vortec and LT1 heads - 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 03-07-2012, 11:47 PM
Registered User
 
Join Date: Mar 2012
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
vortec and LT1 heads

can you show me the difference between vortex and LT1 heads and can i use LT1 heads on my vortex engines

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-08-2012, 12:58 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,657
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
I think you mean Vortec. And no, LT1 heads will not interchange on to Vortec blocks or any of the classic small blocks for that matter. Why is because the LT1 is reverse cooled. While LT1 heads will bolt on the classic small blocks, none of the coolant ports line up. However you could weld the coolant ports up and drill the ones to match the older blocks but there's no reason to do so due to the time and cost involved. Lastly, Vortec heads were designed after the LT1 heads. They have the same ports and combustion chambers only difference is they are standard flow cooled.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-08-2012, 08:16 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,484
Wiki Edits: 0

Thanks: 20
Thanked 388 Times in 364 Posts
Quote:
Originally Posted by DoubleVision
I think you mean Vortec. And no, LT1 heads will not interchange on to Vortec blocks or any of the classic small blocks for that matter. Why is because the LT1 is reverse cooled. While LT1 heads will bolt on the classic small blocks, none of the coolant ports line up. However you could weld the coolant ports up and drill the ones to match the older blocks but there's no reason to do so due to the time and cost involved. Lastly, Vortec heads were designed after the LT1 heads. They have the same ports and combustion chambers only difference is they are standard flow cooled.

Having worked several sets of LT1 and Vortec heads I can say they do NOT have the same ports or chambers. I don't know where this idea started but its not at all truth. The "iron lt1" heads may be a copy of the Vortec's but I have not worked on any of those.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-08-2012, 09:54 AM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 35
Posts: 1,609
Wiki Edits: 0

Thanks: 15
Thanked 9 Times in 9 Posts
Quote:
Originally Posted by ap72
Having worked several sets of LT1 and Vortec heads I can say they do NOT have the same ports or chambers. I don't know where this idea started but its not at all truth. The "iron lt1" heads may be a copy of the Vortec's but I have not worked on any of those.

Here is some info on the basis for the Vortec heads:

Quote:
Starting in 1996 on several GM Trucks and Vans, the L31 Vortec heads came on the scene. Not just a modification of existing heads, but complete redesign using the 1996 Caprice/Impala SS LT1 cast-iron head castings as a base. The biggest change GM made in the new design was revising the water jacket so the new Vortec heads could be used on conventionally cooled small blocks. The idea of using the 1996 LT1 cast iron head as a starting point for a new performance stock head came from the fact that it was the highest flowing LT head used by GM. The 1996 Caprice/Impala heads outflowed the Corvette Aluminum LT1 heads by as much as 20 cfm on the intake side. The cast iron Vortec head was in development six months longer than the aluminum head, and during that time, GM engineers tweaked the intake and exhaust ports for additional flow. The cast iron Vortec heads was one of the first to purposely integrate tumble instead of large swirl numbers in the design.
Information from www.onedirt.com
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-08-2012, 09:58 AM
sbchevfreak's Avatar
Licenced Automotive Technician
 
Last photo:
Join Date: Feb 2004
Location: Land of big Easter eggs, Alberta
Age: 35
Posts: 1,609
Wiki Edits: 0

Thanks: 15
Thanked 9 Times in 9 Posts
Some more, from Sallee Chevrolet:

Quote:
P/N 12558060 L31 350 Vortec Cylinder Heads (See options below.)


Small block Vortec heads, the head with huge performance gains that everyone is talking about.
This production Vortec iron cylinder head was first used on the 1996 pickup truck RPO L31 with fuel injection. The intake and exhaust port are very similar to Corvette 350 LT1 heads. America’s favorite high performance cast iron small block cylinder head offers big power and bigger value. The Vortec cylinder head's fast burn combustion chamber and high velocity ports combine to produce big horsepower out of the box. The Vortec head can be mildly ported for additional performance and can be milled up to .040” for increased compression ratio. This head includes 1.94” intake valves and 1.50” exhaust valves, springs and retainers, and pressed-in 3/8” studs. This head with compatible valves flows more air than bow tie head P/N 10134392, but the casting may not be as durable. It is a 20 to 40 horsepower bolt on increase over earlier cast iron small block heads. The water passages are the same as the original 1955 small block design. The eight-holt intake bolt pattern is totally different than the early model V8 12-bolt design. The Vortec head REQUIRES a Vortec style intake manifold due to its improved manifold mounting flange and gasket design and raised intake ports. It is not recommended that the heads be modified to accept early design intake manifolds (They will never match up right.). Use new manifold P/N 12366573, 12496820, 12496821, 12496822, or any others that we have listed below for correct matching to the Vortec head. Vortec heads fit all small block engines produced 1955 to present, excluding LT1/LT4 reverse coolant flow engines and current LS1 style “GEN 3” engines.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-08-2012, 10:17 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,484
Wiki Edits: 0

Thanks: 20
Thanked 388 Times in 364 Posts
So simply put, there's no relation to LT1 heads other than the Vortec was developed after the iron LT1 head was?

I wish this would put an end to the "well they're the same except for the cooling" comments, but it won't.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-08-2012, 11:56 AM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 7,095
Wiki Edits: 0

Thanks: 4
Thanked 541 Times in 457 Posts
Quote:
Originally Posted by ap72
Having worked several sets of LT1 and Vortec heads I can say they do NOT have the same ports or chambers. I don't know where this idea started but its not at all truth. The "iron lt1" heads may be a copy of the Vortec's but I have not worked on any of those.
More than less an X2. While the vortec and LT1 show some general similarities in the approach to ports and chambers, the detail execution is unique to each.

The iron LT1 heads are much more similar to the Vortec, where the aluminum LT1/4's ports and chambers are more similar to those of the GMPP aluminum Fastburn head.

I don't know whether any of this reflects the limitations between casting processes for aluminum or iron; or whether the differences reflect changes to optimize combustion around the different heat transfer rates of these materials; or whether it's just the result of different performance goals. But when set side by side I agree that they are noticeably different in detail while being similar in general layout.

I always find it amazing that combustion chambers that vary slightly in detail can vary so widely in performance. It certainly speaks to the complexity of events happening in extremely short periods of time.

Bogie
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-08-2012, 01:39 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,484
Wiki Edits: 0

Thanks: 20
Thanked 388 Times in 364 Posts
Quote:
Originally Posted by oldbogie
More than less an X2. While the vortec and LT1 show some general similarities in the approach to ports and chambers, the detail execution is unique to each.

The iron LT1 heads are much more similar to the Vortec, where the aluminum LT1/4's ports and chambers are more similar to those of the GMPP aluminum Fastburn head.

I don't know whether any of this reflects the limitations between casting processes for aluminum or iron; or whether the differences reflect changes to optimize combustion around the different heat transfer rates of these materials; or whether it's just the result of different performance goals. But when set side by side I agree that they are noticeably different in detail while being similar in general layout.

I always find it amazing that combustion chambers that vary slightly in detail can vary so widely in performance. It certainly speaks to the complexity of events happening in extremely short periods of time.

Bogie
Another comment I have is that I'm not so sure the Vortec chamber is "superior" to the lt1 design, both of them have shortcomings and both of them are pretty good but they are different. The LT1 has a distinct advantage of more material there for porting though and IMO can lead to a more optimized head from the valve out- but from the valve in the taller port of the Vortec head is better but the LT1 head has a better short turn (not that the Vortec's is bad because its rather good compared to older heads).
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: 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
Oppinions EQ lightening heads and EQ vortec heads eatonde Engine 16 02-19-2013 12:00 AM
dart heads vs vortec heads repeat Engine 48 03-10-2012 09:05 PM
putting 305 vortec heads on an pre-vortec 350 thor1022 Engine 11 01-12-2011 04:17 PM
Will a intake off vortec heads fit non-vortec heads nobody_1250 Engine 13 12-27-2010 06:02 AM
Vortec heads or 1971 487x LT1 heads? speedfrk3 Engine 2 10-07-2002 05:12 PM


All times are GMT -6. The time now is 12:43 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.