440 6pk Cam Selection Tips

Just wanted to pick the brain of the camshaft gurus please. I am currently building a 440 .030 over 10.5 CR and will be topping it off with some Trickflow 240 heads and the 6pk setup. Backed by a 727 and 3.55 gears or 3.23 not sure yet. The car will mainly be a street cuiser, It's got a 22-2500 stall, I would like good street manners, ease of tuning that idle AFR, broad torque range but an engine that will be respectable in the 6k+ range. I want to take advantage of the excellent trickflow airflow. I will be using a Solid Flat Tappet cam. As is my preference. I am looking for suggestions since I will be having the cam custom ground. Here's what I am thinking so far;

550 lift In/Ex
112 LSA?? I am aiming for ease of tuneability of the 6PK
230-236 @.050 duration?? Not sure if that's too much
What should the overlap be? Mid 60's??
Any other spec I should be considering?

Honestly I am still learning the effects of LSA, overlap. I have read multiple articles, most apply to Chevy SBC and I have an understanding how much the cylinder head combustion chamber plays a roll in all this so the few Mopar big block info available obviously uses the wedge head design thus changing the data vs the heart shape of the TF. Or I may just be overthinking it.

I intend to use Engle to grind the cam, I have had great experience with them in the past. They usually offer great advice but it's the weekend and theyre close so I thought I would get a leg up on advice during the weekend.

Thank you

The most important thing is Headers or manifolds, that has EVERYTHING to do with the right cam

My apologies I failed to mention that, Edelbrock 6pk manifold and long tube headers

Call Mr Porter & have him get you a cam, he is VERY smart & sells cams fast68plymouth is his user name

Thanks for the tip

Closer LSA will give you more bottom end, wider will help make them idle smoother with more intake manifold vacuum at idle, if that is what you want.
Does your car have power brakes? If so that is a concern also
The last six pack street pump gas motor I built for myself had a solid roller cam with 260 degrees duration at .050 intake valve lift with .420 lobe lift, the exhausts lobe had 266 degrees @ .050 with .409 lobe lift. I ended up switching the rocker arms from the 1.5 ratio to 1.6 ratio Harland Sharp aluminum roller rocker set up
I built that motor, 505 C.I. 400 blocs, to race on the streets in Los Angles, which I didn't get to do before getting that car finished
It was fats, 9.993 ET at 134.8 MPH in the 1/4 mile corked up with full 3.0 inch exhaust system on it exiting at the rear bumper
Are you using stock vacuum carbs or after market mechanicals?
If using stock type vacuum carbs use the outer carbs idle mixture screws in the base plates to help get the idle fuel mixtures set for the best idle, all the stock ones I've work on like from 1/4 to 1/3 a turn out from gently bottomed
I would use the center carb for the final fine tuning and setting the idle speed
IHTHs

Thanks for the tips,
Yes it is power brakes and I would like enough engine vacuum to be able to operate them properly. Surprisingly the previous unknown cam only produced 10 inches of vacuum and it worked well but that was with a single 4bbl setup.

The outboard carbs are factory VS. and I already have the parts necessary to be able to tune them properly, the baseplates and the metering plate jet kits.

Your car sounds like a wicked setup. I already got my drag racing cars I want this to be a great cruiser but I want the idle sound of the 383 HiPo for reference for this setup

https://www.forbbodiesonly.com/moparforum/threads/bob-karakashian.154501/

Yup I’ve already talked to Bob a few times. Problem is that he doesn’t have any cores to have a cam grounded from. It’s been a few weeks since I talked to him I could reach out again to see if anything has changed.

Spoke to him a couple of weeks or so ago, he was expecting some cores, didn't know when yet. Don't have an update yet.

[hi

what about the ols mopar 284 /528 makes appp 16 in vac would prob do every thing you listed .

i've got an engle/hughs 30/38 (230/.515 intake/238/.538 exhaust) i won't be using. it's a hydraulic rather than solid. i've used the engle k65 solid for years. it's 238/.510 lift.

On my 440-6, I went with a hyd. flat tappet cam with about 250 degrees of duration (@.050") and .550 lift. I ran long tube headers as well. What made a HUGE difference was having the carbs dialed in by someone who specifically knows six pack systems really well. Most of us know how to change, jets and power valves, but there are guys out there who know what factory 3x2 systems need to work with a bigger cam. I had a NHRA Sportsman Class guy do mine, and it was night and day.

As far as your camshaft goes, the duration on the camshaft is what forms your power-band. You're running good heads that can easily take advantage of more duration than you're wanting to run. The limiting factor in your combination (as it relates to a cam choice) appears to be your stall speed. With 2000-2500 rpm stall (perfect for the street) I think you're going to want a camshaft with between 230-240 duration at .050" lift on a 440. Any more duation and I think you may need more stall to match.
I agree an LSA of 112 may be a good choice for your power brakes. A general rule of thumb is that the tighter the LSA (bigger number) the more tame your idle characteristics will become and more engine vacuum you'll produce. So an LSA of 112 will idle smoother than say a wider LSA of 108 degrees.

Don't spread misinformation about LSA, Lobe separation angles means when the cam lobe is at max lift from TDC, the same lobes ground on 104 LSA will have a lot rougher idle with less manifold vacuum than a cam with the same lobes ground on a 112 LSA due to less over lap at TDC on the wider LSA
Another change by widening or tightening or widening the LSA with the same lobes is generally tighter makes more bottom end losing top end power and wider loses bottom end while gaining more power higher in the RPM band.
Poor flowing heads like tighter LSA to benefit the bottom end and better heads can use wider LSA with more duration and lift to allow the motor to make peak HP at a higher RPM. Don't forget that the lobe design and how much lift and duration as well a LSA need to be optimized to get the best results from any motor and combination of race parts or street and strip parts

a tighter lsa number will have more overlap (rougher idle, less vacuum) than a wider lsa number. a 110lsa seems to be the accepted sweet spot for most performance cams but that doesn't mean it's ideal for all situations. a lot of variables here and being a street build some compromise will probably have to be done. personally i don't like "hot" cams for street use (they can be a nuisance) but some folks love'em. i can try to post some engle blue sheet profiles if needed. one thing for sure about engles is don't try to do a direct comparison with a comp cams grind.

Lobe seperation angle has nothing to do with tdc.It is how many degrees the intake and exhaust lobes centers are apart from each other.

Come on now, what does LSA measure from
A cam ground on 104 LSA means that maximum lift on both lobes (as long as both lobes are equal in duration and symmetrical lobes) is at 104 degrees before top dead center on the exhaust lobes and 104 degrees after top dead center, correct?
If the same lobes are ground on a 110 LSA then max lift occurs at 110 degrees before and after TDC, correct In that situation (wider lobe separation angles) the amount of valve opening overlap at TDC is reduce which in many cases affect idle vacuum and the HP and torque curves
You are correct on the camshaft having nothing to do with the crankshaft and pistons at TDC other than TDC on the crankshaft is used in designing the cams to work the best for the application they are design for, stock or all out racing cams, the camshaft degrees are used in relation to the crankshaft but the cam travels half as fast as the crank does due to most modern motors are four stroke engines so the cam has to open and close both valves over 720 degrees of crankshaft degrees in relation to top dead center and bottom dead center for one complete power cycle, correct?
Details are important, correct

Lobe separation angle is simply the angle between the the lobe centers.

Where those occur with relation to tdc is up to the engine builder.
The amount of overlap is directly related to LSA and cannot be changed.
Again, all that can be dictated by the builder is the timing of the events.

Exactly. Nothing more, nothing less.

The lobe separation angle is the only cam duration spec that is given in camshaft degrees.

It is not directly linked to the installed “centerline”......... which will end up where the assembler puts it.

Agree, I messaged you regarding your help for a custom cam.

In relation to what ?

LSA isn't in relation to anything else. The LSA exists even if the camshaft is sitting in a box or on the bench.

Nothing, that's it

Cab,

With all do respect, I'm certainly not intentionally spreading misinformation about camshaft characteristics. However, I did make a mistake, and I think it's causing the confusion. In my simple example, I should have said: "A general rule of thumb is that the Wider the LSA (bigger number) the more tame your idle characteristics will become and more engine vacuum you'll produce. So an LSA of 112 will idle smoother than say a Tighter LSA of 108 degrees." My mistake was that I confused the terms Tighter and Wider.


Other than that, I don't see any conflict in the information I've provided the topic starter and the information you provided. I hope this helps clear things up. Sorry for any confusion.

-Dan

From the centerline of one lobe to the other. Thats it.

Something around 239/243 @.050 and .620/.620 gross lift (1.6:1 rockers) would work really nice and let you get the heads to breathe.

I would run a 109 lobe center in maybe at +2 (107 ICL)

Something like the old Ultradyne NF70/NF62 .904 (Chrysler lobe)

This would give you a nice 162/164 degrees @.200 but mild seat to seat so the idle will be sweet.

I think Bullet still grinds the old Harold U/D cams

A solid flat tappet adjusted for lash is about 8-10 degrees smaller at .050 than a hydraulic so this is really a pretty mild cam. that's only 23 degrees of @.050 overlap if my math is still good, lol. With a dual plane six pack and headers that's about perfect.


EDIT:

This Hughes grind is dead on what I would consider picking:




Category : D- Big Block (Low Deck) : Camshaft : Flat Tappet, Solid


HUG STL3842BS3-9

BB SLD FLAT TAPPET CAM 238/242 -109ºLSA

3 BOLT .372"/.376" LOBE LIFT

$241.35


Flat tappet solid big block "B/RB" camshaft.

Hughes "real" Chrysler cam

All of our big block solid cams are three bolt.

Basic guidelines (These are not absolutes, just guidelines to help you get close on a cam choice)
Use: Street Performance, high rise dual plane intake & headers. Mildly ported cylinder heads
Idle: Noticable
Converter: 3000 stall +
Rear gear: 3.55+