rebuilt 496 sounds like a diesel? Updated with video
#1944646
11/03/15 11:07 PM
11/03/15 11:07 PM
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Joined: Feb 2009
Posts: 1,707 Nebraska
70VcodeCoronetRT
OP
top fuel
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OP
top fuel
Joined: Feb 2009
Posts: 1,707
Nebraska
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Ok finally got the six pack tuned in and running on the idle circuit. But my concern is this 496 sounds like a diesel. I had the short block put together by a local shop. It is a mild .040 496 with a Mr Six Pack cam. Roughly 471 I 490 E hydraulic. Diamond dish pistons, eagle rods and crank. It doesn't sound like it's coming from the rocker area. I even pulled a valve cover and everything looked good. It sounds like from the block area. Under the intake maybe. Sounds like piston slap. Timing is 18 initial. And has 40lbs oil pressure at idle warm. With a standard oil pump. The motor doesn't miss or stumble at all. Seems to run good. Just sounds like it wants to fly apart. Any ideas before I pull it back out? Thanks
Last edited by 4406forPOWER; 11/07/15 11:17 AM.
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1944672
11/03/15 11:24 PM
11/03/15 11:24 PM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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My guess would be piston rock. There's most likely not a whole lot of skirt in the bore relative to the pin at BDC. I've heard a few strokers that sounded like a coffee can full of rocks at idle. Don't know that I would be all that worried, but it's hard to say without actually hearing it in person. The "diesel" description is common with this issue, not necessarily a problem.
"use it 'till it breaks, replace as needed"
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Re: rebuilt 496 sounds like a diesel? long
[Re: TRENDZ]
#1944674
11/03/15 11:26 PM
11/03/15 11:26 PM
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Joined: Nov 2005
Posts: 15,119 85086
moparpollack
Lil Herman
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Lil Herman
Joined: Nov 2005
Posts: 15,119
85086
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Yup sound like BDC piston rock.
56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1944699
11/03/15 11:42 PM
11/03/15 11:42 PM
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Joined: Feb 2009
Posts: 1,707 Nebraska
70VcodeCoronetRT
OP
top fuel
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OP
top fuel
Joined: Feb 2009
Posts: 1,707
Nebraska
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I have to work tomorrow. But I'll try and get a video up Thursday.
Last edited by 4406forPOWER; 11/03/15 11:46 PM.
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1944854
11/04/15 04:19 AM
11/04/15 04:19 AM
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Joined: Mar 2003
Posts: 4,848 Memphis
HemiRick
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master
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Memphis
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^^^^^I 2nd the above, a buddy of mine built a 383 w keith black pistons that were too loose and it sounds just like a diesel.
Take care, Rick 68 Coronet R/T 440 & 68 Charger 528 Hemi,and 5 Challengers! 6 cyl, 318, 360, 383, 451
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Re: rebuilt 496 sounds like a diesel? long
[Re: HemiRick]
#1944917
11/04/15 11:07 AM
11/04/15 11:07 AM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
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master
Joined: Jun 2008
Posts: 3,916
usa
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^^^^^I 2nd the above, a buddy of mine built a 383 w keith black pistons that were too loose and it sounds just like a diesel. all those hypers are noisey when cold but if they're a couple thousands too loose then you really need to turn the radio up.
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1945205
11/04/15 08:05 PM
11/04/15 08:05 PM
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Joined: Feb 2011
Posts: 4,302 Nebraska
72Swinger
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master
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Nebraska
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My Arias pistoned 400 rod, 3.75 stroke 400 sounded like that for 19 yrs. I finally traded it for a 6.1 Hemi. Piston slap ala mode. Goes away with RPM in my experience.
Mopar to the bone!!!
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1946364
11/06/15 04:12 PM
11/06/15 04:12 PM
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Joined: Jan 2005
Posts: 12,424 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,424
Kalispell Mt.
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Streetwize what cam is in that 517? What exhaust? Sounds awesome!
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: rebuilt 496 sounds like a diesel? long
[Re: lewtot184]
#1946967
11/07/15 03:08 PM
11/07/15 03:08 PM
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Joined: Oct 2003
Posts: 996 Queens, New York
Harley
super stock
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super stock
Joined: Oct 2003
Posts: 996
Queens, New York
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doesn't sound much different than my 440 solid lifter, light piston, street engine. is some of that noise valve train related? what type of tappet? any oil restrictors? what rockers? Same here.
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1947056
11/07/15 06:25 PM
11/07/15 06:25 PM
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Joined: Jan 2003
Posts: 75,134 A Banana Republic near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,134
A Banana Republic near you.
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Sheet from the machine shop shows a final oversize of 4.360. Using the Diamond 52417 piston. which is a 4.360 bore piston. That doesn't tell you what clearance he set it at .
running up my post count some more .
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1947100
11/07/15 07:56 PM
11/07/15 07:56 PM
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Joined: Jul 2005
Posts: 712 California
BigDaddy440
super stock
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super stock
Joined: Jul 2005
Posts: 712
California
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My first 440 with KB hypers sounded like a diesel at Idle...I mean you could hear that sound a bit. I was told it was a common hyper piston sound. The engine is still running to this day after 15 years with no issues..street / strip.
1969 A12 Roadrunner 1970 Plymouth Cuda 1968 Dodge Dart
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1947410
11/08/15 09:55 AM
11/08/15 09:55 AM
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Joined: Jun 2008
Posts: 10,847 Oakdale CT
gdonovan
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I Live Here
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Oakdale CT
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Looks like .005 piston to wall clearance. If I'm reading his scribbles correct. Sounds on the loose side, but is a stroker so that might be normal (I have no experience with storkers yet) My memory is fuzzy after 25+ years but the TRW forged slugs in my 440 were set to 3 and 1/2. Motor has been together forever, buzzed to 7200 and hit hard with nitrous too. Cast pistons run tighter than forged as they expand less.
"I think its got a hemi"
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Re: rebuilt 496 sounds like a diesel? long
[Re: 70VcodeCoronetRT]
#1947455
11/08/15 12:09 PM
11/08/15 12:09 PM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
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master
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Posts: 2,540
Milwaukee WI
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The issue is pistons are not the same diameter at the top as they are in the skirt. with a stroker, the skirt hangs out of the bore at BDC, and the piston is generally much shorter, the top of the piston fits the bore looser, and that is why it "rocks" at BDC.
"use it 'till it breaks, replace as needed"
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