Stock block or?

[revhead347]

Ok, so I'm back on using a stock block. I just see threads of split blocks even at relatively low power numbers and get scared. I broke the crank and block in my '85 GT and it only put down 220hp and 270ftlbs to the wheels. I was just driving it with the cruise control on when it went.

There is a very good reason for that. Nobody starts a thread for a block that didn't split. I put almost 500hp to the tire on a 347 stock block, and it lasted 85,000 miles before it had a failure unrelated to the block. I didn't make a thread for it.

300 whp on a stock block is well within the safe margin. With TF170cc heads, I would stick with the stock stroke. Those heads don't flow enough to make a 331 worth it. I would use the money towards a good tune. Don't rev it up too high. High RPM is usually what splits a stock block. With TF170 heads, there won't be any reason to rev it higher than 6500rpms, not even that high really.

Kurt

 

[TOOLOW91]

There is a very good reason for that. Nobody starts a thread for a block that didn't split. I put almost 500hp to the tire on a 347 stock block, and it lasted 85,000 miles before it had a failure unrelated to the block. I didn't make a thread for it.

300 whp on a stock block is well within the safe margin. With TF170cc heads, I would stick with the stock stroke. Those heads don't flow enough to make a 331 worth it. I would use the money towards a good tune. Don't rev it up too high. High RPM is usually what splits a stock block. With TF170 heads, there won't be any reason to rev it higher than 6500rpms, not even that high really.

Kurt

High rpm and a bad tune up . They just went 5.08 to the 1/8 with a Stock production block in a fairmont . I’ve seen much higher hp stock block stuff lately , not that I am an advocate but I believe the tuning and tuners are a lot better and not rattling them apart at the same rate they used to .

 

[revhead347]

High rpm and a bad tune up . They just went 5.08 to the 1/8 with a Stock production block in a fairmont . I’ve seen much higher hp stock block stuff lately , not that I am an advocate but I believe the tuning and tuners are a lot better and not rattling them apart at the same rate they used to .

It's a great discussion to be had. All these people doing LS swaps because the block can handle a few more hp. The stock 302 got a reputation for splitting back when no one did a tune, and half the people making that kind of power had ripped the fuel injection off and put a toilet on. Now what's his name up in South Carolina is putting over 900hp through a totally stock short block. Maybe it's time to go back and see if the block was really the problem.

Kurt

 

[TOOLOW91]

It's a great discussion to be had. All these people doing LS swaps because the block can handle a few more hp. The stock 302 got a reputation for splitting back when no one did a tune, and half the people making that kind of power had ripped the fuel injection off and put a toilet on. Now what's his name up in South Carolina is putting over 900hp through a totally stock short block. Maybe it's time to go back and see if the block was really the problem.

Kurt

They are still very erratic and nothing consistent about one vs another staying together but it’s definitely impressive

 

[HotFox]

The reason or part of the reason that my stock block 331 is still running 470whp after 9 years.
Your stock balanced 302 is the same force on the block at 6K then mine at 8K. Yup it sees 8,300rpm at the track, 7,600rpm on the street.

 

[revhead347]

For what it's worth, my 500hp tire 347 was 50oz imbalance.

Kurt