Stock 5.0 block limits

9

94stroker

New Member

Aug 2, 2005

12

0

0

Nov 26, 2007

#1

• Nov 26, 2007

• #1

What are the limits of a stock 5.0 block N/A. No nitrous no boost just N/A high rpm like 8500+. Will a stock block handle the stress or will it just split in half? I'm trying to figure out my budget for a new motor for my 1995 cobra and i was looking into the new boss block but I'm still on a budget and $1700 is a lot of money.

 

BlownFiveLiter

have car, will race....wait, it doesn't run

15 Year Member

Nov 29, 1999

3,133

18

108

Chicagoland

Nov 26, 2007

#2

• Nov 26, 2007

• #2

The typical rule of thumb is around 450-500 horsepower for a stock block, but that can still be pushing it. If you're planning on 8500 RPM, you definitely need that thing balanced. I'd get it as close to a zero imbalance as possible. My next engine, regardless of power output will be built on an aftermarket block, simply for peace of mind. I'm thinking I may go 351 based though, so I could probably get away with a stock block in that case, since they can handle more power than the 5.0 blocks can.

 

9

94stroker

New Member

Aug 2, 2005

12

0

0

Nov 26, 2007

#3

• Nov 26, 2007

• #3

In the dyno sim the motor was making close to 525 at 7900 or so but only lost 30 horse power at 9200. I don't think th block will take it will a boss block handle that ?

 

BlownFiveLiter

have car, will race....wait, it doesn't run

15 Year Member

Nov 29, 1999

3,133

18

108

Chicagoland

Nov 26, 2007

#4

• Nov 26, 2007

• #4

I'd be more concerned about the valvetrain handling the RPM than I would the block handling the power. The Boss block is supposed to be able to handle quite a bit (definitely over 500), but I haven't read anything official that states its maximum recommended power yet. For $200 more, you can get a Dart block and know it'll handle the power. Either one is going to need machining, but for the money spent, I'd much rather spend it once on a block that's proven to handle the power.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

Nov 26, 2007

#5

• Nov 26, 2007

• #5

9200 RPM?

 

D

Djstorm100

Member

Aug 5, 2007

109

0

16

Nov 26, 2007

#6

• Nov 26, 2007

• #6

What will the block it self take? I got a built bottom end

 

5spd GT

"the 5.0 owns all"

Founding Member

Aug 7, 2002

9,516

6

99

Arkansas

Nov 26, 2007

#7

• Nov 26, 2007

• #7

8500+ rpm is a NO GO with a stock block. I would not trust that at the stock power level and balance.

As for camshafts, good luck getting a hydraulic roller to be stable at that rpm

The Boss and Dart blocks are very comparable in power capability. I would choose the Dart at this point and time though.

Typically a stock rotating assembly can outlast the block. So a "built" bottomend is only as tough as the block itself.

 

mootang

New Member

Dec 5, 2004

907

0

0

texas

Nov 27, 2007

#8

• Nov 27, 2007

• #8

if you plan to rev the engine that high i would deffinatly go with a boss or dart based block.

 

Don 95Vert

Founding Member

Oct 1, 1999

1,091

1

39

Delaware, OH

Nov 27, 2007

#9

• Nov 27, 2007

• #9

The stock EEC is about all done at a little less than 7000 - just too many processes to control, you end up losing spark and fuel control because the processor is too slow. You'd more than likely need something like an AEM as well besides what others have already mentioned.

 

zenboy99

Founding Member

May 12, 2002

2,212

0

47

Madison, WI

Nov 28, 2007

#10

• Nov 28, 2007

• #10

There are a few guys that I know of in the NMRA Pure Street class making over 400rwhp in a NA 306 revving over 7000rpm. But those cars are strickly drag cars so they don't see alot of miles.

Sorry if I hijack the thread, but how does the block strength of the Dart compare to the Boss block?