383 Mopar Purple Cam

[RemCharger]

ahah true... a .590 would wake it up but suck in this instance thing sounds amazing though, kinda want one

This is basically the same cam as a .590 , in a 383 with -1 heads. There's quite a lull out of the hole with a 3500 stall, but you can hear it turn on after 5grand. Shift at about 7200

 

[furious70]

I have a 484 in my 440 with a 5spd TKO and 4.10 Dana.
I would not put the 484 in a street 383 personally without some converter and gear.
When you say more than stock cam do you mean the 2bbl cam or the roadrunner cam?

 

[WileE]

If you got nothing else, but "stock" intake, exhaust, etc. you'll be better off with the 280/474. None... of the others listed.

 

[Cranky]

Depends what you are looking for exactly.. but i will say i ran a .484 purple shaft and it was by far my favorite cam i ran.. decently drivable and pulled great. I switched to a .509 in the same car and hated it soo much after that

Depends on the combo....and what the cam is set at WITH a degree wheel. Over the years I've found that 383's like the 509 better than the 440 did but they have to be set up with some advance in the 383....like 4 degrees advanced....at least.

Back about 1970 I put a 280 degree Crowler (I think) cam in my 64 Sport Fury 383 and it really hurt it off the line. I’m not sure a bit more compression will help much. More like better heads and looser converter or bit better gearing.

What was the cam set at?

That .590 will reeeeeally wake it up!
after 5500 rpm.

I have some experience with the old .590 and found they also like some advance dialed in even with a 440.

Oh yes sorry, it's going in a 1971 dodge charger and I don't want a racing cam. More of just a step or two up from the stock cam

Are you building the engine or is a shop doing it? If it's a shop, I hope they have some experience in Mopars. Keep in mind that aftermarket pistons are never what they are advertised as.....if they are advertised at say 9.5 they will do well to make 8.5. The advertised compression is always (what I have found anyways) the max that you can achieve with thin head gaskets and the smallest combustion chambers available.

Also, never just install a cam using the 'dot' method. ALWAYS degree it in! The dot method is a crap shoot. Yeah, you'll hear about the ones that do it that way and never had a problem but you hardly ever hear about the ones that had problems or even wrecked the engine on start up because the 'dots' were not in the right place or the cam wasn't made on spec? And it happens. Who will admit to doing that!!?? lol There's LOTS of info on the net about cams and you would be wise to learn about them.....yeah, it's 'cornfusing' at first but even if you learn the basics, you'll be ahead of many. Not saying anyone here has done that but.....the more you know, the better off you'll be. Sorry for the long post.

 

[lewtot184]

All of those purple cams will adversely effect power brakes. The 280/474 would be the limit for me. It's about 2 steps more than a stock cam and is enough to "test" your tuning abilities.

 

[Cranky]

All of those purple cams will adversely effect power brakes. The 280/474 would be the limit for me. It's about 2 steps more than a stock cam and is enough to "test" your tuning abilities.

Power brakes?? Ok lol. I've had a couple of 'older' cars with PB's but not very many.....the ones with the soft stuff usually weren't modified

 

[Curiousyellow71]

Get better pistons! Unfortunately the options are limited. Decking the block or smaller cc head may be needed.
To my knowledge..all 1971 383s are low compression engines. Likely not 9.5:1 unless it has had a upgraded piston or a lower cc head stuck on it.

We built a 71 383hp in 1992.
The original 346 heads were shaved to 74cc to raise the compression. We were big on mopar performance back then and it got the 484 cam 108 Lsa. 1 3/4 headman headers, performer 383 intake and a 850 thermoquad.
Even with the heads shaved it was low compression yet. I think it was like 8.9:1. No way would it run power brakes..it liked 4.10s but needed more convertor..
Now days you can buy a electric vacuum pump if the engine lacks vacuum.

I have fond memories of mopar performance...but, I would not choose any of them now. I would run a cam that builds more compression and runs more vacuum with more lift. Lastly, I would be worried about what lifter I was buying in a kit. There are a lot of crap hydraulic lifters out there.

 

[That_1_71_Dodge]

yeah for me it would be the .484.. it has a slight lope to it but nothing bad... the .474 if you wanted a little softer but i really loved that 484

Here is the 484... i know it's just a video.. but just to get an idea of idle quality..


And you don't want a .590 He was being sarcastic...thing sounds amazing though

yeah for me it would be the .484.. it has a slight lope to it but nothing bad... the .474 if you wanted a little softer but i really loved that 484

Oh sweet thank you, I will look over these. Thank you so much

 

[That_1_71_Dodge]

It wasn't really sarcasm,, just a true statement. But not applicable to this build..
Yes the 284 mopar is a decent choice for basic hot street cam

Oh ok thanks

 

[That_1_71_Dodge]

Do you have power brakes?
Do you care about fuel mileage?
Can you tune a carburetor?

The 484 isn't very stock and too big for most street cars. Mileage will be Gone!

It has disk brakes, brand new. I don't care all too much about fuel mileage, and I have an uncle to can do that stuff

 

[That_1_71_Dodge]

Get better pistons! Unfortunately the options are limited. Decking the block or smaller cc head may be needed.
To my knowledge..all 1971 383s are low compression engines. Likely not 9.5:1 unless it has had a upgraded piston or a lower cc head stuck on it.

We built a 71 383hp in 1992.
The original 346 heads were shaved to 74cc to raise the compression. We were big on mopar performance back then and it got the 484 cam 108 Lsa. 1 3/4 headman headers, performer 383 intake and a 850 thermoquad.
Even with the heads shaved it was low compression yet. I think it was like 8.9:1. No way would it run power brakes..it liked 4.10s but needed more convertor..
Now days you can buy a electric vacuum pump if the engine lacks vacuum.

I have fond memories of mopar performance...but, I would not choose any of them now. I would run a cam that builds more compression and runs more vacuum with more lift. And I would be worried about what lifter I was buying in a kit. There are a lot of crap hydraulic lifters out there.

I was thinking of putting a purple cam with an advantage duration of 272. With a lift of 0.455 Also what kind of hydraulic lifters do you recommend for this build

 

[That_1_71_Dodge]

If you got nothing else, but "stock" intake, exhaust, etc. you'll be better off with the 280/474. None... of the others listed.

I am completely rebuilding it but am thinking of keeping the stock pistons

 

[That_1_71_Dodge]

Depends on the combo....and what the cam is set at WITH a degree wheel. Over the years I've found that 383's like the 509 better than the 440 did but they have to be set up with some advance in the 383....like 4 degrees advanced....at least.

What was the cam set at?

I have some experience with the old .590 and found they also like some advance dialed in even with a 440.

Are you building the engine or is a shop doing it? If it's a shop, I hope they have some experience in Mopars. Keep in mind that aftermarket pistons are never what they are advertised as.....if they are advertised at say 9.5 they will do well to make 8.5. The advertised compression is always (what I have found anyways) the max that you can achieve with thin head gaskets and the smallest combustion chambers available.

Also, never just install a cam using the 'dot' method. ALWAYS degree it in! The dot method is a crap shoot. Yeah, you'll hear about the ones that do it that way and never had a problem but you hardly ever hear about the ones that had problems or even wrecked the engine on start up because the 'dots' were not in the right place or the cam wasn't made on spec? And it happens. Who will admit to doing that!!?? lol There's LOTS of info on the net about cams and you would be wise to learn about them.....yeah, it's 'cornfusing' at first but even if you learn the basics, you'll be ahead of many. Not saying anyone here has done that but.....the more you know, the better off you'll be. Sorry for the long post.

Ok I will do that, me and my Dad are building the motor with not all too much experience with Mopar's, so we will do some research about how else to install them. We've always done the DOT method with Chevys.

 

[Curiousyellow71]

I was thinking of putting a purple cam with an advantage duration of 272. With a lift of 0.455 Also what kind of hydraulic lifters do you recommend for this build

The best lifters are currently made by Hylift Johnson...unfortunatly they have gotten pricey, Hughes engines sells them. If you can..Buy old stock lifters from 20 years ago or more. Original lifters can also be reground by a few shops. Roads lifters also use hylift Johnsons bodies and Machine them. Comp cams has introduced a new coating because they had so many failures. Trusting a coating is still concerning.

You may want to just get a cam and lifters from Hughes engines instead of the purple grind. Hughes are ground by howards. They would be a upgrade over the MP cams. I am saying that partly because I have ran the MP .455 cam in a 383. It wasn't what I hoped it would be. Lunati voodoo and comp XE also do well in lower compression engines. They are fast rate cams which don't suit every application.

 

[Geoff 2]

The 272 Purple cam would be idea. Go bigger at your own risk.....
NOBODY has mentioned the high rod/stroke ratio of the 383. That means it does tolerate a lot of duration, will be down on vacuum & tq at lower rpms. See the link below. Although it talks about the 440, the warning is there for the same reason: high r/s ratio of the 440. [ 383/440 have higher r/s ratios than ANY other BB engines ].

Lifters. If you do not want lobe/lifter failure, have your factory lifters re-faced.

 

[493 Mike]

The best lifters are currently made by Hylift Johnson...unfortunatly they have gotten pricey, Hughes engines sells them. If you can..Buy old stock lifters from 20 years ago or more. Original lifters can also be reground by a few shops. Roads lifters also use hylift Johnsons bodies and Machine them. Comp cams has introduced a new coating because they had so many failures. Trusting a coating is still concerning.

You may want to just get a cam and lifters from Hughes engines instead of the purple grind. Hughes are ground by howards. They would be a upgrade over the MP cams. I am saying that partly because I have ran the MP .455 cam in a 383. It wasn't what I hoped it would be. Lunati voodoo and comp XE also do well in lower compression engines. They are fast rate cams which don't suit every application.

I concur. A lot of technology has passed/put into production since the purple grinds were developed.
Mike

 

[Don Frelier]

The mopar .455 272 deg. cam is a great fit for all around use in the 383.
I don't think you can go wrong with one of these.
I ran one for 20 years and it did everything well, even got good mileage.
I had KB hypereutectic pistons and heavily milled down 906 heads here it was 9.4 : 1.
(Ignore the messy wiring as this was phase 1 of converting to EFI and the poor production quality)
I don't know why but the microphone in my phone picked up alot of lifter clatter but it was actually pretty quiet.


In 2020 I pulled it out and change to E-street heads with a Lunati 10230702K with a single plane intake.
I didn't measure the volume on these heads but it's likely close to 10:1 now.
I lost some low end but it's quite powerful midrange. A bit of a nasty idle doesn't shake much but it's far from quiet.
Here's the first cold start last spring after sitting for 6 months.

 

[PRHeads]

My .02-
If the engine will retain the stock carb, intake, exhaust manifolds, and particularly if it has PB, I’d be using a cam that’s def smaller than the Purple 474/280.

Something more along the lines of a Crower 267HDP.

 

[lewtot184]

The 272/.455 isn't available from Mopar but a speed pro cs1148r should be identical. A compcams 21-305-4 may work well also. The old crane 272hmv would give more area under the curve than a stock cam and I believe howards has the lobes in their master catalog, if you know how to chase them.

These 383 cam threads are usually the same. There's always the big hydraulic crowd. There needs to be a law that you can't title a 383 mopar until you've done the big hydraulic cam thing. This would be the only way people would learn once and for all to never do it. What may work at the track usually never works on the street.

 

[PsyOps]

My .02-
If the engine will retain the stock carb, intake, exhaust manifolds, and particularly if it has PB, I’d be using a cam that’s def smaller than the Purple 474/280.

Something more along the lines of a Crower 267HDP.

OP, you never said if you were going to change the intake/carb or run headers, etc. If not, it would be worth reading the @Andyf article on cam selection for a 383 with stock exhaust manifolds (maybe someone here can point you to that - I can't remember where I saw it, maybe PHR?). You said you wanted a cam one step more than stock. Without any additional information on carb/intake & exhaust, the recommendation from @PRHeads seems the most closely aligned with your goal. Finally, many of the kind folks offering advice on cam choice here are using their 440s as examples but they are mixing apples to oranges. A 383 is not a 440; a 383 is much more sensitive to cam selection as @lewtot184 was alluding to. Keep asking the good questions and we'll help you get there.