engine blocks

[blackv6]

Bout to start my engine build. Need to ask u guys on center or off center blocks. My car is going to be street and track, I keep hearing different opinions about them can you guys shed some light for me

 

[charlief1]

Unless you're building a Stage II block it's a moot point. All of the stock blocks are off center. You also have the choice of on center if you go with a TA block.

 

[blackv6]

Yes it is an aluminium ta block that i am going with. is there a hp or rpm advantage to either one of them

 

[charlief1]

No, but the on center blocks will reduce the stress on the rods and crank some. The original block has offset rods to help with the alignment of the cylinder bore to the rod journal that is on the stock block. The only issue you will have is accessory alignment if you try and use the stock mounts.

 

[Mike E]

The strength is in the on-center rod, but up to 1000hp they are probably equal. The problem is that there is only one 1000+hp on center rod available. Crowers at $1400 a set. Under 1000hp, there are only narrow journal on center k1 rods.

For off center there are 4 different k1 rods, eagles, scat and crower.

In my opinion if your shooting for over 1000hp, use on-center and buy the crowers. Under 1000 go off center and if you push it above 1000 later you can still get a crower off center billet rod.

 

[Sagecoach]

Aren't there some heater-clearance issues with the on center blocks vs. the off center?

 

[Mike E]

There are no more heater box clearance issues than stock if you use production style heads. Stage 2 heads have heater clearance issues no matter which block you use.

The only problem the on center block creates is with the timing cover and accessories. The drivers side head and timing cover move forward ~.120" and the passenger head goes back the same amount. Its an easy fix with a couple spacers for the balancer and distributor gear.