My buddy's shop put on LS7 heads on a LS1 block. He's having all kinds of problems. Water puking out of the overflow. Oil problems. Etc. Do you think any of this has to do with the heads and block.

thanks,
Steve

 

Yes they are not designed to mate to a Ls1 block, neither are the L92, LSXr head or the C5r head.

He's gonna have to go back to a LS1/LS2 style head.

 

wow, a shop did that? I can't believe how many shitty shops I've heard about in the last month
But yeah, those heads are a no-go on a LS1

 

dam! those people seriously dont belong around any lsx engines.
not even a spun bearings 4.8.

 

Thanks guys. Keep it coming. The shop always has an excuse. Changing head gaskets, thermostat, water pumps you name it. My buddy's car is a race car. He has to take it to a track every time to see if it runs. Never gets more then 3 laps before something happens.

Steve

 

Look here for a full chart of compatibility in the LSx series
http://images.google.com/imgres?imgu...a%3DN%26um%3D1

 

that sucks, thouse heads will only work w 6 liter or larger blocks

 

Even a 6.0 block isnt enough. LS7 requires 4.1 bore minimum. There is some debate that 4.08 MIGHT be enough but i dont know if anyone has actually tried it yet.

my question is if the block has been sleeved??? No shop in there right mind would install ls7 heads on a 3.9 bore... I dont think the valve would even open.

If the block has indeed been sleeved then i bet they did a **** job sleeving it and thats where the problems are coming from.. If it hasnt been sleeved then i dont see how the thing even runs.

 

He did mention that the block was sleeved. At one time they blamed some sort of o-ring that was not sealing right. Then it was the wrong head gasket. Now they think the pulley is the wrong size on the water pump. I don't think the shop knows what's going on. They just keep guessing at my buddy's expense.

Steve

 

sounds to me like they screwed up the sleeves and are trying to put blame elsewhere... if its blowing out water and having oil issues its likely the sleeves weren't installed correctly assuming the head gaskets are good. I dunno, i dont know too much about the sleeving process except if its screwed up you have oil and water issues. I dont see how the size of the water pump pulley would affect anything.

 

Sounds like it isn't a speed shop, but more of a regular maintanance car.

 

This shop is only a speed shop. They must not know much about LS motors from what it sounds like. This is actually his second motor from them. They couldn't get the Warhawk block to work either. My buddy ordered a crate LS7 motor today. He's tired of all the BS. It goes in a C6 Z06.

Thanks for your help.
Steve

 

your buddy must have a lot of cash... thats a lot of wasted money that shop cost him...