Top Swap for Supercharger L36 to L67

broke_collegekid

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Anyone ever do a top swap on their regular 3800 Naturally Aspirated engine? I'm reading about it a lot on Grand Prix forums but haven't found much info specific to the Lesabre, despite the engine and process most likely being the same. Top swap is basically swapping out the top half of the engine from my L36 naturally aspirated to the top half of the supercharged L67 engine. I'll be going to the junkyard today to pull some parts off some cars I've been eying as well. Any info would be appreciated!

My transmission is in good enough condition after I installed a shift kit and new fluid/filter. Hard shifting is gone even after driving for a while in the summer so I think it's in good shape.
 

2007LucerneCXL

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You can check 3800pro forum, all others that deal with this for that matter, for additional information. I would recommend writing up a build sheet on what is involved and parts, also add a budget for possible reconditioning of parts.
 

Ultra Ego

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Probably the two main obstacles you will have is 1) The compression ratio of the N/A engine is higher. Pressurizing that will more easily cause detonation, and 2) You will need to remap the ECU to change how much fuel is delivered at a given rpm and load.

You may be able to buy the ECU from the boneyard where you are buying your supercharger. With a different compression ratio, even that computer will be off, but not as far off as your N/A one.

There are writeups on the 3800 forum, and other places. 2007Lucerne is correct. Make a list of the parts and see if it is financially possible.
 

2007LucerneCXL

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Just tossing this in as it has somewhat of a build list, not saying that the ZZP kit is or isn't a option. They kind of run down what's needed, which may be a little bias lol, but it's not bad having something to start with.
L36 Supercharger Kit
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broke_collegekid

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Just tossing this in as it has somewhat of a build list, not saying that the ZZP kit is or isn't a option. They kind of run down what's needed, which may be a little bias lol, but it's not bad having something to start with.
L36 Supercharger Kit
Yeah I took a look at that kit, which seems pretty expensive relative to what I could get buying the main parts at a junkyard and buying new gaskets/fluids and a pcm tune. The kit actually has custom parts made by ZZP to make the top swap less cumbersome, since if I use l67 parts it looks like I'd need to switch a lot more parts out including the heads.
 

2007LucerneCXL

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Yeah it's up there on price, but its good shopping list of what's needed to do a used L67 top end swap. Really more for a FYI as some of the forums are a little light on details of what may really be involved.
 

Thunderhawk09

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going that route sounds like It would be better just getting entire L67 donor engine you could have the whole thing swapped in less time than tearing that one down and building it back up when I did my engine swap for two bad cylinders took 9.5 hrs
 

MelsRegal

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Yeah I took a look at that kit, which seems pretty expensive relative to what I could get buying the main parts at a junkyard and buying new gaskets/fluids and a pcm tune. The kit actually has custom parts made by ZZP to make the top swap less cumbersome, since if I use l67 parts it looks like I'd need to switch a lot more parts out including the heads.
You did read the part about compression ratio? Seems like an excellent opportunity to grenade the engine the first time you get on it. Installing a complete engine is the way to go.
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broke_collegekid

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You did read the part about compression ratio? Seems like an excellent opportunity to grenade the engine the first time you get on it. Installing a complete engine is the way to go.
I don't have much technical car knowledge lol. All I'm reading is that people seem to be able to succesfully "top swap" a L36 engine.

After what you guys are saying I will look into the idea of buying a whole L67. I was more into the idea of the top swap since it didn't seem to have to involve an engine hoist.
 
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