509 vs custom

[Anthony 71 Paisley]

Good Morning all. My inexperience leads me to a question. I am in the middle of having 440 built for my 71. .060 over , stealth heads with bowl work ( still to be completed), 1.5 harland sharp , Icon 9953 pistons should put me right around 10.5 ish . Kinda loosely based off the LOWLY 440 build. My question is this

I am going with a Bullets recommendation ( not sure if everything they do is custom or if its a shelf part but they are out of stock ) but the specs seem very similar to me as a 509 cam except a little more lift . Mine will be a hydraulic roller though. I understand that less friction is better but I always hear about faster ramp speed as being the benefit ( also break in ) to a HR. It may be my inexperience but i don't see much difference between the 2 cams . I guess having the timing events would help to see a difference but looking at them on paper i wouldn't know the difference anyways. Will the HR be that much of an improvement over the purple shaft?

Bullet
Intake

242 @.050”

.347” lobe lift, .520” with 1.5 rocker

298 duration @.006”



Exhaust

248 @.050”

.344” lobe lift, .516” with 1.5 rocker

305 duration @.006”



112 lobe separation

108 intake centerline



@.050”

IO 13
IC 48
EO 60
EC 8
---------------------------------------------
Mopar Purple
Intake Duration at 050 inch Lift: 248

Exhaust Duration at 050 inch Lift: 248


Valve Lift with Factory Rocker Arm Ratio: 0.509 int./0.509 exh.

Lobe Separation (degrees): 114

 

[CBODY67]

The wider lobe separatioin of the MP Purple 509 might make the idle characteristics a slight bit better. Chrysler didn't offer the .050" specs as the cam pre-dates that, but allegedly about 80% of advertised duration, they usually claimed later on.

You can probably find the timing events on the cam card for the cams or in other Chrysler Direct Connection Race Manual literature (for the MP Purple Shaft)?

Seems like you might well need a 2800 stall speed converter and a 4.30 gear to make things work well with that cam?

Roller cams and flat tappet cams have different lobe profiles. The roller cam will have a smoother top to the lobe than the flat tappet will, for example. Generally quicker lifts, too. Either way, you'll need valve springs to match your cam! Plus clearancing the valve/piston areas to ensure they don't hit each other!

Just some thoughts,
CBODY67

 

[Anthony 71 Paisley]

My convertor stalled around 2500 with the small block I'm thinking I should be around be around 2800 with the BB but what do I know ? If I have to get something looser I will.
It's a 46Rh with 3.91 gears . I had given them all the info when they specced it out.
I guess I'm just not seeing too much of a difference but I'm hoping I'm happy (I have my fingers crossed)

Valve springs the builder will handle as I dont have knowledge, tools or money to waste if I booger it up.

 

[Anthony 71 Paisley]

I thought the duration was the degreed time it spent in that area of the cam. So if thry were both 248 @ 50 I was understanding it as they would both be very similar. But i guess the roller would be more duration at the higher lift while the flat tappet would be still ramping

 

[FURYGT]

I am no cam expert but I do know that most of the cams on the market are not designed for the torque monster engines that we need in our heavier C Body cars.

The engine builder that built my pump gas 520" had a custom cam made based on the weight of the car, the flow of the ported heads etc. and I couldn't be happier with it. Regrettably the cam specs went with the engine builder to his grave.

 

[Anthony 71 Paisley]

That's kinda what concerns me as well.
I'm not running high gear . I will stand on it every now and then but it's a street car maybe will see a track once every 2 year (if that). The 509 cam I thought is typically a cam you see in a light car with and even better with a 4 speed in that car.
I doubt I'll be disappointed as it should be a huge difference over the mild 360.

I was concerned about the dwindling supply of cams and wanted to place an order to get the ball rolling. I trust they will do a better job than I could but still nervous.
I would have thought a little less duration and a little more lift , .545ish
Reading alot about Stealths & should not be a problem to run them to .550 after some massaging.

 

[stubs300]

That's kinda what concerns me as well.
I'm not running high gear . I will stand on it every now and then but it's a street car maybe will see a track once every 2 year (if that). The 509 cam I thought is typically a cam you see in a light car with and even better with a 4 speed in that car.
I doubt I'll be disappointed as it should be a huge difference over the mild 360.

So you basically want to put a race cam in a street car? I think you'll find yourself very disappointed even over the 360. Good Luck

 

[70bigblockdodge]

If you can keep cylinder pressure it will be better. You really need a measured C.R. not a catalog one. Your vacuum is not going to be great with a 248°@.050, so don't expect great throttle response. It will need to get over 3000 rpm right away converter does that. That loose of a converter and a heavy tall geared car makes a miserable ride. I honestly would bring the duration down 10-15 ° minimum.
That 292/509 cam was miserable in any car I ever had it in except a gutted 440 a body, and even that had 4.10 gears out back and no traction which was my stall converter.

 

[Anthony 71 Paisley]

No I dont want a race cam... again that's what makes me nervous about the cam recommendation. It's similar to 509 which i believe works in a light 4 speed car, not a c body.

So you basically want to put a race cam in a street car? I think you'll find yourself very disappointed even over the 360. Good Luck

 

[Anthony 71 Paisley]

I also dont know if I would consider a 112 (509) cam a "race cam"

 

[stubs300]

I also dont know if I would consider a 112 (509) cam a "race cam"

Well it certainly isn't a street cam, the 112 has nothing to do with it!

 

[Anthony 71 Paisley]

Well it certainly isn't a street cam, the 112 has nothing to do with it!

Wouldn't the 108 purple shaft be more of a "racey cam " than the 112 ?
509 lift if just starting to get to where a decent set of ootb street heads are working.
The duration is time at lift ,no ? With faster ramp speed shouldn't they fall off quicker too and in turn give better drivability over flat tappet ?

 

[furious70]

Yes the 112 will be a little more friendly.
The 509 is a pretty lazy cam, u wouldn't expect a roller to be similar at all, it would defeat the purpose.
509 would make you unhappy. But don't know they the roller is like it.

 

[CBODY67]

(IF not interested in a "race cam", why considering such a wild cam?)

One year at Mopar Nats, I happened across a guy with a '69 Newport 2-dr hardtop. 383, 509 MP flat-tappet cam, single plane intake 780cfm carb, 4.30 gears. He had the rear wheels tubbed for wider tires (N50s?). He was quite pleased with it and was quite successful at harassing the young 'uns in their new Z/28s and such. Seems like he had a 3000rpm converter in it, too?

I'm thinking that you need something more like the original Street Hemi Purple Shaft 284 cam, or something a bit smaller from Lunati and such. The original Direct Connection Purple Shaft cams were the 284/284 Street Hemi grind and the 292 .509" grind. Both hydraulic flat tappet cams.

The newer "Purple Shaft" cams will not have the 112-114 lobe separation, but something more like an aftermarket 108-110 degree lobre separation (as they are probably a line of cams which MP co-opted to sell?). Playing off the name, more than anything else? FWIW

Your existing 2500rpm converter will stall higher with more power in front of it, so it'll probably be good. The 3.91 gear will be good, too. What you ALSO need to realize it that in OD, the effective rear axle ratio will be about 2.7, which will mean the engine will be running at about 2000rpm at 55mph or so. NOT the power band for a very large cam, as you've mentioned. Otherwise, everything will be good until you hit OD, unless you're running 75+mph, even with a 440.

All things considered, might need to re-think your cam, intake manifold, and such a bit? Maybe something closer to a 440 GTX cam (Chrysler B/RB HP cam)? Even with a milder cam, the lower gears will help things along in getting up to speed, then use the lower-rpm torque to run the OD on the highway.

Just some thoughts,
CBODY67

 

[Anthony 71 Paisley]

Comparing to

(IF not interested in a "race cam", why considering such a wild cam?)

One year at Mopar Nats, I happened across a guy with a '69 Newport 2-dr hardtop. 383, 509 MP flat-tappet cam, single plane intake 780cfm carb, 4.30 gears. He had the rear wheels tubbed for wider tires (N50s?). He was quite pleased with it and was quite successful at harassing the young 'uns in their new Z/28s and such. Seems like he had a 3000rpm converter in it, too?

I'm thinking that you need something more like the original Street Hemi Purple Shaft 284 cam, or something a bit smaller from Lunati and such. The original Direct Connection Purple Shaft cams were the 284/284 Street Hemi grind and the 292 .509" grind. Both hydraulic flat tappet cams.

The newer "Purple Shaft" cams will not have the 112-114 lobe separation, but something more like an aftermarket 108-110 degree lobre separation (as they are probably a line of cams which MP co-opted to sell?). Playing off the name, more than anything else? FWIW

Your existing 2500rpm converter will stall higher with more power in front of it, so it'll probably be good. The 3.91 gear will be good, too. What you ALSO need to realize it that in OD, the effective rear axle ratio will be about 2.7, which will mean the engine will be running at about 2000rpm at 55mph or so. NOT the power band for a very large cam, as you've mentioned. Otherwise, everything will be good until you hit OD, unless you're running 75+mph, even with a 440.

All things considered, might need to re-think your cam, intake manifold, and such a bit? Maybe something closer to a 440 GTX cam (Chrysler B/RB HP cam)? Even with a milder cam, the lower gears will help things along in getting up to speed, then use the lower-rpm torque to run the OD on the highway.

Just some thoughts,
CBODY67

I didn't think it was a wild cam . On paper it's pretty much gibberish to me. I went with the Bullet recommendation. I was figuring the" LOWLY 440" type build but with the HR would be a good combo for the 71.
I started poking around at different specs and had seen it seemed similar to to purple shaft... I like the sound but I dont think it belongs in my car. If the HR roller & the 112 makes a difference in power , idle quality/ vacuum I'm all about it but again put 10 different cam specs next to each other on paper and i can see the difference just like anyone else. I just dont know how it affects the engine especially when talking about timing events.
I guess I'm just hopeful itll make me smile , anyways I got word today it shipped from Bullet so I'm already taking that fork in the road

 

[Anthony 71 Paisley]

Yes the 112 will be a little more friendly.
The 509 is a pretty lazy cam, u wouldn't expect a roller to be similar at all, it would defeat the purpose.
509 would make you unhappy. But don't know they the roller is like it.

I hope it doesn't act much like the 509 , if that's the case I think I'm just worrying over nothing

 

[CBODY67]

Cam "size" is displacement-relative. More displacement, more cam, and vice versa. Considering that a '69 Road Runner "upgraded" with the orig 284 Street Hemi Direct Connection) cam, 4-speed, 3310 Holley, 3.91 gears, and stock tires would get close to "Hemi Territory" (as tested by CAR LIFE back then) means that the 284/284 cam is pretty wild. Consider that the worse the cyl heads might flow, the more cam it takes to make power to compensate for the poor flow characteristics, by observation.

By the same token, port flow numbers can equate to "dyno horsepower" at 6000rpm, but if the ports don't flow well at low lifts, then street driving can suffer a bit in the lower rpm levels. As port flow velocity is not as good, especially with large port dimensions.

Cam, intake manifold, and carb size can be a delicate balancing act to make happen for best results. Sometimes, being more conservative can work better in the real world, but not make those high numbers on the dyno.

Keep the OD turned off!

Just some thoughts,
CBODY67

 

[WorkerBee]

In case some members didn't know there are two versions of the 509 cam. Mopar Performance added a more street friendly 509 cam to their line of Purple Shaft camshafts.

Part# P5007698 with 114 LSA

The original version part# P4120237 with 108 LSA

 

[stubs300]

In case some members didn't know there are two versions of the 509 cam. Mopar Performance added a more street friendly 509 cam to their line of Purple Shaft camshafts.

Besides Comp cams, there's much better cam companies than Mopar that produce better cams. I could give the OP some great advice from Steve Dulcich about cams, but he probably wouldn't understand it, let alone follow it!

 

[Anthony 71 Paisley]

Besides Comp cams, there's much better cam companies than Mopar that produce better cams. I could give the OP some great advice from Steve Dulcich about cams, but he probably wouldn't understand it, let alone follow it!

I took advice from Bullet, thanks for sharing your extensive knowledge. You've shared so much helpful advice I dont know where to begin. If your reading comprehension needs some tweaking hooked on phonics works wonders for some.
I never said I was getting a purple cam, I was comparing a roller to a flat tappet. Not only did you not offer helpful advise you try to insult if someone doesnt take your BS info as gospel. Thank you if my Bullet shows up and I'm unhappy with it , I'll bite it and get another.
If you could've explained the differences maybe would be a different story..... All you said is 509 bad , no race cam...
Maybe I'll talk to Steve , but yes I wouldn't take advice from a keyboard warrior trying to fling insults when someone asks a question. Have a good day.