Piston Change question
Thread Starter
7th Gear
Joined: Nov 2015
Posts: 7
Likes: 0
Piston Change question
I currently have a LQ9 408 in my vette and need to change out one of the pistons. Was curious if anyone knows if I can change out the piston and rod without having to remove the engine from the car, and just swap the piston out? Or am I going to have to pull the engine out of the car?
Thanks
Thanks
Melting Slicks
Joined: Mar 2012
Posts: 2,800
Likes: 456
From: USA
changing a piston
You could change a piston without removing the engine. You will have to remove the oil pan which will involve dropping the front cradle. The engine will have to be supported when the cradle is dropped. The heads can both removed in the car. I pulled the engine from the top to rebuild my LS1. It was not that bad a job but you can definitely change one piston with the engine in the car. Good luck 
Thread Starter
7th Gear
Joined: Nov 2015
Posts: 7
Likes: 0
Awesome thank you, So even though its an LQ9 the piston and rod can be changed inside with the engine still in the block? About how long does it take roughly to swap them out if you know? I really don't want to have to pull the whole engine, so if I can just swap them out without by not having to pull the engine would be a life saver.
thanks
thanks
AMP Racing
Joined: Aug 2006
Posts: 10,754
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
How long it takes depends on how much beer you have...
Get a friend to help and you should be able to do it in a day... A long day... So, maybe two...
I presume you have no desire to hone the cylinder for the new ring/piston install? If it was a junk yard motor, I'd say so what... But a 408 I presume is not a junk yard build.
Get a friend to help and you should be able to do it in a day... A long day... So, maybe two...
I presume you have no desire to hone the cylinder for the new ring/piston install? If it was a junk yard motor, I'd say so what... But a 408 I presume is not a junk yard build.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Yes it can be done from the BOTTOM without removing the engine.
Yes,, You should hone that cylider bore to seat the new rings.
You will be in the repair for about two full days if not longer depending on you skill level.. Between cradle removal and reinstall and oil pan removal and reinstall and head removal and reinstall, its a labor intensive repair. The piston will need to pop out of the TOP. Thats where removing the head comes into play.
You have to find a way to support the engine when the cradle is removed. I put some tall truck jack stands where the engine mount pads are on the engine block.
If you have OEM piston rods, the big end has a FRACTURE FIT parting line. Make SURE that you reassemble it so the fracture fit is correct!!
Bill
Yes,, You should hone that cylider bore to seat the new rings.
You will be in the repair for about two full days if not longer depending on you skill level.. Between cradle removal and reinstall and oil pan removal and reinstall and head removal and reinstall, its a labor intensive repair. The piston will need to pop out of the TOP. Thats where removing the head comes into play.
You have to find a way to support the engine when the cradle is removed. I put some tall truck jack stands where the engine mount pads are on the engine block.
If you have OEM piston rods, the big end has a FRACTURE FIT parting line. Make SURE that you reassemble it so the fracture fit is correct!!
Bill
Last edited by Bill Curlee; Dec 5, 2015 at 11:05 AM.
