Main caps 400 SBC Don't know what to do! - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 03-11-2008, 10:46 AM
TorkMonster400's Avatar
uninteresting default message
 
Last wiki edit: Working with chromed bolts
Last journal entry: A couple of pics of the car
Last photo:
Join Date: Mar 2008
Location: Fort Walton Beach Fl
Posts: 236
Wiki Edits: 4

Thanks: 0
Thanked 0 Times in 0 Posts
Main caps 400 SBC Don't know what to do!

I'm going to try to strengthen the bottom end a little any suggestions? I've looked into splayed caps but I'm thinking it could cost a little much. Has any one tried billit main caps? Or where to find them?
Attached Thumbnails
Click image for larger version

Name:	DSCN0319b.jpg
Views:	136
Size:	130.6 KB
ID:	28548   Click image for larger version

Name:	DSCN0320b.jpg
Views:	243
Size:	197.1 KB
ID:	28549  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-11-2008, 11:24 AM
CNC BLOCKS NE's Avatar
CNC Blocks Northeast
 
Last photo:
Join Date: Sep 2006
Location: NORTHEAST
Age: 54
Posts: 1,429
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
Billet caps would be a better choice over stock if your are going to be making some decent power, first thing is to get the cylinders sonic tested begre cleaning as that may not be a good block to start with and don't by core shift as thats not very accurate.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-11-2008, 11:35 AM
Double_v23's Avatar
Horsepower Enthusiast
 

Last journal entry: Finished BMOD001FH
Last photo:
Join Date: Jul 2007
Location: Mooresville, NC
Posts: 1,495
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
Just remember any time you change the caps you have to have the block line bored. It is not just a matter of bolting them on. That being said the cost of installing billet 4 bolts and billet two bolts may not be all that much different. Just the machining time to drill and tap the extra main bolt holes.

You may want to consider installing lifter valley girdles as well if you are going to be really twisting the block with a bunch of torque.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-11-2008, 01:02 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,710
Wiki Edits: 0

Thanks: 3
Thanked 406 Times in 351 Posts
Quote:
Originally Posted by TorkMonster400
I'm going to try to strengthen the bottom end a little any suggestions? I've looked into splayed caps but I'm thinking it could cost a little much. Has any one tried billit main caps? Or where to find them?
Anytime maincaps are replaced several machine operations need to be accomplished.

First is the register with the block, this is the recession into which the cap fits. It needs to almost be a press fit. Your machinist will have to machine the block and or caps to achieve this along with proper side to side and front to back alignment. The bolts do not do this, contrary to what a lot of people think. The bolts hold the parts together, they do not provide alignment of parts. If the caps don't seat right in the register and don't align right with the principle axes of the block, it won't be long before it all comes apart.

Second is alignment of the crankshaft bore to the block centerlines. This process is accomplished after the block and caps are machined to hold proper alignment with the planes of the block. This latter process is often referred to align boring or if only very little adjustment is needed, align honing.

These processes will need to be accomplished if you replace your existing caps with billet 2 bolt or any 4 bolt, factory or aftermarket. So aside from drilling and tapping for the extra bolt holes of the 4 bolt caps, the processes and costs are the same either way you go except for the cap cost.

Bogie
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-13-2008, 04:01 AM
Member
 
Join Date: Nov 2001
Posts: 447
Wiki Edits: 0

Thanks: 0
Thanked 11 Times in 10 Posts
400 main caps.

Why is this a concern. SBC's have very little main bearing problems. By the looks of the rust on the engine, this must have powered a submarine. Just kidding. The 400 two bolt main caps are fine for anything up to about 450 HP. For added security you might replace the main bolts with studs from a reputable company like ARP. Usually messing with main caps causes more problems than it solves. The 400 SBC two bolt is actually more desirable than the 4 bolt block. The bigger main cap (Diameter 2.65 journal crank on 400 compared to 2.45 for a 350) causes the outside bolts on the 4 bolt blocks to actually weaken the block in the main web area making them more susceptible to cracking under high stress. On a 400 always use a oil pump mounting stud instead of the bolt. The rear main cap is not very thick and the torqueing action of the bolt can distort the rear cap.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-13-2008, 05:44 AM
CNC BLOCKS NE's Avatar
CNC Blocks Northeast
 
Last photo:
Join Date: Sep 2006
Location: NORTHEAST
Age: 54
Posts: 1,429
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
Quote:
Originally Posted by Studebaker
Usually messing with main caps causes more problems than it solves

Boy we are one of the biggest buy of Program caps in the N/E and we put a lot of caps on SBC's and no problems yet.

Been doing this for 30 plus years please enlighten me on the problems I have been causing.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-13-2008, 07:24 AM
Member
 
Join Date: Nov 2001
Posts: 447
Wiki Edits: 0

Thanks: 0
Thanked 11 Times in 10 Posts
400 Main caps.

I was saying that he shouldn't just assume there us something to be repaired without checking the main bore for distortion. A lot of these SBC blocks have no problems to start with. the time and cost involved to install splayed main caps for a street engine that goes to the drag strip on occasion is just not needed.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-13-2008, 01:54 PM
CNC BLOCKS NE's Avatar
CNC Blocks Northeast
 
Last photo:
Join Date: Sep 2006
Location: NORTHEAST
Age: 54
Posts: 1,429
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
We have machined alot of blocks for splayed caps over the years as the old stock ones sometimes don't cut it even for the street.

Check this guys thread out
http://ls1tech.com/forums/showthread.php?t=652566
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-13-2008, 02:29 PM
Double_v23's Avatar
Horsepower Enthusiast
 

Last journal entry: Finished BMOD001FH
Last photo:
Join Date: Jul 2007
Location: Mooresville, NC
Posts: 1,495
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
Hey CNC I know you always weigh in about 400 blocks and most of the time it is in the negative (which I agree with) but lets say a guy just couldn't bring himself to get a Little M.

What steps would you take to give it the best shot at survival
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-13-2008, 02:56 PM
TorkMonster400's Avatar
uninteresting default message
 
Last wiki edit: Working with chromed bolts
Last journal entry: A couple of pics of the car
Last photo:
Join Date: Mar 2008
Location: Fort Walton Beach Fl
Posts: 236
Wiki Edits: 4

Thanks: 0
Thanked 0 Times in 0 Posts
I talked to my machine guy today, he said I will be fine w/ a stud kit. This is a street motor no RPM's over 6000/6500. It is a very reputable shop here in town that both Hotrod shops said to go to. I'm not pushing huge horsepower or anything I just wanted a little extra insurance.

As for the rust I know, It sat in the back of a shop for a good 10yrs. I've had it since I was 17, I just never did anything with it, now I have a little extra cash and a FREE Camaro so why not?

I was told all the rust will come off during the block cleaning at the shop? Is this a problem?

The free Camaro (lots of dew outside sorry)
Attached Thumbnails
Click image for larger version

Name:	Camaro.jpg
Views:	106
Size:	117.1 KB
ID:	28595   Click image for larger version

Name:	Camaro2.jpg
Views:	81
Size:	85.5 KB
ID:	28596   Click image for larger version

Name:	Camaro3.jpg
Views:	109
Size:	99.4 KB
ID:	28597  

Last edited by TorkMonster400; 03-13-2008 at 03:38 PM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-13-2008, 08:50 PM
Member
 
Last photo:
Join Date: Feb 2005
Location: chillicothe oh
Age: 47
Posts: 1,445
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If you stud it it should be align honed as the studs put a different clamp load on the caps possibly pulling them out of round.And bolts will do just as well as studs the problem is cap breakage and block webbing pulling out at high power levels never seen a bolt break yet.And for what you are doing you will probably be just fine as is.Now if you are going for big power listen to Carl it is cheaper in the long run I have raced dirt track claimer classes for years making pretty decent power(550 to 625) depending on cam and head restrictions. But this was on small tires that didn't hook real well and not with slicks and great traction.The only one I broke was due to a dummy attack engine was a 406 with 15 to 1 comp with a 500 2bbl and I didn't have the right gear for the track and was lugging the engine hard and broke a cap.Also had advanced the timing from 36 degrees to who knows what because it wasn't coming off the corner hard enough.Like I said a case of the stupids. All this really means is if I was you building a street car I wouldn't be worried at all.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-13-2008, 10:19 PM
CNC BLOCKS NE's Avatar
CNC Blocks Northeast
 
Last photo:
Join Date: Sep 2006
Location: NORTHEAST
Age: 54
Posts: 1,429
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
Quote:
Originally Posted by Double_v23
Hey CNC I know you always weigh in about 400 blocks and most of the time it is in the negative (which I agree with) but lets say a guy just couldn't bring himself to get a Little M.

What steps would you take to give it the best shot at survival
Sonic test is the first thing we do and most of the time we machine blocks for other engine builders and after a season of circle track racing they seem to be cracks here and there.

And with the splayed caps they seem to help against the webbing cracking. The biggest problem with the 400 blocks is the big bores makes for much weaker webbing over a 350 block and with the bigger mains makes the webbing weaker.


Now go to the decks thinner decks and bigger bores make for a weaker decks and weaker cylinder walls.

Don't get me wrong we still machine them if a guy wants one machined and we have built some that have been around 450 horse and no problems.

We get a lot of calls from the IMCA guys always looking for 400 blocks to replace their broken one.

We try to build dependable engines at our shop and we feel the Dart or Bowtie block is just a little bit better.

Most 400 blocks don't pass a sonic test when they come in the shop for work .
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 03-13-2008, 11:25 PM
Registered User
 
Last photo:
Join Date: Jun 2007
Location: TN.
Posts: 287
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
cnc what is your absolute minimum you look for when sonic checking?


thanks sam-missle
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 03-14-2008, 10:07 PM
CNC BLOCKS NE's Avatar
CNC Blocks Northeast
 
Last photo:
Join Date: Sep 2006
Location: NORTHEAST
Age: 54
Posts: 1,429
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
Quote:
Originally Posted by sam-missle
cnc what is your absolute minimum you look for when sonic checking?


thanks sam-missle
At .040 over not to be under .160 on the thrust side and on a 350 block on the wrist pin side at a.040 not to be under .075
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
427 sbc out of a 400 camaro409 Engine 23 08-02-2009 09:25 AM
More machine shop advice. 400 sbc jtybt Engine 16 02-17-2006 04:30 PM
400 SBC project - questions... Mad Maggot Engine 24 01-05-2005 09:24 PM
400 SBC Newbie thecamaroguy Engine 13 12-08-2004 08:09 AM
0.060 over 350 sbc or 0.040 over 400 splayed cap sbc tony350ss Engine 4 05-17-2003 09:02 PM


All times are GMT -6. The time now is 08:30 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.