SBC .60 over HELLPPPP. - 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 03-03-2012, 07:23 AM
Registered User
 
Join Date: Mar 2012
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
SBC .60 over HELLPPPP.

i have a sbc bored .60 over with flat top pistons and a texaes speed ms4 cam with a .649 .609 lift solid roller.. my question is can i run 305 double hump heads they have 2.02 valves my cam specs say to use shorter pushrods 7.425 length im not sure what stock is but they are shorter then the ones i pulled out of motor. i just dont want valves hitting pistons but i would like to have the compression and valves from those heads.


    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-03-2012, 08:08 AM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls, Washington
Posts: 5,223
Wiki Edits: 9

Thanks: 102
Thanked 131 Times in 122 Posts
I've never heard of any 305 heads that are true "double hump", or any with 2.02 valves for that matter, 305's only have a bore of 3.736, they would have had major cylinder clearance and shrouding issues with 2.02 valves.

You wouldn't have valves hitting pistons with longer pushrods. The cam lift and duration are what the are, and that is what will dictate whether they hit pistons, long/short pushrods will only change the valve train geometry, unless you had them adjusted too tight, and that can happen with any rod length. You would have other major issues if that were the case.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association

Last edited by 68NovaSS; 03-03-2012 at 08:14 AM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-03-2012, 12:23 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by Kris Thompson
i have a sbc bored .60 over with flat top pistons and a texaes speed ms4 cam with a .649 .609 lift solid roller.. my question is can i run 305 double hump heads they have 2.02 valves my cam specs say to use shorter pushrods 7.425 length im not sure what stock is but they are shorter then the ones i pulled out of motor. i just dont want valves hitting pistons but i would like to have the compression and valves from those heads.

Solid roller p-rods are going to be a lot shorter than stock SBC (~7.8"). Exactly how long depends on a lot of things. If you know who's roller lifters you are using you can get close enough to the right length to start the geometry measurements to get the exact length needed.

HERE is a list of valve train points to check.

I don't think those 305 heads- regardless of how much porting has been done- will ever support a solid roller cam w/that kind of lift and duration. The only thing they have going for them is a small chamber, but even they won't be so small once the chambers are unshrouded to let the 2.02" x 1.60" valves breath. The ports are just too small to flow at the lifts and RPM that cam is going to need to make power like it should. The engine will run, but it will not be anywhere near where it should be, power-wise.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-03-2012, 04:34 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,112
Wiki Edits: 0

Thanks: 24
Thanked 264 Times in 247 Posts
Seen them before. Premium fuel, nasty sounding, turd. Then the guy puts one of them in a VAN of all things.. Complains that the power brakes and the trans don't work right, has no power.. Wanted my shop to correct the problem!!!
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 06:24 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.