porting question? - 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 01-13-2003, 01:34 PM
Member
 
Join Date: Jan 2003
Location: canada
Posts: 30
Wiki Edits: 0

Thanks: 7
Thanked 0 Times in 0 Posts
Post porting question?

I have read alot of threads here and by the sound of it porting is a good thing. what exactly is porting, what parts can u port, is it tough, or how much would a pro charge? ballpark? thx finman.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-13-2003, 01:40 PM
ronb's Avatar
Member
 
Last photo:
Join Date: Dec 2002
Location: Clearwater,FL.
Posts: 381
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

depends on what you want to port? some aftermarket heads like edelbrock and afr flow great right out of the box. the cost of a port job will also depend on how much porting needs to be done???
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-13-2003, 02:00 PM
Member
 
Last photo:
Join Date: Sep 2002
Location: Halifax, NS
Age: 34
Posts: 108
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

<a href="http://www.sa-motorsports.com/diyport.htm" target="_blank">DIY porting</a>
check this article. i bought a grinder at canadian tire for $60cdn and buy dremel bits as i need them. it's probably more economical to buy a set of bits though. unless you're rolling in dough, don't pay somebody to do this. it's not hard to do and kinda fun - just take your time. practice on junk heads if you can, and be very careful around valve seats!!!
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-13-2003, 02:07 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Cast iron head porting is an endless subject. The novice can increase flow on a stock set of heads simply by matching the intake and exhaust ports to the manifolds bieng used and deburring and polishing rough factory castings. This is done by transfering the dimentions from the manifold to the ports using a cheap set of gaskets or heavy construction paper. Relieving the valve bowls requires machine work. Once the combustion chambers have been polished, they have to be CC'd to get them all back to the same size. This can be done with a peice of plexiglass with 1/8 holes located over the chambers. You'll need an accurate means of delivery to measure exactly how much mineral oil you deliver to each chamber to determine it's exact size. Starting with the smallest chamber, carfully buzz off material, preferably from high spots in the castings, till all chambers look alike and all CC out the same.

I'd practice on an old set of junk heads first.

It's fun and rewarding - just DO IT!
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-13-2003, 03:51 PM
TurboS10's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Auto Terms and Definitions Used in Modern Engine T... Last photo:
Join Date: Sep 2002
Location: Texas
Age: 37
Posts: 3,463
Wiki Edits: 2

Thanks: 0
Thanked 0 Times in 0 Posts
Post

[quote]Originally posted by PrimeMover:
<strong>Relieving the valve bowls requires machine work. </strong><hr></blockquote>

All it takes to bowl port is a carbide burr, die grinder, and some patients.

Chris

[ January 13, 2003: Message edited by: TurboS10 ]</p>
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-13-2003, 03:59 PM
Member
 
Join Date: Dec 2002
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

I used to port two stokes when I was younger that was fun but there it's more about changing the timing in allready well made ports, it's heaps more rewarding in the rough casting quality you get in old Chev heads. I use a cheap air powered die grinder, get a long nose one aswell if you can, it's probably not very efficient using a compressor all day to power it but it gives you very good speed control. With that I use a carbide cutter which you can get from your local engineering supplies shop, they last just about forever. I also use cheap chinese grinding stones sometimes but really the carbide cutter cuts faster and smoother and doesn't wear out, then I polish the exhaust ports and combustion chambers with those flapper sanding wheels, as long as your carefull with the valves seats (cutting down the casting ridge right near the seat with a carbide cutter is like walking in a knifes edge, exhilarating stuff!: )) then the rest of the job is easy as you like. Everyone that owns a small block chev should own this book "How to Build & Modify Chevrolet Small-Block V-8 Cylinder Heads (Powerpro Series) by David Vizard" his other books are great too but this one, it's special
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-13-2003, 06:58 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

"All it takes to bowl port is a carbide burr, die grinder, and some patients."

Lots and lots of patients! Thankyou. If you can uniformly blend and port valve bowls like a good fly cutter can, your hired. a die grinder burrs and crocus paddles are only good for finish work, unless of course, you want to make a career out of destroying good vintage cast iron cylinder heads.

<img src="graemlins/nono.gif" border="0" alt="[nono]" />
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-13-2003, 07:31 PM
Member
 
Join Date: Oct 2002
Location: Upstate NY
Posts: 93
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

good advice... and primemover, as an aspiring machinist (mostly self-taught), i'm curious. how do you flycut valve bowls?
-z-
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-14-2003, 06:11 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

steppenwolf - I was in a hurry when I posted, My mistake. I've flycut surfaces in a Bridgeport but I've never done valve bowls with them, sorry. What DO I use to rough cut bowls with? I use a Bowl Hog, on a valve guide madral with three 60-75 degree carbides. Definatly NOT a BURR in a die grinder!! <img src="graemlins/nono.gif" border="0" alt="[nono]" />
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-14-2003, 06:48 PM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,974
Wiki Edits: 0

Thanks: 2
Thanked 89 Times in 72 Posts
Post

I have done all my heads with a burr and a die grinder? Works just fine?
__________________
Outlawed tunes from outlawed pipes
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-14-2003, 06:57 PM
Member
 
Join Date: Oct 2002
Location: Upstate NY
Posts: 93
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

thanks, prime... had me scratchin my head there for a while. on the other hand, it does seem that a die grinder would work...?
-z-
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-14-2003, 08:00 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Fourjaw - We all have our Neanderthal moments... What do ya' use to clean the gasket surfaces on those spendy aluminum heads - a chain saw or a bastard rasp? <img src="graemlins/crash.gif" border="0" alt="[crash]" />
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 01-14-2003, 08:21 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Just so ya'll don't go away mad, die grinders and burrs are great for match porting intake and exhaust ports and cc'ing combustion chambers. Using them for initial bowl relief is like using a screwdriver for a punch. There is a better way, and it's well worth the cash. I'd never sic a novice on a decent set of castings, equipped with nothing but a die grinder. I wouldn't do it and I wouldn't tell anyone else to either. There are all kinds of "Assembled" heads available that I wouldn't give you fifty bucks for, without seeing the bowls, for obvious reasons.

I've been ripped off before, can ya' tell?

Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 01-14-2003, 08:22 PM
PrimeMover's Avatar
Sittin' on top of the world...
 
Last photo:
Join Date: Dec 2002
Location: Portland, Oregon
Age: 63
Posts: 467
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Just so ya'll don't go away mad, die grinders and burrs are great for match porting intake and exhaust ports and cc'ing combustion chambers. Using them for initial bowl relief is like using a screwdriver for a punch. There is a better way, and it's well worth the cash. I'd never sic a novice on a decent set of castings, equipped with nothing but a die grinder. I wouldn't do it and I wouldn't tell anyone else to either. There are all kinds of "Assembled" heads available that I wouldn't give you fifty bucks for, without seeing the bowls, for obvious reasons.

I've been ripped off before, can ya' tell?

Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-15-2003, 04:46 AM
Member
 
Join Date: Dec 2002
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Post

Once I read a guys web site where he ported his own heads and got a slightly worse flow on the after ported exhaust port at some lifts but you only had to look at the pictures to see that it was a bad port job, that's the only time I've heard about not gaining flow and he still gained heaps and heaps of flow on the intake with a grinding stone in the bowls, he just didn't grasp the exhaust concept.

I still say anyone with steady hands can make any shape they want down to +or- one millimeter _easily_ with a carbide cutter and a air powered die grinder, how can you get a good port bias going just cutting the bowl with a machine? *confused alot*. The standard bowls on my 305 were the most garbarge part of the whole engine, they were classic production line stuff, big ridges all over the place, they wern't going to do anything apart from smash air straight into the back of the valve, maybe it's a different story for high tech aluminium heads, but I really can't see how you could ever make an old iron head worse than they come from the factory especially if you read a book about it first
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 09:54 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.