Picking up a 400 SBC - Page 4 - Chevelle Tech
Engine General Engine Discussion.

 73Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #46 of 89 (permalink) Old Dec 2nd, 19, 12:47 PM
Lifetime Premium Member
Louis
 
Join Date: May 2008
Location: Bohemia, LI, NY
Posts: 1,446
Re: Picking up a 400 SBC

This is my 4 bolt main 406 with 11:1 compression. Started as 2 barrel motor. It smokes my tires every time I hit the gas.

71350SS and 427L88 like this.

Louis
69 Chevelle Malibu Sports Coupe Change to SS
11:1 TR406sbc/AFR227/Comp cam 280HFT/3500 RPM Stall conv./TH 350/12 bolt 410 Gears
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Original owner

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
lg1969 is offline  
Sponsored Links
Advertisement
 
post #47 of 89 (permalink) Old Dec 2nd, 19, 12:54 PM
Gold Member
Gene
 
Join Date: Sep 2000
Location: Buffalo NY
Posts: 14,762
Re: Picking up a 400 SBC

Lookit, give me a 406 c.i. small block, good heads, a relatively big [email protected]" SFT cam( assuming marginal heads) , in a well setup light 64 or 65 chassis..... and it'll eat rats for breakfast! We had 383 ci RATKILLERS before ( Mike Norman in his 65) .

Think of those early 327 Chevelles beating up on 396's all day long.

Sounds like a decent platform Aaron, no matter how aggressive you choose to go.

Come on Mark! Do a 400 SBC!
Aaron, 77 cruiser and 71350SS like this.

Gene
ACES 3112/Team Chevelle Gold #62
Be big, be a 'builder'!
427L88 is offline  
post #48 of 89 (permalink) Old Dec 2nd, 19, 1:51 PM
Lifetime Premium Member
Tom
 
Join Date: Oct 2006
Location: Firestone, CO
Posts: 1,436
Re: Picking up a 400 SBC

Quote:
Originally Posted by Aaron View Post
Well, I finally got the time to tear down the 400. It had 462 heads on it. Looked to have a factory steel shim head gasket. I don't know about the bore of it yet. I do know it has not been decked. The pistons are still in it right now. Will get them out tomorrow. The oil was pretty new and clean. The pistons looked to be dished with very small valve reliefs. Are these stock pistons you think?
I looked a couple years ago for some shim head gaskets for a 400 and couldn't find any. Did GM use them on 400s? I also didn't think 400s ever had 462 heads from the factory?

Am I full of crap?
Aaron and 71350SS like this.

70 Camino...Roller

69 Malibu Stock 307, Reverse Manual TH350, 4,500 Stall Edge Converter, 4.56 Spool 35 Spline 12 Bolt

76 C20 VortecPro 496 628HP 655 lb/ft TH400 Edge Converter, 4.10 14 bolt
Tommy the Cat is offline  
 
post #49 of 89 (permalink) Old Dec 2nd, 19, 2:30 PM
Lifetime Premium Member
 
Join Date: Jul 2000
Location: In the Shadow of GIANTS stadium,N.J.
Posts: 7,908
Garage
Re: Picking up a 400 SBC

Quote:
Originally Posted by 68Chevele View Post
Well if that the case Mark, build a 400 and use the production Vortec heads and show the real potential of the 400 the same way you did the PP 468. I am sure you could get 270 cfm from those little 170cc runners. What did you say before, you just needed 500hp to run in the 10's?, should be easy with a nice 406. I'm all in for this build for sure.
IMO a built 400 needs 200 or 220 heads to make power because of the larger bore or if they're AFR's then maybe a 195 will work

Quote:
Originally Posted by Aaron View Post
Well, I finally got the time to tear down the 400. It had 462 heads on it. Looked to have a factory steel shim head gasket. I don't know about the bore of it yet. I do know it has not been decked. The pistons are still in it right now. Will get them out tomorrow. The oil was pretty new and clean. The pistons looked to be dished with very small valve reliefs. Are these stock pistons you think?
that's great that the engine looked that clean Aaron and that description sounds like the stock pistons especially if its a stock 4.125 bore.I'd like to know if the 462 heads had the steam holes drilled because I think someone dropped those heads on that 400 short block and ran it that way.Also do the 462's have 2.02 valves ?

Quote:
Originally Posted by Aaron View Post
Got the pistons out. I believe they are GM pieces as I mentioned before. The rods are stock and it had a stock GM oil pump as well as stock GM cam. The cam had no numbers or markings. Cam looked very good as did lifters. Looks to be a virgin bore!! Hoping there are no cracks!
Did the timing chain have a steel or a plastic gear ? If its a steel gear maybe they changed the cam too along with the heads then ran it that way.Sounds like it was a good runner.
Aaron likes this.

John
71 El Camino SS
406 SBC M21 3.31 12 bolt
"Quality is always remembered,long after the price is forgotten"
71350SS is offline  
post #50 of 89 (permalink) Old Dec 2nd, 19, 2:32 PM
Team Member
Tom
 
Join Date: Sep 1998
Location: Mustang, OK USA
Posts: 12,508
Re: Picking up a 400 SBC

I have gone through MOST of the comments (but not all), and have discovered there is a lot of misinformation and some minimal knowledge about SB400s.

FIRST
ALLLLLLLLLLLLLLL the 70-72 400 blocks ONLY had 4bolt mains, REGARDLESS of casting number. PERIOD!
ALLLLLLLLLLLLLLL the 73-80 400 blocks ONLY had 2bolt mains, REGARDLESS of casting number. PERIOD!
The 70-74 400 blocks had 3 freeze plugs.
About 1975, 400 blocks had 2 freeze plugs-------------BUT THERE WAS A RAISED CENTER BOSS WHERE A FREEZE HAD BEEN EARLIER!
Then about 76, the center boss was gone and all 400 blocks had 2 freeze plugs-----------REGARDLESS of casting number.

GM pushed the 400 block way beyond reasonable limits, and as I presume everyone knows, the 400 blocks have siamesed cylinders. BUUUUUUUUUUT, in spite of this, the SB400 is an excellent foundation to build on.
When building a SB400, as many have mentioned, HAVE A COMPETENT MACHINE SHOP THOROUGHLY CHECK IT AND INSPECT FOR VALLEY CRACKS!!!!!!!!!!!
Regardless of 2- or 4-bolt mains, use main cap studs instead of bolts ----------------- FOR A PERFORMANCE BUILD! For a street driver, bolts are OK.
Over the years, it has been determined by extremely knowledgeable engine builders tha the 2-bolt block is the better choice--------------BUT ON MY PERSONAL 4-BOLT BLOCKS, I HAVE HAD ZERO ISSUES!

For a more or less bone stock 400, the stock length rods (5.565in) are OK. BUUUUUUUUUT, for a healthy street-performance-driver, the 5.7 (350 style) rods are a better choice. For a full out performance 400, then the 6.0in rods are an even better choice. BUUUUUUUUUUUT, the down side with 6.0in rods (in my opinion) is that the wrist pin is into the oil ring groove and the pistons are very short and have MINIMAL skirts. The potential is greater for piston rock inside the cylinders.
IF, IF, IF, IF, IF the 400 heads are to be re-used, the ONLY good ones are the 70-74 versions. In 75, GM started cutting off material of the head castings (across the entire board of SB Chevy heads) and all 75-later heads had TWO exhaust cross over passages in the center of the heads (greater possibility for cracking in the center of 75-later heads).
Personally, I like to use stock 70-74 400 heads. They were built with 1.94-1.5 valves, and ANY good machine shop can open them up for 2.02-1.6 valves (I only use stainless valves) and NEVER, NEVER, NEVER have hard seats installed!!!!!!!!!!!!!! With the exception of BIG trucks and extended heavy duty service, there is now enough years of experience which has shown that the use of unleaded fuel in engines that do not have hard valve seats has NOT been detrimental to the valves/seats.
I have one 420SB which has been stroked .100 (the rod journals were offset ground down to small journals) and good, small journal 327 style rods were used. It's in my jet boat and I have seriously abused that engine----------------and just like a Timex, it keeps on ticking!
Since 1972, I have personally built about 25 SB400 with no problems. In my family, there are 5 SB400s that have been running for about 20yrs.
Many of you have seen one of them.
Oh ya, and they are all built with factory GM blocks.
Attached Thumbnails
Click image for larger version

Name:	CB06 trailer.jpg
Views:	5
Size:	47.7 KB
ID:	609772   Click image for larger version

Name:	DSC_0945.jpg
Views:	6
Size:	83.8 KB
ID:	609776   Click image for larger version

Name:	DSCN0522_zpsjzexpzf1.jpg
Views:	4
Size:	185.0 KB
ID:	609778   Click image for larger version

Name:	DSCN0553.jpg
Views:	5
Size:	106.2 KB
ID:	609780  

Click image for larger version

Name:	DSCN1599.jpg
Views:	4
Size:	68.7 KB
ID:	609782  
Attached Images
File Type: bmp Chevelle.bmp (1.22 MB, 13 views)

Tom Parsons
TC# 474
#3 FOREVER!!!!!
Light travels faster than sound. That is why some people appear to be bright until you hear them speak. (unknown)
DZAUTO is offline  
post #51 of 89 (permalink) Old Dec 2nd, 19, 2:40 PM
Team Member
Tom
 
Join Date: Sep 1998
Location: Mustang, OK USA
Posts: 12,508
Re: Picking up a 400 SBC

This is the 420, and it is the only one with aftermarket heads (DART). It has 2.05 intake valves and 220 intake runners.


Attached Thumbnails
Click image for larger version

Name:	100_0174.jpg
Views:	6
Size:	95.9 KB
ID:	609784   Click image for larger version

Name:	100_0178.jpg
Views:	8
Size:	99.1 KB
ID:	609786  
Aaron likes this.

Tom Parsons
TC# 474
#3 FOREVER!!!!!
Light travels faster than sound. That is why some people appear to be bright until you hear them speak. (unknown)
DZAUTO is offline  
post #52 of 89 (permalink) Old Dec 2nd, 19, 3:18 PM
Lifetime Premium Member
 
Join Date: Jul 2000
Location: In the Shadow of GIANTS stadium,N.J.
Posts: 7,908
Garage
Re: Picking up a 400 SBC

Quote:
Originally Posted by Tommy the Cat View Post
I looked a couple years ago for some shim head gaskets for a 400 and couldn't find any. Did GM use them on 400s? I also didn't think 400s ever had 462 heads from the factory?

Am I full of crap?
I don't think so.Here's the only listing I could find for 462's
3767462------327-----62-67----1.72/1.50
and
3782462----327--67---1.94/1.50--Corvette 2.02/1.60
and
3814462---350---67---1.94/1.50-
and this one
3890462---302/327/350---62-68---1.94/1.50 2.02/1.60--64cc Doubble humps

I found these listings here :
Chevy Casting Number identification - Block casting numbers
Aaron likes this.

John
71 El Camino SS
406 SBC M21 3.31 12 bolt
"Quality is always remembered,long after the price is forgotten"
71350SS is offline  
post #53 of 89 (permalink) Old Dec 2nd, 19, 6:38 PM
Team Member
Tom
 
Join Date: Sep 1998
Location: Mustang, OK USA
Posts: 12,508
Re: Picking up a 400 SBC

Flat top pistons, about 10:1 compression (runs on 91 octane NON-ethanol), flat tappet hyd cam (off the shelf from Summit) with .510-.512 lift and 235deg @ .050 lift.



Aaron and 68post like this.

Tom Parsons
TC# 474
#3 FOREVER!!!!!
Light travels faster than sound. That is why some people appear to be bright until you hear them speak. (unknown)
DZAUTO is offline  
post #54 of 89 (permalink) Old Dec 2nd, 19, 7:44 PM
Tech Team
 
Join Date: Aug 2018
Posts: 387
Re: Picking up a 400 SBC

I've only owned one 400 sbc (ok, a 406) and that thing was a little beast. I'm embarrassed to say I know almost NOTHING about that particular engine except this: It pushed a roughly 3000 lb foxbody mustang to 6.70's in the 1/8th on pump premium with the timing pulled back to 29 degrees in preparation for a nitrous shot that I didn't end up using due to unexpected problems with the kit. It had enough vacuum for power brakes. It had a set of unported performer rpm heads on it and a fairly low rise single plane intake on it. I know nothing about the cam except that one was present in the engine. Don't know whether it was a roller or flat tappet, never pulled a valve cover off the engine. Did some horse trading and got rid of the car. I would recommend a 400 for sure.
Aaron likes this.

'71 chevelle, 468, TH400, 12 bolt posi w/3.08's, drinks a lot of 87 octane.
v8440 is offline  
post #55 of 89 (permalink) Old Dec 2nd, 19, 9:31 PM Thread Starter
Lifetime Premium Member
 
Join Date: Oct 1998
Location: Florida
Posts: 10,910
Re: Picking up a 400 SBC

Quote:
Originally Posted by lg1969 View Post
This is my 4 bolt main 406 with 11:1 compression. Started as 2 barrel motor. It smokes my tires every time I hit the gas.

http://www.youtube.com/watch?v=wCG7lnacgGg
Very nice Louis!!

67 chevelle malibu / SS/ custom

Currently undergoing a metal work to remove all rust, if I ever get there.

Cant decide on prostreet or cruiser with a 4 speed.
Aaron is offline  
post #56 of 89 (permalink) Old Dec 2nd, 19, 9:34 PM Thread Starter
Lifetime Premium Member
 
Join Date: Oct 1998
Location: Florida
Posts: 10,910
Re: Picking up a 400 SBC

Quote:
Originally Posted by 427L88 View Post
Lookit, give me a 406 c.i. small block, good heads, a relatively big [email protected]" SFT cam( assuming marginal heads) , in a well setup light 64 or 65 chassis..... and it'll eat rats for breakfast! We had 383 ci RATKILLERS before ( Mike Norman in his 65) .

Think of those early 327 Chevelles beating up on 396's all day long.

Sounds like a decent platform Aaron, no matter how aggressive you choose to go.

Come on Mark! Do a 400 SBC!
Gene

I plan on using a 200 to 210 head like a Brodix or AFR and maybe Straub hyd. roller. Car will be a M22 rockercrusher car with 4:10 gears.

Just a fun weekend street cruiser, probably will never see a track.

I recently moved all my track equipment over a 87 S10 that I have that has been backhalfed.

67 chevelle malibu / SS/ custom

Currently undergoing a metal work to remove all rust, if I ever get there.

Cant decide on prostreet or cruiser with a 4 speed.
Aaron is offline  
post #57 of 89 (permalink) Old Dec 2nd, 19, 9:37 PM Thread Starter
Lifetime Premium Member
 
Join Date: Oct 1998
Location: Florida
Posts: 10,910
Re: Picking up a 400 SBC

Quote:
Originally Posted by Tommy the Cat View Post
I looked a couple years ago for some shim head gaskets for a 400 and couldn't find any. Did GM use them on 400s? I also didn't think 400s ever had 462 heads from the factory?

Am I full of crap?
Tom

I don't have a clue.

I will say that it appears that someone maybe of degreased the engine and took the heads and intake off as well as the oil pan and put a gasket kit in it. The oil pan was painted silver and had a fel pro gasket on it. The blue one you know. The block was painted what appears to be Ford Blue. The heads were painted silver.

Maybe someone installed the shim gaskets and the 462 heads....

67 chevelle malibu / SS/ custom

Currently undergoing a metal work to remove all rust, if I ever get there.

Cant decide on prostreet or cruiser with a 4 speed.
Aaron is offline  
post #58 of 89 (permalink) Old Dec 2nd, 19, 9:42 PM Thread Starter
Lifetime Premium Member
 
Join Date: Oct 1998
Location: Florida
Posts: 10,910
Re: Picking up a 400 SBC

Quote:
Originally Posted by 71350SS View Post
IMO a built 400 needs 200 or 220 heads to make power because of the larger bore or if they're AFR's then maybe a 195 will work



that's great that the engine looked that clean Aaron and that description sounds like the stock pistons especially if its a stock 4.125 bore.I'd like to know if the 462 heads had the steam holes drilled because I think someone dropped those heads on that 400 short block and ran it that way.Also do the 462's have 2.02 valves ?


Did the timing chain have a steel or a plastic gear ? If its a steel gear maybe they changed the cam too along with the heads then ran it that way.Sounds like it was a good runner.
I plan on using a 200 to 210 head...like a Brodix, Profiler, or AFR.

The oil on the dipstick was very clean....once I started to drain the engine and what not...it turned black. As I mentioned, I do think its a stock bore based on the pistons. Maybe I can post some pics. I have no idea on the steam holes...I have looked over the heads that much yet. I will have to verify what valves are in it. I will not be able to do that till the weekend.

The timing chain was metal. I pulled the cam out and the lobes and lifters all looked good. There were not stampings on the front of the cam or the back...nothing...makes me think its a GM cam.

The motor was in a mud truck....

67 chevelle malibu / SS/ custom

Currently undergoing a metal work to remove all rust, if I ever get there.

Cant decide on prostreet or cruiser with a 4 speed.
Aaron is offline  
post #59 of 89 (permalink) Old Dec 2nd, 19, 9:49 PM Thread Starter
Lifetime Premium Member
 
Join Date: Oct 1998
Location: Florida
Posts: 10,910
Re: Picking up a 400 SBC

Quote:
Originally Posted by DZAUTO View Post
I have gone through MOST of the comments (but not all), and have discovered there is a lot of misinformation and some minimal knowledge about SB400s.

FIRST
ALLLLLLLLLLLLLLL the 70-72 400 blocks ONLY had 4bolt mains, REGARDLESS of casting number. PERIOD!
ALLLLLLLLLLLLLLL the 73-80 400 blocks ONLY had 2bolt mains, REGARDLESS of casting number. PERIOD!
The 70-74 400 blocks had 3 freeze plugs.
About 1975, 400 blocks had 2 freeze plugs-------------BUT THERE WAS A RAISED CENTER BOSS WHERE A FREEZE HAD BEEN EARLIER!
Then about 76, the center boss was gone and all 400 blocks had 2 freeze plugs-----------REGARDLESS of casting number.

GM pushed the 400 block way beyond reasonable limits, and as I presume everyone knows, the 400 blocks have siamesed cylinders. BUUUUUUUUUUT, in spite of this, the SB400 is an excellent foundation to build on.
When building a SB400, as many have mentioned, HAVE A COMPETENT MACHINE SHOP THOROUGHLY CHECK IT AND INSPECT FOR VALLEY CRACKS!!!!!!!!!!!
Regardless of 2- or 4-bolt mains, use main cap studs instead of bolts ----------------- FOR A PERFORMANCE BUILD! For a street driver, bolts are OK.
Over the years, it has been determined by extremely knowledgeable engine builders tha the 2-bolt block is the better choice--------------BUT ON MY PERSONAL 4-BOLT BLOCKS, I HAVE HAD ZERO ISSUES!

For a more or less bone stock 400, the stock length rods (5.565in) are OK. BUUUUUUUUUT, for a healthy street-performance-driver, the 5.7 (350 style) rods are a better choice. For a full out performance 400, then the 6.0in rods are an even better choice. BUUUUUUUUUUUT, the down side with 6.0in rods (in my opinion) is that the wrist pin is into the oil ring groove and the pistons are very short and have MINIMAL skirts. The potential is greater for piston rock inside the cylinders.
IF, IF, IF, IF, IF the 400 heads are to be re-used, the ONLY good ones are the 70-74 versions. In 75, GM started cutting off material of the head castings (across the entire board of SB Chevy heads) and all 75-later heads had TWO exhaust cross over passages in the center of the heads (greater possibility for cracking in the center of 75-later heads).
Personally, I like to use stock 70-74 400 heads. They were built with 1.94-1.5 valves, and ANY good machine shop can open them up for 2.02-1.6 valves (I only use stainless valves) and NEVER, NEVER, NEVER have hard seats installed!!!!!!!!!!!!!! With the exception of BIG trucks and extended heavy duty service, there is now enough years of experience which has shown that the use of unleaded fuel in engines that do not have hard valve seats has NOT been detrimental to the valves/seats.
I have one 420SB which has been stroked .100 (the rod journals were offset ground down to small journals) and good, small journal 327 style rods were used. It's in my jet boat and I have seriously abused that engine----------------and just like a Timex, it keeps on ticking!
Since 1972, I have personally built about 25 SB400 with no problems. In my family, there are 5 SB400s that have been running for about 20yrs.
Many of you have seen one of them.
Oh ya, and they are all built with factory GM blocks.
Tom...great post as always.

I think I have a 76 and up block.

Im having a local shop that does all the local drag racers machine work check it out. He has a complete machine shop at his home.

I may use studs versus bolts for my build...I like insurance.

Sounds like the 5.7 rod is the way to go....I will not be reusing the iron heads...will be using something like a 200 to 210 Brodix, AFR. or Profiler head...aluminum of course.

67 chevelle malibu / SS/ custom

Currently undergoing a metal work to remove all rust, if I ever get there.

Cant decide on prostreet or cruiser with a 4 speed.
Aaron is offline  
post #60 of 89 (permalink) Old Dec 2nd, 19, 9:49 PM
Lifetime Premium Member
Tom
 
Join Date: Oct 2006
Location: Firestone, CO
Posts: 1,436
Re: Picking up a 400 SBC

I looked all over and couldn't find a 4.125" steel shim gasket. Do the ones on your engine clear the bore?

I'm really intrigued by this. I looked everywhere for a set.

70 Camino...Roller

69 Malibu Stock 307, Reverse Manual TH350, 4,500 Stall Edge Converter, 4.56 Spool 35 Spline 12 Bolt

76 C20 VortecPro 496 628HP 655 lb/ft TH400 Edge Converter, 4.10 14 bolt
Tommy the Cat is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome