Cam choices for 500ci+ RB

[SlinktRR]

I'm in the planning stages for a new build. Right now I have two motors. The 71 383hp is complete, in the car and is mostly stock other than the MP cam that's in it. I bought this used a few years back and it runs great, solid street engine. I took the stroked 440 short block (no heads, needed rebuild) that was in the car out and replaced it with the running 383, idea being to build the 440 at some point. 2015 is that time.

1969 440 bored 0.050" over
4.25" stroke crankshaft
MP P4529427 flat tops (400 0.030 over pistons)
3000 stall converter
manual brakes
1 7/8 Hooker headers, 2.5" pipes

I want to use either a solid or hydraulic flat tappet to keep things manageable on cost. Heads will be either 915 iron or the trick flow 240 78cc's which are coming out soon. I have been looking at the holley street dominator intake so I can keep hood clearance with the 70 air grabber, carb is open at this point.

This is my short list of cams:
1) Voodoo 60304 276/284 .513/.531 110 LSA
2) Comp XE285HL 285/297 .545/.545 110 LSA
3) MP528 284/284 .528/.528 112 LSA

Would like to see what other cams are out there. Not planning to track the car but would definitely like more torque than I have now. How much lift can I afford with the pistons I have? Wouldn't be averse to buying new pistons either, but trying to use what I have if possible. Looking for 10+ inches vacuum and mid range power.

 

[mentor70]

you have some tough perimeters to work around.

70 hood clearances stink.

first of i think your cam choices are a little on the small side for a 500.

you will need to lock down your desired fuel choice, cylinder head choice to really nail down the combo.

personally, i wouldn't even consider an OE head for a 500, just not enough flow to really make it worth your while.

my last 500 had Edelbrock RPM heads, and a cam similar to the 509, with Ross flat tops, ended up with a mechanical compression of 11.5, and running cylinder pressures that didnt like Cali pump 91.

ended up going with a large Hughes mechanical to fix that issue, the mechanical compression supported the larger cam with no drama at all, serious hard core idle!

my current build is a stock stroke 440, Stealth heads,, CNCed by Hughes with that Comp cam you have on your prospect list. should have the same HP as my 500, with 80-100 less lbs of torque.

 

[m79ded]

Big inch motors need lots of cam and good flow on the heads, unless you gut up those 915 and spend lots$$$ you will be holding back the potential. I absolutely agree with Mentor, get a set of Eddy's or stealth heads and work them over you will be glad you did, but not your tires LOL!!!!!!!!!!!

As far as cam goes go for something in the 240 @50 you need it.
This is a good choice for a motor like yours:
Part Number: 32208
Mopar Hydraulic Flat Tappet Camshaft
Crower Cams
Chrysler/Dodge/Mopar - 350, 361, 383, 400, 413, 426 & 440B
Performance level 4 - Hi-Draulic Hauler - Extremely violent mid-range and top end horsepower.
INT/EXH - Dur @ .050” Lift: 249°/253° RR: 1.5/1.5 Gross Lift: .530”/.546” LSA: 108° RPM: 3200 to 6500 Redline: 6500

Or you can call Bullet Cams or Cam Motion Both are great cam companies, this way you get a cam to fit you application.

 

[IQ52]

What is the compression height of those P4529427 pistons, what length rod? Or can you just measure the deck height if the short block is together?

The Trick Flow head is supposed to come CNC ported and would a far better choice than the 915.

 

[Bigal75]

Wait for the TF heads and then have a custom solid lifter cam ground for your combo. Does it have to run on 91 octane or can you afford to mix fuel? I found that the local airport sells ll100 for not much more than super unleaded so I mix that in and everything is happy.

 

[SlinktRR]

Thanks everyone. IQ, the compression height is 1.825" and the pistons are 0.030" down at TDC. I ran it through the calculator and it should be around 10.5 compression with 915 heads. Big Al, I'm planning to run 93 octane, but I didn't know you could get 100 away from the racetrack. Will look at that for sure.

Thanks m79, I'm going to check out some cams based on the specs you posted.

 

[IQ52]

Pretty sure you will have to flycut the pistons for piston to valve clearance, especially with the Trick Flow 2.19/1.81 valves. And everyone of the cams mentioned will be on the verge of or into detonation with your proposed combinations.

 

[MOPOWER871]

Im running a stroked 440 (493) edelbrock rpm heads 84cc , hydlalic roller cam , 3000 stall,my final compression ratio is 9:7.1 this cam works well for me can drive it all day long on todays pump gas. It a crane pt #689531 /HR-230/352-25-12 this is the cam card

 

[HEMI-ITIS]

If you don't have heads or a cam, I would talk to Dwayne porter or Muscle mike in NJ. They have done this HUNDREDS of times and know the deal!

 

[SlinktRR]

Now looking at the following two based on rec to see if I can run on 93 at 10.5 CR. Am I on the right track?

1) Hughes solid HTL3742BS Intake/exh @.050 237/242 Lift 0.534/0.543 109 LSA
2) Crower hydraulic 32207 Intake/exh @ .050 238/249 Lift 0.528/0.552 108 LSA

I can still opt for edelbrock 84cc's to lower the compression if needed, thanks mopower. HEMI-ITIS is muscle mikes shop the one in Lodi?

 

[m79ded]

I found a thread that is interesting reading for you.
BTW the Crower cam is a better choice


http://www.forbbodiesonly.com/moparforum/showthread.php?27404-Help-with-cam-choice-500-quot-RB

 

[HT413]

Hey will, have you run your combo and cam through Wallace's calculator to figure the dynamic compression ratio? Sure helped me to get my head closer to where it needed to be... http://www.wallaceracing.com/dynamic-cr.php

Also, in comp's website there is a link to their camquest software. Not sure there is an option for that stroker beast though.

 

[IQ52]

Now looking at the following two based on rec to see if I can run on 93 at 10.5 CR. Am I on the right track?

1) Hughes solid HTL3742BS Intake/exh @.050 237/242 Lift 0.534/0.543 109 LSA
2) Crower hydraulic 32207 Intake/exh @ .050 238/249 Lift 0.528/0.552 108 LSA

I can still opt for edelbrock 84cc's to lower the compression if needed, thanks mopower. HEMI-ITIS is muscle mikes shop the one in Lodi?

I believe you are going in the wrong direction. But you are getting plenty enough advise and I am muddying the waters...........I'm out.

 

[lewtot184]

I believe you are going in the wrong direction. But you are getting plenty enough advise and I am muddying the waters...........I'm out.

these types of posts always lead in one direction and i don't blame you for bugging out. people don't understand valve timing.

 

[SlinktRR]

I believe you are going in the wrong direction. But you are getting plenty enough advise and I am muddying the waters...........I'm out.

I really appreciate the feedback, the good thing is I have time to change direction. One of the (many) parts I'm missing is what cam specs affect dynamic compression and cylinder pressure the most, that's what I'm reading on and using the calculators for. Going through the process will hopefully get me enough information for when I go to the machine shop and builder to get the right setup. I'm trying to take the time to plan as much as possible before I take the block to the shop and start getting things moving.

 

[HT413]

Intake closing event is what affects dynamic. The intake valve is open during the intake stroke but is not fully seated as the piston begins to travel upward away from BDC during the compression stroke. The cylinder cannot begin to build pressure until the valve is closed, instead the intake charge direction is reversed and is blown right back out into the intake. At high RPM this reversion is minimized because the intake airmass has so much momentum it can't be stopped, which is why late intake closing events favor high rpm's and early intake closing events favor lower rpm performance. The sooner the valve closes after BDC, the higher the dynamic compression ratio.

Comp has a great little tutorial.

http://www.compcams.com/Pages/416/valve-timing-tutorial.aspx

 

[Kern Dog]

It is good that you are doing research on all this. The mistakes one can make at this point really affect the amount of trouble you will have later. In 2004 when I built my 440/493, I was told by Hensley that 10.8 to 1 compression would run fine on the street with premium fuel.
Define Premium!
In California the best we get at the pumps is 91. The east coast guys get 93 or better. Those 2 points do make a difference if you are straddling the line.
The bigger the cam, the more compression you can get away with, sure. There are trade-offs though. Big cam means a high stall converter with an automatic and deeper axle gearing. This makes part throttle cruising less fun, at least for me.
I took advice from here and elsewhere and used a big cam as a crutch for high compression. The result was a car that was faster than anything I'd ever driven but not much fun for cruising or casual drives. The rough idle, loose converter and all impressed people but annoyed me. I'm going to pull this cam I have now and install a MP 528 I bought over the summer. Lots of positive reviews on that cam. I have 1.6 rocker arms which moves the lift up nicely.
My point is to seriously consider your end goal. If this will be a 98% street car, choose a cam and compression ratio that allows you to enjoy the car. Adding race gas, reducing the ignition timing, water injection....These do help crutch a high CR engine for street use. I'd rather give up some high rpm HP to have a fast, knock-free engine.

 

[383man]

If you don't have heads or a cam, I would talk to Dwayne porter or Muscle mike in NJ. They have done this HUNDREDS of times and know the deal!

This is the best advise I can give you also. Many of us know cams and heads very good and I always picked my own cams but in a post like this you get to many opinions thrown at you that all mean well but most if not all of us are not pro's at cam picking for a total combo. I always build my own engines but on my last eng the 493 in my 63 I called "Dwayne Porter" and had him spec a cam for my combo as he is a pro who does this stuff everyday and we are not pro's like him. Many of us know our stuff but we dont build engines everyday and spec and make the best cam for the combo everyday like the pro's do. And they see what works more often then most of us. I can tell you that IMO the cams you listed are way to small if you want to make the most of a 500 plus cube eng and you definetly want the best heads you can afford to push some air through that combo.

But honestly you have talked and listened to all of us so call a pro and have them spec a cam for your combo when you decide on the best heads you can afford. Any pro who specs your cam will need to know all the info on your full build including the car weight , gear , trans and all the info that affects the cam decision and specs. I myself recomend "Dwayne Porter" at 802-951-1955 as he is one of the best for sure but there is also other real good cam people to call and get a profesional opinion. Good luck , Ron

 

[6t4polara]

Well said Ron.

 

[SlinktRR]

Intake closing event is what affects dynamic. The intake valve is open during the intake stroke but is not fully seated as the piston begins to travel upward away from BDC during the compression stroke. The cylinder cannot begin to build pressure until the valve is closed, instead the intake charge direction is reversed and is blown right back out into the intake. At high RPM this reversion is minimized because the intake airmass has so much momentum it can't be stopped, which is why late intake closing events favor high rpm's and early intake closing events favor lower rpm performance. The sooner the valve closes after BDC, the higher the dynamic compression ratio.

Comp has a great little tutorial.

http://www.compcams.com/Pages/416/valve-timing-tutorial.aspx

Thanks for the information Dan, I'm going to go with the recommendations and call up an expert and a few of the cam companies. Probably will contact Engle, Hughes and Crower for some ideas and try to zero in on a cam.

Thank you to everyone. I'm looking forward to the build but will take the time to get everything ironed out.