HEY GRUMPYVETTE?
I,m building a 604 big block to put in my 1981 C3. Can you recommend a cam for this ( I'm in New Zealand )
Dart big M block 10.2" tall deck
Big Chief 18 deg heads
Hank the Crank 4.500" 4340 crank
BME 4.625" pistons
BME 6.800" rods
Dart tunnel ram with 2 x Barry Grant Demon 1095's
11.5:1 compression ( 96 octane pump gas )
Standard diff
Gearbox yet to be decided
Street use toy
Any idea on what sort of cam I should run ? solid, roller or hydraulic roller ? and what lift and duration ?:
ID like to know, some other factors than you listed,
like the the car weight,(with driver)
rear gear ratio,
transmission to be used,
cross sectional area, and length of the intake ports, in both the heads and intake manifold,
header length and diam.
, exhaust diam. and type of mufflers,
tire diam.
rocker ratio.
max spring bind and valve train clearances
spring load rates
max piston to valve clearances at TDC
piston dome height (IF ANY)
and if youll ever use nitrous?
then I can run it thru my notes and a couple software programs to narrow the choices down to a very limited range
but with a 4.5" stroke, and that displacement,and high port flow rates you won,t be spinning over about 6000rpm so a roller cam of some design is almost mandatory
BTW
NICE HEADS ETC.
http://www.dartheads.com/products/c...ig-block-chevy-heads/bbc-big-chief-heads.html
http://www.dartheads.com/products/i...anifolds/bbc-tunnel-ram-intake-manifolds.html
Thanks for the prompt reply.
Sorry if I apper a bit vague with some answers but have only just aqcuired the car which was imported from Japan by another person who due to finances sold it to me.
The car is pretty much standard and body wise will remain stock apart from being converted to right hand drive.
I dont know the diff ratio - its as it came.
I am collecting parts for the project as I go.
I havent decided what trans to use - probably a robust auto - TH 400 ? Any suggestions ?
I dont have headers yet nor exhaust but probably something like 2 1/8" and 3" pipes or so - again any suggestions?
Tyres will probably be something like 17" or 18 " with a fairly low profile tyre.
Rockers are shaft mounted Jesel 1.7 ratio ex and 1.75 ratio inlet
Pistons are flat top and again I dont know clearances.
I do not have springs yet as was waiting to match with cam etc.
Valves are 60 mm dia inlet and 48 mm ex
Head ports are 65mm x 45mm and 100mm long ( CNC ported )
Manifold ports are 65mm x 45 and 150mm long matched
No we wont be running nitrous
Thanks - they are nice heads
Sorry I cant give you any more info
Why do you say a roller cam needed ?
Appreciate your help
Thanks for the prompt reply.
Sorry if I appear a bit vague with some answers but have only just acquired the car which was imported from Japan by another person who due to finances sold it to me.
The car is pretty much standard and body wise will remain stock apart from being converted to right hand drive.
I don't know the diff ratio - its as it came.
I am collecting parts for the project as I go.
I haven't decided what trans to use - probably a robust auto - TH 400 ? Any suggestions ?
I doubt ANY th400 is going to hold up long, for street use Id be thinking
http://www.jericoperformance.com/jerico4.pdf
http://www.lencoracing.com/ST1200MasterPage.html
I don't have headers yet nor exhaust but probably something like 2 1/8" and 3" pipes or so - again any suggestions?
headers should be about 40" long x 2.25"primary and have about a 3.5" collector about 15" long
http://forum.grumpysperformance.com/viewtopic.php?f=56&t=185
Tyres will probably be something like 17" or 18 " with a fairly low profile tyre.
have fun getting traction...
Rockers are shaft mounted Jesel 1.7 ratio ex and 1.75 ratio inlet
Pistons are flat top and again I dont know clearances.
I do not have springs yet as was waiting to match with cam etc.
Valves are 60 mm dia inlet and 48 mm ex
Head ports are 65mm x 45mm and 100mm long ( CNC ported )
Manifold ports are 65mm x 45 and 150mm long matched
thats roughly 4.5sq inch at the ports enterence, and the port throats probably closer to 4 sq inches, the ports and 9.8" long runners, also will work at that rpm range
you can use these calculators but youll find the tq peak will be near 5000rpm so thats where the cam should produce peak torque on a STREET CAR
http://forum.grumpysperformance.com/viewtopic.php?f=52&t=796
http://www.wallaceracing.com/runnertorquecalc.php
http://www.wallaceracing.com/machcalc.php
http://www.rbracing-rsr.com/runnertorquecalc.html
http://www.wallaceracing.com/chokepoint.php
No we wont be running nitrous
Thanks - they are nice heads
Sorry I cant give you any more info
Why do you say a roller cam needed ?
because, theres no logical reason to buy true performance heads and then restrict the port flow significantly with a comparatively low lift flat tappet cam, and you get far more lift and duration from a hydraulic, or solid roller cam
heres CROWERS CONTACT LINK ID CALL THEM FOR A CAM SUGGESTION
http://www.crower.com/misc/contact.shtml
but for what your trying to do ID sure make it plain and clear this is to be driven on the street, where max long term durability is the key factor and youll be expecting well over 760-800hp plus , have max torque and to not exceed 6000-6300rpm, to maximize the engine longevity by much (obviously you could get far more peak hp but its basically useless with the tires your thinking of running and the potential torque you could produce)
your engine should easily exceed these hp/torque numbers, (below) by over 100hp with its better heads etc.
without knowing the rear gears or tire diam. I could only give a rough guess on the cam, but Id probably be looking at something with about a 264/270 duration @.050 lift on a 110-112lsa and a 680-700 lift, as that gives the best compromise between hp/tq and allows use of pump octane fuel.
http://www.ultrastreet.net/engines/632_bigdawg.asp
http://www.ultrastreet.net/engines/598_lowdeck.asp
I,m building a 604 big block to put in my 1981 C3. Can you recommend a cam for this ( I'm in New Zealand )
Dart big M block 10.2" tall deck
Big Chief 18 deg heads
Hank the Crank 4.500" 4340 crank
BME 4.625" pistons
BME 6.800" rods
Dart tunnel ram with 2 x Barry Grant Demon 1095's
11.5:1 compression ( 96 octane pump gas )
Standard diff
Gearbox yet to be decided
Street use toy
Any idea on what sort of cam I should run ? solid, roller or hydraulic roller ? and what lift and duration ?:
ID like to know, some other factors than you listed,
like the the car weight,(with driver)
rear gear ratio,
transmission to be used,
cross sectional area, and length of the intake ports, in both the heads and intake manifold,
header length and diam.
, exhaust diam. and type of mufflers,
tire diam.
rocker ratio.
max spring bind and valve train clearances
spring load rates
max piston to valve clearances at TDC
piston dome height (IF ANY)
and if youll ever use nitrous?
then I can run it thru my notes and a couple software programs to narrow the choices down to a very limited range
but with a 4.5" stroke, and that displacement,and high port flow rates you won,t be spinning over about 6000rpm so a roller cam of some design is almost mandatory
BTW
NICE HEADS ETC.
http://www.dartheads.com/products/c...ig-block-chevy-heads/bbc-big-chief-heads.html
http://www.dartheads.com/products/i...anifolds/bbc-tunnel-ram-intake-manifolds.html
Thanks for the prompt reply.
Sorry if I apper a bit vague with some answers but have only just aqcuired the car which was imported from Japan by another person who due to finances sold it to me.
The car is pretty much standard and body wise will remain stock apart from being converted to right hand drive.
I dont know the diff ratio - its as it came.
I am collecting parts for the project as I go.
I havent decided what trans to use - probably a robust auto - TH 400 ? Any suggestions ?
I dont have headers yet nor exhaust but probably something like 2 1/8" and 3" pipes or so - again any suggestions?
Tyres will probably be something like 17" or 18 " with a fairly low profile tyre.
Rockers are shaft mounted Jesel 1.7 ratio ex and 1.75 ratio inlet
Pistons are flat top and again I dont know clearances.
I do not have springs yet as was waiting to match with cam etc.
Valves are 60 mm dia inlet and 48 mm ex
Head ports are 65mm x 45mm and 100mm long ( CNC ported )
Manifold ports are 65mm x 45 and 150mm long matched
No we wont be running nitrous
Thanks - they are nice heads
Sorry I cant give you any more info
Why do you say a roller cam needed ?
Appreciate your help
Thanks for the prompt reply.
Sorry if I appear a bit vague with some answers but have only just acquired the car which was imported from Japan by another person who due to finances sold it to me.
The car is pretty much standard and body wise will remain stock apart from being converted to right hand drive.
I don't know the diff ratio - its as it came.
I am collecting parts for the project as I go.
I haven't decided what trans to use - probably a robust auto - TH 400 ? Any suggestions ?
I doubt ANY th400 is going to hold up long, for street use Id be thinking
http://www.jericoperformance.com/jerico4.pdf
http://www.lencoracing.com/ST1200MasterPage.html
I don't have headers yet nor exhaust but probably something like 2 1/8" and 3" pipes or so - again any suggestions?
headers should be about 40" long x 2.25"primary and have about a 3.5" collector about 15" long
http://forum.grumpysperformance.com/viewtopic.php?f=56&t=185
Tyres will probably be something like 17" or 18 " with a fairly low profile tyre.
have fun getting traction...
Rockers are shaft mounted Jesel 1.7 ratio ex and 1.75 ratio inlet
Pistons are flat top and again I dont know clearances.
I do not have springs yet as was waiting to match with cam etc.
Valves are 60 mm dia inlet and 48 mm ex
Head ports are 65mm x 45mm and 100mm long ( CNC ported )
Manifold ports are 65mm x 45 and 150mm long matched
thats roughly 4.5sq inch at the ports enterence, and the port throats probably closer to 4 sq inches, the ports and 9.8" long runners, also will work at that rpm range
you can use these calculators but youll find the tq peak will be near 5000rpm so thats where the cam should produce peak torque on a STREET CAR
http://forum.grumpysperformance.com/viewtopic.php?f=52&t=796
http://www.wallaceracing.com/runnertorquecalc.php
http://www.wallaceracing.com/machcalc.php
http://www.rbracing-rsr.com/runnertorquecalc.html
http://www.wallaceracing.com/chokepoint.php
No we wont be running nitrous
Thanks - they are nice heads
Sorry I cant give you any more info
Why do you say a roller cam needed ?
because, theres no logical reason to buy true performance heads and then restrict the port flow significantly with a comparatively low lift flat tappet cam, and you get far more lift and duration from a hydraulic, or solid roller cam
heres CROWERS CONTACT LINK ID CALL THEM FOR A CAM SUGGESTION
http://www.crower.com/misc/contact.shtml
but for what your trying to do ID sure make it plain and clear this is to be driven on the street, where max long term durability is the key factor and youll be expecting well over 760-800hp plus , have max torque and to not exceed 6000-6300rpm, to maximize the engine longevity by much (obviously you could get far more peak hp but its basically useless with the tires your thinking of running and the potential torque you could produce)
your engine should easily exceed these hp/torque numbers, (below) by over 100hp with its better heads etc.
without knowing the rear gears or tire diam. I could only give a rough guess on the cam, but Id probably be looking at something with about a 264/270 duration @.050 lift on a 110-112lsa and a 680-700 lift, as that gives the best compromise between hp/tq and allows use of pump octane fuel.
http://www.ultrastreet.net/engines/632_bigdawg.asp
http://www.ultrastreet.net/engines/598_lowdeck.asp