3800Pro Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hey, so I currently have a 2000 monte carlo ss, fair amount of work done by previous owner (brother) but not sure entirely what other than headers back exhaust replacement. Due to a fuel line leak the top end exploded.

I have recently acquired a complete engine from a 97 gtp with everything except the starter in good condition.

I am wondering if I would be best off just doing a top swap, doing top and lower internals or a complete swap. I have heard the monte is high compression pistons while the gtp low and am guessing there is likely other issues I am unaware of so looking for pro/cons of each and advice. I am by absolutely no means a mechanic but have done 2 straight engine swaps (identical) and one rebuild personally as well as countless minor repairs or helping friends. Essentially tell me go change "x" part from a pile and I may look at you confused but hand me "x" part and I can probably change it as fast as anyone lol
 

·
Super Moderator
Joined
·
562 Posts
You'll need the ability to tune the computer, or buy a reprogrammed one specifically for this ($300 or so). It's not horrible, but there's more than just bolting the parts together that happen to fit nicely because it's from almost the same engine. (I've said a better version of that 4-5 times in the past few months here.)

Up to you if you want to prepare by calling a vendor such as ZZP, and order a computer tuned to have it running with the PCM they'll program and ship you back. Since it's a non-supercharged car, it's pretty safe to say there's not much actually done to it that you'll be losing in the previous engine. Modifying regular 3800's wasn't a very worthwhile endeavor (oh, and the "high" compression is just 9.4:1 compared to the supercharged 8.5:1, but if you're not going to be doing much beyond the swap, it's safer to stick with the GTP block as-is).
 
  • Like
Reactions: abyss0

·
Registered
Joined
·
5 Posts
Discussion Starter #3
Thanks for pointing out the ecm, was aware of that and haven't decided if I am going to grab a programmer myself or get just send it off to somewhere to get done. Ya most of the work was done around the idea that it would eventually get either super or turbo charged so it is all external to the engine like the exhaust and cold air intake, I know he did a fair bit of work to it just not really sure what besides those two things.

Again not really a mechanic, are their issues I should know about regarding the compression difference? To my line of understanding I would get higher power from keeping the higher compression but add additional stress to components but have been told before their is more to it than just that.
 

·
Super Moderator
Joined
·
562 Posts
Read the LeSabre thread comments, particularly the one I said in the past 24hrs regarding the compression differences (benefit of having a long-lived forum vs. disappearing social media discussions). It's splitting hairs, honestly, and comes down to how much extra parts/work you want to invest before putting it together. Based on your comments thus far, the simpler swap of not having to dig into the engine would make things far more simpler than dealing with tearing 2 engines down for a minor change in the end. That doesn't even take into account what may or may not have happened to your current engine when it failed, and you're about to gamble days/weeks of work that it's not hurt.

If you've made the decision of what you want to do already, go for it and don't worry about getting commentary on it. I'll share my input only because I have, and continue to, assemble these engines in all configurations at all budget levels... there's considerations I try to take based on what people mention when laying out their situation, and I try to suggest things that will get them rolling quicker with a good result and more enjoyment than headache, hopefully.
 
  • Like
Reactions: abyss0

·
Registered
Joined
·
5 Posts
Discussion Starter #5
Appreciate you taking the time to reply and pointing towards the answers I was looking for. Hadn't made any decision as to which method was best for my needs although had been leaning towards keeping the block stock for purely sentimental reason. Most likely thinking I will do a partial rebuild of the new one just to make sure everything is in good condition and then drop that one in. It's fully loaded so not looking to have anything extreme just looking to take it to the next level, after that may stay as is or may get more done. Hardest part being I know I can do the work, I just get completely lost talking to most mechanic friends who get into complicated explanations that you need to know about 20 different engines to follow them explaining.
 

·
Super Moderator
Joined
·
562 Posts
Thanks, and something I always go by... If you can't explain it simply, you don't really understand it (or trying to unnecessarily impress or overwhelm rather than inform). Working in a very scientific job, we deal with this exact issue daily, and I can even point to highly regarded old timers like Dr. Feynman talking about quantum physics on his porch in simple terms.

I think whatever you do under the hood, having the car to drive will ultimately be something you get to enjoy after it's done. Be sure to wear-out various YouTube videos, past forum discussions, and vendor sites to see what all the details are. You'll be more comfortable making a plan and know what it'll require, cost/parts/work-wise, to get things together and running.
 
  • Like
Reactions: abyss0

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Entirely agree with that advice and have lived by it for many years now, I understand enough about enough subjects I often come across as a "know-it-all". I have also been quick to point out there are many subjects I only grazingly or simply don't know and have no issue acknowledging them. Mechanics is one I understand more because I understand the tools than anything else lol
 

·
Registered
Joined
·
33 Posts
Abyss i did this very swap 3 years ago on my 01 ss. The l67 is a damn near drop in and go swap. 4 things that i know will need addressed.

1st the na 3800 uses a smaller toque converter bolt pattern than the sc3800. I used the sc 3800 flywheel and just enlong the holes. I didnt want to use the na flywheel because the rotating assembly are different between the two.

2nd my injector plugs are different because i run e85. But i still think they are different anyway.

3rd the fuel line ends need to be replaced at the fuel rail. The na fittings are at a different location from the sc engine.

4th obviously the engine ecm. You can use the stock monte ecm and have it flashed with a gtp file. If you try to use the gtp ecm the bcm will give you fits with the security relearn but i believe it is possible to use one.
I would also drop in the engine versus doing a top swap. The cons of doing the swap outweighs the pros.
 
1 - 9 of 9 Posts
Top