Cam choice? - 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 09-27-2010, 07:40 PM
Registered User
 
Last photo:
Join Date: Aug 2005
Location: North Dakota
Age: 39
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Cam choice?

I was wondering what you fellas thought about what cam to use for my 72 K20?

355
KB 12cc dish pistons(193)
.015 in the hole
882 heads(I know, its what I have to work with)
Victor head gasket with .026 thickness and 4.1 diameter
Hei
Edelbrock Performer
Q-jet
Hedman long tube headers
4 speed
4.10 with 285/75-16

I was looking at the smallest of the Voodoo line or the summit 1102 because I am not sure the Voodoo is worth the extra money for the current set up. Any other suggestions? Thanks in advance.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-27-2010, 09:37 PM
Custom10's Avatar
my KARMA ran over my DOGMA
 

Last journal entry: SS
Last photo:
Join Date: May 2009
Location: Saskatchewan, Canada
Age: 49
Posts: 1,068
Wiki Edits: 0

Thanks: 10
Thanked 21 Times in 19 Posts
You can take a look at this link for calcs on compression ratio.

http://www.kb-silvolite.com/calc.php?action=comp

It is useful in determining what the cam has to work with. Your set up is about 8.5:1 static CR if using 76 cc for the 882's is that what they are? have you measured/cc'd them?

Look for specs on the cam namely the intake closing point, plug these into the calculator using the 5.7 rod length of the 350. You may want to consider going with the earlier closing cam to help build up some cylinder pressure as you are down there on compression.

the voodo, is that the 60100? its at 207/213 dur @ 0.050 and .437/.454 lift on a 112 LSA advertised at 250/256 dur

The 1102 is at 204/214 @ 0.050 and .420/.442 on a 112 LSA adv 262/272 dur

IMHO either cam would not be a mistake in this case at 8.5 DCR and running the setup you have.

The voodo is listed at a wider rpm range from 1000-5000, the 1102 is 1200 -4800. The voodo may require closer attention to the valve springs, those cams have an aggressive ramp rate, but it would be my choice if cost was not an issue.

2 more of my cents
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-27-2010, 10:56 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,205
Wiki Edits: 326

Thanks: 594
Thanked 757 Times in 647 Posts
I get 8.52:1 SCR, so you're right on the money Custom10.
Schatzy, I don't recommend flat tappet camshafts any more due to the high number of failures in the past few years. But I think you are right on the money with the cam timing you're looking at for the SCR of the motor. I would be very careful though, in the choice of cam and lifters from one manufacturer. There are still some of those "white box" lifters floating around in the marketplace. I'm not saying that Summit or anyone else would intentionally supply you with offshore lifters, but I would be very careful to source the lifters along with the cam in one package direct from a known cam grinder. This is just my opinion based on inferior lifters showing up in the marketplace. Also, take some of the grinder's claims of power range with a grain of salt. Any cam you stuff in the motor only has a 3500 rpm range of power. Some of these guys will try to tell you that the cam makes power from idle to 5500.

Here, for instance, is a cam and lifter set from Crane that comes as a package from the factory if you order direct from the factory and not from a middleman supplier who can change lifters and not tell you. Again, I'm not accusing anyone of anything. I'm just saying that additional profit is a powerful incentive.
See the 100032 cam and kit here....This is what I would use in your motor....
http://cranecams.com/pdf/_catalogs/m...010-54-107.pdf
You'll want to afford yourself every advantage that you can in order to insure long life from the flat tappet cam and lifters, so please read through this list and take advantage of these suggestions....
http://www.crankshaftcoalition.com/w...ips_and_tricks
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-28-2010, 07:00 AM
Registered User
 
Last photo:
Join Date: Aug 2005
Location: North Dakota
Age: 39
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the replies. I know its only going to have 8.5 compression that is why I am staying conservative on the cam. I thought about going with a roller since I have a cam and lifter set on the shelf but the cam is way to big, so I have considered going with a smaller roller but the heads have the "Z28" style springs and this is just going to be a motor to throw in the truck for now because the 383 that I had someone build has a nasty vibration from 2000 rpm on. I plan on changing to an automatic when the funds and time allows and probably change to a different engine combo then.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
283 cam choice JohnyR17 Engine 5 01-08-2008 01:45 PM
383 cam choice HSR383TPI Engine 13 11-10-2007 09:11 AM
XE274H cam sound like? Heads Choice? Help me decide on combo for chevy 400 Warrant Engine 10 03-01-2006 02:58 PM
cam choice??? ko.17 Engine 9 03-20-2005 12:12 PM
Cam choice for new GM 260hp crate motor Iceberg Engine 3 02-21-2005 11:03 PM


All times are GMT -6. The time now is 11:26 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.