Big Valves in #46 - 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 02-17-2010, 09:39 AM
UngerMarkus's Avatar
TuckīnīRoller
 
Last photo:
Join Date: Mar 2009
Location: AUSTRIA
Age: 27
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Big Valves in #46

Hi guys!

Iīd like to put big valves (2.11/1.77) in my #46 Pontiac heads. I already got the intake valves, but Iīm not sure wich exhaust valves to take. Does anybody have an idea?

Thanks

Markus

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-17-2010, 10:07 AM
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 UngerMarkus
Hi guys!

Iīd like to put big valves (2.11/1.77) in my #46 Pontiac heads. I already got the intake valves, but Iīm not sure wich exhaust valves to take. Does anybody have an idea?

Thanks

Markus
Are these the good '74 GTO 350 #46 heads, or the pressed stud 2-bbl. heads?

If you want 1.77's, go w/the same valve that Pontiac used in all their D-port heads that year.

BTW, the 350 GTO #46 heads w/screw-in studs have 45 degree seats. You will want to verify the angle of the intake seats of your heads. The Pontiac 2.11 valves- if OEM design/type, will have a 30 degree angle.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-17-2010, 10:17 AM
UngerMarkus's Avatar
TuckīnīRoller
 
Last photo:
Join Date: Mar 2009
Location: AUSTRIA
Age: 27
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Iīve got fully ported 2bbl heads.

According to the measurements at rockauto.com the bigger valves are slightly longer then the small ones. Is that a problem?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-17-2010, 10:40 AM
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 UngerMarkus
Iīve got fully ported 2bbl heads.

According to the measurements at rockauto.com the bigger valves are slightly longer then the small ones. Is that a problem?
Not as long as you are using an adjustable valve train AND correctly match the p-rod legnth to get correct valve train geometry- something that you'd be checking, anyway- if you're changing cams, decking the heads/block, changing compressed thickness of the head gasket, etc.

You will want to check and adjust the valve spring installed height, if needed, as well.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-18-2010, 11:26 AM
UngerMarkus's Avatar
TuckīnīRoller
 
Last photo:
Join Date: Mar 2009
Location: AUSTRIA
Age: 27
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well, the bigger valve is 0.009'' (= 0.228mm) longer than the stock valve. Do you think a hydraulic lifter will compensate that? Or do i have to go for poly-locks?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-18-2010, 12:28 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 UngerMarkus
Well, the bigger valve is 0.009'' (= 0.228mm) longer than the stock valve. Do you think a hydraulic lifter will compensate that? Or do i have to go for poly-locks?
I can't positively say one way or the other, to be honest.

The 0.009" by itself will not be enough to cause a problem- provided you aren't at the very top or bottom of the lifter's plunger travel.

I'd try it first w/the stock nuts and bottle neck studs. If they're a no-go, go w/locking nuts.

There have been cases where polylocs haven't had very much engagement on the b/n stud, so see what yours look like when you get to that stage. If you think there's gonna be a prob, you can use new, "regular" rocker arm lock nuts. There is a chance that you'll need hardened spacer washers under the nut to get the correct preload, but if this is the case w/the lock nuts, hopefully the polylocs will have enough engagement.

The better way to go about this, is to install good, straight wall studs and polylocs. There was a thread here just yesterday that had a guy breaking his stock studs, so there is a possibility of it happening.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-18-2010, 12:47 PM
Registered User
 
Last photo:
Join Date: Nov 2009
Location: no longer here
Posts: 293
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
.009 isn't going to cause a problem as when a valve job is done they machine off .002-005 on the tip , you can have the tips machined/ground to remove the excess if you want without any problems ,just make sure your spring installed heights are not affected and the tip isn't below the retainer
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-18-2010, 01:15 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
To see what's going to be needed will take a mock up or three. The spring IH will be the same before/after the tip is ground. Just be sure it needs to be ground in the first place.

Unger- Did you see if the 2.11" valves are 30 degree seats or not? And what is the seat angle of your 46 heads? Anyway, just be sure the machinist is up to speed on the deal.

I don't know what I'd prefer on a 350 Pontiac- 45 or 30.

Last edited by cobalt327; 02-18-2010 at 04:20 PM.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-18-2010, 02:23 PM
Registered User
 
Last photo:
Join Date: Nov 2009
Location: no longer here
Posts: 293
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
on the 350's the 30 degree works better it allows flow to start at a lower lift ,the shrouding will take place in the head , just make sure you have clearance on the valve heads at the edge of the bore , seen too many valves bent this way . with the 2.11's on a 350 you can get away with using the 1.66 exhausts it keeps the flow speeds up , my street motors liked it better with the smaller exhaust valves with a header made more torque you could see on a dyno and in the butt dyno too .
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-18-2010, 02:55 PM
UngerMarkus's Avatar
TuckīnīRoller
 
Last photo:
Join Date: Mar 2009
Location: AUSTRIA
Age: 27
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thanks for your fast replies! I don't have 350 heads. They came on my 1969 400cui 2bbl engine. Now it's got a performer intake, a mild cam (214/224 @ .500" 112^ lsa) and headers.

I'm gonna check the seat angle tomorrow.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-18-2010, 03:28 PM
Registered User
 
Last photo:
Join Date: Nov 2009
Location: no longer here
Posts: 293
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
if its a 400 ,30 degree seat angles work great and the bigger exhaust is ok . .
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 02-18-2010, 04:19 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 UngerMarkus
I'm gonna check the seat angle tomorrow.
Unger, if your heads came on a 400 originally, they will be 30 degree seats on the intakes.

The 350ci GTO heads were the ones w/45 degree seats, I believe- so your valves should be fine- as long as they clear the bore.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 02-19-2010, 04:08 AM
UngerMarkus's Avatar
TuckīnīRoller
 
Last photo:
Join Date: Mar 2009
Location: AUSTRIA
Age: 27
Posts: 90
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Great!

Well, back in the days there were big valve heads available for that engine, so I think this shouldnīt cause any problems.

Thank you very much!
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
Big Block Exhaust Question RamAirZ Engine 2 07-22-2009 04:03 PM
big block trouble steinwinter454 General Rodding Tech 2 12-07-2008 07:43 PM
ideas for big block truck build boatanchors Engine 12 11-16-2008 07:20 PM
Big cars Wmarden Hotrodders' Lounge 16 09-12-2004 08:05 AM
Big Mack Kevin45 Hotrodders' Lounge 0 12-08-2002 12:33 PM


All times are GMT -6. The time now is 04:57 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.