• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Contemplating Top Swap

orange57

orange57

New member
Well I'm contemplating a top swap on the 04 GP GTP. Basically, I can find a N/A motor from the same year or newer, with low miles for a pretty good price. About a third of what I can find a S/C version used for. The motor I have has a slight knock in the bottom end. I'm trying to put together a list of what parts I will need to complete the swap. Please let me know if this is correct.

Head Gaskets
head Bolts/studs
LIM Gasket
UIM Gasket
Valve Cover Gaskets
PCM Tune


From what I have read, the bottom end and con rods are the same between the L26 and L32, with the L26 having a higher comp ratio. Please add to this list as I am going to start gathering parts for this. I already have the LIM and UIM Gaskets.

thanks,

matt
 


Where does one get rocker bolts? Does ARP make them? Anyone have any part numbers?

I think I may go with the ARP Stud Kit for the heads for this, and may order the rocker bolts at the same time if they make them.
 


Honestly get zzps top swap gasket kit, it has EVERYTHING. Also dont try to run a 3.8 pulley on the high compression without headers or e85. Be aware your injector connectors might be wrong. If you want to avoid having to run the dual belt setup you can run ZZPs ssm90 pulley all the way down to a 3.4. Also be aware that a stock supercharged pcm will require a 2 bar map sensor. In your case just buy a 2004+ gtp sensor. Also I recommend all 97+ top swaps run a 2004+ map sensor as well because they are plug and play without cutting wires. Another thing to remember is you dont need the boost bypass solinoid so I wouldent bother adding the wiring. Just tune the boost solinoid check engine light out. Also while you have the heads out its the perfect time to do valve seals at least if not springs as well so you can shift nice and high. Only takes a hour or two with the heads off the car.

I have done 3 top swaps so far so I have hit all of the stumbling blocks at least once. In fact here is the most recent one I helped with.

http://www.grandprixforums.net/topswap-bonnie-build-82238.html
 
Frosty,

Thanks for the tips. I actually have all the parts listed in the kit already except the Head bolts, Rocker Bolts and Head Gaskets, as I was planning on doing the LIM on the car.

I have an 04 GTP and have a slight knock. However, locally, a S/C 3.8 start out at around $1300, and all have 100K plus on them. I can get a 04+ N/A with 10K to 50K miles on it for around $400-700. So that is the reason that I am looking to top swap. I would have all the parts from the GTP and use the N/A, swap everything over and swamp the motor out.

I guess I will have to see if I can find some headers as well. Don't want to blow the engine right after a swap.
 
I doubt you would blow it considering stock engines can have 8+ degrees of kr and drive every day without issues. You have to worry when your running something silly like the 2.8" pulley I have. If I kr I could chunk a piston quickly.
 
i am wanting to run everything stock for now, basically just a short block swap. will headers be necessary? or can that mod come down the line? the GTP has a MPS with the 3.8 pulley on it now. If headers arent necessary i'd like to hold off, as i really just need the car driveable, not a performance machine right now.
 


frosty said:
Honestly get zzps top swap gasket kit, it has EVERYTHING. Also dont try to run a 3.8 pulley on the high compression without headers or e85. Be aware your injector connectors might be wrong. If you want to avoid having to run the dual belt setup you can run ZZPs ssm90 pulley all the way down to a 3.4. Also be aware that a stock supercharged pcm will require a 2 bar map sensor. In your case just buy a 2004+ gtp sensor. Also I recommend all 97+ top swaps run a 2004+ map sensor as well because they are plug and play without cutting wires. Another thing to remember is you dont need the boost bypass solinoid so I wouldent bother adding the wiring. Just tune the boost solinoid check engine light out. Also while you have the heads out its the perfect time to do valve seals at least if not springs as well so you can shift nice and high. Only takes a hour or two with the heads off the car.

I have done 3 top swaps so far so I have hit all of the stumbling blocks at least once. In fact here is the most recent one I helped with.

http://www.grandprixforums.net/topswap-bonnie-build-82238.html
Click to expand...

Hey! that's my build! haha, but yes, Comp cams reusable rocker bolts were great and plus one to everything else these guys Said, and I'd highly recommend headers or e85
 
if you already have a mps and don't want to do headers go up to at Least a 4" pulley if not 4.2" because You will hit KR much easier
 
i dont think i saw anything bigger than a 3.8 on zzp. either way, i need to get the engine and do most of the swap work first. I am leaning towards headers instead of a bigger pulley. it will be a while before I am at that point, as i dont have a lot of free time, so the swap will be done slowly.
 


You guys may be a bad influence on me. Too many choices. So if I think about it....a S/C 3800 would cost me somewhere around $1300 ish, with higher miles. I think I may be able to do a top swap with a low mile N/A engine, and get a cam and headers and make a descent amount of power.....need to clear the work bench off in the garage.
 
orange57 said:
You guys may be a bad influence on me. Too many choices. So if I think about it....a S/C 3800 would cost me somewhere around $1300 ish, with higher miles. I think I may be able to do a top swap with a low mile N/A engine, and get a cam and headers and make a descent amount of power.....need to clear the work bench off in the garage.
Click to expand...

I did, see my sig... and so far my best time in the 1/8th mile is 8.7@83 with still tire spin off the line giving crappy 60' times... My L26 motor was very low mileage, like 17K, and only cost me $500. I have a thread that shows the inside of it when I tore it down for the swap. Clean as clean can be.. :D
 
db, do you have a link to your thread? This is mostly going to be what happens. I am going to pick up an engine stand this weekend and look to get a low mileage N/A motor next week and start tearing things down.
 
You must log in or register to reply here.
Back
Top