Clearancing the head for the 276 cams - The Saab Link Forums

Go Back   The Saab Link Forums > Saab NG900 '94-'98 and 9-3 '99-'02 Forum > Performance Modifications for the NG900 / Old 9-3

Performance Modifications for the NG900 / Old 9-3 This forum contains PERFORMANCE related Q&A's for the NG900 and 9-3. This may also include suspension.

SaabLink.net is the premier Saab Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 12-05-2007, 07:58 AM   #1
Nick Taliaferro
Elder
 
GenuineSaab's Avatar
 
Join Date: Feb 2004
Location: Springfield, MO USA
Posts: 3,232
Send a message via MSN to GenuineSaab Send a message via Skype™ to GenuineSaab
Clearancing the head for the 276 cams

The main reason limiting the use of the 276 10.4 compared to the drop in 264 9.6 sets is the physical clearance in the head to swing the larger lobes. The head needs a little grinding at the top edge of the lifter bores. This has to be done off the car with the head apart. The cams wont spin in the head the lobes are so big! We should see how it goes on the 2.0L Nira car. Going back together with new springs too. Probably late next week before we get time to paly. Big dyno day on this Saturday.

You can see a little difference compared to the t5 cams.


Steven violating it.. Also lightly ported the exhaust side, limited to matching it to the manifold flange.


Gallery Here
__________________
Nicholas Taliaferro

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2.0 GOOSE 500whp + 8500rpm = 11.06 @125 E85
Viggen 439whp / 447tq 12.43 @114 on Gt2871.64, (Now 511whp Gt3076)
Nordic E85 9-3 SS Aero 320hp / 350ftlbs
GenuineSaab is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 12-05-2007, 08:16 AM   #2
Live, eat, and sleep by TSL
 
SAAB9-3USA's Avatar
 
Join Date: Jun 2007
Location: Bloomington MN
Posts: 1,204
Send a message via MSN to SAAB9-3USA
i have been wondering if the 264 were drop i didn't see anything saying the weren't and the 276 said head needing machining . Hence the question . thanks for answering it.
__________________
Quote:
Deek ur a funny little f***** arent you b****
SAAB9-3USA is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-05-2007, 09:28 AM   #3
Live, eat, and sleep by TSL
 
Join Date: May 2004
Posts: 1,122
Quote:
Originally Posted by GenuineSaab View Post
The main reason limiting the use of the 276 10.4 compared to the drop in 264 9.6 sets is the physical clearance in the head to swing the larger lobes. The head needs a little grinding at the top edge of the lifter bores. This has to be done off the car with the head apart. The cams wont spin in the head the lobes are so big! We should see how it goes on the 2.0L Nira car. Going back together with new springs too. Probably late next week before we get time to paly. Big dyno day on this Saturday.
Personally did not feel secure putting the 9.6mm lift Enem's without modifying the head physically, due to ananomous clearances. End result did look like this
http://www.stcf.net/viggen/Head/images/DSC_2696.JPG
Vigge is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
 
Old 12-05-2007, 02:14 PM   #4
Saz
TSLMember
 
Join Date: Oct 2007
Posts: 32
coppin
Saz is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-05-2007, 05:49 PM   #5
JZW
Elder
 
Join Date: Oct 2006
Location: Boulder Colorado
Posts: 3,153
Quote:
Originally Posted by GenuineSaab View Post
The main reason limiting the use of the 276 10.4 compared to the drop in 264 9.6 sets is the physical clearance in the head to swing the larger lobes. The head needs a little grinding at the top edge of the lifter bores. This has to be done off the car with the head apart. The cams wont spin in the head the lobes are so big! We should see how it goes on the 2.0L Nira car. Going back together with new springs too. Probably late next week before we get time to paly. Big dyno day on this Saturday.

You can see a little difference compared to the t5 cams.


Steven violating it.. Also lightly ported the exhaust side, limited to matching it to the manifold flange.


Gallery Here
Come on now, besides port matching, there are pleanty of rough casting areas that can be smoothed out and the bowl area is a great place to open up and smooth out the flow and of course the big gains are seen from porting and polishing the short radi side.... Do it once and do it right I say

John
__________________
b234r ng900, E-85 Holset Super [email protected] mph a mile high 645whp/650wtrq Sae Denver
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JZW is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-06-2007, 11:51 AM   #6
Elder
 
saabsbreakdown's Avatar
 
Join Date: Nov 2005
Location: Gig Harbor, Washington
Posts: 2,624
Send a message via AIM to saabsbreakdown
Quote:
Originally Posted by JZW View Post
Come on now, besides port matching, there are pleanty of rough casting areas that can be smoothed out and the bowl area is a great place to open up and smooth out the flow and of course the big gains are seen from porting and polishing the short radi side.... Do it once and do it right I say

John
smoothing those surfaces is a waste of your time, porting is what is important not polishing.

http://en.wikipedia.org/wiki/Cylinder_head_porting
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Car 178 - 1975 Saab 99 EMS

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
saabsbreakdown is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-06-2007, 01:59 PM   #7
 
mike saunders's Avatar
 
Join Date: Mar 2004
Location: Boston, MA
Posts: 6,468
Ditto.....open the flow, then let it go.
mike saunders is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-06-2007, 05:50 PM   #8
JZW
Elder
 
Join Date: Oct 2006
Location: Boulder Colorado
Posts: 3,153
Quote:
Originally Posted by saabsbreakdown View Post
smoothing those surfaces is a waste of your time, porting is what is important not polishing.

http://en.wikipedia.org/wiki/Cylinder_head_porting
Not on the exhaust side, the mirror finish speeds up velocity and keeps carbon from building up and that never hurts

They kind of go hand in hand anyway, you ruff it in by porting and you polish it to help keep the carbon from building up. I even polished my combustion chambers and you should have seen how clean they were at 6k, even the engine builder was amazed...

John
__________________
b234r ng900, E-85 Holset Super [email protected] mph a mile high 645whp/650wtrq Sae Denver
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JZW is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-06-2007, 06:05 PM   #9
JZW
Elder
 
Join Date: Oct 2006
Location: Boulder Colorado
Posts: 3,153
Quote:
Originally Posted by mike saunders View Post
Ditto.....open the flow, then let it go.
Polishing the exhaust side keeps the carbon build up to a minimum and that helps flow and also polishing the combustion chambers does two things, it reduces carbon build up and it smooths out any sharp edges that can cause pre-ignition. I have an article too...

http://www.sa-motorsports.com/diyport.aspx

John
__________________
b234r ng900, E-85 Holset Super [email protected] mph a mile high 645whp/650wtrq Sae Denver
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JZW is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-07-2007, 05:55 PM   #10
 
mike saunders's Avatar
 
Join Date: Mar 2004
Location: Boston, MA
Posts: 6,468
Quote:
Originally Posted by JZW View Post
Polishing the exhaust side keeps the carbon build up to a minimum and that helps flow and also polishing the combustion chambers does two things, it reduces carbon build up and it smooths out any sharp edges that can cause pre-ignition. I have an article too...

http://www.sa-motorsports.com/diyport.aspx

John
John,

Always consider the source of information. SA is Standard Abrasives, a company that manufactures head porting kits. Of course they'll advocate polishing heads to a mirror finish -- they make the abrasive bits that you'll presumably be induced to buy after reading how well your car will perform.

Think of it this way: If you asked a butcher whether red meat has cholesterol, he'd probably tell you no.
mike saunders is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-07-2007, 07:10 PM   #11
Live, eat, and sleep by TSL
 
Join Date: Mar 2005
Posts: 1,956
At the risk of going off topic here maybe this applies maybe not.

In my first fluid dynamics class we went to the wind tunnel and were presented with some different spheres, one was smooth, the other slightly rough, and then some other ones. We were asked of the smooth and rough sphere which would create the least drag? The answer we all thought was the smooth one. We fired up the tunnel and it turns out it was the rough one!! The reason in this case is that the rough surface creates turbulence, which lessens the wake (as the sphere travels through the air) to be smaller, and therfore creates less pressure drag. I'm not even sure I am calling this right, (pressure drag; its been a long time and its late). This is the drag attributed to the wake your car, ball etc leaves in its path. Think of a semi trailer passing through the air, its basically a low xone of pressure behind the trailer acting like a suction cup to pull on the trailer.

Of course, this is not a sphere, and there are a ton more variables in a head than on a sphere. Still, I am thinking a little roughness might aid in reducing drag as the air travels around corners and such in the same way that the roughness on the sphere helps reduce the drag caused by the pressure difference.

BTW, I'm sure most of you know it, thats why there are dimples on a golf ball.....


Tboy

Last edited by Tboy; 12-07-2007 at 07:13 PM.
Tboy is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-07-2007, 07:12 PM   #12
JZW
Elder
 
Join Date: Oct 2006
Location: Boulder Colorado
Posts: 3,153
There are more articles out there, I only gave one quick one to show you can always get both sides of the theory. I think the theory of porting and polishing also comes with some black art knowledge.There are many secrets guys share on the ways to make a better flowing head. You pick up a few of those here and there and do what you think will give you the best flow through that head for the application of the motor. Light touch up to big material removal.

This reminds me of another black art subject and that was prop carving for our 190mph rc pylon planes. Many ideas on the best theory to make a good prop, article after article on flow and mach numbers and where the tip of the prop reaches the speed of sound and this causes a shock wave that robs lots of thrust or hp. There where a few guys that could always make a very fast carved prop, they had the black art and if anyone ever shares some of those secrets, you may find yourself with a very good flowing head.

I definetely see less carbon build up in all my ported and polished pieces on the exhaust side, including the head of course, exhaust manifold, turbine.

That is enough reason for me to do it right there.

I have done a lot of porting and polishing on smaller pylon race engines and have tried all kinds of different things. I just don't think I could be convinced it does not do at least some good. Air has to move over a smoother surface with less friction in my mind.

The intake has to be somewhat ruff for good fuel atomization, but the exhaust side must flow better on a mirror finish. I don't know if the gains are enough to measure, but it sure seems correct in theory.

John
__________________
b234r ng900, E-85 Holset Super [email protected] mph a mile high 645whp/650wtrq Sae Denver
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JZW is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-07-2007, 07:17 PM   #13
Live, eat, and sleep by TSL
 
Join Date: Mar 2005
Posts: 1,956
OK since I'm already into this one of my pet peeves is people relating IC engine exhaust as a flow. Its anything but. Its a series of pulses, one right after another!! Thats why people make equal length headers to minimise the chance these pulses will collide, or interfere with each other.

Now, certainly a turbo will smooth this out to a large degree......

Tboy
Tboy is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Old 12-08-2007, 07:01 AM   #14
JZW
Elder
 
Join Date: Oct 2006
Location: Boulder Colorado
Posts: 3,153
Quote:
Originally Posted by Tboy View Post
OK since I'm already into this one of my pet peeves is people relating IC engine exhaust as a flow. Its anything but. Its a series of pulses, one right after another!! Thats why people make equal length headers to minimise the chance these pulses will collide, or interfere with each other.

Now, certainly a turbo will smooth this out to a large degree......

Tboy
Exhaust side is the in the head..... Mainly refering to the bowls and ports and valve area on the exhaust side.

Exhaust has flow and is discussed all the time. What hurts flow, what helps flow, mandrel bent pipes vs. crimped bent pipes, cats, mufflers and the list just keeps on going.

Pulses have to flow through the pipes of the exhaust anyway and flow dynamics apply there as well as anywhere else piping and restictions are present...

John
__________________
b234r ng900, E-85 Holset Super [email protected] mph a mile high 645whp/650wtrq Sae Denver
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
JZW is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the The Saab Link Forums forums, you must first register.
Please enter your desired user 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:
Vehicle Info.
Enter your vehicle information (year, model, mods)
Insurance
Please select your insurance company (Optional)

Log-in


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 -8. The time now is 02:13 PM.


Powered by vBulletin® Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.5.2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
All content is copyright The Saab Link and it's original authors.


 

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.