or if you have camshaft/engine building software program and dont mind typing in some info..
my software is not working..

i have or need the specs for this cam . I am wondering if i got it right..
Having a very hard time getting someone to grind it.. I was thinking if i change some numbers to make it easier to grind. I want to see if the new grind numbers makes a big difference.
or change...
if i have to change lobe profiles on this thing i want to see how much it hurts the power output.

368" smallblock
11.8-1 compression
solid mech roller

INTAKE DUR.......@ .050 268
eXHAUST DURATION @.050..272
INT LOBE LIFT...........294 1.6 ROCKER
EXHAUST LOBE LIFT.......313 1.5 ROCKER
LOBE SEPARATION.........108
INT CENTER LINE.........104
EXHAUST CENTERLINE......112
INSTALLED AT............102
VALVE LASH..............015

Are you sure about the lobe lift? 0.300 lift seems to be very, very low.

Looks like he confused the advertised durations with the lobe lifts. Also, it would be easier to say it's a 108 LSA and installed 6* advanced.

is this some kind of lift restricted engine?

That's kinda a hydraulic roller lobe with cam ground 4 degrees advance and installed 6 degrees advance. Somebody should be able grind it.

the heads are done at 450/.460" lift.
trying to get as much duration at max lift as possible.
it has offset pushrods on the intake and the rockers are offset.
the intake rockers are 1.6 ratio
the exhaust are 1.5 . Im trying to avoid buying new exhaust rockers as the 1.6 dont line up as well and the body on these have been modified to fit the shaft hold downs.. if i get new 1.6 exhaust ill have to order special one off rockers or try to modify a shelf 1.6 rocker..
i was just gonna keep the 1.5 exh rockers and make it up on the cam lobe the exhaust flows plenty in relation ship to the intake in terms of %.
Its only a lift rule based on the head flow. they are all done flowing on the intake side after .460 lift. fwiw.

ported iron J heads castings done up like a t/a
lift....Intake exhaust.... flow
200.. 125.08...100.30
300 .. 191.25...136.88
400 ,..244.80...153.4
450 .. 255.18...158.12
460 .. 257.20...159.30
500 .. 223.78...162.84
...................165.20
...................165.20
average flow on intake 213.79 (to .460" lift)
average flow on exhaust 141.60 (to .460" lift)
the exhaust computes to a 93% of the intake average


it has no pushrod pinch. intake window opened to remove pinch
and epoxy in the roof at the valve guide boss to get air to flow on both sides of the valve guide boss into the bowl.

294 cam lobe with a 1.6 rocker = 470.4" lobe lift
313 cam lobe with a 1.5 rocker = 469.5" lobe lift
with a .017 valve lash i will net 4.53" lift
the specs i posted are correct.
this will be a solid mechanical roller lifter

it seems getting big duration at such a low lift is the hard do. cam grinder wise..I am having trouble getting someone to grind this.
technically i am having trouble getting a core for a solid roller to start with...

when i say if i got it right..i mean will it work the best.
the spcs i have are correct. I am just not sure if they are the right specs to achieve what i want ..which is to hold the valve at max flow for as long as possible.

But you aren't going to have any duration at .460 valve lift with the cam that you are asking for. The tip of the roller nose has almost zero duration and then the valve starts closing again.

Just put a normal cam in there with 0.400 lobe and then you'll have a lot of duration at .460 valve lift.

Listen to andy, put a normal lobe in it and don't worry about it.

Seems odd though it loses that much flow after the peak especially with as much modification as you have done. I am not a fan of a J head but it should flow more than that higher than that.

Unless there is some rule about the heads we're not aware of, you should be able to get them to hang on better than that.

Not a roller, but NHRA dwell type lobes will hold the valve near peak lift for a long time, and they are available in those kinds of durations/lifts.

Two words:

Call Bullet

You're welcome....

if you want to see what lobes are available download "comp cams master lobe catalogue" then pick the lobes you want and have them grind it.

But I am with andy, I would lift it a little higher.

http://www.compcams.com/Technical/Catalogs/CamLobeMasterCatalog.pdf


Joe

Bullet has a couple NHRA stocker dwell type hyd roller lobes really close to those specs, and you can just run solid roller lifters on them.

I think the trick will be finding a semi-finished roller core that can accommodate that small of a lobe lift, without starting with an UGL core.

does anyone have a cam program they can run my cam through?
my software has a corruption.
the heads where built for a cam lift rule..yrs ago. i have another motor being built. i just want to put the heads back on this one so i can run it for the time being.
bullet needs a core . i tried to have callies make me one but they dropped the ball...already talking with bullet months ago.
i had a grinder in n/c through a nascar friend who was gonna grind it but we need a core to start with to get any duration.
i am trying to go with a roller to take advantage of the faster rates.

it will have more if i use a roller lifter and a lobe to maximise it.

i dont want to go past or too far past peak flow because i dont want to get into the stall/turbulence after peak.. it gets turbulent because the air speed was maximised pretty decent at low lifts.
the heads were ported to maximize low lift flow on the old valve lift rule of .485



I already did this with the last cam.

i had a solid tappit in it before with 250 duration but it was a .485 total lift. the motor was too peaky.. with poor average numbers. My thought was either go past max lift so the valve sees max flow twice .once on the way up and then on the way down..this was an attempt to keep velocity and flow through the peak.
but the motor didnt like it.. it had a very peaky power curve..


i am trying to see if i stay out of the turbulent lift range to see if the power is better across the board.


this new/latest attempt is to see if going the other way with this new proposed cam will make better numbers.

the car left very strong but just fell off pulling high gear for instance. My competitors always drove bye me in high gear.
i want to see if i can make it work better...mostly to just complete the thought/process of this motor.(the lift rule isnt a factor anymore..i just want to complete my original concept.)
I have another motor with aluminum heads there is no class limits on this motor but i will need different headers and change a bunch.. which will most likely take the car off the track for a long while fitting a new setup...

Are different heads, or trying to improve the high-lift flow of the current heads, an option? Otherwise, it sure seems like you're jumping through some hoops to crutch those heads with an oddball cam. Doesn't look cost effective to me.

i built this new cam on my old software. after computing it looked like it would be an improvement.
however my software is fubar right now.

when the cam grinder/cam shaft core builder kicked it back..
i want to see if i can tweek these last cam numbers to a profile that will not be soo difficult to grind or source.

we where sort of going after the dwell cams but with a solid roller.

Just seems like too much time & money when its not even a class requirement to follow. Not that I haven't gone off on my own tangent on occasion to prove something like this to myself, but those are also often the same things I look back on when all is said and done and ask myself: What was I freakin' thinking???