440 6 Pack Camshaft Selection?

[LR1970]

Hi, any suggestions on camshaft selection for a 440 6 Pack. Does the six pack perform well with larger cams? I have a new 509 cam I was thinking of using.

Thanks

 

[65 Plymouth Satellite 426]

I Had A Comp Cams XL285HL .545/.545 Hydraulic In My Six-Pack Motor! Ran Like Hell!

 

[RustyRatRod]

Impossible to tell from the information you've provided. You have a 440 six pack. That's all we know. It could be a 7.5:1 motor or a 13.5:1 motor or anywhere in between. The camshaft requirements will be much different from one extreme to the other. Maybe include stuff like.....

Compression
Exhaust
Manual or auto
Converter stall if auto
Gear ratio
Type of car
Weight of car

 

[LR1970]

Thanks for the feedback, this is what I am planning.

72 Plymouth Roadrunner
440 +30 forged pistons
Howards Alum rods
Street ported 906 heads with OS valves
509 cam
Headers with 3 inch exhaust
Auto with 3000 stall
8 3/4 with 3.5 gears

I would like to run a 6 pack, but maybe I am better off using a dual quad with twin 600 Elelbrocks or a Performer RPM with 800 holley. 6 Pack is the most expensive set up so I was looking advice before I buy anything.

Thanks

 

[RustyRatRod]

Just a question. Why the aluminum rods? Also, the 509 cam is much too big for a 3.55 gear. The converter is about right but if you're dead set on the cam, you need at least a 4.10.

 

[Meep-Meep]

One thing to note is the six pack is a divided plenum dual plane intake and that design provides better signal to the carbs for improved streetability. I'm running a six pack now with the MoPar .455" / 272 cam and 10.1:1 compression and it runs pretty good on the street for just something I threw on. Throttle response is quite snappy!

Now, I did have a pretty bad track day with it last week but it's not because of the engine combo. I believe my carbs have issues (coming in too soon causing a huge bog) and will start diagnosing the problem and post the results. This problem was discovered with slicks, which put a big load on the engine, but with street tires I can't keep the wheels from spinning when the outboard carbs come in.

I believe you will be better off with a cam on the milder side to preserve good vacuum signal and keep the power in the range that best suits the intake. The super stock guys ran the special Weiand single plane six pack tunnel ram to better match the big cams for high RPM power. Or the STR 14-6.

 

[Meep-Meep]

Oh, and you may want to consult with this Armenian fellow about six pack cams. I understand he has a special grind he made up that works pretty well.
http://sixpacksixbbl.homestead.com/mrsixpackHOF.html

 

[LR1970]

Thanks for the input and advice. I went Alum rods because the rods that came with the engine looked tired so I decided to just buy new ones. They are a little lighter than stock so i might loose some touque. 3.5 gears because I am using 15 inch wheels with 60 tyres. This is a street car.

 

[Meep-Meep]

Aluminum rods on a street car? Curious. Everything I have read advises against that, but that's a different discussion.

 

[RustyRatRod]

Aluminum rods on a street car? Curious. Everything I have read advises against that, but that's a different discussion.

Kinda where I was goin...but yeah, I didn't wanna get into that and booger up the subject. Maybe the OP should start a thread about it and we can have at it. lol

 

[LR1970]

Just read this about Alum rods on the street.


http://www.enginebuildermag.com/Item/16280/connecting_rods_so_many_choices.aspx?page=2

On the street, old myths about aluminum rods are slow to die. Some say aluminum rods won’t last and must be replaced after 15,000 to 20,000 miles if they are used on the street. However, makers of aluminum rods say a set of high grade forged aluminum rods can last upwards of 100,000 miles in a street application. It all gets back to cost and weight. If a customer wants throttle response, or has a high revving engine, light rods of either aluminum or steel would be a good choice. But for a high torque, high load motor with a limited rpm range, steel rods would probably be better

I was after a fast reving engine with good throttle response, just need the cam and induction to go with it. I don't thrash my cars, don't understand why you would spend mega bucks on things and then trash them. 100 000 miles, I will replace the rods on my 175th birthday!

 

[LR1970]

New tread started about Alum rods

 

[Bigun426]

If the car is mainly going to be driven on the street use the stock HP cam from back in the day.It was the same grind as the 6 pack cam but the original 6 pack used different lifters. The factory engineers had it right the first time. Complement the set-up with HP exhaust manifolds ---- 2/12 in dual exhaust with H pipe---- a good modern ignition and the correct heat range spark plugs.

 

[Meep-Meep]

If the car is mainly going to be driven on the street use the stock HP cam from back in the day.It was the same grind as the 6 pack cam but the original 6 pack used different lifters. The factory engineers had it right the first time. Complement the set-up with HP exhaust manifolds ---- 2/12 in dual exhaust with H pipe---- a good modern ignition and the correct heat range spark plugs.

The original six pack cam lifter to lobe interface was a low taper. I believe this was to add more bearing surface contact for higher valve spring rates.