Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

help on lm7 block

Thread Tools
 
Search this Thread
 
Old 12-22-2013, 03:44 PM
  #1  
Staging Lane
Thread Starter
 
rollwithit's Avatar
 
Join Date: Oct 2013
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Default help on lm7 block

just got the 862 heads off and noticed there was water in a couple of the cylinders and now theres rust... looks like its gonna have to be boared.. where can i get a set of pistons and use stock internals? this was supposed to be a budget build.
Old 12-22-2013, 04:25 PM
  #2  
TECH Addict
iTrader: (88)
 
Burken01's Avatar
 
Join Date: Mar 2005
Location: Anaheim, Ca
Posts: 2,923
Likes: 0
Received 13 Likes on 12 Posts

Default

Originally Posted by rollwithit
just got the 862 heads off and noticed there was water in a couple of the cylinders and now theres rust... looks like its gonna have to be boared.. where can i get a set of pistons and use stock internals? this was supposed to be a budget build.
Had the engine been sitting?

Minor surface rust won't kill an engine, see if you can wipe the rust off with brake cleaner..

And how much water?

Could be when you pulled the heads some of the coolant went in

Post some pics
Old 12-22-2013, 04:43 PM
  #3  
On The Tree
 
Treyvs's Avatar
 
Join Date: Oct 2010
Location: PHX, AZ
Posts: 175
Likes: 0
Received 4 Likes on 3 Posts

Default

Originally Posted by Burken01
Had the engine been sitting?

Minor surface rust won't kill an engine, see if you can wipe the rust off with brake cleaner..

And how much water?

Could be when you pulled the heads some of the coolant went in

Post some pics
Agreed, and to expand on your original question, look into some "Junkyard Dog" pistons from WISECO. They are forged units and will work with the stock connecting rods .945" wrist pins.
Old 12-22-2013, 05:05 PM
  #4  
TECH Senior Member
iTrader: (16)
 
1FastBrick's Avatar
 
Join Date: Apr 2007
Location: JunkYard
Posts: 9,276
Received 412 Likes on 293 Posts

Default

Speed Pro has replacement style pistons as well as Mahle and Enginetech.
Old 12-22-2013, 08:59 PM
  #5  
Staging Lane
Thread Starter
 
rollwithit's Avatar
 
Join Date: Oct 2013
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Burken01
Had the engine been sitting?

Minor surface rust won't kill an engine, see if you can wipe the rust off with brake cleaner..

And how much water?

Could be when you pulled the heads some of the coolant went in

Post some pics
motor has been out in my shop for 3 months.... i bought it off craigslist. No telling how long they had it out. I will try the pic thing
Old 12-22-2013, 09:37 PM
  #6  
Staging Lane
Thread Starter
 
rollwithit's Avatar
 
Join Date: Oct 2013
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Burken01
Had the engine been sitting?

Minor surface rust won't kill an engine, see if you can wipe the rust off with brake cleaner..

And how much water?

Could be when you pulled the heads some of the coolant went in

Post some pics
tried to clean. sligthly pitted. If i bore to 3.950 any idea what piston i can use with my stock internals?
Attached Thumbnails help on lm7 block-ncm_0012.jpg  
Old 12-22-2013, 09:41 PM
  #7  
Staging Lane
Thread Starter
 
rollwithit's Avatar
 
Join Date: Oct 2013
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Treyvs
Agreed, and to expand on your original question, look into some "Junkyard Dog" pistons from WISECO. They are forged units and will work with the stock connecting rods .945" wrist pins.
any part #s or links to for pistons? Im new to the ls world, dont know much about them, trying to learn. could i use a ls6 piston with my stock internals?
Old 12-22-2013, 10:27 PM
  #8  
TECH Addict
iTrader: (88)
 
Burken01's Avatar
 
Join Date: Mar 2005
Location: Anaheim, Ca
Posts: 2,923
Likes: 0
Received 13 Likes on 12 Posts

Default

Originally Posted by rollwithit

any part #s or links to for pistons? Im new to the ls world, dont know much about them, trying to learn. could i use a ls6 piston with my stock internals?
Check out Thompson motorsports..

They have killer ls shortblocks

The machine work to bore/hone the cylinders and to find another piston to fit and assembly will be more money than a TMS shortblock
Old 12-23-2013, 01:22 AM
  #9  
TECH Resident
iTrader: (2)
 
baronsmith98's Avatar
 
Join Date: Feb 2013
Location: Brunswick, GA
Posts: 831
Likes: 0
Received 0 Likes on 0 Posts
Default

Look at either Wiseco or Mahle. They should have a piston with the right diameter and compression height that will fit the stock wrist pin. Bore and hone should be around $250 and another $200ish to balance rotating assembly. Before that though I would try a ball hone and see if it cleans up them check your piston to cylinder wall clearance and see if you could still use them being it is a budget build. I was in your shoes a few months ago but just bit the bullet and went ahead and bored it out.
Old 12-23-2013, 03:48 AM
  #10  
TECH Apprentice
 
cobalt964's Avatar
 
Join Date: Sep 2013
Posts: 320
Likes: 0
Received 0 Likes on 0 Posts
Default

guy on youtube lightly sanded the rust down, then just ran it as is. chech it out. look up the squirter 5.3 on youtube. he is on here too.
Old 12-24-2013, 09:32 AM
  #11  
Staging Lane
Thread Starter
 
rollwithit's Avatar
 
Join Date: Oct 2013
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
Default

looks like i can ball hone it out! can i use same rings, or should i replace old with new?

?2- if i have to get new ones-what would the ring gap need to be for boost



Quick Reply: help on lm7 block



All times are GMT -5. The time now is 02:07 PM.