need some help building my 400 sbc :) - 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 12-28-2011, 02:56 PM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
need some help building my 400 sbc :)

Hey guys whats up tony here. I recently bought a motor from a guy to put in my truck for 500 heard it run and drove it before i paid for it. Well when i went to pick it up i noticed it had 3 freeze plugs on the side of the block so i ran the numbers right then and there (3951511) said 4 bolt mains online. Tore it apart to put a little work into it all the pistons are dish but say 30 on top of them all does this mean its bored. 30?? Then i pulled the pan and it was a 2 bolt. I got all excited cuz i kept reading 4 bolts wernt as strong. So the truck i want to put this in is
1982 chevy k30
4:10 gears.
4 speed manual trans
44" tires.
I want the motor to make good power as i read that i shouldnt rev past 5k witch is fine cuz i dont mud race but i do drive this truck as a daily to. And my 355 sits at 2400 rpm at 65. The gears should be fine. My 355 had no problem breaking the rears loose

I was at the local junk yard today and found a set of L31 vortech heads. 1255806 ??? I believe how will these perform on my 400 or 406. After i drill the steam holes? im unsure of cam im going to run. I dont want to think to far or to big. I want to put my money at the right spots to have a strong pulling motor and some ponies. Thanks for all your help
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-28-2011, 03:41 PM
bad436z28's Avatar
Registered User
 

Last journal entry: 79 z28 436sbc/4speed bright cobalt blue metallic,soon to be.
Last photo:
Join Date: Dec 2011
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thats a myth u can run the 400 chevy past 5,000 rpms,u run mine past 7,000 rpms,just need good internals to do it.the 2 bolt block is the stronger of the two.them vortec heads should give a good performance boost over the 400 ones.im at 436 cu inches and making 630 hp in my 400 block,you just need to have the cylinder wall thickness checked.mine was at .300 anything mast .200 u can build about 500 hp with and be safe.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-28-2011, 04:40 PM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Nice nice im liking wat im hearing. Should i do any kind of porting or polishing? At least gasket match?? What are your ideas on cams?? I dont understand cams at all iv read and read and i just dont understand
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-29-2011, 05:51 AM
bad436z28's Avatar
Registered User
 

Last journal entry: 79 z28 436sbc/4speed bright cobalt blue metallic,soon to be.
Last photo:
Join Date: Dec 2011
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
yes if u can afford to port and polish it will surely help,it will wake them vortec heads up considerablyalso if u wanna put big cam in it u will need new springs to handle the higher lift,how much horsepower u wanna make,im running a compcams solid roller at 600 intake and ,610 on exhaust,but im also running RHS racing heads 220cc.the biggest and most important thing is not to run the stock crank,get one of the eagle nodular steel cranks there only about 200 bucks it will greatly help it stay alive.just let me know what kind of hp u wanna make and i can recommend a good cam,and if u want roller or flat tappet cam.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-29-2011, 06:16 AM
zildjian4life218's Avatar
Listen and Learn
 
Last wiki edit: DIY junkyard electrical fan controller
Last journal entry: SBC 305 Twin Turbo
Last photo:
Join Date: Dec 2008
Location: WNY/Rochester, New York
Age: 25
Posts: 1,512
Wiki Edits: 7

Thanks: 41
Thanked 6 Times in 6 Posts
Quote:
Originally Posted by atcoscrazyest69
Nice nice im liking wat im hearing. Should i do any kind of porting or polishing? At least gasket match?? What are your ideas on cams?? I dont understand cams at all iv read and read and i just dont understand
I wouldn't touch the heads if you don't have experience porting. The vortec heads flow great from the factory I wouldn't try to mess that up. You will probably need to have the lift issue taken care of. From the factory the vortec heads don't allow for more than .460-.480" lift. Machine shops can fix this for you by cutting down the valve stem or by running a different spring, retainer, and lock setup. But chances are you should have the heads sent to a machine shop to get cleaned up, magnafluxed, valve job, and have the guides checked. while they are at it ask them to increase the max lift to say .550" that will be more than you should need clearance for.

Also with the block already being .030" over I would take it apart and check the bores to make sure you can reuse them. I have never heard great things about cutting 400s past .030" without it being sonic checked.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-29-2011, 07:16 AM
bad436z28's Avatar
Registered User
 

Last journal entry: 79 z28 436sbc/4speed bright cobalt blue metallic,soon to be.
Last photo:
Join Date: Dec 2011
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
400 beast

yeah u wanna be sure to have it sonic checked,that determines the cylinder wall thickness if u weant to build high horsepower they need to be atleast.200 thickness in all cylinsder walls,yeah ur right i wouldnt port them heads myself unless ur very expierenced at it,vortec heads are hard to port because they already flow so well,but if u can afford to have them ported by a professional then it would help.i would defanetly haqve new valves and springs put in with new valve seals and guides.then u have no wories if ur cam will be ok to run in there,and if u can afford the machine work i would have the eagle billet 4 bolt main caps installed.then u can make some serious horsepower and not worry about ur block falling to pieces.yeah 550 lift is more than u will ever need,plus them heads wont flow very well beyond 550.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-29-2011, 08:21 AM
zildjian4life218's Avatar
Listen and Learn
 
Last wiki edit: DIY junkyard electrical fan controller
Last journal entry: SBC 305 Twin Turbo
Last photo:
Join Date: Dec 2008
Location: WNY/Rochester, New York
Age: 25
Posts: 1,512
Wiki Edits: 7

Thanks: 41
Thanked 6 Times in 6 Posts
what exactly are your goals with this truck? depending on that the limited lift may not be an issue. but in order to choose a cam the trucks usage needs to be figured out. you already supplied tire size , rear gear ratio, and transmission which are all key players. r u rebuilding the bottom end? or taking it apart, cleaning, and measuring everything to make sure its good? or just leaving it as is? from what I read the steam holes arent really an issue or concern but I could be wrong and hopefully someone steps in and can clarify that. I have actually been thinking about doing a Vortec headed 406 for awhile. just waiting to trip across a decent block.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-30-2011, 11:55 PM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i heard the motor run and it has barely any miles on it sence rebuild i honestly dont even think the rings are broken in yet. the crank is not stock. but it doesnt not have any numbers on it. iv done port and polish work before but only 2 sets of heads and allot of quads and dirtbike. i did take the bottom end apart completly the cam bearings rod bearings and mains dont have a single scratch in them. in fact the point thats at the tips of bearings when you get them new was still there !! the cam that appears to be in it seems like a stock gm replacement but im unsure and didnt look to far into it because i want to beef it up a little im not looking to get up to 500 horse. i just want to make decent power but still be able to get up and go at highway speeds.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-31-2011, 12:09 AM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i did rip apart the heads. the heads btw came off a 98 tahoe with only 28xxx miles on it that was rolled over. i put new valve seals in ran my engine wire brushes threw all the ports to clean it up a little had some surface rust. i opened up the exhaust ports a little bit to increase flow coming out. while i was in the cleaning stage i went ahead and drilled the steam holes in the heads. was allot easier then i made myself think. i just really dont want to under power it but at the same time i dont want to overkill it with a cam. id rather not do the lift increase at this time. funds are limited working parttime due to no work. id like to run roller and have a whole gen 3 roller 355 in my truck now that i can steal the lifters for but its more work then im looking for at the time. i really just need a ballpart with numbers for the cam..... idk what to do like i said im cam illiterate
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-31-2011, 12:24 AM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
maybee....http://www.compcams.com/Company/CC/c...?csid=225&sb=2
??????
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-31-2011, 06:36 AM
Registered User
 
Join Date: Jul 2009
Location: Atl
Posts: 43
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
re: need some help building my 400 sbc :)

Hey bud....sounds like you're gonna have one hell of a motor when you're finished. Comp cams make an above stock cam that can be used w/ the current spring set up on your vortecs. The part # is 12-246-3 & it can be purchased at Engine Parts Warehouse or Summit for under $150. It has an intake & exhaust lift of .490. That's about as high as you wanna go (although you could actually go up to .498). You will, however, need to use a 2200-2500 stall converter. You also need to be very mindful of the type of pistons you run w/ the vortec heads. If you stick w/ the dish pistons your compression ratio should be fine but if you upgrade to flat tops you won't be able to use pump gas. Good luck!!!
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 12-31-2011, 07:41 AM
streetbruiser's Avatar
Registered User
 
Join Date: Nov 2011
Location: Illinois
Posts: 76
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
found a set of L31 vortech heads. 1255806 ???

I thought vortech heads had casting numbers ending in 906 or 062. You might want to double check that you have what you think you have.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 12-31-2011, 10:15 AM
Registered User
 
Join Date: Dec 2011
Posts: 25
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
yeaaa i forgot the 2 on the end i know what i have REAL vortec heads only have 4 intake bolts on each head. anyway the pistons are dish. i do not need a convertor im running a 4 speed manual top loader ?rockcrusher... very low ended trans
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 12-31-2011, 03:33 PM
bad436z28's Avatar
Registered User
 

Last journal entry: 79 z28 436sbc/4speed bright cobalt blue metallic,soon to be.
Last photo:
Join Date: Dec 2011
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
cam choice

ok now that i have an idea what ur looking for,yes i do build engines mostly for sprint cars but have built a few truck ones also,mostly for family.im liking the lunati vodoo cams as i have had good luck with them,lunati part#60103 thats an awesome cam put that in my brothers 406 last year and he loves it,its in a 75 chevy truck with 12"of lift and 36"tires.so check it out and tell me what u think it has good torque down low and awesome power on top.my brother uses his truck for mud running competitions.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-01-2012, 08:52 AM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 580
Wiki Edits: 0

Thanks: 0
Thanked 23 Times in 22 Posts
Just my 2 cents FWIW,
You said it doesn't have the stock crank. While you have it apart measure the rods to see if they are the stock or not. 5.565" stock rods are not recommended for high rpm that the Lunati Voodoo part#60103 1800-6200rpm range is recommended. That rpm range is usually based on a 350 and you can drop it a few hundred rpm for a 400, but the lift(504") is still too much for a set of stock vortec valve guides/springs/retainers.
With those gears/tires and a cruise rpm of 2400rpm IMO you would be much better off with a cam that has a lower range for a lot more low end throttle response and torque and be done with about the same rpm as you stated in your first post"5K".
I've used a Comp Cams 260 High Energy grind in a 350 and know that the rpms are limited to about 5200 by the springs ability to control the valves, but it pulls great from idle(630) all the way to the red line. It only has .447" lift which will work with stock vortec heads.
With a 400 you could probably use a Com Cams 268 High Energy( Summit PN CCA-12-210-2 for specs). It has a .454" lift that should be safe with your guides/seals, but needs to be verified by mock up. The 1500-5500 rpm range will somewhat act as a safeguard/limiter to keep from throwing a rod due to excessive rpm.
Also you really need to find out the volume of your piston dish to be able to calculate your compression ratio. Also measure how far in the hole the piston is at TDC. You could get a large syringe along with a flat piece of plastic and measure both volumes at the same time to input into one of the many online CR calculators. You really need to do this before you buy the cam. Your CR may be too high to use the cam I mentioned. The only way to know is to measure before its too late! 9.5:1 is the highest I would run with the 268 in a 400 with iron heads. Like I said, just my 2 cents.
Good luck,
ssmonty
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
Building 362 sbc marcsmithracing Engine 2 07-07-2011 01:23 PM
Hi all, building a '67 C10 67C10shorty Introduce Yourself 2 03-17-2011 07:02 PM
New to building a rod dap_nh Introduce Yourself 1 12-28-2006 12:59 PM
need some help building a 454 inquiring_mind2 Engine 10 10-15-2004 09:21 PM
Building an Engine or Building a Combination. . . Cstraub Engine 3 10-13-2004 03:39 PM


All times are GMT -6. The time now is 11:37 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.