Pennock's Fiero Forum
  Technical Discussion & Questions - Archive
  ATTN: Northstar Swappers: Valve sizes?

T H I S   I S   A N   A R C H I V E D   T O P I C
  

Email This Page to Someone! | Printable Version


ATTN: Northstar Swappers: Valve sizes? by HTXtremes
Started on: 10-28-2007 07:26 PM
Replies: 10
Last post by: Russ544 on 10-29-2007 10:01 PM
HTXtremes
Member
Posts: 341
From: Mansfield, AR
Registered: Sep 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post10-28-2007 07:26 PM Click Here to See the Profile for HTXtremesClick Here to Email HTXtremesSend a Private Message to HTXtremesDirect Link to This Post
Ok, like the title says I'm looking for the diameter of the valve faces on the 4.6 liter Northstar heads. Also does anyone know the specs or where I can find the specs on the N* cams (lift and duration)? If some one has a pair of heads laying around could you get a measurement of the widest point on the valves as installed (outside of one intake to outside of one exhaust at a diagonal). Trying to see if I can install N* heads on the smaller bore Aurora 4.0.

------------------
'88 Coupe (extensive mods underway)
http://www.fiero.nl/forum/Forum2/HTML/086359.html

[This message has been edited by HTXtremes (edited 10-28-2007).]

IP: Logged
PFF
System Bot
ryan.hess
Member
Posts: 20784
From: Orlando, FL
Registered: Dec 2002


Feedback score: (1)
Leave feedback





Total ratings: 319
Rate this member

Report this Post10-28-2007 08:12 PM Click Here to See the Profile for ryan.hessClick Here to Email ryan.hessSend a Private Message to ryan.hessDirect Link to This Post
I think there was someone who tried installing northstar heads on the 4.0 to get lower compression for a turbo.

Not sure if they were successful or not. Or maybe it was vice versa to get higher compression.

N* cams vary... there's the 275hp and 300hp version. Difference is in the intake lobes.

The 300hp have 266 duration and .370 lift intake, 244 duration .339 lift exhaust

IP: Logged
Russ544
Member
Posts: 2136
From: S.W. Oregon
Registered: Jun 2003


Feedback score: (3)
Leave feedback





Total ratings: 86
Rate this member

Report this Post10-28-2007 10:22 PM Click Here to See the Profile for Russ544Send a Private Message to Russ544Direct Link to This Post
It's challenging to get an accurate measurment on the diagonal across the valves due to the shrouding, but it's pretty close to 3.36 . if this puts you in the ballpark, get back to me and I'll try for a more accurate measurment when the sun is up .

Russ544
IP: Logged
HTXtremes
Member
Posts: 341
From: Mansfield, AR
Registered: Sep 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post10-28-2007 11:09 PM Click Here to See the Profile for HTXtremesClick Here to Email HTXtremesSend a Private Message to HTXtremesDirect Link to This Post
That does help Russ, The bore of the Aurora is 3.425", I was looking at going .060" over for more clearance, that would leave me with 1/16" of an inch on each side. If the valve are angled in much it would provide even more clearance when the valves opened.

Were you able to get the diameters of the valves, Russ?

Thank you both for your time and measurements, this helps out alot!

------------------
'88 Coupe (extensive mods underway)
http://www.fiero.nl/forum/Forum2/HTML/086359.html

IP: Logged
ray b
Member
Posts: 10002
From: miami
Registered: Jan 2001


Feedback score: N/A
Leave feedback





Total ratings: 304
Rate this member

Report this Post10-29-2007 10:06 AM Click Here to See the Profile for ray bClick Here to Email ray bSend a Private Message to ray bDirect Link to This Post
I doNOT think you can bore a sleve that far

------------------
Question wonder and be wierd
are you kind?

IP: Logged
Russ544
Member
Posts: 2136
From: S.W. Oregon
Registered: Jun 2003


Feedback score: (3)
Leave feedback





Total ratings: 86
Rate this member

Report this Post10-29-2007 10:37 AM Click Here to See the Profile for Russ544Send a Private Message to Russ544Direct Link to This Post
I'll measure the valve dia when I get home this eve. it was cold and dark out where the heads are stored last night.

Russ544
IP: Logged
ryan.hess
Member
Posts: 20784
From: Orlando, FL
Registered: Dec 2002


Feedback score: (1)
Leave feedback





Total ratings: 319
Rate this member

Report this Post10-29-2007 11:19 AM Click Here to See the Profile for ryan.hessClick Here to Email ryan.hessSend a Private Message to ryan.hessDirect Link to This Post
You live in Oregon, it's always cold and dark out.

The valves are 1.30" and 1.14" INT/EXH according to my engine program. And I think I pulled those numbers from the factory service manual.
IP: Logged
Russ544
Member
Posts: 2136
From: S.W. Oregon
Registered: Jun 2003


Feedback score: (3)
Leave feedback





Total ratings: 86
Rate this member

Report this Post10-29-2007 11:45 AM Click Here to See the Profile for Russ544Send a Private Message to Russ544Direct Link to This Post
 
quote
Originally posted by ryan.hess:

You live in Oregon, it's always cold and dark out.

The valves are 1.30" and 1.14" INT/EXH according to my engine program. And I think I pulled those numbers from the factory service manual.


Only at night. in the day time it's cold and light out.

I'll double check the size later today anyway

Russ544
IP: Logged
Russ544
Member
Posts: 2136
From: S.W. Oregon
Registered: Jun 2003


Feedback score: (3)
Leave feedback





Total ratings: 86
Rate this member

Report this Post10-29-2007 07:38 PM Click Here to See the Profile for Russ544Send a Private Message to Russ544Direct Link to This Post
OK. I did some more measuring and came up with
intake valve = 1.310
Ex vlv = 1.144

diagonal across closed valves. will be less when near deck height (open) = 3.357

diagonal across valve pocket opening at widest point = 3.665


BTW, I just looked at your F-40 build thread. pretty cool. keep posting. what do you plan to use for an induction sys? what about the ECM?

Cheers,
Russ544

[This message has been edited by Russ544 (edited 10-29-2007).]

IP: Logged
HTXtremes
Member
Posts: 341
From: Mansfield, AR
Registered: Sep 2007


Feedback score: (2)
Leave feedback

Rate this member

Report this Post10-29-2007 09:29 PM Click Here to See the Profile for HTXtremesClick Here to Email HTXtremesSend a Private Message to HTXtremesDirect Link to This Post
I'm going to use twin T3 turbos for now, upgrade to ball bearing turbos later. The ECM will be the 7730.

Thank you for the compliments, and for your help!

I'm thinking of having the 4.0 machined for the 4.6 valves the porting and polishing! Desktop Dyno 2000 is saying around 553 peak HP at 8k rpm and 427 ftlbs torque at 5500.

------------------
'88 Coupe (extensive mods underway)
http://www.fiero.nl/forum/Forum2/HTML/086359.html

IP: Logged
Russ544
Member
Posts: 2136
From: S.W. Oregon
Registered: Jun 2003


Feedback score: (3)
Leave feedback





Total ratings: 86
Rate this member

Report this Post10-29-2007 10:01 PM Click Here to See the Profile for Russ544Send a Private Message to Russ544Direct Link to This Post
sending pm shortly

Russ544
IP: Logged
PFF
System Bot



All times are ET (US)

T H I S   I S   A N   A R C H I V E D   T O P I C
  

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock