307 performance - 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 08-21-2002, 03:04 PM
Registered User
 
Join Date: Aug 2002
Location: Texas
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Lightbulb 307 performance

I am looking to beef up a 307 sb chevy engine. I have countless of testemonials of the potential of the 307 yet no one has informed me of the process of turning this 130hp sleeper into heavy-hitting contender...if anyone has any info that could be usefull please share <img src="confused.gif" border="0">

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-21-2002, 03:58 PM
Keith Boisvert's Avatar
Member
 
Join Date: Oct 2001
Location: Fitchburg, Ma
Age: 44
Posts: 49
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

I don't know about a powerhouse, but I had a 307 in a 72 Chevelle, and it had 350 heads on it. These worked good and it brought the 307 from 130 to 230 horse. The 130 hp rating also included a 2bbl carb and all the emission crap. Once that is off you jump in horses a bit anyway. I'm sure that someone else would be able to recommend an awesome cam/crank swap.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-22-2002, 09:12 AM
bullheimer's Avatar
NEVER use credit cards!
 

Last journal entry: car with tt2's, (stockers going back on)
Last photo:
Join Date: Jan 2002
Location: North of Seattle
Posts: 2,529
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 4 Posts
Post

okay this is right out of a HRM article: 307 is a stroked 283. same crank as large journal 327. use keith black #166 hypereutectics with a 4cc dome and then you need stock chevy 400 5.565 inch rods. mill the block .025 and piston deck clearance will be .005. with 30 overbore you have 311cid. with 64cc chamber heads and 4cc dome you have 10:1 compression and @350HP doesnt mention cams but whatever you can put in a 350 will work just the same.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-25-2008, 11:33 AM
307 getting an energy boost
 
Last photo:
Join Date: Dec 2008
Location: maryland
Age: 23
Posts: 33
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
are u guys sayin that the 350 heads will bolt up to the 307?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-25-2008, 08:25 PM
Member
 
Last photo:
Join Date: May 2003
Location: Shreveport LA
Age: 64
Posts: 5,103
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
350 heads will bolt up physically, but you need to be aware of different combustion chamber sizes. Your 307 probably has ~70cc chambers.

Large-chamber (76cc) 350 heads will drop your compression ratio, which means power goes down a little, fuel consumption goes up a little, and you won't be able to realize the full performance gain from a camshaft upgrade. A camshaft upgrade with a compression ratio downgrade makes an engine weak at low RPM, and not as strong as it could be at higher RPM.

Small-chamber 350 heads (64cc), will increase your 307's compression ratio, and you might see a small power & fuel economy increase. The big payoff is when you go to a camshaft with more duration, which will raise the point in the RPM range where your torque peak occurs, and you'll see a significant increase in horsepower. The higher compression ratio will keep it from losing so much low-end grunt when you use a "bigger" cam.

Make sure the heads you get have the accessory holes in the ends like your current heads have, or you'll play hell mounting your alternator, power steering, etc. If they don't have the proper holes, you can't just drill and tap them and expect them not to break. Sometimes they don't, but I wouldn't chance it. '69 & '70 300HP 350 cars (not trucks) would be the primary source for small-chamber heads with accessory holes, but '96-'99 L-31 Vortec 350 truck heads are better, although they do require a specific intake manifold.

Bullheimer's right on target with using 283 pistons and 400 rods in a 307. The only available aftermarket 307 pistons have their height reduced as much as .020", and will decrease performance and efficiency, and increase the chance of detonation if you use low-octane gas.

Last edited by jimfulco; 12-25-2008 at 08:38 PM.
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



All times are GMT -6. The time now is 03:19 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.