383 street cam help

[wyrmrider]

let's compare apples and oranges
I did not say that elgin had crane profiles
I said Elgin had similar profiles for about $100 less
if you want to spend 150 dollars there are better choices than 40 year old designs
an easy on the valvetrain .904 grind is easier on the valvetrain than a more maxed out chevy grind

yy1 we were talking about solids
What did the Andy F article show?
that the Racer Brown shorter duration worked better with that build
and
that closing the intake early (short duration and 108 lca seemed to really help
the solid grind RB only had about a half inch lift once you take the lash out

 

[rlem1977]

Acquired a 70 383HP going into a 72 Charger. Not torn down yet, but appears to be unmolested, still having a points distributor. Plan on a light rebuild (if there's such a thing). Preferably a bump over stock. Charger will be a cruiser 90% of the time, but a little Mopower when needed. My 1st pump gas, exhaust manifold build. Assuming the innards look good, plan on honing, reringing, bearings. Should I stick with the 906's with new seats, or use 452's or equivalent? What's a good cam for this rebuild, 4120235 Purple? Different head gasket to wiggle closer to 9.0? I believe the 70 engine is 9.5. I'm using a Performer RPM with either Eddie or Holley which is another question. I'm always wrenching on my 6bbl RR carbs, and I want this car's carb trouble free. This will be an automatic car, with either a 2.94 or 3.23. Thanks in advance guys!

Engine build:
http://www.hotrod.com/articles/mopp-1205-383-big-block-engine-build/

Intake recommendations:
http://www.hotrod.com/articles/hrdp-0712-mopar-intake-manifold-comparo/

 

[BSB67]

pretty sure comps MM series are .904 tappet.

Correct.

 

[YY1]

I thought this thread was about a good "street cam", not .530 lift solid cams.

 

[wyrmrider]

Good street cam with 2.91 gears should be thinking about 260 not magnum 268 duration then as much area at .200 as you can get
with 1.5 rockers somewhere around 450 lift
now interstate only or saturday night street then 10 degrees moves our torque up- simple as that

 

[rumblefish360]

I thought this thread was about a good "street cam", not .530 lift solid cams.

Agreed but it is also what your willing to put up with and also the biggest problem is point of view. Just what is a big cam, to much gear, streetable?
Opinions will vary like women’s shoes.

 

[wyrmrider]

I just go back to what lewtot said in post 14
"one thing to keep in mind is that 383's are very easy to screw up with too much cam."
And I agree on a lower compression 383 or 400
even the Magnum cam is too big with 2.91 or 3.23 gears Factory used the Magnum converter with the standard cam in the low compression 400 and the Magnum cam and converter in a 400 is a real dog with 3.23 gears.
So were back to finalizing heads and compression and exhaust but even with a true 9:1 he is going to get the intake valve shut early
you can't give up any torque at 2500
Think of an "engine masters" flat torque curve
now 3.55 and 9.5 real compression I can think bigger
But it's easy to get Magnum lift in a Standard duration cam
go look in the Comp Cams Lobe master list and look at the intensities
The do not have a short .904 HL cam except custom grind from the 4x4 list but look at the intensities compared to their old chevy masters
the .904 HL is actually less radical
(less radical over a bigger lifter instead of more radical over a smaller lifter)
lots of choices when he get's to that point

 

[rumblefish360]

The Magnum cam as in the factory Magnum cam?

The enginemasters 383 vs 383 shoot out uses a Hyd. Roller @ 230/236 @ .050. The incoming torque is quite nice. With the proper torque converter I see zero problems with a low 3.23 gear.
I’d have no problem doing a copy cat engine. Or just using that same cam with better parts.
Proceed to the 9:00 mark.

 

[wyrmrider]

yes the factory Magnum cam
really lazy so it gives up a lot
we tested this one for Chrysler compared to the next several size bigger purple shafts
compression makes a big difference
Low compression you have to get the intake closed early to build cylinder pressue
Agree 100% but I do not think a HR is in the budget besides a good .904 grind is also almost is good unless you get a Mike Jones Inverse radius flank HR
however he has 2.91s
I think I've seen that video but i'll take another look
cheers

 

[rumblefish360]

I get the cost of a roller being a bit much for the intended purpose but the video is a close as possible level playing field as possible with the engines and it just simply shows what can be done. The idea of me introducing the video is to show that a reasonable size (and off the shelf cam) can do a reasonably decent job of low end torque production. Over all, that engine would not be bad to run in an everyday driver. A smaller cam would be best with the limited gear ratio being used.

A decent solid lifter cam can replace the HR cam and still have excellent results.

The factory Magnum cam is a catch 22 since it had to idle smoothly and still produce acceptable hp results for the era it was used in.

I have been in a few 3.23 geared, 383 Raod Runners and nver thought they sucked.

I also find it a joke to even mention inverse cams and other such things on the idea of this subject. Why even mention it on this topic when perameters are low and the rear ratio 2.91?

 

[wyrmrider]

AND Warranties
I'm at all thinking HR for this build but if I was I'd go IR
When I was service manager in the 70's 383's did not suck- not till they really dropped the compression
So instead of the Magnum cam being a performance cam it became a smog cam
We had customers who could not pull a boat up the ramp with 400's and magnum cam- they were not happy-car would not move till you gave it lots of throttle then the tires would spin- horse trailers were worse and those wagons typically had 3:23 gears
with low compression I like stock cam duration with Magnum Lift (with tall gears)

 

[moper]

Not meant as a low blow, but simple commentary based on observation.
Cams and their lobes have no idea what manufacturer they are going in. Any commentary to the contrary is strictly drinking the Hughes cool aid.
I run a lot of what's listed as Ford profiles on my custom cams. Why? Because pushing the limits of the mechanical relationship between the lobe and lifter is asking for problems. The block machining of the lifter bores sucks as bad as the rest of the work, and the wear now existing in available blocks. Not to mention the required spring pressures and potential issues with oils and flat tappets - which is pretty much the bulk of what I run (I build street and street/strip engines).
In a car where the owner wants a snappy engine with no worries and limited initial investment, a more modern grind with some "extra" under the curve is preferred and will fit the bill. Doesn't matter who made it as long as the quality is high and the grinding accurate.

 

[rumblefish360]

And so hence my often made comment of comparable content, “There’s no real need to take full advantage of the .904 lifter to make lower because it is stressing the valve train” (into early retirement or breakage.)

Very few cams actually take advantage of the .904 lifter diameter. Including the ones that say they do marketed to regular guys for the regular hot rods. So much in fact, your really still miles away from the half way point. They will open the valve aggressively on the initial jerk and then again on the second jerk so much as to cause a noisy valve train that everyone complains about.

 

[wyrmrider]

Well sort of
With say Elgin you get a high quality cam- you do from all the big Detroit grinders
Agree 100% about the lifter bores
We regularly bore chevys out to Ford or Mopar size as an alternative to more expensive bronze bushings just to true them up- and sometime we slide the lifter bore over so there is more lifter on the opening side than the closing
that said we do run lobes that know what motor they are going to run in
Starting with the valve weights and springs and working backward through the rocker motion and lifter bore angles
The Cam ends up as a result instead of trying to control unknown valve train with stiffer springs
I do not know if Hughes does it that way or who designs/ grinds his cams
You have .904 profiles from Crane, Lunati, Bullet, Comp, Engle in their catalogs and Crower and others- even Chet Herbert by special request
no need to settle for a "one size fits all lobe" that is 40 years old

 

[rumblefish360]

There basically was never was a need to settle for a one size fits all love but 99% of the buyers will just open up a catolog (or internet page) and order what they see (kind of) fits there idea for the intended goal.

 

[wyrmrider]

you got that right rumble
many of the catalog grinds are universal- and ground by the big Detroit grinders by subcontract
What I do is compare the Mopar listing to the SBC and if they are the same pass
then try and find the grinds or lift/duration in the master lobe listing
I do find I can get the same upper lobe profile with
about 10 degrees less seat duration by using a mopar lobe and I'll take 10 degrees every time
Harvey Crane made all aware of smoothing and Jerk- most of the newer lobes from most everyone are smooth
If you look at the Comp master lobe catalog they give the intensities The Mopar HL series is no more and mostly less intensive than the chevy grinds
cheers

 

[rumblefish360]

Yes! Mr. H Crane. Good readings.

My Comp catolog took a walk. I’m very unamused!!!!!


If one takes the time to look at all the numbers, a good learning experience awaits. Also, as mentioned, Mr. Cranes writing, Harold B’s, etc....

It takes the right ramp and the right. Characteristics to get that aggressive cam in and quietly working.

Again, it’s not needed for the basic street and street strip design but I would t shy away from it at all if I was getting serious about matters.

I grabbed a new never used Ultra Dyne grind for my mostly strip small block that will spot a M1 tunnel ram. It is not a all out race car project but a serious attempt to have fun, make some nice power and stomp a few heads into the ground. (Someone is always faster....)

A serious race car is a bit out of budget.

 

[wyrmrider]

Not only not finding the MOPAR cams and thus giving up some cam tuning options they tend to "go to the bottom of the page" in the catalog
and we end up with a 509 with stock exhaust on the street
lucky the Mopar Performance cams are full size base circle and can be reground down a notch or two, reface the lifters (sometimes better than new if they had a big chamfer and back on the road happier

 

[Officer Higgins]

the engle k56 intake/k58 exhaust is a good combo. the bob k cams used to be engle's.

spoke with both engle and bob on tuesday engle still makes his cams he proudly said it and chris at engle said it. Hughes are not engle cams anymore from what i understand davd hughes is difficult.

 

[wyrmrider]

I have not added Bullet to my list as I have not called to find out what their advertised (adv) lift is
But Bullet also has an extensive MOPAR list as does Howards
Lunati has many Comp has 3
I do not know if Comp's AMC cams will fit well on the smaller mopar base circle but if I had a Mopar in say a Jeep or 360 motorhome I would ask (but there are other choices)
I've used many Engle- but not recently as I am supposed to be retired
they have several series- one is street and easy on the valve train
another takes pro level set up and break in
Isky uses different advertised lift for each of their series
Megacams are simalar to Direct Connection for example
let us know what you come up with