what's the weak link?

98COBRA281

10 Year Member

Nov 24, 2007

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Port St. Lucie, Florida

Aug 11, 2008

#1

• Aug 11, 2008

• #1

i know that 400rwhp is about the most you want to throw a stock bottom end, but what is the weak link? pistons, rods, or crank? after i finish my build i would like to spray 100 shot or so

 

J

justinschmidt1

Member

Jun 15, 2005

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Aug 11, 2008

#2

• Aug 11, 2008

• #2

I dont know for sure but im pretty sure the pistons and rods are the weakest links...although the stock crank probably cant handle too much more either.

 

CobraRed_96_GT

Active Member

May 20, 2006

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UCSD/La Jolla

Aug 11, 2008

#3

• Aug 11, 2008

• #3

Limit is around 420-440rwhp - and that's on a car that sees it a lot, even tho spray adds gobs more torque than HP, it's not used every time you get on the throttle. The common giving point is the rods as they are powdered metal - and also the rod bearings if the oil is low. The crank isn't too shabby at all.

 

SaleenGT2001

Well-Known Member

Jul 18, 2005

2,811

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58

Four Oaks NC

Aug 11, 2008

#4

• Aug 11, 2008

• #4

the rods are usually the first to go at around 420-450. crank and pistons soon follow at 500-550

 

blckstng96

Member

Apr 13, 2004

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Aug 12, 2008

#5

• Aug 12, 2008

• #5

rods are the biggest pieces,then the rest follows.only thing going for the bottom end is the block haha.

 

twogts4us

15 Year Member

Apr 1, 2004

4,188

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79

Dunedin, FL

Aug 13, 2008

#6

• Aug 13, 2008

• #6

Pistons and Rods for sure. Cranks, even the simple cast ones like in the 2V, typically don't fail without some help...
I'd have no problem just upgrading the pistons and rods and leaving the cast crank alone...if funds were tight. But if you had the extra money, I'd opt for the Cobra (or 5spd Mach 1) forged crank.

 

flstang65

10 Year Member

Dec 6, 2007

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SE Georgia

Aug 13, 2008

#7

• Aug 13, 2008

• #7

use forged rods, pistons and crank, then put a girdle on the bottom end to avoid being the weakest link...goodbye!

 

98COBRA281

10 Year Member

Nov 24, 2007

1,348

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Port St. Lucie, Florida

Aug 13, 2008

#8

• Aug 13, 2008

• #8

flstang65 said:

use forged rods, pistons and crank, then put a girdle on the bottom end to avoid being the weakest link...goodbye!

Click to expand...

yeah ive been looking into forged crank, rods, and pistons, anybody know any good brands, that wouldn't kill my saving's account

ive also been looking in 03/04 cobra cranks, but there 8 bolt, and then ill need to get a new flywheel too.....

 

J

jprovence

New Member

May 20, 2007

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Albany, OR

Aug 13, 2008

#9

• Aug 13, 2008

• #9

If funds are that tight, just do the rod and piston combo with some good bearings, cobra HV oil pump and pick up tube, and put it all together. Could be well under 2g's for a 600hp capable street car that would last along time. Building the short block is the easy part. Its cramming the air is the hard part.

 

flstang65

10 Year Member

Dec 6, 2007

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SE Georgia

Aug 14, 2008

#10

• Aug 14, 2008

• #10

check coast high performance, livernois and eagle. there are several people out there that have good parts and good prices. sometimes if you call and talk to the people in person they will do like a 10% discount. also, IMO, a stock oil pump would be fine, just add a windage tray.

 

98COBRA281

10 Year Member

Nov 24, 2007

1,348

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Port St. Lucie, Florida

Aug 14, 2008

#11

• Aug 14, 2008

• #11

jprovence said:

If funds are that tight, just do the rod and piston combo with some good bearings, cobra HV oil pump and pick up tube, and put it all together. Could be well under 2g's for a 600hp capable street car that would last along time. Building the short block is the easy part. Its cramming the air is the hard part.

Click to expand...

ive been looking into this oil pump, but IDK why the price is so cheap

Ford Racing M-6600-D46 - Ford Racing High Volume Oil Pumps - summitracing.com

 

98COBRA281

10 Year Member

Nov 24, 2007

1,348

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Port St. Lucie, Florida

Aug 14, 2008

#12

• Aug 14, 2008

• #12

jprovence said:

with some good bearings.

Click to expand...

any brands?

 

B

blubullett

Member

Jun 22, 2006

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Modesto, CA

Aug 14, 2008

#13

• Aug 14, 2008

• #13

98COBRA281 said:

any brands?

Click to expand...

coated mahle/clevite.

 

98COBRA281

10 Year Member

Nov 24, 2007

1,348

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Port St. Lucie, Florida

Aug 14, 2008

#14

• Aug 14, 2008

• #14

how about these

Clevite Engine Parts MS2007H - Clevite H-Series Main Bearings - summitracing.com

and these....

Clevite Engine Parts CB1442H - Clevite H-Series Rod Bearings - summitracing.com

 

Mustang92

SN's #1 1%er

Jun 6, 2001

6,467

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79

South Florida

Aug 14, 2008

#15

• Aug 14, 2008

• #15

Rods and pistons as everyone else mentioned. Crank failures are mainly due to low oil or oil pump failures otherwise they can handle quite a bit. Far as I know all forged cranks are 8 bolt and the most common ones are the stock Cobra cranks.

Bill