#21  
Old 12-04-2022, 07:30 PM
mgarblik mgarblik is offline
Ultimate Warrior
 
Join Date: Mar 2005
Posts: 6,035
Default

We ran the Grocery Getter wagon for years with a stock block 455 and an N cast crank. 3 different blocks. After years and years of running around 1000-1100 HP. Zero broken or cracked N cranks. Ended up with 3 broken blocks. All cracked through the #2 main oil feed hole up to the cam tunnel. But our combination was a little different than yours. We had 5 billet main caps. Also aluminum connecting rods. But we ran it to 7500 rpms hundreds of times with a manual transmission and did 15-20 second 1/8 mile burnouts @ 7000 RPM's. Man, that was fun. IMO, with 4-bolt main caps, the crankshaft will be the last part to fail. Rods first, then the block, last the crankshaft. I have never run big HP with a 2-bolt main cap Pontiac. So can't help you on that part.

The Following 3 Users Say Thank You to mgarblik For This Useful Post:
  #22  
Old 12-04-2022, 08:26 PM
Bill Eveland's Avatar
Bill Eveland Bill Eveland is offline
Ultimate Warrior
 
Join Date: Apr 2004
Location: Glasford Il
Posts: 3,650
Default

I had an issue with cap walk at 2 and 3 at a lower level than what your trying to build in a .060 over 469 at 6500. I ended up putting the the available longer dowel pins for the main caps to help tighten everything back up.

__________________
Illinois Outlaw Gassers

6.27@107
9.97@131
The Following User Says Thank You to Bill Eveland For This Useful Post:
  #23  
Old 12-04-2022, 11:06 PM
Hillard's Avatar
Hillard Hillard is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Springfield, Ohio
Posts: 1,329
Default

We ran a 455 with stock crank, stock 2 bolt main caps and bolts, Eagle rods and Ross pistons. All steel 67 GTO w/ full interior and 9" slicks. Best was 10.51 @ 127. Shifted at 6300 and went through the traps about 6700. And although we didn't race every weekend, we did it for years.

The Following User Says Thank You to Hillard For This Useful Post:
  #24  
Old 12-05-2022, 07:03 AM
25stevem's Avatar
25stevem 25stevem is offline
Ultimate Warrior
 
Join Date: Jan 2022
Posts: 1,744
Default

It’s very easy to tell if a 100% polished out crank is cast or steel.

Drill a shallow 3/16” hole in the the flywheel end of the crank as close as you can get it to the crank centerline.
If the crank is cast you’ll drill out chips, if it’s steel you’ll get long shards.

My bet is since you say it has a center square cheek that it’s a factor nodular iron crank.

__________________
I do stuff for reasons.
  #25  
Old 12-07-2022, 05:33 PM
Dragncar Dragncar is offline
Ultimate Warrior
 
Join Date: Mar 2004
Location: Humbolt County California
Posts: 8,283
Default

Quote:
Originally Posted by 25stevem View Post
It’s very easy to tell if a 100% polished out crank is cast or steel.

Drill a shallow 3/16” hole in the the flywheel end of the crank as close as you can get it to the crank centerline.
If the crank is cast you’ll drill out chips, if it’s steel you’ll get long shards.

My bet is since you say it has a center square cheek that it’s a factor nodular iron crank.
The crank is not 100% polished out. The profiled counterweight is just cut on a lathe. Very shinny.
I did do the drill thing years ago. Scat forged came out as spirals. OEM cast came out very small chips, powder like.
This crank had a bit larger pieces than the PMD cast crank.
I am thinking it started out life as a Eagle cast steel crank since they did not weld up the thrust with Ni rod-wire.

  #26  
Old 12-07-2022, 06:19 PM
PAUL K's Avatar
PAUL K PAUL K is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Sugar Grove IL USA
Posts: 6,282
Default

Quote:
Originally Posted by PAUL K View Post
455? If so you are right at what I consider the limit. Aluminum rods would help the situation.
I would like to modify my answer as I misunderstood the question. Your crank is good for a lot more power than you're are asking about. The two bolt main caps are the week link at your power level. Anything you can due to reduce reciprocating weight will help along with main studs and over size main cap locating pins.

__________________
Go fast, see Elvis!
www.facebook.com/PaulKnippensMuscleMotors
The Following User Says Thank You to PAUL K For This Useful Post:
  #27  
Old 12-07-2022, 07:16 PM
slowbird's Avatar
slowbird slowbird is offline
Ultimate Warrior
 
Join Date: Jan 2001
Location: Montgomery, IL
Posts: 10,638
Default

Quote:
Originally Posted by PAUL K View Post
over size main cap locating pins.
Easier to say larger dowel pins

  #28  
Old 12-07-2022, 07:40 PM
PAUL K's Avatar
PAUL K PAUL K is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Sugar Grove IL USA
Posts: 6,282
Default

Quote:
Originally Posted by slowbird View Post
Easier to say larger dowel pins
The transmission alignment dowel pins?

__________________
Go fast, see Elvis!
www.facebook.com/PaulKnippensMuscleMotors
  #29  
Old 12-07-2022, 09:01 PM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

Factory 2-bolt Main Caps will be fine with NA and well-Balanced. sure there are better tings.

  #30  
Old 12-07-2022, 09:05 PM
PAUL K's Avatar
PAUL K PAUL K is offline
Ultimate Warrior
 
Join Date: Feb 2004
Location: Sugar Grove IL USA
Posts: 6,282
Default

Quote:
Originally Posted by Half-Inch Stud View Post
Factory 2-bolt Main Caps will be fine with NA and well-Balanced. sure there are better tings.
You're probably right, all the way until the number two main cap separates and becomes two one bolt caps.... and assuming you don't mind some main cap fretting

__________________
Go fast, see Elvis!
www.facebook.com/PaulKnippensMuscleMotors
  #31  
Old 12-08-2022, 07:22 AM
25stevem's Avatar
25stevem 25stevem is offline
Ultimate Warrior
 
Join Date: Jan 2022
Posts: 1,744
Default

So Mike S ( the OP) your good to go it seems!

Half inch stud will guarantee you that up at the 700 hp level with your motor being NA with its two bolt caps, that a good balance job is the ticket to keeping it all together!

__________________
I do stuff for reasons.

Last edited by 25stevem; 12-08-2022 at 07:27 AM.
  #32  
Old 12-08-2022, 09:27 AM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

Well no, but saving money on a 1/4 mile grenade is a balancing act. Post #21 reads well to me.

Whatever the ECM does is the right answer, if you got the money to pay out for that solution. I don't.

See, i went with Studded and redoweled Steel MainCaps awhile ago: the Block showed a split up #2 web. Must have been the heavy TRWs, SD Rods and typical sized balancer. And the steel mounts.

I bought a 2-bolt drilled 455 block, cast caps stock bolts that had several hundred high rpm rounds in the low 9s. Inspected well. Sold it last year to a fella that will race it. Had/has aluminum rods and super light sbc 400 slugs and thinwall 927 pins.

Midplate and front plate seem to be the economical feature that keeps the main webs intact.

  #33  
Old 12-09-2022, 07:48 PM
blueghoast's Avatar
blueghoast blueghoast is offline
Ultimate Warrior
 
Join Date: Jan 2011
Posts: 2,396
Default

Lots of good stuff here, I use longer bigger dowls I make my own
two bolt studded mains and alluminium rods and a good bal job.
My allum rod 464 SM headed motor seen 7000 quite a bit with no prob's

GT.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:34 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017