Blocks, Does Big Bore equal weak?

Do you know of anyone running a GM Gen VI block at Ø4.600" bore or larger while making 1600 or more HP?

 

Yup. So many I can't count. The blocks that can go bigger then 4.60 and run those kinds of numbers are;
Merlin Pro - The best of the aftermarket blocks
Dart Big M
CNC bowtie
The plain Bowties
Then the Merlin II and III are O.K. at that, but not great.

Again, lots depends on the tune ups. It does not matter your bore, if you detonate, you are going to hurt stuff, etc. (But you already know that.)

 

I'm curious why you feel " Merlin Pro - The best of the aftermarket blocks " are the best ?

What about :
New Century
CN Blocks

????

Just curious !

 

I ran my 4.600 Merlin 3 at 25# of boost for 2 races. It cracked 3 cylinders and split the middle bolt hole in half. Bought another one and same thing happened. EGT's were 1150 to 1200 and the timing was 30 degrees. HP level was in the 1800 range. Switched over to a Merlin Pro at 4.56 and no problems so far.

 

He is talking about boring a GM block, so I assumed that we were only talking iron blocks for this duscussion. CN's are the best, bar none! The Dart billets are really nice as well. But Merlin Pros are the best of the iron blocks.
Hope this clears it up.

 

I can see the light now , Thanks !

 

Thanks for the replys guys, this is an existing motor which is a Gen VI block. We were weighing out our options and one was to bore it to 4.600. We are shooting for 1800-1900 HP, at least eventually...

The last two brand new from top to bottom motors we've built are Big M blocks

 

You keep saying that it is a Mark 4. But what mark 4? Is it a standard bowtie? A CNC bowtie?
Does it have iron caps or billets? Are the outside bolts on the caps skewed or straight up and down? Because this is going to be the difference. And there is a big change between 1600 and 1900 horsepower. At 1900, the standard bowtie is not going to last through eternity. (Unless you are talking a turbo engine.)

 

No not Mark IV, I'm talking Gen VI (generation 6) CNC bowtie, 8620 steel splayed caps, etc...

http://www.sallee-chevrolet.com/ChevyBareBlockTallDeckBigBlockV8s/24502502.html

 

The CNC bowties are a nice piece. I had one in the shop just a few weeks ago that has been over 4.610 for nine years in a nitrous pro mod. (Of course, it was a pro mod back when it first ran, and now it is a solid top sportsman car that could never qualify for a current pro mod field.) Great blocks and I have had great luck with them.