QUESTION: 360 LA cam in a magnum engine?

[E911manager]

New mopar guy and I need some help..

Does anyone know if you can use a older LA style cam in a later model magnum engine? Two issues I am concerned about.

1. The LA cam has a longer snout for the manual fuel pump. Will this hit the timing cover if I use the magnum timing cover?

2. The LA cam is supposed to have oil holes for the bearings. What issues will this cause if any?

Been on magnumswap.com but doesn't really answer these questions.

I have a 1994 360 magnum all stock and want to put a mild cam in it. I am going with a carburetor on a Edel 7577 intake so I can keep the factory AC compressor (in case i decide to put air on later). I plan on running an electric fuel pump also..

 

[WP29440SE]

isn't the 94 magnum a roller cam?

at any rate, if it were me , I would just get a new one, they arent that expensive

 

[bobtile]

Magnum engines are rollers.

 

[YY1]

Is the base circle the same?

You would be forfeiting the higher possible lift rate, but you'd be gaining the durability.

I'd like to know as well.

Same thing could be asked of pre-Magnum roller LA motors.

Sure would make for an easy answer to all those zinc threads.

 

[sleepar]

Different rocker ratio also... just get a cam for the magnum.... Or use a cam for a poly 318...

 

[Budnicks]

Biggest differences is the Magnums vs LA blocks & heads camshaft etc.,

Magnums oil the heads/rockers thru the push rods, use drilled or hollow style 5/16 Ball & Ball push-rods,
not a shaft style stamped steel rocker like the LA's have, that oil the top-end of the engine thru the rocker-shafts...

Magnum rockers, they work independent {like a sbc}, they are also 1.6:1 ratio vs 1.48:1 ratio
{or less ratio in stamped steel} of the LA shaft style rockers...

Magnums are also equipped with hydraulic roller lifters/camshafts with less "cam" lift
{depending on what OEM cam, not aftermarket stuff}
mainly because of higher rocker ratios in the Magnums to compensate...

Magnum Heads have a vertical bolt pattern on the intake side {vs the 90* versions on the LA heads}
of the heads that except Magnum style intakes,
an the LA {pre-93 style} intake would have to be modified, for the vertical Magnum style intake bolts,
to work or to be able to be used on a Magnum headed block...

Also;
Magnum cams don't have/use any mechanical fuel pump eccentric
{or a mechanical fuel pump, they are all efi, electric pump}
no provisions even for one on the front of the camshaft or Magnum timing cover...

Magnum Hyd Rollers aren't that expensive, the MP OEM R/T version cam, fitted with a set of 1.7:1 rockers,
is a great camshaft/rocker combo, especially for a street car/truck, in the properly set up engine
& a good set of Edelbrock RPM Alum. or Mopar Performance Magnum R/T style cast iron {or MP Alum} Magnum heads,
they both flow way better than the best of the LA style heads "Out Of The Box" anyway, there's also allot of room for improvements/porting or larger valves if wanted/needed to...

There's a great book with a ton of info if your going to build a Magnum,
Mopar Performance #P5007610 "Magnum Engines 2nd Edition", it's like $30,
another is the Mopar Performance #P5249704 "Engines 9th Edition", it's like $25,
both books cover Magnums performance upgrades etc., the latter covers most the rest of Mopar's
performance based B-RB, LA & Magnum engines too...

I'd highly suggest you get a few books on the subject or at least one good one, for referrence
There's a bunch of other How To Books on SB Chryslers/Mopars
http://chucker54.store.yahoo.net/collectables---literature.html

Sorry, if I didn't answer your question directly,
I hope this helps

good luck newbie

 

[rumblefish360]

Different rocker ratio also... just get a cam for the magnum.... Or use a cam for a poly 318...

Use a poly cam? VERY VER VERY BAD ADVICE!!!!

- - - Updated - - -

New mopar guy and I need some help..

Does anyone know if you can use a older LA style cam in a later model magnum engine? Two issues I am concerned about.

1. The LA cam has a longer snout for the manual fuel pump. Will this hit the timing cover if I use the magnum timing cover?

2. The LA cam is supposed to have oil holes for the bearings. What issues will this cause if any?

Been on magnumswap.com but doesn't really answer these questions.

I have a 1994 360 magnum all stock and want to put a mild cam in it. I am going with a carburetor on a Edel 7577 intake so I can keep the factory AC compressor (in case i decide to put air on later). I plan on running an electric fuel pump also..

You can use any see style "LA" cam in a Magnum engine, no problem, just use hollow pushrods, though the actual fit of the cam snout is something I have not personally crossed or heard about.
The biggest issue you actually face is the probable lack of a mechanical fuel pump boss on the Magnum engines timing cover. Early Magnum engines had the boss though it was removed short after the engines arrival.
Worst case, you pick up a electric pump and plumb it in at the rear of the car as close to the gas tank and as low as possible. You can get pumps limited to carb pressures. And since your doing it anyway, no problems there.

The cams minor differences in oiling are small and not a problem.

Just do some math. "LA" cam lift divided by 1.5, them multiply by 1.6 which will equal the new lift. Modify the Magnum heads accordingly to the new lift if need be.

New roller "Magnum" cams from Comp Cams are approx. $315 from Summit racing.

 

[YY1]

So the base circle is the same, and using the Magnum pushrods works (since they're already in the engine)?

 

[rumblefish360]

YY1, I don't know if the base circle is the same but I do know the different style lifters require different pushrods. The Magnums being smaller.
I have a Magnum & LA engine on hand. Though the Magnum is about to be installed in a '79 Magnum.

I did not swap out the OE roller cam.

 

[YY1]

My point was that the roller lifters are already in the Magnum block, along with the pushrods that go along with them.

You made it sound like the OP would need to swap out the pushrods for some reason if he put an LA cam in a Magnum motor, but retained the roller lifters.

So we still don't know if the base circle is the same...

This sure would open up some possibilities besides the $300 and up Magnum specific cams that are available.

A while ago, I asked if the roller LA 318 had a different cam (implying base circle and/or higher ramp rate) than the non-roller LA, since the lift and duration specs were the same.

I never got an answer to that one either.

You would think that a practically dirt cheap upgrade to roller lifters (for use on standard LA cams) would generate a LOT of interest in this day of low zinc oil.

- - - Updated - - -

OK, I reread the OP, and doesn't say anything about retaining the roller lifters.

Guess that was me

Sure would be nice, though.

 

[AZBelvedere]

Don't think you can use the same push rods. Magnum roller lifters are longer than flat tappet. When I did my magnum headed LA 408 stroker, I had to measure for pushrod length and have the heads clearance bored for the new push rod angle.

 

[sleepar]

A solid or hydraulic lifter takes a different profile than a roller lifter.... in theory it works... but why?? The right cam for the set up is out there.. that's why there are tons of cams for sale everywhere... the 360 cam in a magnum is waste of time.

- - - Updated - - -

I would be curious to a magnum cam gear and heads on a LA block...

 

[rumblefish360]

A solid or hydraulic lifter takes a different profile than a roller lifter.... in theory it works... but why?? The right cam for the set up is out there.. that's why there are tons of cams for sale everywhere... the 360 cam in a magnum is waste of time.

- - - Updated - - -

I would be curious to a magnum cam gear and heads on a LA block...

This is done often. The problem is the rollerifters are taller than the LA lifters and the lifter bores are shorter. This leads toow oil pressure when the oil band is exposed.

IF you have a later roller LA, then the swap is doable. Though the stock 360 cam is more of a broom stick than the 5.2 Magnum cam. Pushrod tunnel clearance can be an issue. The angles are more severe.

The Magnum head on a LA block is a nice and cheap upgrade, though it is not expolsive in power. The slight better flow and 1.6 rockers are the plus.

I would not use a er lifter on a flat tapper cam since the lobes are designed to rotate the lifter in the bore where as the roller does not.

 

[sleepar]

This guy has all the parts to make a killer combo... there's a thread on for a body's where it's been done... I have a solid lifter set up for a 273 I have used... but that's all my experience on early LA stuff.

 

[YY1]

Rotation- good point...but the actual "roller" is narrower than the lobe, so wouldn't it "miss" the edges, IIRC where the rotation comes from?

 

[rumblefish360]

At FABO, there is a "Magnum" section. Dealing with swaps mostly but a bunch of tech engine wise is in there as well. So far, all I have done are small blocks. The base circle question is one I can not answer.

Popular Magnum head swap heads are;

Stockers - cheap, can be ported out OK. They can make over 400 as cast with 2.02/1.6 valves installed.

EQ or Iron Ram - best bang for the buck. The EQ's come in LA or Magnum style head. IIRC, you can order the LA version and grind down the pedastels to rework the head for Magnum gear while retaining the use of LA intakes.

Edelbrock - less flow in the low lift areas (less flow on the curve) greater flow potential in the high lift area.

Most LA block/engine builds use LA cams and take advantage of the 1.6 rocker. I have never seen or remember anyone having issues with cams and a base circle issue.

I would say, but again, do not know for fact, the base circles are the same.

 

[E911manager]

This is a low budget build. The magnum cams are about 300.. Added to the intake, distributor, midsump pan, blah blah blah then the price keeps going up. Plus there are not that many options without a custom ground which puts you up in the 400 range. The options for a LA style cam are endless so to use a 150 dollar cam lets me put more money toward other things...