Re: piston out of deck????'s
[Re: rice2muscle]
#897136
01/05/11 09:29 PM
01/05/11 09:29 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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You need to check the piston to head clearance... I had a engine that was .030 out and at 8000 the piston would JUST touch in one small area so I ground that area on the head on a freshen up
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Re: piston out of deck????'s
[Re: rice2muscle]
#897137
01/05/11 09:35 PM
01/05/11 09:35 PM
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Joined: Jul 2010
Posts: 2,091 Delray beach, Florida
Performance Only
top fuel
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top fuel
Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
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there's different ways to look at it. they do make head saver shims for that so you can maintain the proper piston placement. if it's a stock rebuild daily driver deal, that's a good option. if your doing other mods as well, then that's a whole different scenario.
machine shop owner and engine builder
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Re: piston out of deck????'s
[Re: rice2muscle]
#897140
01/05/11 10:11 PM
01/05/11 10:11 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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If you are running a closed chamber head you could get a cometic gasket .055 thick and get a nice tight quench area, even fel pro sells a head gaset that thick in there kits for small blocks at least.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: piston out of deck????'s
[Re: rice2muscle]
#897141
01/05/11 10:14 PM
01/05/11 10:14 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
another quick question, not tyring to start a debate war here just wondering... will i make more power if i were to just get more compression? or if i were to stroke it but have lower compression?
Stroking it gets you more CI and that wins
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Re: piston out of deck????'s
[Re: HotRodDave]
#897142
01/05/11 10:16 PM
01/05/11 10:16 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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depends on how much compression and displacement we are talking about.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: piston out of deck????'s
[Re: HotRodDave]
#897143
01/05/11 10:33 PM
01/05/11 10:33 PM
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Joined: Aug 2005
Posts: 4,101 Yes
sixpakdodge
master
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master
Joined: Aug 2005
Posts: 4,101
Yes
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I ran a .055 over 440 with the piston .013 out of the hole. It loved head gaskets. It burned through a set of the .055 Cometic's right near the dowel pin, just like it did to the 1009 Fel Pro's I originally had on it. I had a set of .066 Cometic's on it when the block split due to fatigue. (Block had A LOT of runs on it.) I kept going thicker in attempt to lower the compression. It didn't make much of a difference though, the car ran the same. I was running 452 open chamber heads that were milled, but still open chambered, with flat top pistons. Definitely check, double check, triple check, and then check again, the piston to valve/head clearance. I didn't have any problems with the piston to valve or piston to head, but it's very crucial.
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Re: piston out of deck????'s
[Re: hemigod426]
#897145
01/06/11 09:24 AM
01/06/11 09:24 AM
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Joined: Jul 2008
Posts: 30,424 Florida STAYcation
dOrk !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,424
Florida STAYcation
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Quote:
Quote:
not going to blow head gaskets like the first machine shop says??
What SOME of these so-called "professionals" say is flat-out SCAREY sometimes.
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Re: piston out of deck????'s
[Re: dOrk !]
#897146
01/06/11 12:07 PM
01/06/11 12:07 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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What SOME of these so-called "professionals" say is flat-out SCAREY sometimes.
True, dat. Remember: "I do it for money" is what makes you a professional - not being good at it. Look at Congress...
Boffin Emeritus
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Re: piston out of deck????'s
[Re: StripeHOG]
#897150
01/06/11 07:40 PM
01/06/11 07:40 PM
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Joined: Nov 2003
Posts: 6,293 Rock Springs
Bob_Coomer
master
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master
Joined: Nov 2003
Posts: 6,293
Rock Springs
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what kind of engine? What kind of pistons, and heads? The machine shop you speak of, doesnt give trust worthy answers, my guess is there machine work isnt trust worthy either. Talking about a .020 positive piston to deck clearance then referring to piston to valve questions is a bit confusing. This needs checked also, but piston to head is more critical in this much positive piston height than valve to piston.... Both need checked at any rate. Is this a pump gas engine, or suppose to be? I haven't seen anyone ask yet, but having that much piston height is going to increase the compression a bunch. Running 11:1+ compression will cost you power, and cause engine damage running today's pump gas. Where a properly tuned 9.5:1 engine with the correct/optimal spark timing will not only make more power, but be more dependable any way you slice it. More isn't always best in a performance engine.
[color:"red"]65 Hemi Belvedere coming soon [/color] [color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: piston out of deck????'s
[Re: rice2muscle]
#897153
01/07/11 06:05 PM
01/07/11 06:05 PM
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Joined: Nov 2003
Posts: 6,293 Rock Springs
Bob_Coomer
master
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master
Joined: Nov 2003
Posts: 6,293
Rock Springs
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well your pushing the limits with pump gas even with aluminum heads. I will take a guess and say the ignition system is computer controlled closed lop system that constantly monitors engine spark and knock, detonation, and pre ignition. If the computer see's one of these problems it will just pull a bunch of timing out of the engine to help out. This is bad for performance. Lets say the same engine with less compression around (lets say 10:1) now has the same thing going on but the computer doesnt see any spark knock. The engine is operating at full potential and optimal timing. The lower compression engine now will out run the engine with more compression every time like this. My 01 SS Camaro would detect a knock and pull timing out until I fill the fuel tank up. This is a decade old technology BTW. On out V-8's a engine making good power at say 34-36 deg total timing will loose a easy 5% maybe as much as 10% if you pull the timing down 10 deg to 24-26 deg easy. So in this case the increased compression's gain in power is offset more by the now none optimal timing curve... Plus nothing will kill a engine quicker than pre ignition, and detonation. Just some food for thought. Later Bob Just drop my old engine in between the Honda's fenders and dont worry about it
[color:"red"]65 Hemi Belvedere coming soon [/color] [color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: piston out of deck????'s
[Re: rice2muscle]
#897155
01/08/11 01:27 PM
01/08/11 01:27 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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a crank with 5mm longer stroke and the rods to go with it with my stock pistons
Are the rods 2.5mm shorter than stock?
Boffin Emeritus
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Re: piston out of deck????'s
[Re: polyspheric]
#897157
01/10/11 01:48 AM
01/10/11 01:48 AM
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Joined: Jun 2010
Posts: 42 napa, ca
rice2muscle
OP
member
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OP
member
Joined: Jun 2010
Posts: 42
napa, ca
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Quote:
a crank with 5mm longer stroke and the rods to go with it with my stock pistons
Are the rods 2.5mm shorter than stock?
the crank is 4.3 mm longer of a stroke and the rods are 1.5 mm shorter.
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