Stock, BUDGET 400sbc. 58cc heads too small? - 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 02-11-2011, 12:57 PM
MrChevyDC3's Avatar
Member
 

Last journal entry: 1st day out!
Last photo:
Join Date: Nov 2003
Location: Detroit
Age: 37
Posts: 126
Wiki Edits: 0

Thanks: 9
Thanked 1 Time in 1 Post
Stock, BUDGET 400sbc. 58cc heads too small?

Sup Guys.

About to disassemble a stock 400sbc to see exactly what went wrong in it. It's running now, but it has a slight knock and <10psi oil pressure while driving I want to get this thing back together with minimal parts, probably just a head and cam change. This will go in a weekend warrior, street cruising machine. A buddy has a set of World Product S/R 58cc at a VERY nice price. My questions are...

1. Will these heads bring my compression up too high? I'm willing to run premium gas.

2. Cam suggestion? Keep budget in mind. I've also learned that a larger cam with plenty overlap can offset high compression, so....?

3. How bad would it be to keep my stock rods and pistons? If it turns out to be something wrong with them, can/should I just get them fixed and stick with a stock sized replacement?

I appreciate your help with this. I'm looking for a reputable machine shop in the lower Michigan area right now. I want to go thru this once and have a strong, reliable motor when done, and hopefully some change left over to complete my 355/Roots supercharger project!!!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-11-2011, 01:47 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 595 Times in 545 Posts
The main problem w/this engine is going to be in the bottom end. Crank and/or bearings, not the pistons and bores. There's a chance the rods will need to be resized if the rod bearings are what went bad. If that happened, you should put a set of ARP rod bolts in the rods before resizing them.

To use 58cc heads, you'll need to measure the piston dish volume on the pistons in it now, and measure the deck height. Those things along w/the head gasket thickness will determine what the CR will be when all's said and done.

So there's no way to give you an exact "yes" or "no" answer about the heads at this point. If this engine is going to get the blower- the heads are out unless you use some big dished pistons to lower the CR.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-11-2011, 02:33 PM
MrChevyDC3's Avatar
Member
 

Last journal entry: 1st day out!
Last photo:
Join Date: Nov 2003
Location: Detroit
Age: 37
Posts: 126
Wiki Edits: 0

Thanks: 9
Thanked 1 Time in 1 Post
THanks!!!!

I concur that these heads are not "blower-friendly", so I'm saving that for the 355 that I have out back. I plan to get on that right after I get this 400 spinning. It was suggested that I get new bearings and resize the rods (I believe they are 5.65) at minimum once I take my engine to the shop. I'll definitely look into getting ARP bolts in the rods also. I'm trying to keep shop costs as low as possible. But I WILL do what's necessary to keep this engine spinning for years to come.

I'm wondering, if this engine has the same pistons/ deck height as it came with (out of a '71 Chevy sedan), is there no way to 'guesstimate' those values?

Also, anytime I read up on those World S/R heads, it says for "305ci". Is that to say they're too restrictive for a 400ci? I just don't wanna buy these and have a detonation-prone or choking motor.

Thanks again!!!
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-11-2011, 03:21 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 7,684
Wiki Edits: 0

Thanks: 10
Thanked 151 Times in 139 Posts
Worlds reference to these heads being for "305's" is two things. That is the application the heads are intended for, thus the 58cc chamber, and the fact that World has moved the valve centerlines a bit to allow a better fit of the 1.94" intake valve and have it not be as shrouded by the small bore of the 305. They will work as good as the ordinary SR on you 400 if you can keep the compression ratio down, they are not a bad head, as good as any "Fuelie/Camel hump" head is.

Just as a rough guess, with the standard undecked block, an .041 composition head gasket, and an estimate of 22cc dish volume for the stock piston it would put you at 9.7-1 compression. If the piston is 18cc it would be 10.1-1. You might search the web and see if you can pin down the dish volume on the stock piston. I believe it is 18cc but don't know for sure, I have heard 22cc also.

The stock 400 rod is 5.565" long.

If you need to lower the compression ratio more you could always grind the chamber larger, a deshrouding of the intake valve side of the chamber for better flow could get you 2-4cc, maybe 6cc if you open it up around the exhaust valve also. Relatively simple job. They just won't fit a 305 as well again if you do grind them.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-11-2011, 03:31 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 7,684
Wiki Edits: 0

Thanks: 10
Thanked 151 Times in 139 Posts
I should add the SR's for 305's used to be with the altered valve location, but may not be anymore, I could find no current mention of this fact on World's site. The "special" 305 heads may have only been made back before World Products split from Dart.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-11-2011, 06:00 PM
Registered User
 
Join Date: Aug 2008
Location: kansas
Posts: 49
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
1: steam holes will need to be drilled in the heads

2: I measure the dish depth on a stock 400 piston to be .200

3: Add .020 piston down in hole plus .200 dish plus .041 head gasket gives a very unfriendly quench distance for 9.7:1 compression

4: Short rods on the 400 sbc causes more side thrust and many times the bore is gouged out just below the top of the piston travel and needs boring and new pistons.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-12-2011, 01:44 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
You will be miles ahead with a set of vortec heads on your 400.
Any preceived or real extra cost over your buddies offer will be worth it.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-12-2011, 03:16 PM
OLNOLAN's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Louisiana
Posts: 1,004
Wiki Edits: 0

Thanks: 209
Thanked 63 Times in 53 Posts
Cr

Hey Mr. Chevy, Your CR is gonna be too high for pump gas with about any piston you use with 58cc chamber heads. The following is w/a .030 overbore.
L2467F flat 2 valve relief=11.84
H400P flat 4 valve relief=11.59
L2352F .083 dish=10.53
H601P .135 dish 4 valve relief=10.78
You're gonna need a 72cc chamber head to run it on pump gas, they will put you between 9.21 and 10.17 depending on the piston you choose. I think others here are ball parking 350 CI, CR numbers. This is a 400 4.155 w/.030 overbore x 3.75 stroke. olnolan
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-12-2011, 07:41 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Quote:
Originally Posted by OLNOLAN
Hey Mr. Chevy, Your CR is gonna be too high for pump gas with about any piston you use with 58cc chamber heads. The following is w/a .030 overbore.
L2467F flat 2 valve relief=11.84
H400P flat 4 valve relief=11.59
L2352F .083 dish=10.53
H601P .135 dish 4 valve relief=10.78
You're gonna need a 72cc chamber head to run it on pump gas, they will put you between 9.21 and 10.17 depending on the piston you choose. I think others here are ball parking 350 CI, CR numbers. This is a 400 4.155 w/.030 overbore x 3.75 stroke. olnolan
A KB168 22cc piston will work fine with a 58cc head. Pretty much anything with a dish is good.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-13-2011, 06:48 AM
OLNOLAN's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: Louisiana
Posts: 1,004
Wiki Edits: 0

Thanks: 209
Thanked 63 Times in 53 Posts
22cc Dish

Quote:
Originally Posted by F-BIRD'88
A KB168 22cc piston will work fine with a 58cc head. Pretty much anything with a dish is good.
Hey fbird, Even a 22cc dish still puts you at nearly 10:1 w/the small chamber head. Way to much compression to run on todays pump piss on the street.

Each to his own, but 10:1 is too high for a daily driver. olnolan
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-13-2011, 11:48 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Quote:
Originally Posted by OLNOLAN
Hey fbird, Even a 22cc dish still puts you at nearly 10:1 w/the small chamber head. Way to much compression to run on todays pump piss on the street.

Each to his own, but 10:1 is too high for a daily driver. olnolan
No its not. 10:1 is just right for premium pump gas fueled high performance motor. 11:1 would be really,really pushing it. I recommend keeping it under 11:1 for street pump gas "daily driver".

Never pick a camshaft to "bleed off compression". All you are going to achieve is building a inefficient motor.
Pick the cam based on where you want to make the power and torque.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 02-14-2011, 03:58 PM
MrChevyDC3's Avatar
Member
 

Last journal entry: 1st day out!
Last photo:
Join Date: Nov 2003
Location: Detroit
Age: 37
Posts: 126
Wiki Edits: 0

Thanks: 9
Thanked 1 Time in 1 Post
So, in order for me to use the 58cc World S/R's, I definitely MUST buy new pistons? I've read that the vortechs don't like to spin over 5k. I don't plan on revving this thing to the moon, but a 6500 redline or so would be nice. Depending on the shape of my rods (and pistons), I was hoping to only clean up the rods, find some budget heads and a matching cam and get this thing on the road. I already have a Edelbrock RPM air gap, Holley 650 carb, 2800 stall and 3.42 gears w/posi out back. th350 trans. Just wanna roast some hides and let it stand up to a few of these ricers out here now. My buddy wants 250 for the heads, complete. Should I look into buying a vortech setup( heads, intake, machining to get lift past .500) instead??? Thanks for all the advice. Payday is friday, I'll be making a decision by then!
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 02-14-2011, 04:09 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 7,684
Wiki Edits: 0

Thanks: 10
Thanked 151 Times in 139 Posts
I would buy them at that price if they don't need rebuilding and make them fit my needs by grinding the chamber larger if necessary. It isn't hard to do, and that way you can dial in the compression ratio.

If you can do a little port work a bowl blend and guide boss slimming would really wake them up.

I guess it would depend on your ability to modify them to your needs.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 02-14-2011, 04:44 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 595 Times in 545 Posts
Another opinion...

Quote:
Originally Posted by MrChevyDC3
I've read that the vortechs don't like to spin over 5k. I don't plan on revving this thing to the moon, but a 6500 redline or so would be nice. Depending on the shape of my rods (and pistons), I was hoping to only clean up the rods, find some budget heads and a matching cam and get this thing on the road. I already have a Edelbrock RPM air gap, Holley 650 carb, 2800 stall and 3.42 gears w/posi out back. th350 trans. Just wanna roast some hides and let it stand up to a few of these ricers out here now. My buddy wants 250 for the heads, complete. Should I look into buying a vortech setup( heads, intake, machining to get lift past .500) instead??? Thanks for all the advice. Payday is friday, I'll be making a decision by then!
If you want to have a cam that wants to peak at >6000 RPM, the SR's are not what I would use. Nor are the production Vortec's. Neither the Vortec or SR 305 head will be a good match for anything over 5000 RPM on a 400 SBC, given their 170cc intake port volume and the 1.94 x 1.50" valves. Not to mention the problems w/getting the CR down far enough that a cam w/a <5K RPM peak can be used. If I had to use either, it would be the Vortec due to its better combustion chamber shape, etc.

If it were me, I'd be looking real hard at one of the budget aluminum heads bought bare w/the seats cut for 2.02" x 1.60" valves. Aluminum heads can tolerate around 1:1 more compression than an iron head. On your 400 w/64cc chambers, 12cc dished stock pistons, a 0.060" quench, 0.030" overbore, the CR would be around 10.3:1- doable w/Al heads, not so much w/cast iron, at least not w/any cushion to speak of.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 02-15-2011, 06:58 AM
MrChevyDC3's Avatar
Member
 

Last journal entry: 1st day out!
Last photo:
Join Date: Nov 2003
Location: Detroit
Age: 37
Posts: 126
Wiki Edits: 0

Thanks: 9
Thanked 1 Time in 1 Post
3 options

So it looks like at this point I can plan to go one of three routes

1. CHEAPEST-- World S/R 58cc head. Highest compression option, and I'll have to get some machining done to them to dial in a better compression ratio. I GUESS I can be satisfied with a 5500 rpm redline Also the machining will help them flow better. But they are assembled complete with ARP studs

2. MID PRICE-- The Vortech setup. Same buddy has asome Vortech heads and an intake for a higher price, but they're stock. I'd have to get them worked over to accomodate lift, and buy some valve covers. But if I'll be "miles ahead" in performance, it may be worth it?? Still 5k redline though???

3. Highest cost--- Keep searching for some better aluminum heads that will have me at my optimum compression and I can tailor my redline accordingly.

Seems like I have some decision making in order. I'm kinda leaning towards getting some work done on the S/R's. While looking for some affordable aluminums.
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
58cc EQ 305 Heads on low compression 1977 smog 350 ? wade786 Engine 9 12-27-2010 12:57 PM
Stock 302, Small budget, Need horsepower! help! phatso2012 Engine 2 08-29-2010 05:05 PM
Rpm Air Gap Intake Onto A Stock 400sbc jarhead_615 Engine 2 04-20-2010 06:27 AM
can i run a 480 lift cam with 58cc heads Mr. Wormy Engine 2 07-09-2006 09:21 PM
58cc vortec iron heads Leon Weathers Engine 2 12-23-2002 05:36 PM


All times are GMT -6. The time now is 10:40 AM.


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.