Some Advice on 10:1 please
Some Advice on 10:1 please
Ok I plan on slapping in a 383 into my Z28 one day and i may have found the motor/engine for the job through jegs i'll through in the specs on the short block assemblie in a sec. any way i was wondering to get the 10:1 compression on want I have to put on the correct heads right, It's been a while since my engine build/rebuild class and i haven't yet taken machine shop class and figured i'd ask you guys.
Here's the info. and a link.
Short Block Assemblies
Blueprint Engines Short Block Assemblies are a great basis for a drivable and reliable high performance engine. All rotating assemblies are balanced within 2 grams on a computerized balancer.
Block:Seasoned, hand picked 69-79 drivers side dipstick cores (2 or 4- bolt), .040'' max overbore
Cylinder wall thickness ''sonic tested''
Cylinders bore angle corrected to be 90° perpendicular to crank centerline
Cylinder bore centerline corrected to be exactly centered over crank centerline
Decks machined parallel to crank centerline
Right and left side decks machined equal distance from crank centerline
Main bearing bores align honed to correct size and straightness
Cylinders computer honed to tolerance of 200 millionths of an inch
Cylinders plateau finished for virtually instant break-in
Screw-in oil galley plugs installed in place of soft plugs
Rotating Assembly:
Hastings Moly rings
Keith Black hypereutectic pistons
Standard or 10-10 undersized journals on cast crank
Clevite bearings
Chevy 5.7'' heavy beam rods
Blacklight magnufluxed
Stress relieved and shot peened
Indexed and stroke corrected during grinding
Oil hole chamfered for improved flow
Super ''micro-polish'' for superior finish
Here's the info. and a link.
Short Block Assemblies
Blueprint Engines Short Block Assemblies are a great basis for a drivable and reliable high performance engine. All rotating assemblies are balanced within 2 grams on a computerized balancer.
Block:Seasoned, hand picked 69-79 drivers side dipstick cores (2 or 4- bolt), .040'' max overbore
Cylinder wall thickness ''sonic tested''
Cylinders bore angle corrected to be 90° perpendicular to crank centerline
Cylinder bore centerline corrected to be exactly centered over crank centerline
Decks machined parallel to crank centerline
Right and left side decks machined equal distance from crank centerline
Main bearing bores align honed to correct size and straightness
Cylinders computer honed to tolerance of 200 millionths of an inch
Cylinders plateau finished for virtually instant break-in
Screw-in oil galley plugs installed in place of soft plugs
Rotating Assembly:
Hastings Moly rings
Keith Black hypereutectic pistons
Standard or 10-10 undersized journals on cast crank
Clevite bearings
Chevy 5.7'' heavy beam rods
Blacklight magnufluxed
Stress relieved and shot peened
Indexed and stroke corrected during grinding
Oil hole chamfered for improved flow
Super ''micro-polish'' for superior finish
The static compression ratio is calculated using different critical
measurements from the short block assembley, head gasket selection
and combustion chamber volume.
Calculators are available to do the hard work , all you need is exact
measurements for the following to get started:
Cylinder Head Volume
Piston Head Volume
Gasket Thickness
Gasket Bore
Cylinder Bore Diameter
Deck Clearance
Stroke
With these in hand go to one of the many online calculators to determine
the static compression ratio. Once the short block is built you can alter
head gasket specifications and combustion chamber volume to get the
compression ratio exactly where you want it.
Here's a link to the calculator that I use:
http://kb-silvolite.com/calc.php?action=comp
Seeing that this is a copy/paste from a Jegs catalog, there's no point of posting this in the Advanced Section.

Anyway, if you click on "details" in the catalog, it'll show the following:
# 383ci Short Block Assembly4-Bolt Main Block
# Flat Top Pistons
138-BP3830
Approximate Compression Ratio
58cc Chamber 11.11:1
64cc Chamber 10.38:1
68cc Chamber 9.96:1
72cc Chamber 9.57:1
76cc Chamber 9.21:1
Pretty straightforward.

Anyway, if you click on "details" in the catalog, it'll show the following:
# 383ci Short Block Assembly4-Bolt Main Block
# Flat Top Pistons
138-BP3830
Approximate Compression Ratio
58cc Chamber 11.11:1
64cc Chamber 10.38:1
68cc Chamber 9.96:1
72cc Chamber 9.57:1
76cc Chamber 9.21:1
Pretty straightforward.
oh ok cool, sorry i seem kinda dense, so if i wanted the 10.38:1 i'd go with the 64 cc heads then huh, should i consider the dome pistoned engine or the just stick with flat top, cause I'm not gonna be racing it i just want a diff. motor in it besides a 305 and every one has a 350,
oh ok cool, sorry i seem kinda dense, so if i wanted the 10.38:1 i'd go with the 64 cc heads then huh, should i consider the dome pistoned engine or the just stick with flat top, cause I'm not gonna be racing it i just want a diff. motor in it besides a 305 and every one has a 350,
According to the chart, 64-68cc heads will give you around a 10:1 SCR on the flat tops that come with the engine.
DCR? That's an entirely different issue.
Mike
Last edited by Kraest; Feb 14, 2007 at 09:52 AM.
ok, dense moment again, SCR, DCR??? I know the last part of that is Compression Ratio, but whats the S/D mean.
Also, this is gonna sound kinda stupid but it may not so here i go. Have any of you ever watched Supernatural.... is so the Impala on that show, I'd like to know which cam should I go with in order to get basically that sound?
Thanks for you help
Mike
Nick
Also, this is gonna sound kinda stupid but it may not so here i go. Have any of you ever watched Supernatural.... is so the Impala on that show, I'd like to know which cam should I go with in order to get basically that sound?
Thanks for you help
Mike
Nick
Static/Dynamic
Google them since I don't have the time to type it up.
http://www.empirenet.com/pkelley2/DynamicCR.html
Google them since I don't have the time to type it up.
http://www.empirenet.com/pkelley2/DynamicCR.html
oh ok cool, sorry i seem kinda dense, so if i wanted the 10.38:1 i'd go with the 64 cc heads then huh, should i consider the dome pistoned engine or the just stick with flat top, cause I'm not gonna be racing it i just want a diff. motor in it besides a 305 and every one has a 350,
Go with more compression and figure your DCR. Not over 9.0DCR. The DCR is dependant on the camohttp://www.empirenet.com/pkelley2/index.html[/EMAIL]http://www.empirenet.com/pkelley2/index.html
This will figure your DCR
This will figure your DCR
Last edited by 1racerdude; Feb 27, 2007 at 07:02 PM.
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