Alright, school me on stock roller cams....

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Cuda416

Cuda416

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Ok, been looking for a 318/5.2L .432 roller cam to put into a 5.9 ever since I read about them to get a little extra something out of an otherwise stock setup.

As I understood it, these were PRE magnum cams. So, I pulled one from a 85 5th ave and it measures 0.390 (.260 x 1.5).... ?? Are the .432 cams in fact, found in the 5.2 magnums?

I know I can get a regrind or new cam altogether, (leaning towards a regrind at the moment) but I'd just like to get this information correct "just because"....
 
j par said:
They're not cheap...
Class DISMISSED....
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"Stock" is operative and I can get them for $20 ands some time at the bone yard.. :) Yes i realize how hackish that sounds but this is my kids car and we just want to wake it up a bit while he saves for better stuff.
 
I've heard the 5.2s had a "larger" cam (more duration and lift) than the 5.9, but I've never actually measured them. I can't remember the specifics on either though.
 
RammerJammer75 said:
I've heard the 5.2s had a "larger" cam (more duration and lift) than the 5.9, but I've never actually measured them. I can't remember the specifics on either though.
Click to expand...

Yeah same here. There is a lot of conflicting info and this one measures nowhere near the .432 i was expecting.
 
Looking at Melling's Spec for the 5.2 Magnum cam, Intake lift is around .390" Both of these wee Spec'd for a 2000 Ram 1500 on Rock Auto's site, which may be wrong.

5.2
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5.9
upload_2021-7-19_8-19-11.png
 
Yes from my understanding the larger 318 cams came out of the 5.2 magnum engines not roller 318s
 
I'll post some specs on replacement cams. I believe being that it's an '85 this one may have been replaced at some time. I have a cousin who worked at a Dodge dealership and he said the first year hydraulic roller 318s had a higher than normal warranty rate on cams and lifters.
 
Magnum heads had 1.6 ratio rockers.....LA's had 1.5 so the same cam in different heads would yield different valve lifts. .288 at the lobe would be a .432 lift @ 1.5
>>>.270 @1.6 would be a .432 lift.
 
Just looked it up and confirmed 318 la roller cams are 240/.391. Factory la 360s are 252/.410.
 
pishta said:
Magnum heads had 1.6 ratio rockers.....LA's had 1.5 so the same cam in different heads would yield different valve lifts.
Click to expand...

That's what I'm working off if regarding the pre-magnums having the 1.5 vs 1.6. For some reason I thought the 5.2 mags had 1.5 but that doesn't make sense right now.

The goal is to get the .432 cam from a 1.5 rocker engine, presumably not a 5.2 mag, and use it in a 5.9 mag with 1.6 rockers to get "almost" .460 from it.
 
Here is a stock cam 1990 318 TBI roller cam short block out of a 1991 D 150 Pickup. Engine is dated 1990.

Converted this engine over to 4 bbl with 1406 600 cfm Edelbrock using the slightly modified 318 TBI intake manifold and the 4 bbl adapter.

Plain and simple adding more fuel with the 4 bbl on that stock roller cam really woke it up performance wise, and lots of fun to have the 4bbl secondaries to play with now too.

100% Stock 318 short block with the Factory 302 closed chamber heads.

Could not be happier how this all turned out. Idles nice too, sounds thoaty out the dual exhaust tailpipes too along with the resonators I have at the rear bumper.

Resized_20200603_204317_8931.jpeg


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Redrilled TBI intake manifold to accept 4bbl adapter. Using this manifold it port matches the stock 318 heads for the smooth port flow.

20200611_130042.jpg


Screenshot_20210718-205127_Gallery.jpg
 
Get a regrind and they will lower the floor to get your .432 lift but that will require pushrods unless your valvetrain is adjustable as all performance builds should be anyway. Just makes sense.
 
pishta said:
Get a regrind and they will lower the floor to get your .432 lift but that will require pushrods unless your valvetrain is adjustable as all performance builds should be anyway. Just makes sense.
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Yeah, I'm not opposed, but I've seen it mentioned in more than one thread that this should work. Just to exhaust this option and stay close to stock as possible.
 
pishta said:
Magnum heads had 1.6 ratio rockers.....LA's had 1.5 so the same cam in different heads would yield different valve lifts. .288 at the lobe would be a .432 lift @ 1.5
>>>.270 @1.6 would be a .432 lift.
Click to expand...

Yep, the rocker ratio "boost" is what I was after.

.288 at the lobe would be .461 @1.6
 
from other sites I got this
stock 5.9 Magnum cam
250/264/110 installed at 119.
this makes the Ica to be 64* to work with 9.4 compression 360M engines
But ...... that also kills the Effective overlap, which with log-manifolds doesn't make much of a difference.
However, in a low-compression engine, you cannot afford that 64* Ica, and with headers, you would be sacrificing I'm guessing about 10 hp over the nose. SO
IMO, a better install would be in at 106. This puts the Ica at 51*, and increases the Effective overlap to the maximum possible. But yes, you will lose the idle-lope, while picking up a lotta pressure. Pressure is power.
In a true 8/1 engine, this install is predicted to make 15psi. Count 'em .. 15psi! that's a lot.

I cannot speak to the veracity of the 119 install, but several sites I visited are fairly confident about it, PLUS, logically, if you install that cam in an 9.4 Scr Magnum, the pressure would go thru the roof, probably well into detonation with iron heads. Even 9.2 is too much for a 51* install, with pressure around 165 at sealevel.
I don't have specs for the 5.2M cam
Jus trying to help.
 
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AJ/FormS said:
from other sites I got this
stock 5.9 Magnum cam
250/264/110 installed at 119.
this makes the Ica to be 64* to work with 9.4 compression 360M engines
But ...... that also kills the Effective overlap, which with log-manifolds doesn't make much of a difference.
However, in a low-compression engine, you cannot afford that 64* Ica, and with headers, you would be sacrificing I'm guessing about 10 hp over the nose. SO
IMO, a better install would be in at 106. This puts the Ica at 51*, and increases the Effective overlap to the maximum possible. But yes, you will lose the idle-lope, while picking up a lotta pressure. Pressure is power.
In a true 8/1 engine, this install is predicted to make 15psi. Count 'em .. 15psi! that's a lot.

I cannot speak to the veracity of the 119 install, but several sites I visited are fairly confident about it, PLUS, logically, if you install that cam in an 9.4 Scr Magnum, the pressure would go thru the roof, probably well into detonation with iron heads. Even 9.2 is too much for a 51* install, with pressure around 165 at sealevel.
I don't have specs for the 5.2M cam
Jus trying to help.
Click to expand...

Yessir, any and all help is appreciated.

What we have is simply a stock 98' 5.9 magnum that's been converted over a carb using LA parts installed in a 65 Valiant.

Right now, we have the very restrictive 273 manifolds but are planning on installing magnum manifolds,I know that can be a pain in the *** but in the spirit of short term, low buck gains, and saving for better stuff, we're going to try. Hey, it's hot rodding right?

Also installed
Air Gap intake knockoff
HEI ignition mod
600 holley w/vac sec

So, the car "will" have...

Magnum Ex manifolds (TTI's or Doug's to follow)
Modified distributer (weld the governor plate and change the springs)
A "better" cam. Thinking of an Oregon regrind #1341 (218/224 @ .050”, 270/276 adv, .482”/.482” lift)
8.8 R/E with 3.73's (I'd like to change these to 3.55's)

Long term goals are a full "proper" rebuild for a strong street/strip tool around and piss chivies off, kind of build.
 
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Cuda416 said:
What we have is simply a stock 98' 5.9 magnum that's been converted over a carb using LA parts installed in a 65 Valiant.
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Check your cylinder pressure then. With iron heads, 165 is about the limit for pump gas.
If the stock Magnum cam is still in that engine, and your pressure is down at 150 or less, then check your Installed-Center-Line. Maybe you already have a pretty good cam, just severely retarded. Fifteen psi at low rpm is a VERY BIG deal.
 
AJ/FormS said:
Check your cylinder pressure then. With iron heads, 165 is about the limit for pump gas.
If the stock Magnum cam is still in that engine, and your pressure is down at 150 or less, then check your Installed-Center-Line. Maybe you already have a pretty good cam, just severely retarded. Fifteen psi at low rpm is a VERY BIG deal.
Click to expand...

Will do AJ, thanks. It is the stock cam.
 
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