Looking for advice on a Cam for 426 Hemi

[70chall440]

As the title saying, I am looking for some advice on a cam for my 66 426 Hemi that is going into my 70 Roadrunner. The engine specs are

Bore: 4.305
Stoke: 3.750
CR: 10.4:1 (calculated)
Trans: 4 speed
Rearend: 8 3/4 w/3.55 (planned)

I am planning on running headers (Hooker or TTI). I have hydraulic lifters already, but am not necessarily tied to them. I would love to run a roller but a bit spendy. I will be running EFI on this engine.

I am not looking for max power, I am looking for drivability and reliability. This car is going to be more of a driver/hotrod than really anything else.

Any advice is appreciated.

 

[Lionized]

As the title saying, I am looking for some advice on a cam for my 66 426 Hemi that is going into my 70 Roadrunner. The engine specs are

Bore: 4.305
Stoke: 3.750
CR: 10.4:1 (calculated)
Trans: 4 speed
Rearend: 8 3/4 w/3.55 (planned)

I am planning on running headers (Hooker or TTI). I have hydraulic lifters already, but am not necessarily tied to them. I would love to run a roller but a bit spendy. I will be running EFI on this engine.

I am not looking for max power, I am looking for drivability and reliability. This car is going to be more of a driver/hotrod than really anything else.

Any advice is appreciated.

Do you have an intake selected already or will you be matching it with your cam selection?

 

[70chall440]

Sorry, I should have addressed that. Currently I have MP single 4BBL intake which currently I am planning to use. There is a possibility that I would go dual quad down the line which I know is a dramatic difference, but for right now I am planning on sticking to the single 4bbl intake.

 

[wyrmrider]

find your head flows somewhere and post
do you have the 66 adjustable rockers?
springs?

 

[70chall440]

Here are some numbers I found online, I have no idea if my heads flow close to this (I do have the 66 adjustable rockers)

426 street hemi head, 4.350 bore and clay radius tested at 28":

Lift Int. Ex.
100 85 70
200 154 128
300 231 170
400 285 205
500 308 230
600 315 240
700 320 236

 

[Lionized]

Sorry, I should have addressed that. Currently I have MP single 4BBL intake which currently I am planning to use. There is a possibility that I would go dual quad down the line which I know is a dramatic difference, but for right now I am planning on sticking to the single 4bbl intake.

If you plan to use that particular intake with FI make sure you mill the plenum divider about 1/4" - 3/8" to balance the air/fuel flow to both banks and not mess up your MAF readings. You could also use a carb spacer if you have the underhood space. Use the tallest you can.
As for a cam, here's one to consider:

https://www.lunatipower.com/voodoo-hydraulic-flat-tappet-cam-chrysler-426-hemi-268-276.html

 

[70chall440]

Great advice, thank you.

 

[wyrmrider]

I do not now if Mike has any street cams but his designs are state of the art
I just ordered one for our W2 circle track build
http://jonescams.com/street-performance/ (break if you sign up for speedtalk hot pass)
else if hyd or long life street try Engle
or pm Dart19666 (go over to fabo) at Crower (break for fbbo members)
There is also Jim at Racer Brown
it's not a sbc so good luck with the big grinders teck support
we are using beehive springs and edm lifters
you thinking of lash caps- good idea with 5/16 valves
if thinking roller post back

 

[70chall440]

I do not now if Mike has any street cams but his designs are state of the art
I just ordered one for our W2 circle track build
http://jonescams.com/street-performance/ (break if you sign up for speedtalk hot pass)
else if hyd or long life street try Engle
or pm Dart19666 (go over to fabo) at Crower (break for fbbo members)
There is also Jim at Racer Brown
it's not a sbc so good luck with the big grinders teck support
we are using beehive springs and edm lifters
you thinking of lash caps- good idea with 5/16 valves
if thinking roller post back

Thanks for the info, I will looking into those. I have not considered running lash caps

 

[wyrmrider]

I did not ask but is that a dual plane or a single plane manifold
lash caps help with the geometry if you go to a higher than stock lift cam
figure on half the increase in lift .050 for a + .100 lift cam
and they wear better and spread the load out on your rockers
viton stem seals if the heads are off and you are going to upgrade the springs etc or do a valve job

 

[70chall440]

It is a dual plane I believe, MP PN 4452034

 

[wyrmrider]

good choice for a driver
remember EFI does not like a lot of overlap
well most mopars don't
all the power gets blown out the exhaust, reversion, charge dilution
etc
30 degree intake seats? be sure and mention that
30 degree seats flow more at low lifts but are more prone to reversion
so you open the intake later
see what jones comes up with
he understand all the picky details

 

[HEMI-ITIS]

There are several people to consult,and then buy the valvetrain from them. PRH,Smothers Bros,Marsh Performance,Vignogna racing and Dave Dudek.All notable hemi guys you can't go wrong with.Go over your combo and let them make recs!

 

[toolmanmike]

Here's a video that might help you understand cams a bit more.

 

[HEMI-ITIS]

The vid may help but you should really talk to an expert about the entire package.They have built a **** ton of these and they would know bestest!

 

[toolmanmike]

The vid may help but you should really talk to an expert about the entire package.They have built a **** ton of these and they would know bestest!

True that. Quite a list of experts. We often don't know how knowledgeable the OP is. The video is a good place to start.

 

[HEMI-ITIS]

PRH has an edge because he is a porter with a good flowbench and has been doing this foreva!!!

 

[70chall440]

Thanks all. I do understand cams and how they work, I was however thinking that someone out there might have a good one that they have used previously.

 

[wyrmrider]

problem with experts is finding one that builds the application that you want to build
I relied on BIG JOE the late Joe Sherman for SBC cam advice= he built and dynoed many many over the years
I'd say I'm an expert on 413-440 Motorhomes and later 360 mtorhomes/ trucks/ marine
which translates to street daily driver builds
I did do some hemis and Stage v conversions but did not get into picking the customers cams much, some early fuel motors-so what
I did work on some road race 303s and 340s 50 years ago
make me an expert today?
I worked on round and round AMC's sort of a lost art tocay
did lots of machine work and listened to customers Buick head SBC all kinds of od ball stuff
Listening to the video
he is spot on on using flow for lift
using sound to pick
bigger is definately not better- luv it
so far nothing about the spring giving pressure back but in general he's right
agree with him on long rods
I do think rod ratio makes a difference on where you wet your valve events
say 318 vs 440 stroker are quite different (or 3" stroke 5.7 rod vs 383/ 400)
what he says about duration fitting to rpm range you need

 

[TetanusShot]

You mentioned choosing between Hooker & TTI. The TTI's are worth every penny.

I tried them both on my own '70 road runner with a megablock-based Hemi and Schumacher mounts. The 2 1/8" TTI's didn't even need any dents to clearance them.