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Re: 383 Quench Question
[Re: JoesMopar]
#926028
02/13/11 09:18 PM
02/13/11 09:18 PM
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Joined: Nov 2004
Posts: 843
Suffolk,VA
ireland383
super stock
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super stock
Joined: Nov 2004
Posts: 843
Suffolk,VA
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Quote:
Ok, how about the KB 400's, zero deck the block, 84cc Edelbrock heads (don't want to machine them incase I want to use them on a 440 later on), and a .040ish head gasket.....what CR are we talking about? Does this sound good?
I come up with 9.890:1. I used the .040 KB400's on my build to achieve the 9.9:1. Use this calculator. http://www.kb-silvolite.com/calc.php?action=comp
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Re: 383 Quench Question
[Re: JoesMopar]
#926029
02/13/11 09:54 PM
02/13/11 09:54 PM
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Joined: Jan 2003
Posts: 74,974
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,974
U.S.S.A.
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Quote:
Ok, how about the KB 400's, zero deck the block, 84cc Edelbrock heads (don't want to machine them incase I want to use them on a 440 later on), and a .040ish head gasket.....what CR are we talking about? Does this sound good?
No need to zero deck the block just a cut to make it SQUARE to the crank centerline is all you need to do. 
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Re: 383 Quench Question
[Re: JoesMopar]
#926031
02/13/11 10:11 PM
02/13/11 10:11 PM
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Joined: Nov 2004
Posts: 2,825
Sk. Canada
RemCharger
master
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master
Joined: Nov 2004
Posts: 2,825
Sk. Canada
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Quote:
Can anyone tell me the best way to get quench from a 383 using the 906 heads? I looked at the Edelbrock closed chamber heads on Summit and I don't know if it was a misprint or what but it listed the bare 84cc heads for $900+ each. I think I want to use the 906 heads anyway, and if I don't like them I can always change things later on.
I'm not building a racing engine, just a nice street engine. I'm shooting for 375-400HP.
If it helps my other list of parts will be a Performer RPM, 750 carb (not sure which), XE 274 cam and matching springs, stock rockers, MP ignition, Dougs headers, and 2 1/2" exhaust. Not sure on the pistons, that depends on what you guys recommend for the 906's. The car also has a 727/3.23 SG set up.
Thanks 
To the original question..
My thoughts, to get quench with a 906 and a .039 gasket , the piston would need a quench pad of around.120 height above deck.
On my street 383 I used .060 milled 516s with .080 in the hole pistons. It will not run on reg gas and makes somewhere around 425 hp. Its cheap and ez, works well. With my cam choice and 3.23s it needs to see 25-30mph before it turns on.
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Re: 383 Quench Question
[Re: JoesMopar]
#926032
02/14/11 12:38 AM
02/14/11 12:38 AM
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Joined: Jul 2006
Posts: 528
N.W. Indiana
DblOJoe
mopar
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mopar
Joined: Jul 2006
Posts: 528
N.W. Indiana
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Quote:
Ok, how about the KB 400's, zero deck the block, 84cc Edelbrock heads (don't want to machine them incase I want to use them on a 440 later on), and a .040ish head gasket.....what CR are we talking about? Does this sound good?
That's the best thing to do, I used the KB 162's and cut my heads down to 70cc to get compression. It runs pretty good but was pretty costly for what it is. The KB 400's weren't out when I built it though.
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Re: 383 Quench Question
[Re: 71383beep]
#926033
02/14/11 06:02 PM
02/14/11 06:02 PM
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Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
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master
Joined: Dec 2006
Posts: 3,533
Indiana
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You could just go find some closed chamber 516 or the even better 915 head if you're looking to keep your project cheap.
Fixed. Just in case anyone comes researching thru this thread at a later date...
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Re: 383 Quench Question
[Re: JoesMopar]
#926039
02/14/11 11:53 PM
02/14/11 11:53 PM
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Joined: Jul 2006
Posts: 528
N.W. Indiana
DblOJoe
mopar
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mopar
Joined: Jul 2006
Posts: 528
N.W. Indiana
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Quote:
So with the dome of the KB 400 are there any issues with valve clearance or?
If I don't zero deck the block and just slap on a set of Edelbrock 84cc heads, .040ish head gasket and KB 400s what would be CR be?
If you don't zero deck it the pistons will likely be around .030 in the hole and only give you 9.43 with a .040 gasket or you could use a steel shim and be around 9.87.
Zero deck and a .040 gasket would be 10.11
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Re: 383 Quench Question
[Re: DblOJoe]
#926040
02/15/11 12:12 AM
02/15/11 12:12 AM
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Joined: Dec 2008
Posts: 2,782
USA
JoesMopar
OP
master
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OP
master
Joined: Dec 2008
Posts: 2,782
USA
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Quote:
Quote:
So with the dome of the KB 400 are there any issues with valve clearance or?
If I don't zero deck the block and just slap on a set of Edelbrock 84cc heads, .040ish head gasket and KB 400s what would be CR be?
If you don't zero deck it the pistons will likely be around .030 in the hole and only give you 9.43 with a .040 gasket or you could use a steel shim and be around 9.87.
Zero deck and a .040 gasket would be 10.11
Cool, would there be any chance at that point with the pistons interferring with the XE274 cam?
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Re: 383 Quench Question
[Re: JoesMopar]
#926041
02/15/11 12:21 AM
02/15/11 12:21 AM
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Joined: Jul 2006
Posts: 528
N.W. Indiana
DblOJoe
mopar
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mopar
Joined: Jul 2006
Posts: 528
N.W. Indiana
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Quote:
Quote:
Quote:
So with the dome of the KB 400 are there any issues with valve clearance or?
If I don't zero deck the block and just slap on a set of Edelbrock 84cc heads, .040ish head gasket and KB 400s what would be CR be?
If you don't zero deck it the pistons will likely be around .030 in the hole and only give you 9.43 with a .040 gasket or you could use a steel shim and be around 9.87.
Zero deck and a .040 gasket would be 10.11
Cool, would there be any chance at that point with the pistons interferring with the XE274 cam?
No, but you should still check to see how much clearence you have.
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Re: 383 Quench Question
[Re: Dean_Kuzluzski]
#926043
02/15/11 07:52 AM
02/15/11 07:52 AM
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Joined: Jan 2005
Posts: 4,862
the frozen wastes...
Pale_Roader
Swears too much
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Swears too much
Joined: Jan 2005
Posts: 4,862
the frozen wastes...
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Quote:
Quote:
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You could just go find some closed chamber 516 or the even better 915 head if you're looking to keep your project cheap.
Fixed. Just in case anyone comes researching thru this thread at a later date...
Well i'll be humdinger...whoops! my bad. I am glad you caught that!
I fixed my post too, but yes kb 162's some meat off of the block, and worked 516's with a decent cam will get you 400 hp which is what the OP is after. I also receomend a full point more if going to edelbrock in which case different pistons are the better route.
Holy doorstops Batman!! There's still a use for them old 516's!?!?!?
I've asked the question on the Race forum before, got no definitive answer..................Which is better quench w/compression (516 closed chamber) or the marginally better airflow of an "no quench" open chamber head (906,902,346,452)??
I've got this same conundrum right now, or well, had it. I've decided that i'd rather have a crappier flowing head with quench for a nicer, more efficient engine than say, a possibly more powerful engine, thats less efficient, with an open chamber head and no quench. I'm still trying to figure out how far to go with porting my 516's. They dont quite port as well as the newer heads, but thats all i know. Never done a set. Until i can get a solid answer on that, i'll just clean 'em up a bit, big-valve the exhausts and shop for something better while i'm driving around on them.
And it must be just me, as i've seen no one else comment on this, but am i the only one here that has a problem with the whole quench pad idea? I understand the idea, and the need, and the lack ov better options, but it just seems so hokey to me. I'm not a fan ov domes on pistons either generally. From what i've seen, a cheap newer brand (Probe, Diamond, Ross) forged piston isn't that much more than a KB (at least where i live), and to move a pin (compression height) on a set ov pistons doesn't add that much more to the cost. I'd pay $200 more for pistons to get the true zero deck, even if it did mean i'd be stuck with 516's for a while.
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Re: 383 Quench Question
[Re: Pale_Roader]
#926044
02/15/11 11:10 AM
02/15/11 11:10 AM
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Joined: Jan 2003
Posts: 8,936
Holly/MI
Dean_Kuzluzski
master
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master
Joined: Jan 2003
Posts: 8,936
Holly/MI
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Quote:
I've decided that i'd rather have a crappier flowing head with quench for a nicer, more efficient engine than say, a possibly more powerful engine, thats less efficient, with an open chamber head and no quench.
"Possibly more powerful....that's less efficient" Not to bash but sounds like an oxymoron.
With the variance on combustion chamber from cylinder to cylinder (w/open chamber), bowl & template porting, exhaust valve update to 1.74, cubic inch size considered, using a flattop piston, and ultimately good quench................I'd be surprised to see an open chamber combination actually make better power. And then it would only be in the upper rpm range.
Not that anyone would ever waste the time to do an actual build/dyno comparison. 
R.I.P.- Gary "Coop" Davis 02/09/68-05/13/04
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Re: 383 Quench Question
[Re: Dean_Kuzluzski]
#926045
02/15/11 04:44 PM
02/15/11 04:44 PM
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Joined: Jan 2005
Posts: 1,647
IL
71383beep
top fuel
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top fuel
Joined: Jan 2005
Posts: 1,647
IL
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Quote:
Quote:
I've decided that i'd rather have a crappier flowing head with quench for a nicer, more efficient engine than say, a possibly more powerful engine, thats less efficient, with an open chamber head and no quench.
"Possibly more powerful....that's less efficient" Not to bash but sounds like an oxymoron.
With the variance on combustion chamber from cylinder to cylinder (w/open chamber), bowl & template porting, exhaust valve update to 1.74, cubic inch size considered, using a flattop piston, and ultimately good quench................I'd be surprised to see an open chamber combination actually make better power. And then it would only be in the upper rpm range.
Not that anyone would ever waste the time to do an actual build/dyno comparison.
Well what happened to me was a comparison. With the 906 heads and KB 162's with just a freshened deck the car ran like crud and would barely hold a tune. I had other issues, but could tell that something was not right.
On the 2nd rebuild I knew better and I had the shop pull the motor apart and we figured out that the old combo was running 7.8:1 CR...
For the second build I gave them a set of 516s I had laying around and they put in the larger exhaust valve and ported them for better flow. they also cut the deck some and I had a true 9.2:1 CR. With a CC nostalgia .474 cam and a mighty demon 650 on a street dominator intake the motor was dyno'd and ran 396/430 hp/tq. I was happy as my target was 400 hp and the car runs great. So if you already have the 162's they can be made to work.
If I had to do it again I would go with diamond pistons and I would have hunted down a set of 915s. But my next build for the car will be a stroker 400.
'73 GK6 Challenger Rallye - 340 4-Speed
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