8.1L 496 vortec big block chevy, what is it? - 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 08-01-2004, 12:52 PM
406 ss monte's Avatar
eat a beaver, save a tree
 
Last photo:
Join Date: Dec 2003
Location: greeneville, tn
Age: 43
Posts: 605
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
8.1L 496 vortec big block chevy, what is it?

i found a 496 bbc. i've never heard of it before. is it the same as the 454's & any other big block chevy? do the bolt up like the older ones? do they use the same heads, intake, & other bolt on's? are they a good choice for a build up? like i said, i've never heard of them. i know about the 454 stroker 496, but this is a factory short block. thanks for your help.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-01-2004, 01:40 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,240
Wiki Edits: 0

Thanks: 30
Thanked 298 Times in 278 Posts
It is a factory, heavy truck motor. Cast iron crank. Strictly a low rpm workhorse. It is based in the latest series of big blocks, with their cooling and oiling differences, one piece rear main seal. As built, there is nothing hi-performance about it. Heads are small port truck.. But, those glorious cubic inches! Add some hot rod parts and you should have a real stump puller..
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-01-2004, 01:46 PM
406 ss monte's Avatar
eat a beaver, save a tree
 
Last photo:
Join Date: Dec 2003
Location: greeneville, tn
Age: 43
Posts: 605
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
will the older heads & intake bolt to the new block? do any of the 496's come with steel cranks? it's a lot of motor, but if the older stuff wont bolt to it, i can't use it.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-01-2004, 08:44 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,240
Wiki Edits: 0

Thanks: 30
Thanked 298 Times in 278 Posts
I am told that none of the older stuff will work. 502 heads will work. Cranks are all cast, and use one piece seal type flywheel.

I accidently acquired one for the shop this spring from a local truck repair shop for $75.00 (core engine). They thought it was a 502, as it uses all the same external parts. This one had a noise, that turned out to be a spun rod. The rods are longer than a stock big block. I believe they were +.400 stock. We ground the crank and resized the rod. Freshened the rings and bearings and sold it to some very lucky person on Ebay. I would have liked to keep it..
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-01-2004, 09:36 PM
406 ss monte's Avatar
eat a beaver, save a tree
 
Last photo:
Join Date: Dec 2003
Location: greeneville, tn
Age: 43
Posts: 605
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
aren't the 502, & 396,427,454 heads all the same as fare as the bolt pattern on the deck surface? if they are, why wouldn't the older heads, intakes, & distributors work?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-01-2004, 10:54 PM
Member
 
Last photo:
Join Date: Aug 2002
Location: Seattle
Posts: 62
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I have one in my Suburban---345 hp and 460/470 lb-ft torque. They have distributorless ignition....so a manifold swap would be in order---I "thought" these were an all together different block than the newer mark 5 big blocks----could be wrong. With a good computer tweak and a cold air intake guys have seen 50-75 hp gain at the rear wheels on a dyno.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-02-2004, 03:50 AM
deuce_454's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Copenhagen, Denmark
Age: 39
Posts: 1,000
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
aren't the 502, & 396,427,454 heads all the same as fare as the bolt pattern on the deck surface? if they are, why wouldn't the older heads, intakes, & distributors work?
actually they are not the same.. the waterpassages are diferent, if you try and bolt a mark 5 head to a mark 4 block the water will pour into the oil.. and if the new vortech 8.1 is reverse cooling nothing will work.. it would be like bolting a set of camelhumps on an lt4. it might bolt up, but cooling would be non existent...

but with some tall reared gears i think it would be a killer engine, and if you can have it cheap.. have at it..
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-02-2004, 09:01 AM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,240
Wiki Edits: 0

Thanks: 30
Thanked 298 Times in 278 Posts
Correct. The water passages are different and the oiling is different. They do use a coil pak but the block is still for a distrib. The intake is impressive looking with the black and aluminum theme carried over from the cast valve covers.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-02-2004, 12:00 PM
406 ss monte's Avatar
eat a beaver, save a tree
 
Last photo:
Join Date: Dec 2003
Location: greeneville, tn
Age: 43
Posts: 605
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
all there is is the short block, so if the older "good" heads wont work, i can't use it. i'm sure the heads & they use anen't worth a dime for 600 horse power like i'm wanting.

how can you tell the differance from all the blocks to know what it is? like the differance in a mark 4 & a mark 5 block?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-02-2004, 01:35 PM
deuce_454's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Copenhagen, Denmark
Age: 39
Posts: 1,000
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
the best way to check engine type is to look up your castingnumber. im betting yours is a 12556110. its a 01 up 4-bolt, Gen.VII 8.1L, "Vortec 8100", Truck engine

im not sure if you can get performance heads for a gen 7. but mercruicer just came out with a performance big block based on that engine that put out about 425 Hp with gen 7 heads, 9:1 comp and a 5000 rpm marine cam, so dont dispare

Last edited by deuce_454; 08-02-2004 at 01:46 PM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-07-2004, 07:02 PM
Member
 
Last photo:
Join Date: Sep 2002
Location: New Jersey
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
There is limited swapability between the 8100 and most other bigblocks.The shortblock is a gen 6 type lowdeck with a 4.25" bore and 4.375" crank and stock length heavy duty rods.The crank is nodular iron with winged counterweights and is a good performance piece.I assembled a 555 using the crank from a 8100 vortec in a later 502 block{.030" over} and with lightweight pistons and steel 4.385" rods it lives fine making 850 hp at 7000rpm.We had some of the prototype stuff when it first came out and GM's intentions were to build a 496 inch shortblock that used standard bigblock valve angles and valvetrain components but had symetrical port prostock style heads ib it.The early version that I worked on had a 10 bolt head pattern like a ford motor but it used massive 5/8" studs.The intake used 4 bolt per side composite plastic intake.The heads flow very well and with a little bowl blending and some 2.25" intake valves they will outflow even the best aftermarket standard bigblock heads,and the cross section is small enough to make it all very streetable.Like I saud,the heads are very prostock like.I never worked with an entire production engine,but I know that the production piece uses a standard bigblock head bolt pattern and gen 6 water passages,and will use at leas regular mark 4 rocker arms if the studs are correct.It would be a great performance piece,and when I first got it I was working on building a combination to run my rae car in a class that requires production part number car or truck casting engine blocks and heads,with displacemnt limited to whatever you could stuf in a stock block,and since the original prototype was a siamsed wall casting,I was looking into it as the ultimate loophole combination once the engine went into production.The rulemakers required carbs and a regular distributor and sheet metal intakes or distributorless coversions were illegal,so the engine lost it's potential.All in all,if you dont mind working with the efi,the longblock has lots of potential for a drag race or stret rod buildup.Good luck.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-08-2004, 12:01 PM
Member
 
Join Date: Apr 2004
Location: carmichael, CA
Age: 39
Posts: 91
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
there is a post at ls1tech.com about performance heads and a intake for the 8.1 motor. the parts were expencive but they were aluminum and would make alot of power.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-08-2004, 12:24 PM
GoneNova/406's Avatar
Member
 
Join Date: Aug 2003
Location: columbus,ohio
Age: 59
Posts: 1,163
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
if you would jump over to mortec.com,i think you can look at their bore and stroke list for big block chev's and find out that a 496 is a stroked 454=4.250x4......496=4.250x4.37....i'd almost rather have one of these than a 502which is 4.66x4
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-08-2004, 03:02 PM
deuce_454's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Copenhagen, Denmark
Age: 39
Posts: 1,000
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
4.5x4, id say that getting the 496 shortblock and installing the rotating assembly in a bored 502 block with some aftermarket gen 6 heads, pro topline 320 or dart 360 allong with a rollercam is your best ticket.. a healthy mechanical-rollercammed well breathing 555 bigblock should be good for 750 Hp on pump gas with mufflers
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-26-2006, 04:19 PM
Duke of Cruel's Avatar
Car nerd
 
Last photo:
Join Date: Jul 2006
Location: sweden
Age: 40
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 406 ss monte
i found a 496 bbc. i've never heard of it before. is it the same as the 454's & any other big block chevy? do the bolt up like the older ones? do they use the same heads, intake, & other bolt on's? are they a good choice for a build up? like i said, i've never heard of them. i know about the 454 stroker 496, but this is a factory short block. thanks for your help.

its an vortec big block , same as the truck engines and in family with ls1/ls6 etc.
DoC
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:
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: 2 (0 members and 2 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



All times are GMT -6. The time now is 06:27 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.