Help me choose a cam - 500ci

I'm collecting the final parts for my build but I'm still missing a cam. Here is what I have:

500ci (4.25" stroke - 4.34" bore 440 block)
Trick Flow 240 heads ootb (lightest spring package but don't mind changing them)
10.5 compression ratio - 0.040 quench
Indy dual plane 440-2d intake manifold
2" headers (Dougs)
Rocker arms not purchased but will probably be a set of 1.5 or 1.6 PRW + B3RE geometry kit

4-speed with 3.09 low and 1:1 4th gear
Rear end: Dana 60 with 3.33 gears --> 10.3 starter gear

Car: 70 Charger R/T - weight around 4000lbs

This is a street car so low and mid rpm torque is important.

As for a cam:

I'd like to get a solid flat tappet cam for simplicity, power (compared to hydraulic cam), rpm stability, cost. Solid roller would be nice but maybe at a later stage.

Single pattern or dual pattern cam? Afaik split/dual pattern cams were designed with a longer exhaust duration to mitigate the poor flow of exhaust manifolds. Since the TF heads have pretty good exhaust ports and I have long tube headers a longer exhaust duration might not be necessary - thoughts?

Duration wise I was thinking about low 240 @ .050

Lift? ramps should be streetable..

I found the following lobes in the Bullet Cam's master list. What do you think?

Master______advertised___@050__@200___lobe lift__valve lift (1.5)___valve lift (1.6)__lash
FC270/360_____270______240___157____.3600_____.540__________.576______.012
FC269/350_____269______242___159____.3500_____.525__________.560______.011
FC275/365_____275______244___161____.3650_____.548__________.584______.014

LSA? I'm thinking about 112° for a broad torque curve..

What about these two Hughes cams?

Duration @050__lobe lift_____lift 1.5 RR____lift 1.6 RR
238/242______.372/.376___.558/.564___.595/.602 - 109° LSA
242/246______.376/.384___.564/.576___.602/.614 - 109° LSA


Sorry about the long post - I hope I still get some suggestions

Looks to me like you're on the right path. I'd probably use that smaller Hughes cam or I might use the Mopar .528 solid. It really depends on how much noise and vibration you're willing to put up with in a street car vs. how much power you want to make. I prefer smaller cams in my street cars these days.

Spend the money on a solid roller....do it once and then you don't have to worry about a wiped cam lobe from a flat tappet.

Rather than guess why not call a cam grinder and let them pick the lobes?

BTW, that's not much gear for the weight and you are probably a bit low on compression.

I'm glad you already decided on the B3 kit. It's a life saver.

Thanks for the input so far!

Compression is for running pump gas and I'm shooting for 8.3-8.5 dynamic CR.
Gear ratio is set (that's why I got the 3.09 first instead of the regular 2.66) so what cam works best in your opinion?
I'd like to get some ideas before I call any cam company.
Thanks

Start calling

I'm a huge fan of Bullet Cams and they still carry the old Ultradyne lobes.

I run what they call the .403 solid roller in my 440" W2, really easy on the springs and I think it's like .018/.020 lash and with a 1.5:1 rocker it's ~.605 gross lift. I run a 251/259 @ .050 on a 109 spread, I'm using the BAM/MRL lifters. But they have several duration/variations of that street cam.

I'm sure Comp has something very similar, If I were you I'd ask Dwayne (Fast68Plymouth) to spec you the right one.

They are all in the ball park, IMO. I kinda like the larger Hughes. Maybe spread the LSA to clean up the idle if that is important to you.

Remember that the Bullet lash is at the lobe, so you need to multiply by the rocker ratio.

Give Dwayne a call, you’ll be glad you did. He nailed the cam on my 511

If you have 2.19 intake valves, that is over 28 cubes per inch of intake valve. David Vizard has a chart in his book How to build Horsepower and it shows an LSA of about 100 (!) Is best. That is why you need to talk to a company like Bullet or Jones Cams to get the best results. I would stay away from any company that wants to pick out a shelf stock cam for your combo.

I would look at using the biggest Ultra Dyne cam ground on a 108 to 106 LSA and install it at 104 to 102 intake lobe center to get all the bottom end you can with the 1.6 ratio rocker arms
With those lobes ground on one of those LSA you won't be able to tell anyone that you have a "stock" cam
The only bad thing about using a cam like that installed that way is controlling traction, or the lack of the same
Spreading the LSA out to like 112 on a wedge motor kills the bottom end power to gain power at the upper RPM, which is a waste in my opinion

Thats what I did as I have one of his cams in my 10.6 pump gas 493 and I love it. Its a solid flat tappet and works great for my combo which is a street car with a little track time. Ron

Mike at muscle Motors spec'ed a cam for my similar combo. MM lobes, 243@.050 duration, .55" lift, single pattern and 108 LSA. It works quite well and has held up well on both street and road track. Initially I ran stock Eddy springs and then switched to doubles when I started hammering it on the track. I am running Comp cast steel "Pro Magnum' rockers and 3/8" pushrods. I too like the performance and simplicity of mechanical flat tappet.

Your cam pretty much confirms my initial thoughts! How do you like the idle quality with the 108 LSA?

I have David Vizard's book at home and read the part about the LSA. I understand his logic but it seems that hardly anyone (at least by my limited observation) runs such a tight LSA on a street motor (100 or 102).

I agree that running a cam with a super tight LSA may not be in your best interest. BUT, getting an expert opinion on exactly how narrow to go is important because going too wide hurts more than too narrow, an since it is a street application it may be an advantage to run a narrower LSA with less duration on the lobes to reduce overlap. Look at some of the Mopar short track cams as an example.
I just dyno'd a 408 street motor with a cam of 235 intake duration, 249 exhaust duration, LSA 107. A single pattern cam of equal exhaust duration and overlap would have an LSA of 103.5. A duel pattern cam needs to be looked at in a different way rather than dwell on the LSA the cam card says for each. To compare a single pattern cam to a dual, take the extra exhaust duration, divide by four and subtract It from the dual patterns LSA to compare the two cams. If you look at all four valve events you will see that when you do the math and plot them out as on their timing cards, you will see that the only thing that has changed often is the exhaust opening point.
That 408 made killer torque and power for what it is.

Remember that the quality of the cam core is as important as the specs... guys like Jones use a better core than you'll find on a shelf cam.

There are quite a few experts on Moparts as well (and most of them already gave an input) but yes calling a few companies for their opinion is definitely on the agenda (Jones Cams and Bullet cams seem to be universally recommended).

Cam cores: good point! These days it's quite hard to distinguish between real information and marketing BS when it comes to quality.

Mine is a solid flat tappet from Dwayne Porter and he had it nitrided and I use the EDM lifters I got from him. Its been in my car since 2011 with zero problems and still going strong. And its a street car I drive a good bit. Ron

Take a peek at the cam discussion here... I think you'll see how getting advise from a guy in the biz can be just a bit more informative than just talking to a schmoe like me...with apologies to all the other schmoe's out there.


http://speedtalk.com/forum/viewtopic.php?f=1&t=51713

Idle quality with the 243 MM lobe is "fair" IMO. It will idle at 800 or 900 RPM. A little lumpy and a little smelly. With tuning it does pull 13" vacuum at idle and power brakes work fine. Adjusting the timing to around 20 degrees advance and tuning idle mixture to around 14.5 (wideband) helped a bunch in getting clean(er) idle and decent vacuum. I run a manual transmission. My setup will pull clean from 1200 RPM if I don't completely stomp it. It feels steady and strong above 2000 RPM and starts singing as you get above 3000 RPM.

Here are dyno curves after freshen and tuning

Considering that a stock 1968 to 1972 340 came with a 272 duration cam from the factory at about 465 lift, I think either of the above cams will be very mild in a 500 inch motor. Stump puller maybe.
Just my opinion of building Dodge engines the last 40+ years.
Try this link to the Cam article in archives.
http://www.moparts.org/Tech/Archive/motor/5.html

Call Jim @ Racer Brown his CAMS make power he is good at choosing correct cam everything is custom ground 1410 866 7660

Talk to Dwayne Porter on the board here, He picked the cam for my combo, which is similar to yours and it works great. Comp Cams Nitrided cam and EDM lifters.

Would you consider a hydraulic roller? The ultimate in reliablity!

I am using a solid FT cam from Dwayne Porter.
My engine is 470" 10.7-1 .040" quench RPM heads. Performer RPM intake, Comp Pro Magnum 1.5 rockers
244* intake 252* exh. @ .050"
.520 int .540 exh.
110 Lobe sep
Howard's EDM lifters
In @ 106*
Valves adjusted cold @ .012 and .014 "
I have dyno time only and the pulls started @ 3500 so I can't say for sure what we have below that RPM or what vacuum is either.
I would think with your heads and 500" your numbers would be higher, and maybe a lower RPM peak HP .
I hope that this info is helpful ?
Mark

I agree 100%.

Jim wants you to call AFTER 5 pm eastern time. You get to talk to the guy who,is actually going to grind your cam.

Thanks for all the great input! I'll definitely make some calls soon. Good to see that the cams/lobes I came up with are in the ballpark and not totally off.