Bigger valves in 915 BB heads
#1402370
03/14/13 09:43 AM
03/14/13 09:43 AM
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Joined: Jan 2004
Posts: 27,347 Today? Who Knows?
1_WILD_RT
OP
Management Trainee
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OP
Management Trainee
Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
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I've got need of some tech help, I dropped a set of 915 big block heads off at my buddies machine shop, having bigger valves, hardened seats guides & cut them .030 off the deck & .037 off the intake.. Anyway I got a call today & he's concerned about opening the exhaust up enough to put a seat in... Currently the exhaust valve is 1.60 & I bought 1.81 valves, he said he's comfortable with opening enough to run that size valve with out the seat but to put in a seat he's concerned about hitting water.... I thought this was a common upgrade? Thoughts? Thank you for your time & expertise...
"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."
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Re: Bigger valves in 915 BB heads
[Re: JohnRR]
#1402373
03/14/13 12:24 PM
03/14/13 12:24 PM
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Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
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Quote:
The head should have the same amount of material in that area as a head with a 1.74 valve and other than the open chamber it's the same as a 906 . I have a set of 906's with 1.81's , but I don't remember if I put seats in or not ? Call Dwayne Porter , he can tell you definitively , but the wild card is CORE SHIFT.
Does the shop have a sonic tester they could check the area ?
I agree as I would call Dwayne Porter and ask him. I also put 1.81 valves in my old 906 heads but I made the seats in the head and did not install hardened seats. Ron
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Re: Bigger valves in 915 BB heads
[Re: 383man]
#1402374
03/14/13 02:25 PM
03/14/13 02:25 PM
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Joined: Oct 2011
Posts: 559 Idaho
LaRoy Engines
mopar
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mopar
Joined: Oct 2011
Posts: 559
Idaho
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I've put hardened seats for the 1.81 in both the 906 and 915.
Last edited by heyoldguy; 03/14/13 02:26 PM.
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Re: Bigger valves in 915 BB heads
[Re: LaRoy Engines]
#1402375
03/15/13 12:16 PM
03/15/13 12:16 PM
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Joined: Jun 2005
Posts: 95 NW INDIANA
ta3834bbl
member
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member
Joined: Jun 2005
Posts: 95
NW INDIANA
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Not really the same but throwing my 2 cents in. I have 516 closed chambers with hardened seats but only have the 1.74 ex valves. Been on the engine for over 20 years, no problems.
67 Dart GT Convertible 273 68 Barracuda 383 68 Roadrunner 383 4spd 1 '01 Ram 2500 4x4 diesel 2 '02 Rams 1500 4x4's 4.7s 3 '03 Rams 2 1500's 4x4 and 1 2500 hemi 4x4 Oh, and a 03 Grand Cherokee and an '00 durango
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Re: Bigger valves in 915 BB heads
[Re: 1_WILD_RT]
#1402376
03/15/13 01:21 PM
03/15/13 01:21 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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You might see if you can locate Dulcichs' BB porting articles in Mopar Muscle archives. alot of pertinent info that you need to check out regarding port shape/valve sizes/porting benefit differences between early/late heads
live every 24 hour block of time like it's your last day on earth
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Re: Bigger valves in 915 BB heads
[Re: 1_WILD_RT]
#1402380
03/19/13 09:44 PM
03/19/13 09:44 PM
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Joined: Aug 2006
Posts: 2,537 God's Country Maryland
GODSCOUNTRY340
master
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master
Joined: Aug 2006
Posts: 2,537
God's Country Maryland
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Here is a set of my 906 heads with 2.19 stainless valves and 1.88 max wedge exhaust valves. Tell your shop to machine the seats and forget about adding the hardened seats. Just run your carb a little rich and they will last for many, many years.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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