Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396034
10/31/17 01:32 PM
10/31/17 01:32 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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other than a low performance daily driver, I would want .035"-.040" quench.
live every 24 hour block of time like it's your last day on earth
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396037
10/31/17 01:36 PM
10/31/17 01:36 PM
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Joined: Aug 2007
Posts: 6,100 Valencia, España
NachoRT74
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sure... but meaning I can still mill down heads still using 0.039 gaskets... and still have to confirm the corrected block decking.
( I have read around 0.050 is still good )
Once again I still have to get the parts correctly machined ( if that's posible locally!!!!! ) to get the final decision...
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396146
10/31/17 04:30 PM
10/31/17 04:30 PM
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Joined: Aug 2007
Posts: 6,100 Valencia, España
NachoRT74
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I'm actually working on a good enough job... trying to keep the static CR lower as posible keeping on good enough quench numbers, also trying TO NOT SEND MORE PARTS TO UNNEFICIENT MACHINE SHOPS!!! I get really scared everytime I have to send anything to any machine shop!. Before all this squared deck deal I was riding on 10.2-10.3 CR. I guess had pinging due of course the bad quench. Front ones pistons down the deck around 0.015-0.017 and the rears right on zero deck, and using stock composite headgaskets. Diff combustion chambers deepness everywhere, etc... well, what you already know.
I have asked about this many times, I know, and being tiresome. This project has being taking an eternity.
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396301
10/31/17 09:46 PM
10/31/17 09:46 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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I have asked about this many times, I know, and being tiresome. This project has being taking an eternity. Nacho, Keep em coming, we are here to help as much as we can/solve as manny issues as we can/gain & share as much knowledge as we can.
live every 24 hour block of time like it's your last day on earth
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396667
11/01/17 02:09 PM
11/01/17 02:09 PM
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Joined: Jan 2003
Posts: 75,126 A Banana Republic near you.
JohnRR
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dogdays:
yes that was my thought, but my doubt was that because per what I have read on several places the quench/squish area can be on 0.050" rate and still be good even the advice is around 0.040"
John:
that could be good too! and will make to keep the heads unmilled, saving from ANOTHER mistake from machine shop. However that could make also to get really close the piston diameter out of the quench pad close to the head around the combustion chamber to allmost 0.020" I think... isn't that some dangerous ? I recall the combustion chamber bore is sligthly smaller bore than the cylinder bore... isn't ?
Wouldn't actually need to cut 0.020" but maybe the 0.010-12 extras the thicker felpro headgaskets got with bigger bore, and keep using the 0.39 with small bore... in another words, cut the combustion chamber quench area same ammount the pistons leaves the deck. Maybe in fact they are actually close to what I need. I'm pretty sure this area is deeper than the piston quench pad height and maybe close to what I need as mentioned on a previous reply.
I will know just once the block is correctly decked and once assembled measured with clay Once the block is decked drop the heads on the empty block without a gasket ... mark heads for what side they are on ... , now turn the block upside down and look in at the heads for chamber overhang into the bores , scribe the areas that overhang and clean them back to a little outside the scribed marks on the open chamber side of the head and roll over the edge on the plug side , or blend the plug side back also if you need to lower the compression some. the .039 you are getting , is that from the web or from actual crushed gasket that is measured ? I have found the 8519 to be more like .041 ???
running up my post count some more .
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2396982
11/01/17 09:52 PM
11/01/17 09:52 PM
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Joined: Aug 2007
Posts: 6,100 Valencia, España
NachoRT74
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From manufacturer specs
( good idea on the method you described )
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: quench, gasket bore and compressed height
[Re: 360view]
#2397619
11/03/17 12:31 AM
11/03/17 12:31 AM
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Joined: Aug 2007
Posts: 6,100 Valencia, España
NachoRT74
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General Motors research on effect of a tight quench where they varied the percent area of the flat piston surface that nearly touches a matching surface on the cylinder head. Note that if you multiply a 4.00 inch bore by their ratio it is 0.026 inches, which is very tight. Many years later Honda wrote up a technical paper on the science of their first V-Tec design. Honda wrote that the quench had to be a tight 0.75 millimeters, nearly the same clearance as GM found. we talked about this on an old thread I asked about a similar topic, and I remember this diagram being posted, and being honest, I'm not clear on everything said there
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2398210
11/04/17 12:25 AM
11/04/17 12:25 AM
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Joined: Feb 2014
Posts: 234 Brisvegas, Australia
Alchemi
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Kb made those pistons for stock heads
That pistons pad fits the 452 head pad area close to perfectly - any more meat towards the valve would have been excess weight and more compression
Last edited by Alchemi; 11/04/17 12:33 AM.
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Re: quench, gasket bore and compressed height
[Re: NachoRT74]
#2398356
11/04/17 12:19 PM
11/04/17 12:19 PM
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Joined: Aug 2007
Posts: 6,100 Valencia, España
NachoRT74
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Yes I know, and not just 452s, but any open chambers. The deal is that quench pad area is quite often deeper than 0.095" which is the KB215 pistons step height ( my heads were NOS and they are closer to 0.110", but I got them after the pistons ). For a custom step will need KB251s, which are cheaper just right because they need to be cut to needs. I went with KB215s trusting on published expects around for the heads. Maybe KB251 was to be easier to match everything.
Of course the quench step surface on piston matches the quench pad on open chambers, but still is maybe just 25% of the piston area LOL... thats just what I said, not saying just matches 25% of the quench pad on heads
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
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Re: quench, gasket bore and compressed height
[Re: 360view]
#2398921
11/05/17 04:53 PM
11/05/17 04:53 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
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If I may hijack: with 9-1 SCR (class rules) & adequate octane so detonation ain't a concern, would there be a significant power bennie from achieveing quench? better mixture homogenization (sp)?? and less timing needed cuz of a faster burn?? If so I wanna do it the next build.
live every 24 hour block of time like it's your last day on earth
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