406 cam choice help
Hey guys i just bought a motor build off a friend and it came with two cams
RPM operating range 1600 - 5800
Duration advertised Inlet 268°, Exh 280°
Duration advertised @ .050" Inlet 224°, Exh 230°
Valve lift with 1.5 rocker Inlet .477", Exh .480"
Lobe separation angle 110°
Intake @Cam 3574 @Valve 536 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3694 @Valve 554
Rocker Arm Ratio 1.5
my questions is which one of these would be best to use or is there another recommendation you would choose?
not trying to get anyone to do my homework just thought I'd fish for opinions. my goal is to be above 500hp, just wanting to build a street friendly weekend warrior for my camaro.
build i have is
-camel back heads/2.02/3angle valve job/1.5 roller rockers/ported polished
and intake is port matched(single plane)/ and stud girdle
-electric water pump and fans.
-4:11 posi rear
thank you for any input guys.
whats "teeo" i'll get the info if i know. sorry i'm not the best gear head ... YET i'm working on it though
neither of the 2 mentioned.
I was typing from my phone
post info as to what you want as a finished product
If the heads are ported,you will likely reach peak power about 6300 RPM.The heads could mathematically make over 500 hp if you used a 6600 RPM solid roller cam. with close to .600 valve lift. single plane intake,big carb Good CR.9.75 ish good gas/ignition,good headers etc.Those heads have been ported to flow 250 cfm plus. then go for it
remember a 406 needs a bigger cam than what is usuallt advertised for a 350. A flat tappet hydraulic wont get you to 500 hp,with camel bumps,maybe 375-400
well the heads and intake were sent to afr and they did the valves(3angle valve and 2.02), port work and polishing. the guy i got this build from said they told him he should be in the 550hp to 600hp range.... i just dont beleive it. the cam they gave him works best with a 12:1 compression set up and the lower end currently is dished forged pistons with 9.5:1.... i definitly want a pump gas car
so with out buying a new set of heads any suggestions for this build? i do have some $ to play with but i'd hate to have to buy a whole new set of heads when these have'nt even been on a motor since all the work.
i mentioned what i have to work with in the 1st post and like i said i do have some $ to work with as well. i have the block apart right now as i was going to send it to the machine shop to get cleaned, cam bearings and hone job.
i just want to be anything over 500hp... just the goal i have in my head.
thanks guys, for non-gearhead fans like me these forums are a VERY helpful tool and the information you share is greatly appreciated.
I see you said the engine is apart,great!
Get the heads flow tested,find a shop with a flow bench.Bring back some numbers and pick a camshaft to fit your heads. The cam that is used for those heads wont be a hydraulic flat tappet. If you want a hydraulic roller,that will work ok.
look for a 540 lift (roller) that will rev 6400 or a solid roller that will rev 6600.
what exact intake do you have?
what size headers do you have? scattershield?
what kind of clutch?
If you're not going to dyno test this engine how will you ever know if it makes 500 hp or....???
Get the flow bench test on the heads. Make sure they use a radius shape on the intake port, when testing.
Just need the peak flow at high valve lift of 1 intake port. say @ .550" lift
Then need the port flow @.400" lift of one intake port.
You do not need to flow test all the ports.
one intake and one exhaust port is fine.
how much horsepower this motor can make can be determined by the head flow.
That is not the whole story, but the head flow test result start the process.
500hp out of a 406 SBC is not that hard to get but the heads must flow air.
Get your head around using a solid street roller cam + port matched vic JR or Performer rpm manifold
or a hurricane manifold
and 750cfm HP style carb and big headers.
plan on needing a 3000+ stall converter.
I have something in mind for you but need the head flow test.
The second camshaft numbers you posted are a Crane cam but your numbers are not complete.
What is the camshaft part number stamped on the end of the Crane cam.
From what I can tell it is a solid flat tappet cam and is capable of high power.
not a bad cam for a healthy street strip 4006 SBC
Need all the numbers from that cam.
The other cam is a waste of time. Its a dinky street cam.
if the camshaft you got is not brand new, you won;t be reusing it.
Do not reuse a used flat tappet camshaft.
you want a finished real compreession ratio of right about 10.50:1 for this street motor.
ya it matters. start by CCing the cylinder heads chamber volume. to get the true combustion chamber volume.
what is the casting number?
Again, the only way you will ever know if it makes 500 horsepower is to dyno test it.
Last edited by F-BIRD'88; 02-18-2013 at 03:00 PM.
well i do plan on taking it to bakers in grand rapids and having it tuned/dynoed but now i'm trying to wrap my head around your post lol ok so
casting numbers or block?
get the heads flow tested.
cam numbers, one had all this on it.
the other cam had
the second one listed is new and never used the 1st one is what the motor came with.
Its a healthy cam for a street strip 406. It makes great power from 3500 up.
It needs to be degreed in so its installed correctly amd you must use the correct valve springs with it.
Its a real good idea to first run it in at a reduced va;ve springs pressure so the new cam and solid lifters get a chance to get friendly with each other.
Generally that is done by just installing the outer spring of a dual coil valve spring set.
install the outer coil only, at its max allowable installed height ( no spring shims)
Then once it is all broke in reinstall the valve springs correctly at the required installed height.
be sue the ehads are machined correctly for guide boss, valve seal to retainer clearance @ full valve lift.
The stock chevy head will not be right.
This crane cam "saturday night special" (should be pn 110981 F252/3574-2S-6) Althou what you have posted is a partial crane grind number.
Is a good cam choice . Whether the engine will make exactly 500hp depends on a lot of factors.
Mostly the heads and the quality of the engine build.
It will make very good power.
It has a rough idle and needs a 10" 3500 stall converter at minimum.
works best on the street on 92 pump gas with a 10:1 to 10.5:1cr. Beyond that it gets dicey and may need better gas.
11:1 is too much for pump gas.
It will a make a ton of torque in a 406 for sure.
If I was building this motor and wanted to get 500hp+ from this 406 motor I would use the next bigger Crane cam in that "Saturday Night" cam series. (they are all very good cams) and I'm not building this motor.... you are ...
IMHO--- assuming the heads do flow well and you're going to be happy with say 485-490hp on the dyno then go for it. The dyno is the only way to really know for sure. Thats what they make dyno's for.
And it may well crack 500hp on the dyno. But the heads and the build will need to be good.
485 to 490hp is a lot of horsepower. (that is my Magic Squirrel prediction from this bunch of parts) You need to get the engine compression ratio correct
and the heads have to flow. No flow no go..
On that Crane cam set the valve lash cold @ .022"in .022" exhaust.
It will run very very strong, reguardless.
Crane Cams | Automotive Home Page
I had a very similar mechanical street roller in mind for you. They typically make a bit more power.
you can tell further once the head flow test is done.
What intake/carb etc pistons etc etc.
You do not want to build with excessive compression ratio for 92 pump gas.
Ya it matters.
I add this stuff to the oil for the break in. GM EOS (engine assembly lube)
www.molyslip.com The E oil supplement.
what is the casting number on the heads, between the valve springs.?
partial porting/pocket porting will not be enough. You need full effort porting to get to 500hp
The flow test will tell the tale. If they are short on flow there are many ways to correct that
including starting with a new better high flow cylinder head. Remember those are 50+years old.
Last edited by F-BIRD'88; 02-18-2013 at 06:50 PM.
I actually agree with fbird,I too would get the next bigger cam.It will idle rough and work well.I would use a single plane intake and 850 cfm carb,1 3/4 inch primary headers. If you have 4.10 gears keep them if not,go 4.30 or 4.56 depending on tire size.I would be hesitant to go much over 10:1
so how do i find the next size up cam? i really hope that wasn't a stupid question lol
guys you rock, thank you so much for sharing your knowledge.
the pic is the camaro this motor is going in
280hp will turn them into clouds of tire smoke.
Do you actually have a purpose for 500hp.... other than braging rights?
if you will not be using any tire better than those just build it.
as is as 10-15hp +/- will not make any difference.
it will smoke those tires at will reguardless.
And ya that is a stupid question. Look in the crane online catalog.
These Crane cams are powerfull. but will not work thru restrictive typical camaro exhaust.
You need long tube headers... and some sticky tires to make use of 485 to 500hp.
when that 406 eats the OD transmission replace with a th350.
It will. its just a matter of time.
nice looking camaro
Last edited by F-BIRD'88; 02-18-2013 at 07:56 PM.
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