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Crank Case Pressure..
#169876
12/18/08 09:51 AM
12/18/08 09:51 AM
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Joined: Jan 2003
Posts: 4,281 Danville, NH
Mopar_Mike
OP
master
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OP
master
Joined: Jan 2003
Posts: 4,281
Danville, NH
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I understand that heat expands air and therefore the friction in the crankcase you will have pressure in the crankcase area that now needs to be relieved.. So what causes excessive crank case pressure? ie Windage tray? Aluminum heads? What? Do all engines RB, B, etc. create the same amount of pressure regardless of build? Thanks.
RS23L7 4-Speed
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Re: Crank Case Pressure..
[Re: Mopar_Mike]
#169877
12/18/08 09:58 AM
12/18/08 09:58 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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i'd say it's the pistons moving up and down and the crank spinning along with ring blow-by.
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Re: Crank Case Pressure..
[Re: Mopar_Mike]
#169878
12/18/08 10:42 AM
12/18/08 10:42 AM
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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:
I understand that heat expands air and therefore the friction in the crankcase you will have pressure in the crankcase area that now needs to be relieved.. So what causes excessive crank case pressure? ie Windage tray? Aluminum heads? What? Do all engines RB, B, etc. create the same amount of pressure regardless of build? Thanks.
Being that rings have a gap in them and the lack of 100% sealing on the walls you have blow by, this is due to the pressure in the cylinder and that pressure slipping past the rings. All engines do not see the same blow by, if its a "better build" it will have less
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Re: Crank Case Pressure..
[Re: MR_P_BODY]
#169879
12/18/08 01:56 PM
12/18/08 01:56 PM
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Joined: Aug 2003
Posts: 43,097 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,097
Bend,OR USA
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Quote:
Quote:
I understand that heat expands air and therefore the friction in the crankcase you will have pressure in the crankcase area that now needs to be relieved.. So what causes excessive crank case pressure? ie Windage tray? Aluminum heads? What? Do all engines RB, B, etc. create the same amount of pressure regardless of build? Thanks.
Being that rings have a gap in them and the lack of 100% sealing on the walls you have blow by, this is due to the pressure in the cylinder and that pressure slipping past the rings. All engines do not see the same blow by, if its a "better build" it will have less
the movement of the crankshaft and oil flying off the rotating crankshaft and blowby all add up to crankcase pressure. A crankshaft scraper and a windage tray can help reduce and control the windage caused by the flying oil 15 to 45 hp increase on some motors during controlled dyno testing, depends on the RPM , windage and oil scraping. As already said the up and down movement of the pistons add to it also so the higher the RPM the more pumping and more pressurei if not relieved by breathers or a vacume source relieving the pressures. Longer stroke motors seem to make more pressures also due to the larger radius of the rotating parts
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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