Decent heads for street/strip - 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 01-12-2009, 02:33 PM
Registered User
 
Last photo:
Join Date: Jul 2006
Location: Victoria, BC Canada
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Decent heads for street/strip

I'm in the budget of finding a used set of heads for my '81 chevy shortbox daily driver but I was thinking about bracket racing it this year... looking around in the local rag I can only find three sets of heads for sale and almost anything would be better than the smoggers that are on it now. Just looking for opinions, I'm assuming the first pair are the best...

$400- ported and polished 350 heads 1.94 ss intake, 1.50 exhaust valves. Screw in studs and guide plates. Shaved, camaro .600 lift dual valve springs

$300- 041 heads, magnafluxed and decked. They have new seats and guides. All they need are 1.94/1.50 valves to go in

$200- 350 open chamber heads with 2.02 intake, 1.60 exhaust valves. High performance valve job, and shaved aprox. 100 miles on them.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-12-2009, 03:39 PM
Registered User
 
Join Date: Nov 2007
Location: utah
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The 400.00 set doesnt give enough info to make a good judgment. They could be anything from excellent to boat anchors. Ive got a set of "Camaro 350" heads with all those other goodies and I use them as a step to reach my top shelf.

041's are good. The "open chamber" heads are just like what youve already got.

Im a bit curious about the 305 heads. Im seeing threads on the webb comparing them (when ported) to vortec heads. Do they really have that much potential?? Anyone??
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-12-2009, 06:18 PM
GMC boogie's Avatar
Member
 
Last photo:
Join Date: Nov 2004
Location: Louisiana
Age: 49
Posts: 637
Wiki Edits: 0

Thanks: 1
Thanked 22 Times in 22 Posts
041's would be the best choice based on the information you provided.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-12-2009, 06:47 PM
Registered User
 
Last photo:
Join Date: Jul 2006
Location: Victoria, BC Canada
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
65smallblock- I have experienced 305 heads on a 350 and it gives you torque off the line power but they're equivalent to smoggers in the rpm range... It's a bear to reach 4,000 and your pulling hair to ever hit 4,500...
I wouldn't mind hitting 5,000 no problem.

The open chambers are definitly out of the question then, what are a couple of questions that I could ask to find the potential of the p/p 350 heads? So far it sounds like the 041s are the way to go... thanks for the insite.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-12-2009, 06:52 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 7,088
Wiki Edits: 0

Thanks: 4
Thanked 539 Times in 455 Posts
Quote:
Originally Posted by 2wheeler
I'm in the budget of finding a used set of heads for my '81 chevy shortbox daily driver but I was thinking about bracket racing it this year... looking around in the local rag I can only find three sets of heads for sale and almost anything would be better than the smoggers that are on it now. Just looking for opinions, I'm assuming the first pair are the best...

$400- ported and polished 350 heads 1.94 ss intake, 1.50 exhaust valves. Screw in studs and guide plates. Shaved, camaro .600 lift dual valve springs

$300- 041 heads, magnafluxed and decked. They have new seats and guides. All they need are 1.94/1.50 valves to go in

$200- 350 open chamber heads with 2.02 intake, 1.60 exhaust valves. High performance valve job, and shaved aprox. 100 miles on them.
The old story here is that when it comes to horsepower for the buck, you've got to go a long ways and spend a lot of money and effort to equal the Vortec head. Out of the box they're worth a 20 to 60 horsepower increase before your touch them with a die grinder. The amount of power they will provide is dependent on the engine's state of tune. 20 hp being more common to a lower compression, milder cammed engines and 40 aligns to engine's with more compression and cam timing that are capable of more revs than milder engines.

They do limit the lift at the valve to about .47 inch without modification to the upper valve guide and improved valve springs. Socggin-Dickey sells the P/N 125508060 head either OEM or modified for more lift at reasonable prices, not much more than you'd pay for a decent set of preped older heads. GM offers a couple race ready versions, part number 25534421 and more the 25534431. The 060 requires a unique intake that matches the tall port configuration and bolt pattern of the original L-31 Vortec. The latter 2 part numbers while more expensive will use more common intakes in terms of port height and bolt pattern. These heads are tough to beat either in cost or on the track.

One of the problems you have with the old engine is that GM trimmed the compression ratio with piston that uses a circular dish in the crown. One of the big issues, low compression aside, is that these pistons do not make full use of the squish/quench characteristics of any cylinder head and especially modern heads like the Vortec. This results in an engine that is rather detonation prone for the compression ratio. Replacing the pistons with those of a D-dish design do a lot to improve squish and quench which is a considerable asset in keeping detonation minimized for any head, but it really lets you push the Vortec types up into the 9's without difficulty. The other trick is to keep the piston crown to the head's squish/quench deck around .045 to .060 inch. When you assume Chevrolet's usual .025 inch clearance to the deck and a .020 inch shim to a .035 inch multilayer gasket, one arrives at the these clearances pretty quickly. Certainly with a .025 deck, a .053 inch thick gasket is already started into the excessive clearance direction. However, Vortec heads will take about 10ccs out of your current chamber size which will raise your current static compression by close to a full ratio, into the range of 9 to one or more. At this point even if you don't change pistons, the Vortec's improved mixture swirl, faster burn chamber, and better, though not ideal in your case, squish/quench will tolerate this compression.

Folks have put stock into modified 305 heads for many years to get performance somewhat comparable to older (pre 1973) closed chamber performance heads. 65Smallblock was looking at and wonder about the many bloggers claiming success with this. It is possible to make a pretty decent set of heads out these, especially by mid-1970s thru mid 1990s standards, but they just don't produce on par with Vortec/Fastburn heads, more like the L-98 head which ain't bad but a pair of out of the box Vortecs will smoke 'em
by an easy 40 ponies and will smoke older open chambers by 60 before you even start grinding on 'em. In fact the risk to Vortecs/Fastburns is that it's really easy to take the die grinder and cause them to flow less than they did out of the box. Ya got to have a fair idea of what your doing when you put a cutter to these modern heads.

Bogie
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-12-2009, 07:00 PM
cool rockin daddy's Avatar
1.21 giga-watts???!!!!
 
Join Date: Aug 2003
Location: wherever cool cars are
Posts: 1,535
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
I have the 041's on my small block. Good head. However, I am counting the days until I can put some GM Bowtie Vortec 180 heads on it. An easy 30-40 HP upgrade. You won't spend that much more for 'em than you would the 041's after you get valves and install them.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-12-2009, 07:36 PM
Registered User
 
Last photo:
Join Date: Jun 2008
Location: USA
Posts: 1,172
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by cool rockin daddy
I have the 041's on my small block. Good head. However, I am counting the days until I can put some GM Bowtie Vortec 180 heads on it. An easy 30-40 HP upgrade. You won't spend that much more for 'em than you would the 041's after you get valves and install them.
The EngineQuest 180 Vortec head is better than the GM.
EQ is an iron replacement head the circle track guys use.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-12-2009, 09:30 PM
GMC boogie's Avatar
Member
 
Last photo:
Join Date: Nov 2004
Location: Louisiana
Age: 49
Posts: 637
Wiki Edits: 0

Thanks: 1
Thanked 22 Times in 22 Posts
In case you did not know....Cool rocking daddy is talking about the GM BOWTIE Vortec head. A very much improved version of the production "062" head.

I have used one set of EQ "IMCA" heads they produce for class rule dirt racers that have depleted the early 70's large chamber heads.

I have not seen thier Vortec version. They have a quality product but I doubt it's better than the Bowtie Vortec.

If you know something I don't.....please elaborate on your statement.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-13-2009, 02:44 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,285
Wiki Edits: 0

Thanks: 6
Thanked 400 Times in 394 Posts
I have run both vortec heads and fully ported big valve 305 heads on the same 350 in the same car.
I'm not going to say the modified 305 heads are exactly the same or just as good, but they certainly are comparable in performance. Very strong well past 6000 rpm.

Stock OEM 062 vortecs flow 228cfm. My ported 305 heads flow 234cfm.
The key word here is fully ported. If you just do a little, expect a little. They flow about 188 in stock OEM form.

The L-31 vortec heads work really good. Fully ported 305 heads work suprizingly good.

Both are light years ahead of stock smogger heads on a 350.

I'd go for the 041 heads. These work very good to0 especially with some porting.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-13-2009, 10:25 AM
Registered User
 
Last photo:
Join Date: Jul 2006
Location: Victoria, BC Canada
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Okay so I got the casting numbers of the first set of heads and they're 462624... Does that change anything? The machinist also said they are about 68cc. 624s or 041s??
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-13-2009, 10:36 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,285
Wiki Edits: 0

Thanks: 6
Thanked 400 Times in 394 Posts
No question there. Of the two choices the 041's a clear better choice.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-13-2009, 10:40 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,476
Wiki Edits: 0

Thanks: 20
Thanked 385 Times in 361 Posts
Quote:
Originally Posted by F-BIRD'88
I have run both vortec heads and fully ported big valve 305 heads on the same 350 in the same car.
I'm not going to say the modified 305 heads are exactly the same or just as good, but they certainly are comparable in performance. Very strong well past 6000 rpm.

Stock OEM 062 vortecs flow 228cfm. My ported 305 heads flow 234cfm.
The key word here is fully ported. If you just do a little, expect a little. They flow about 188 in stock OEM form.

The L-31 vortec heads work really good. Fully ported 305 heads work suprizingly good.

Both are light years ahead of stock smogger heads on a 350.

I'd go for the 041 heads. These work very good to0 especially with some porting.
When I start clearing off current projects I want to do the 305 head thing. Not for any particular reason, just to expieriment I like to see how far you can push stock parts. I'll probably tune it for ethanol as long as it lasts at the pumps. With gas falling its questionable, even in the midwest. There was a time when you didn't have an affordable aftermarket and hot street cars were all running ported factory castings.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 01-13-2009, 10:43 AM
Registered User
 
Join Date: Nov 2007
Location: utah
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 2wheeler
65smallblock- I have experienced 305 heads on a 350 and it gives you torque off the line power but they're equivalent to smoggers in the rpm range... It's a bear to reach 4,000 and your pulling hair to ever hit 4,500...
Sounds to me like what you had on that 350 was maybe a set of swirl port heads. ?? I think that they were put on 305's and 350's and once in a while some schmucks try to pass them (swirlie) off as Vortecs. The ones Im talking about dont have the swirl ports, Im specificaly looking @ a set of 416 heads.

F-bird, how would you rate a set of ported 305 heads vs a set of old fuelies? Sounds like they would flow about as well.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 01-13-2009, 10:53 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,285
Wiki Edits: 0

Thanks: 6
Thanked 400 Times in 394 Posts
The "old fuelies" refering to the 63 65 327 corvette 461X head with large 170cc ports and 2.02's flows 214 cfm in stock origional OEM form. Of course they flow a lot more than that in full ported form. 260+cfm. (full effort)

On a typical street/strip 350 a "fuelie head" with some port and chamber work that gets the flow up to 230 cfm to 250 ish works very well.

The stock 041's (1.94 valve) flow right around 195cfm in origional form.
They port up real well. Nice HP head.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-13-2009, 11:09 AM
Registered User
 
Join Date: Nov 2007
Location: utah
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 2wheeler
Okay so I got the casting numbers of the first set of heads and they're 462624... Does that change anything? The machinist also said they are about 68cc. 624s or 041s??
According to Mortec the 462624 has 76cc chambers. They are probably just like tha 882 heads Ive got, all show and no go. I call them oxymoron heads. Id steer clear of those ones.

I think Id probly steer clear of that "machinist" as well. He would clearly put lipstick on a pig to try to sell it @ an inflated price.
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
TBI Heads on older motor exmurdoc Engine 1 07-08-2005 06:21 PM
Question about porting my own heads mouseman Engine 10 03-15-2005 07:47 PM
Firebird Heads and Rockers 350bird Engine 4 11-12-2003 10:33 AM
bowtie heads for sbc Eddie Baker Engine 3 11-09-2003 12:02 AM
L98 IROC/TA/Formula heads? dirtlmfan Engine 2 02-17-2003 01:02 PM


All times are GMT -6. The time now is 10:35 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.