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what cam shaft are you running on the street

Gary Lowry

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Just got the 67 Belvedere and want a little more lope. She's a 30 over 440, headers, ign. tricked out AFB with an Isky 256 stick. Has tons of bottom end (as most do) but lays down about 5000. And that is OK I have been fast before, I want a good bumpy cam. I'm looking at the Mopar Purple 484/284. Watch you got.
 
Lunati 60304. Lumpy, good all around cam. Pulls good to 6,100 rpm as far as I know.
 
Just got the 67 Belvedere and want a little more lope. She's a 30 over 440, headers, ign. tricked out AFB with an Isky 256 stick. Has tons of bottom end (as most do) but lays down about 5000. And that is OK I have been fast before, I want a good bumpy cam. I'm looking at the Mopar Purple 484/284. Watch you got.
Skip the 284/484. It sounds good but is not that great of a performer. I had a basically stock 440 with the MP 280/474, it ran great. Later I built a 9.5 to 1 440 with the 284/484. Rougher idle (which was fine by me) But not much of an improvement in power. The 292/509 cam is actually a decent street cam if you have the gears and converter for it. I ran that one for years in my 440/493. I also ran 2 different Comp Cams XE 285 HL cams. Great performance until BOTH went flat. One within 2 months, the other in about a year.
I went with the Lunati 316/326 solid and was amazed at the power and the racy idle but since I don't race the car, the cam was pulled so I could make the car more street and cruise friendly. I now have the MP 528 solid. It idles smoother than the Lunati or the MP 509 but has a slight edge in power over the 509. I never was interested in solid flat tappet cams until the popularity of the direct oiling lifters. These shoot a stream of oil through the lifter to the cam lobe. I like the extra assurance these lifters give to reduce the risk of cam failures.
 
Isky 256 is a Chevy cam, so are the Megacams
really lazy compared to today's cams
The Purple cams are all better than chevy type masters but still not current
for example Mike Jones 256 hyd cam has .305 lift at the cam- compare that with your Isky
now the good news is that the Isky can be installed under the shade tree and will last a long time- it's that easy
the megacams rev like crazy and work good on the top end (the 310) but you give up low end
are you thinking solid?
do me a favor and post up your head flows- don;t know go to the Stan Weiss site and find something comprable
BTW pocket porting mopar heads helps a bunch
you want rump de rump or power- poke a hole in you muffler :)
seriously Mopars do NOT like overlap your intake blows out your exhaust so mileage sucks- even with a cam with Magnum timing- and your exhaust runs hot (hotter)
also your center two exhaust valves overheat (the valves cool mostly on the seat not through the stems)
need your compression- you have 915 heads? they flow like 906 from 68 but have a smaller chamber
so do you have stock compression? Is this an HP motor what gears and stock converter?
THink EDM lifters if you go flat tappet hyd or solid
What springs or new?
Rockers?
So we have to know is this a stock 67 compression 440 standard or HP or has it been rebuilt- can't guess on 50 year old Iron
cheers
don't know post up your cranking compression or post it up anyway
I'm thinking with that short Isky cam your compression must have been lowered somewhere along the line or it would be pinging even on premium
In anycase picking the cam timing- open and closing points comes first
I did cam and radiator testing for Chrysler in the 70's
One size bigger than the "268" Magnum cam was real close or lost on 60 foot times (stock gears and converter) ( the non magnum cam was 260 in mopar method- YOU CANNOT COMPARE MOPAR NUMBERS WITH ANYTHING ELSE WITHOUT A CAM DOC
but you can compare Mopar numbers with other mopar numbers
That 284 was a fine cam but needs gears and converter, works with headers but likes high compression
remember it was designed back when springs were not as good as today so leaves some cam acceleration on the table
 
Ken dog’s 280/480 suggestion was s a good day be IMO for the purple cam line. IF you can find it cheap. It is more in a similar but slightly higher rpm range of your “Fall in its face @ 5K” cam.
Any new cam grinds are equal or better to the older purples.

A “bumpy cam” comes not from the duration but more from how the timing events are occurring. Your typical muscle car cam and s on a 110 centerline. A more radical question doe wwould op be on a 108. A race weight idle sound will be on a 106 or lower.

You can call up the cam company you want to use and ask that the cam be moved down to a 108 which will help bottom end torque.

There is also the Thumper line from Comp Cams. Howard’s has there line as well. Mild cams with race like idle chopping sound while remaining nice and ez to drive on.
 
I use 213/225 @ .050, .450/.458 115 LSA. That's the factory hp camshaft. It doesn't have the Dairy Queen idle, but it doesn't need high spring pressure or special motor oil, so I don't worry about it.
 
I use 213/225 @ .050, .450/.458 115 LSA. That's the factory hp camshaft.
That is NOT the factory hp camshaft. The factory OE cam is larger and the MP factory offered purple shaft is even larger.
 
Here’s the .284/.484 sounds good, doesn’t perform for ****. Had it on my 67 440 with performer intake, Holley 750, Hedman headers, 906 heads. Basically a stockish cam with more lope.


 
"but more from how the timing events are occurring."
Lobe centerlines must be a result- not an input
It's not squeezing the lobe centers together that gives more low end- it's advancing the intake
and there you have to watch your dynamic compression to avoid pinging
What you don't want to do is to increase overlap unnecessarily- which is what squeezing the LCA does
Mopars run hot with overlap and your intake charge gets blown out the exhaust
so what to do?
open the intake later but use a higher acceleration master and/or a higher ratio rocker and close the intake where you would with that squeezed LCA
More with low compression
exhaust is not quite so critical but timing should be designed, not just the LCA spread
cheers
 
"I use 213/225 @ .050, .450/.458 115 LSA. That's the factory hp camshaft."
That is about right for a Magnum cam
"BradH and others have measured it. It's nearly identical to Speed Pro CS-661, Elgin E-1094-P, etc. "
yup- same cam
Duration at .006 292/309 (SAE method .006 AT THE VALVE) or .004 at the cam with 1.5 rockers
Chrysler says 268 on the Intake
why the difference?
Chrysler has a unique yet consistent way of measuring duration. They take the blueprint point where the clearance ramp meets the acceleration ramp and add 4 degrees to the opening and 4 degrees to the close
I basically agree with 67 coronet 440- you can do better today
but 268 and 284 - the 284 is 16 degrees bigger
and the 284 is reasonably lazy and the 268 MAgnum is really lazy- so much so a fast chevy grind will look about the same
HOWEVER the MOPAR grind uses most of the .904 lifter EASILY whereas the Chevy grind would only use a .842 worth of the .904 but radically
Result- the MOPAR method wears better
 
From a post I made in 2015
I dug into Howard's catalog a little further- I'm a paper catalog guy but I did find several Hyd grinds with "cam note" 15 which indicates special for .904 MOPAR lifter-
as with comp there are not any real short ones similar in duration to Dodge Magnum (there may be now)
Howard 720931-11 220-220 .506 lift at 108 lc and recommend 104 icl shortest .904 grind in Howard cat

Engle K58 224 .506 short seat timing

Comp XE275HL 231 .525 shortest .904 grind in Comp Cat 2015
crane none
Lunati Voodoo 220-226 475-494 note the loss of .030 lift compared to Howard
Lunati voodoo 226-234 494-513

The Bullet .904 list is here
http://www.bulletcams.com/Masters/HClobes.htm
Bullet 214 480 similar intake duration to Magnum but more lift
Bullet 220 500
IDK if MikeJones has a range of .904 grinds- worth filling out his recommendation form and find out
http://jonescams.com/street-performance/
especially if you are thinking solid or HR or Solid Roller
 
The mopar 484 is ok for an upgrade from stock, decent midrange, I used one for years and liked it fine.
Switched to a bob k cam and never looked back.
BTW, I still have the low milage 484 with lifters and tming set if interested ( thought I would use it again but probably won't).
 
I’m pretty sure your duration @ .050 is off.
mopars current .050" rating is way off. the factory cams aren't even the advertised 268/284.

I have two cars. one stock 440 with the 272/.455 mopar and the other has a modified engine with an engle k65 solid. a moderate solid will do everything a performance hydraulic can do and more.
 
mopars current .050" rating is way off. the factory cams aren't even the advertised 268/284.

I have two cars. one stock 440 with the 272/.455 mopar and the other has a modified engine with an engle k65 solid. a moderate solid will do everything a performance hydraulic can do and more.
292 extreme solid roller .
 
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