttle. Seems to be bogging a little with WOT, but I'm talking with Ryan on taking a drive down to him for final tuning. Nice to hear the */C whining a little with a generous amount of throttle

I don't know the Bonneville Club'* policy on links, but below is the link to the Reatta.net thread (complete with all my troubles, 2 months work of documentation, really).

http://forums.aaca.org/showflat.php?...sb=5&o=&fpart=

They said it couldn't be done. I did it.

I'm not sure who was telling you it couldn't be done. I presume it wasn't someone here. jr's3800 has spoken many times here how similar the heads and intake ports are between the LN3 and the L27/L67. We've know the swap was possible for some time, but it'* just not practical.

The full drivetrain swap is much more practical from an economic and durability standpoint.

Kudos to you for doing it, and I hope it holds up. (I really don't expect the trans to hold for long, but I do wish you the best).

Thank you willren. Actually, nobody said exactly that it couldn't be done, but a few thought i was a dumb@$* for thinking of the idea.

We'll see about my 4T60. I don't know a lot about these units, but we have a really good auto tranny mechanic as our neighbor and could probably build a performance-oriented 4T60.

Problem we looked into was an ECM (or is it BCM?) that could run a 4T60e and still interface with the touch screen Electronic Control Center

GMtuners did know you had a 94/95 M62, TB, and MAF, right?

yes sir