Small block cams

[slant6billy]

OK, The LA small block went from the early 60s to the beginning of the 90s before the magnum style version took over until 2005 (full size B vans were the last). In the late 80s, the LA small block went to a roller cam. The Magnum went further with the roller cam & roller valvetrain. Now, back in the 90s the magnum was new and cams were a little difficult to get for it to get more bump. Folks were taking the big cams for the LA small block and slamming the into the magnum. Disregarding the magnums rocker ratio of 1.6 vice the LA 1.5 ratio, some had success at this and some found out their application / result was not anything close to desired.

Anyone have success putting the cam from one to the other? Anyone have a KABOOM?

In the difficult middle with a 1992 Pre magnum LA. Looking at the roller cams for the magnums since the flat tappet or hydrolic style LA just seem to be going backwards. I think if folks could slam a LA cam into a magnum, then one could slam a magnum spec cam into a LA. Oil pump primer, distributor, and all else is the same.

I'm not even discussing lifters yet. That is the next step in the process.

Any thoughts?

 

[Joe12459]

I found this thread that might be helpful.
Magnum cam in roller LA block - DodgeTalk : Dodge Car Forums, Dodge Truck Forums and Ram Forums

 

[slant6billy]

I found this thread that might be helpful.
Magnum cam in roller LA block - DodgeTalk : Dodge Car Forums, Dodge Truck Forums and Ram Forums

thanks brother. Now where did you mount your electric fuel pump on your Mirada after you went back to a stock style tank? I'm headed in that direction

 

[Joe12459]

thanks brother. Now where did you mount your electric fuel pump on your Mirada after you went back to a stock style tank? I'm headed in that direction

I used an inline EFI pump on my car. I mounted it to the front facing side of the tank straps. On mine, because I no longer had the plastic shield that came stock, I made a mounting bracket that locates the pump between the two straps, and right at the bottom of the tank.
My son had some issues with vapor lock, so I also installed an inline pump for him. His had the tank shield in place, so I mounted the pump right to the shield, in basically the same place as mine.

 

[slant6billy]

I used an inline EFI pump on my car. I mounted it to the front facing side of the tank straps. On mine, because I no longer had the plastic shield that came stock, I made a mounting bracket that locates the pump between the two straps, and right at the bottom of the tank.
My son had some issues with vapor lock, so I also installed an inline pump for him. His had the tank shield in place, so I mounted the pump right to the shield, in basically the same place as mine.

got a picture of either?

 

[Joe12459]

got a picture of either?

I can take a couple. Give me a few minutes.

 

[Joe12459]

This is little Joe's pump. The photography sucks, because the driveway is still wet and I don't get down that low anymore. I'll get more on the lift if you want.

 

[Joe12459]

This is the EFI pump. Same idea, just a different bracket.

 

[Joe12459]

This is the EFI pump. Same idea, just a different bracket.

View attachment 20424

The photo is a little deceptive. The pump and bracket don't touch the rearend or the tank. There is at least 1 1/2 inch clearance to the rear, and 1/2 inch between the bracket and the tank..

 

[slant6billy]

For your kid's car, regulator up by the carb? Or is the pump only maintaining a pressure head without blowing the carb apart?

 

[Joe12459]

For your kid's car, regulator up by the carb? Or is the pump only maintaining a pressure head without blowing the carb apart?

That's a Carter P74029 pump. It is rated at 5.5 max PSI with no regulator. It provides plenty of fuel for the /six 2bbl. The one in my car is rated at 75 , so I have a 55psi filter/regulator at the firewall.

 

[slant6billy]

That's a Carter P74029 pump. It is rated at 5.5 max PSI with no regulator. It provides plenty of fuel for the /six 2bbl. The one in my car is rated at 75 , so I have a 55psi filter/regulator at the firewall.

Cool thanks

 

[jasperjacko]

How noisy are those pumps?

 

[Joe12459]

How noisy are those pumps?

The Carter is very quiet. The MSD EFI pump is kind of noisy.

 

[BudW]

Chrysler small block camshafts – there are a few differences over the years.

The Poly version and some first generation Hemi’s uses the same camshaft (the first Generation Hemi’s, Poly’s and LA engines have more similarities than differences).

The angle of lifters are at a different (degree) angle than Poly blocks are. I “think” Poly lifter angles are 45’ where as LA engines are at 53’ (or something to that effect). LA pushrods depart from lifter at an angle. Because the lifter holes are drilled into the block at different camshaft degrees, the camshaft lobes are also located at different position on the camshaft itself.

That means a Camshaft blank (pre machined) are different between Poly’s and LA’s, because of the lobe angles located on shaft itself.

LA’s mostly used 4 different grinds through the years (318 2-bbl, 360 2-bbl, 340/360 4-bbl/6-bbl and ’68 340 manual transmission) but they will interchange through the years - until Roller Lifters came about.

The LA camshafts (Roller vs. non-roller) basically are the same – but because roller lifters use different ramp angles and such, the grinds are different (even though the “profile” at rocker arm may be the same). A camshaft machine shop can convert any LA camshaft to any other LA camshaft grind – providing the lobes are not worn down to “round”.

Also non-roller camshafts have a (roughly) 1’ front to rear angle ground into them to help lifter rotate. Roller camshafts do not have that 1’ angle in them sense lifter wheels are flat and lifter rotation is prevented.

Magnum engines use the same basic camshaft “blank” but grind profiles are again, slightly different. Part because of the cylinder head design uses air differently and also because of the different rocker arm ratios. All Magnums use Roller Lifters.

Personally, even though they will interchange, I would leave LA camshafts (non-roller) to LA engines, LA Roller camshaft to LA roller engines and Magnum camshaft to Magnum engines.

Does this make the topic, clear as mud?
BudW

 

[AJ/FormS]

There are two nice things about roller lifters
1) freedom to not worry about flatting the cam during break-in.and
2) they can be reused on multiple cams

There are two nice things about Magnum heads
1) the 1.6 advertised rockers, which may actually be very significant on account of the older LA stamped items seem to measure closer to 1.4, than to 1.5; and
2) the heads flow better than the older stuff, right OOTB

There are many nice things about Magnums. As factory assembled,here are some:
1) they make more power than older LAs, and
2) they make more torque, and
3) they do it with the stock parts
4) And the injected ones are more fuel efficient and
5) they last longer.
6) they respond better to hot-rodding

You can install Magnum heads onto the older LAs, but retrofitting roller lifters, can be tricky and very expensive. One would be WAAAY ahead to just start with a Magnum core.

 

[kkritsilas]

Magnum Heads on an LA block are also possible, and far easier to do with the standard hydraulic flat lifters. Longer length push rods will be needed, and the Magnum heads use pedestal mount rocker arms vs. the shaft mount rocker arms of the LA heads. You can use standard Magnum heads or the EngineQuest equivalents (the EngineQuest heads are based on the Magnum heads, just with cleaned up runners and with more metal added between the valves to prevent cracking in that area). One of the interesting ideas of the EngineQuest heads is that they can be ordered with LA engine intake bolt arrangement instead of Magnum, allowing the use of standard LA type intake manifolds, which is of interest for those who already have an LA type manifold that they would like to keep without redrilling the intake manifold bolt holes.

 

[AJ/FormS]

And you can order a custom FTH cam for your LA engine, with modern fast-rate lifts, that approach and even surpass roller lifter ramp speeds. You can make a lot of power with a fast rate 230ish cam.Enough to go at least 93mph in the 1/8th,lol.
And with a little less cam,say a fast-rate 222, you can make incredible fuel mileage with an overdrive. But you are gonna need some compression to make the numbers; like 11/1 with aluminum heads, maybe 10 to 10.5 with iron, and tight quench
But for a DD or typical streeter, flip a coin, run what you got. If you don't got, well then................. get a Magnum, and run it either way, as your bank account dictates.

 

[8v-of-fury]

Best cam suited for the highest midrange torque/power from an 88 teen'r?

9.0:1 and still packin 160 psi. She just needs to breathe (heads/cam/exhaust) and I bet that 140hp becomes 340hp.