Trevmust

I was wondering if I could swap a LC9 GMC sierra engine into my 86? It's an LS engine so hopefully it mounts the same... But I want it because of the AFM system which would make my gas mileage astronomical hahaha. I sure hope I can pull this off...

Atilla the Fun

We already have a thread about this. Do more searching.

johnw999

I searched, and I came up with this question. I bought an LC9 in February. Anyone want to offer input other than the typical "search newbie" comment?

novaderrik

the cylinder deactivation may or may not add gas mileage, but it will definitely add a couple of extra layers of unnecessary complexity..
this isn't just a simple engine swap scenario- what is your level of knowledge with cars?

johnw999

I've worked on cars, but I'm not a mechanic. I have an 84 trans am, and I've spent some time researching and planning an engine swap. Like most, I considered a rebuilt 305, a 350 crate engine, then a ZZ4, a custom built 350, etc. Then I finally came to the realization that an LS is better, do-able, and not nearly as expensive as I first thought. I'm in my 40's, and I have the time and resources to patiently and properly restore the trans am. I've made good progress with the suspension and brakes. Here is where I am now:

the demand for used LS style engines is up, so a good quality used engine and transmission was a little difficult to find. I found an aluminum 5.3L with low miles for under $1500, so I bought it. I also found a used T56 for a good price. But, I just didn't realize the LT T56 differences and the vvt/afm of the gen iv when I bought. I thought I had a good understanding when I bought, but I didn't. I had to upgrade the T56 anyway, so I got the shop to convert it to the LS style as well. Now I'm ready to deal with the engine. I want reasonable power with the option to upgrade to a remote turbo later. I'll get the DOD delete kit. Now I have to figure out the cam. My questions:

-Will the stock VVT cam be able to handle 8 psi boost?
-If not, I'll get a VVT delete kit and a new cam. Texas Speed and Performance recommends a 220 on a 114 lobe. Can a 3 bolt cam work with a 58x reluctor wheel? The LS book from Texas Speed says a Gen III camshaft can be used in a Gen IV, but I don't see how yet.

I appreciate any help you can offer.

88FormulaKiller

iTrader: (8)

VVT-getting the ecm to be able to control the feature with boost hasnt been figured out with stock or aftermarket ECM's yet i believe as I've looked into this as well as i wanted to retain the VVT and delete the DOD/AFM, also the weak VVT link is in the lifters, puttin high stress on them such as boost or other performance mods to the engine which will increase the chances of failure as they already have issues.

If you delete VVT, you need to swap the cam gear out to the new camshaft to run a Gen 3 cam and get rid of the cam phaser. Dont forget its an E38 or 39 ecm (or an E60 in your case since you want to run a 6speed MT). Ive found a few headaches with how i want to run my own LC9 so ive decided to just rip it down, swap to 24X, delete AFM/DOD/VVT and run it off an 0411 ecm with twin S/C'ers, eccentially a Gen III motor. It'd be nice to run a Gen IV ECM but I want DBC and its just too much of a pain in the ***. Especially with GM's new O.S's for these ECMs.

Since Ive had my LC9 for a few weeks and have done my research on it, my own opinion on it for a swapper is this, buy an L33 5.3 instead lol. I'm keepin my LC9 only becuase of the base cost i got it for. Good luck

johnw999

Thanks. I talked with Texas Speed and Performance, and I went with their recommendations. They were very helpful. I bought a 220r cam on a 114 LSA. It's supposed to work well on 5.3L engine, and it will still be able to run boost without a problem (I may add boost later). I also got a DOD delete kit and a VVT delete kit. The cam is a 3 bolt, and it can work with a 58x reluctor. You probably know better at this point about the reluctor. Will changing the reluctor simplify the swap? I plan on using a Holley Avenger ECM or a Chevy performance ECM that is designed for engine swaps. I don't want a used ECM from a LS camaro that has security stuff disabled.

88FormulaKiller

iTrader: (8)

changing the reluctor to 24x will simplify the swap as far as using a mail order tuned 0411 ECM and brings ECM cost way down, but changning it requires crank removal and not everybody is up for that.