Bigish cam, big motor- BIG redline?

I have a 440, ductile iron main caps, block girlde, 440 source stroker kit- 4.5" stroke. 540" motor.
10.5 to 1 compression
cleaned up Victor heads
MSD igniton locked out at 34*
Single plane intake
electric water pump (only pulley turning is the alternator)
TEMPORARY 870 Vaccum secondaries holley (waiting on Holley EFI)
large stepped headers

Cam is a Crane solid roller, .684 lift at rocker with 1.5 rocker, 324* adv duration says minimum rpm 5000, max 8500

Car is a 68 barracuda, 4 speed 18 spline with 4.10 dana 60. tire is a MT ET street 30 x 12.5

What should I spin this motor to? I really am not looking to kick a rod out of the block, but man this thing doesnt come on untill 5k driving it around on the street.

This is a race car that is street driven ( I would go much smaller and more tame if I were do it again)

With a 4.5" stroke, you've really got some piston speed there...
Hope you have some good rods (and rod bolts!)

Give us the lobe duration at .050 lobe lift and the lobe centers, LSA, and were you installed the intake lobes please.
Are the Victor heads 440 port size or Max wedge intake port size?
how about spring pressures on the seats and open pressures

I'm a firm believer in using the good old butt dyno tach, when the motor quits pulling hard shift it
Use the butt impression first and then look at the tach.
Which brand and style and center to center length are the rods?

here is the cam card
heads are standard port- springs match cam card

Holy crap...284/284 @0.050"!!!

Wow, I honestly thought something hir hairy was "race car only territory" stuff.

Then again, I am sporting a 240/248 in a 408" stroker meant for 95% street use.

I you simply take the cam card rpm values and adjust the to the cubic ratio 440/540, the numbers would be 4,000 to 6,700, FWIW

Yeah that combination would be almost undriveable on the street with 284 duration at 0.050 and a four speed. The problem with that combination is that the cam doesn't turn on until around 5000 rpm but you can't spin it much past 7000 rpm so you have a very narrow power band. You would probably be a lot happier if the duration was 20 degrees smaller.

People used to use big huge cams like that with old 906 heads but a Victor head shouldn't require that much cam, even in a 540 unless it is a high rpm drag race only application. A bracket car with a trans brake and a 5500 stall converter would work pretty well with that cam but a street car with a four speed is going to be a nightmare. Every time you leave a stop light you'll be slipping the clutch since there will be almost zero torque at anything below 2000 rpm.

I am street driving it now. Just got it all together (the car) and am working out the bugs. It isnt bad from a stop actually. Im sure the 4.10s help that out. but cruising under 3k you feel the lope of the cam, LOL! I can just let the clutch out from idle (1100 rpms) and as long as I go slow the car wont stall. But i do agree its bigger than I need. But it is what I have.

Just wodnering what RPM MAX this should go to.

Looks a lot like what we used in the 70’s in Super Stock.
Smaller in lift than the popular Cam Dynamics R-286 which was .750” at the valve with stock 906 heads. Used the then popular 069J B & M converter which flashed around 4500.

With the stock heads they started to lose power around 6600. Not sure how much better your heads are.

set the shift light to 6600, redline 7200, set the rev limiter to 7500. my And running a 284 @.050 on the street isn't the end of the world sounds about right if you want to go fast. As you seem to have found out it will idle and drive. Just keep the right side up.

You could run it on a chassis dyno to figure out ideal shift point.

5k-7k. Sounds right to me.
FWIW...my 575" hemi w/ a 276/284 at .050" cam runs 5000-7200 or so.

I will be on the dyno, but I want to get my EFI on first and start dialing in some of that. Also I have a few small things to fix before that too. Small oil leaks here and there.

I agree with CAB, butt dyno and et slip. It shouldn't take more than 4 or 5 passes to find your sweet spot. I would start your shift rpm at about 6500 and keep moving it up until you get your best et and speed. Trust what your car likes not numbers from a dyno.

With a Stock block 4.500 stroke, and stock main caps, I wouldn't be spinning the thing over 6000rpm.

7000

Of course you can experiment at the track but if you have a power curve from a dyno you can calculate ideal shift points and see if you need to make changes in order to keep it in max average horsepower. Altering the engine combination or gearing if need be.

Why bother

I run a 285@.050" cam in my racecar. 572" it likes 6900. My bet is yours will want more.
Doug

IMHO your biggest problem is trying to shift an 18 spline gear box at 7 grand. been through that.

It might shift once before it blows apart.

stock block, cast iron 2bolt caps, big rpm and power, manual tranny;......what could possibly go wrong?

284@.050 is a big-“ish” cam?

I would have though that easily qualified as a straight up “big” cam.

Especially with 10.5:1CR.

FWIW I agree. That much cam and 10.5 compression? You could run thirty degrees less duration and probably go faster. Todd

a lot of the parts came slowly. I bought this and that. I never had a clear or distinct direction i wanted to go with the build. AND this is what i ended up with.

Im sure a differnet cam (smaller) WOULD HELP, but i dont have one right now.

We will see what happens as I tidy up small things on the car.

Right now I cannot shift (1/2) above 5k, it just wont go into gear. Has no problem doing the 2/3 shift and I haven't tried the 3/4 at any real rpms.

A friend of mine had a ranchero years ago with an Blown alcohol injected hemi and a (a833) 4 speed. It was deep in the 8s. The trans held up as long as he didnt power shift or dump the clutch off the line. He routinely would run mid 9's taking it "easy". He also drove this on the street. But a hard launch would strip the main shaft IIRC.

I’m sure we’ll all enjoy the track reports

LOL... Im sure you all will. Ill try to get good pictures too. HAHAHA, carnage is loved by all.... except those waiting to go after me.

Sounds like you have street clutch disc with the wave spring in between the two discs that expands the higher you rev it
If that is the case swap it out for a race disc that is designed and built to be rev above 5000 RPM and still shift
Been there, done that

Hmm, never heard of a marcel spring dragging a clutch at high rpm.

I have seen some aluminum flywheels flex enough at high rpm to engage the clutch. Would not have thought that possible until swapping a few cars back to steel which cured it.

I am not even sure what brand it truly is. I bought it from american powertrain years ago before they sold centerforce. I feel like at the time they called it "science friction" Maybe Ill give them a call, but in the past, ordering other parts for my swap I was not too impressed with their knowledge of their own products or customer service.


This is the only picture I have of it.

I can see the pressure plate and flywheel fine, not so much on the disc

Here it is. Last one on the page. Dual discs. https://americanpowertrain.com/clutches/

Farq

So how many sheckles dose one of them cost?

And yes since I asked, most likely I cant afford it lols

I honestly do not remember what I spent on it.
But I also got the hydraulic throw out bearing and master for it

That clutch is a parts breaker. Marketing nonsense must sell clutches because I have never used a clutch based on how much horsepower a bean counter thinks it will hold.

Care to elaborate? Or just an opinion based on gut feeling???

Look into soft lock clutches. What you have is a 2 ton toggle switch that beats everything behind it to death. You need to control the application of the clutch or it will break parts. And yes, you can use a soft lock on the street.

so far on street only use, the thing engages like a single disc clutch. Easy to get it rolling from a stop, no over revving it, soft enaggement. I wouldnt know it is a twin disc setup just by driving it. With the hydo TO bearing it is super easy to push in and easy to feather. I would say my Honda (almost 500 WHP) has a stiffer clutch than this.