HOME FORUM RULES CONTACT
     
   
   

Go Back   CLASS RACER FORUM > Class Racer Forums > Stock and Super Stock Tech
Register Photo Gallery FAQ Community Calendar

Reply
 
Thread Tools Display Modes
Old 11-16-2019, 08:39 PM   #1
Dave Noll
Senior Member
 
Dave Noll's Avatar
 
Join Date: Nov 2007
Location: Div. 6, Eastern, WA
Posts: 709
Likes: 2,659
Liked 238 Times in 111 Posts
Default Re: Mopar 383 Connecting Rods

If it was me, for .0001 I'd dig those 60 stock forgings out of that junk pile.
__________________
Dave Noll, EF/S ,?/SA 6526
Dave Noll is offline   Reply With Quote
Liked
Old 11-16-2019, 10:09 PM   #2
Paul Precht
Senior Member
 
Paul Precht's Avatar
 
Join Date: Dec 2001
Location: Elysburg, Pa
Posts: 730
Likes: 353
Liked 309 Times in 118 Posts
Default Re: Mopar 383 Connecting Rods

I assume he is checking those rods with the stock bolts. I have at least 10 sets of stock 383 rods laying around, when I get the time I'll try the torquing and retorquing to check how consistent they are.
Paul Precht is online now   Reply With Quote
Liked
Old 11-17-2019, 02:37 PM   #3
James L Miller
Member
 
Join Date: Apr 2005
Posts: 494
Likes: 6
Liked 25 Times in 16 Posts
Default Re: Mopar 383 Connecting Rods

Quote:
Originally Posted by Dave Noll View Post
If it was me, for .0001 I'd dig those 60 stock forgings out of that junk pile.
Dave, it was my Manley Hemi Pro-I Beam rods that went .0001" out of round after resizing. The big end spec on the Mopar BB rods are 2.5000" to 2.5005" per the Clevite book. I'm assuming that the 383 rods wouldn't repeat within the ,0005" range. I'm sure that was with the stock 383 bolts. I wasn't around when he went through the rod testing on the 383 rods, so I don't know the exact procedure done.

My engine guy also does hardness testing on the rods. I bought a set of Manley 440 Sportsman rods and they were in the HRC 26-29 range. It appears to me that is the normalized hardness for 4340 steel. The hardness on the Hemi I-beams were in the 31.5-39 HRC range (corresponding to 130 ksi to 159ksi yield strength per the EMJ Blue Book charts). Maybe Manley saves money on the Sportsman rods by skipping the heat treatment and final sizing after heat treat steps?
__________________
Mopar 2 Ya!
James L Miller is offline   Reply With Quote
Liked
Old 11-18-2019, 09:09 AM   #4
Larry Hill
Live Reporter
 
Join Date: Oct 2004
Location: Hickory, Ky
Posts: 10,629
Likes: 1,919
Liked 10,681 Times in 2,222 Posts
Default Re: Mopar 383 Connecting Rods

Is your machinist using an AG300 to check size? If so how does he check for straightness of the bore. To check for hourglass or barrel shaped bores.
Thanks

GTX John
How thin, wall thickness, can the pin bore wall be and still live after bushing the pin bore? Does the bushing get burnished or is it a shrink fit?
Thanks
__________________
IHM Used Parts
https://ihmusedparts.com
888-821-1817
Larry Hill is offline   Reply With Quote
Old 11-18-2019, 06:34 PM   #5
James L Miller
Member
 
Join Date: Apr 2005
Posts: 494
Likes: 6
Liked 25 Times in 16 Posts
Default Re: Mopar 383 Connecting Rods

Quote:
Originally Posted by Larry Hill View Post
Is your machinist using an AG300 to check size? If so how does he check for straightness of the bore. To check for hourglass or barrel shaped bores.Thanks
Larry, I don't really know for sure. I saw him put them on the gauge, but I didn't pay attention to the details how he used it close enough. Next time I head to Florida, I'll take my Mitutoyo 2" ring gauge along and have him show me how he does it. Here is a link the Sunnen instructions from the Goodson webpage.

https://cdn.shopify.com/s/files/1/14...cisionGage.pdf
__________________
Mopar 2 Ya!
James L Miller is offline   Reply With Quote
Old 11-18-2019, 07:14 PM   #6
Larry Hill
Live Reporter
 
Join Date: Oct 2004
Location: Hickory, Ky
Posts: 10,629
Likes: 1,919
Liked 10,681 Times in 2,222 Posts
Default Re: Mopar 383 Connecting Rods

It looks like mine
__________________
IHM Used Parts
https://ihmusedparts.com
888-821-1817
Larry Hill is offline   Reply With Quote
Old 11-18-2019, 08:53 PM   #7
Tom Broome
Member
 
Join Date: Sep 2009
Posts: 144
Likes: 80
Liked 88 Times in 43 Posts
Default Re: Mopar 383 Connecting Rods

Larry, that looks like the AG 300 I learned on. We were taught to check the bore against the faceplate, then pull the rod away while holding it steady against the fixed upper point, then gently rock the rod. We would do that at a couple of points, flip the rod over and check the other side. That would allow us to check for barrel or taper. Sunnen used to lease a PG series gauge with a faceplate that slid in and out to check taper or barrel. Even if I could afford one, it would be probably be to finicky for my little un-airconditioned shop.
Tom Broome is offline   Reply With Quote
Old 11-18-2019, 09:21 PM   #8
Tom Broome
Member
 
Join Date: Sep 2009
Posts: 144
Likes: 80
Liked 88 Times in 43 Posts
Default Re: Mopar 383 Connecting Rods

Back to the original post. It's difficult to qualify OEM mass production rods. Small variations in bolt centerline between the rod and cap, how perpendicular the bolt (or nut) spotface is to the bolt centerline affect the repeatability when the bolt is torqued.

Back in the Buick days we would deburr a small spot inside the "H" beam of a Carrillo rod, just above the bolt thread exit. It's been too long to recall the specifics, but I remember it was significant enough to resize the big end. That's when I began to understand how touchy rods can be, and how important it is to maintain consistency between preparation and assembly.

The shop procedure was to hone the big ends individually since the rods run on split journals. It required a lot of attention to keep the stones and guide shoes from wearing in a fashion that caused barrel shaped housing bores.

Last edited by Tom Broome; 11-18-2019 at 09:24 PM.
Tom Broome is offline   Reply With Quote
Old 11-18-2019, 09:27 PM   #9
Rich Biebel
VIP Member
 
Rich Biebel's Avatar
 
Join Date: Jun 2007
Location: Northern New Jersey suburbs
Posts: 2,314
Likes: 25
Liked 544 Times in 213 Posts
Default Re: Mopar 383 Connecting Rods

I did most every rod in a small shop for over 10 years.

All brands and from street rebuilds to race engines of all kinds.

Sunnen manual LBB machine with the gauge.

Did big ends, small ends, bushed rods, offset bushed and reduced pin sizes using bushings we made or bought.

Stock rods used in race engines were generally out of round once run....

Usually a good amount....

We used SPS bolts back then and picked the best looking cores we could find.....Did not matter once it was run....out of round...

Mag, shotpeen, resize, bush pin end....generally

Very difficult to hone big ends or even pin ends and hold them true and without a taper one way or the other....

I would chuck the mandrels up in a lathe and true up the brass guide shoes often and dress the stones....constantly...

I used the gauge to check the rod and as described held it flat and carefully pulled it away from the back reading the size. A very tedious process......honing to size and keeping them as straight as possible....

I always honed rods and let them sit and they change size as the honing process heats them up.....let 'em cool and touch 'em up....

A buddy had a shop with a similar machine but with a power stroker and I don't know if that helped as I think it did pairs of rods at one time...

Honing anything was a time consuming process if you were trying to do as good as possible....

I marvel at the Youtube videos of Block hones that do a V8 without an operator constantly running the machine and checking the bore sizes....

Honing a race block and doing a real good job was the shop owners specialty along with head work.....Any block he honed made better power than previously usually....



I also rebuilt Mack connecting rods a lot......new bushings mostly....big ends were usually pretty good even after a half million miles ! Engines in UPS trucks....
__________________
Rich Biebel
S/C 1479
Stock 147R
Rich Biebel is offline   Reply With Quote
Reply


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 10:32 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright Class Racer.com. All Rights Reserved. Designated trademarks and brands are the property of their respective owners.