lsx or sb2

[rag231]

With the technology that is out now and the price of sb2's dropping. What has been the reliable build and success of each. I have a line on a few sb2's that are better than what I paid for a stage 2 3 years ago.

 

[John Wilde]

I would consider the lsx with the 6 bolts per hole for a forced induction application. It addition the heads can be purchase with a lot bigger chambers making it easier to run and off the shelf piston. The SB2 stuff can work really well too. If you can find someone that already has a SB2 turbo combination that works (like Dusty) it is an option to consider.

 

[Louie L.]

I would go with LSX. The SB2 stuff is cool, but it does have its quirks. Like Buick stage stuff, there is lots of junk out there for sale, so be careful. I also dislike the fact that you have to play some piston games to get the compression low enough for turbo apps.

 

[Dusty Bradford]

With the technology that is out now and the price of sb2's dropping. What has been the reliable build and success of each. I have a line on a few sb2's that are better than what I paid for a stage 2 3 years ago.

It depends on your power goals.

There's no better head for the $$$ than the SB2 stuff. 1800-2000hp capable for $4k and under including rocker arms and all. The downside is the tune-ups are touchy due to the small chambers. You have to be very careful picking the right heads to make sure you don't buy junk. Mine were 286cc runners and flowed 401/280. I made a lot of power with them. Once I got into the 1700-1800 range it was obvious you need to make some serious coolant modifications to keep the center of the head between the 2 exhaust valves cool. Something as drastic as putting most of the water into the motor in between the 2 cylinders rather than in the front of the block.

The camshafts are expensive and require a long wait. Your looking at $800 and at least 3-4 weeks for a full billet cam. The existing cores are all n/a and can't be made into a turbo cam without cutting deep into the heat treat which will make the cam weak. Everything is custom. The valves have to be the correct length for the rocker stand to have the proper geometry. If you have to change to a inconel exhaust you'll need to order the exact length.

In the LSX stuff. I wouldn't run anything other than the 6 bolt stuff for 1200hp and up. The TFS are probably the most affordable 6 bolt heads and they make great power. I tuned a 449ci LSX with a 106 and the TFS 6 bolt heads and it made great power at low boost.

 

[sdteb]

what do you guys think of the iron eagle block with bmf 18 degree heads?

 

[Dusty Bradford]

It would be bad ass.

Call me on the crank if your still interested. It's about to go on racingjunk and yellowbullet.

 

[Louie L.]

Just make sure that the heads are checked out prior to install. Some folks been having issues with BMF stuff lately. For the money the should be perfect as delivered.

 

[cchilly]

The sb2 is very touchy like Dusty stated. I have a friend running N2O with those heads. He has burned up a bunch of times trying to get the tune right. Also sent the heads out to Darrin Morgan to do some work to them as well. That helped out a ton, but still just burnt it up a few weeks ago. Was working good, put a little more onto it and that was it. Running EFI as well if that means anything.

 

[Dusty Bradford]

The sb2 is very touchy like Dusty stated. I have a friend running N2O with those heads. He has burned up a bunch of times trying to get the tune right. Also sent the heads out to Darrin Morgan to do some work to them as well. That helped out a ton, but still just burnt it up a few weeks ago. Was working good, put a little more onto it and that was it. Running EFI as well if that means anything.

Common mistake with the SB2's and NOS is too much fuel. Most think a rich mixture is safe but it will burn the piston faster than anything. And the SB2's do not like a lot of fuel. They were made for NASCAR with fuel efficiency in mind. Where a ordinary head may need 11.3 a/f, the SB2 is happy at 11.6-11.7. The chamber is very efficient, pull some fuel out of it next time.