Fat Hack
09-24-2003, 10:59 AM
Okay, since I did a post on 305 Chevys and small block Fords, I will devote equal effort to the ever-faithfull Mopar maniacs out there in HAMB-Land! Plentiful and cheap to score, the 'LA' engine, or small block Mopar, represents a real bargain to those seeking alternative power for their low buck, home-built hot rod!
I'm going to make a bold suggestion here, based on my personal experience and observations. If you're going to dive into a Mopar small block, you will be best off to start with a 360 cubich inch variant. Yes, the 318 and 273 can be made to run well, but the 360 has the better heads and more cubes to begin with...not to mention, there are thousands of them out there in larger cars and trucks built through the 70s and into the 80s! The 340 is a legendary performer in it's own right, but it was only offered as a performance engine in selected models, and thus...it is harder to find and a little more expensive as a result. Still, if you can score one cheap enough...the 340 is a strong runner!
The 360 Mopar isn't as light as it's Chevy and Ford companions, but it's not a monster, either. They tend to fit pretty well in most chassis designs, and share some superficial characteristics with the Chevy mills...as far as the distributor being in back, the basic layout and such. The oil filters are usually angled, and they can use the small block Ford longer FL1A style filter if there is room. The starter is on the driver's side and is the famous Chrysler gear-reduction type. Headers resemble small block Chevy offerings with the center two cylinders together, but they will not interchange with Chevy units!
On to making some more power! Chrysler always had an excellent factory performance parts program, and there are some great street/strip cam grinds available through them for your little Mopar. The "purple" cams and the 340 four barrel spec cams make dynamite hydraulic choices for the typical street engine. In addition, the Isky Mega Cams are available for small block Mopars, and Edelbrock offers several optional cam kits engineered to work with their intake manifolds, too. Keep the duration @.050" lift specs at or below 224 degrees, and you'll be okay!
Mopar engines use non-adjustable shaft-mounted rocker arms from the factory. This set-up will work fine with most mild hydraulic cams, but if you're drifting into more radical specs, you may have to look into adjustable pushrods or aftermarket rocker arms. Just a thought. I'd stick with a mild grind and just torque the shafts per spec.
Mopar 360s LOVE the basic Edelbrock Performer and Performer RPM intake manifolds! I had an older version of the Performer on a big 1974 Roadrunner, and it hauled ass...with a stock cam and duals with no headers! The single plane Torker 340 works okay, too...at the cost of some low rpm torque. The Torker might be a good choice for a lighter car with more gear, but the Performer RPM is probably better for the majority of mild rods out there.
The factory "six pack" induction systems really rock on a small Mopar...and if you can afford to go that way...it's a dynamite way to make power and look cool, too! Dual quad tunnel rams also seem to work very well on Mopar small blocks. From what I've read and seen people use, two 450 or 600cfm Holleys run strong on an Edelbrock tunnel ram with a decent cam and headers. Surprisingly, torque and midrange power levels actually seem to be boosted on a tunnel rammed 360, in addition to upper rpm power! That might make for a cool visual and performance upgrade if running a small block Chrysler in a rod where the engine is fully exposed. They will run on a stock engine with bolt-on speed parts, but don't push a stock 360 short block much over 5500-6000 rpm!
For carb choices on a single four barrel engine, I like the Holley 750cfm vacuum secondaries as a balance between power and economy. Lighten up the secondary spring and give it a little healthier pump shot to really make the 360 go! Also, a properly built and dialed in Thermoquad works wonders on a 360! They kind of have a bad image, but that comes mainly from confusion and lack of knowledge. They DO work great, but are not as familiar to the masses as the Holley is. I'm so used to tuning Holleys that I tend to put them on everything...but if you have a Thermoquad, you may want to give it a whirl before pitching it!
The Chrysler electronic ignition systems for small block Mopars is really hard to beat. You can get all of the components by buying the electronic ignition conversion kit right from Mopar through your dealer or speed shop. You'll get a brand new distributor, an electronic ignition control module, the proper ballast resistor, and the wiring you'll need. Nothing wrong with points distributors...but the factory Mopar dizzies had a habit of freezing up the advance units and running like crap! For my money, I go with the whole conversion kit! There are three different performance modules for the Chrysler electronic ignition....orange, chrome and gold. The orange box is the best all-around choice for most rods, with the chrome box being a slightly hotter upgrade. The gold box is a racing oriented unit. Use the orange or chrome one for your street/strip Mopar.
Be aware of the fact that there are different ohms ratings on Chrsler ballast resistors! Use the right one for your set-up...either for a points style distributor, or an electronic one. That's another advantage of buying the conversion kit...you get all the right components in one handy package!
From there, a good set of headers is all you'll really need to round out a budget-built 360 Mopar! Run one of these engines in a T-bucket or a Model A, and you'll have an interesting alternative to the typical small Chevy. Carefull shopping can yield you one of these engines for next to nothing...just buy a rusty old van or big ol' Chrysler land yacht and you have a source for other incidentals as well as your engine!
A word on trannys....there are 727 Torqueflites available with the small block Chrysler bolt pattern, but personally I'd recommend the lighter and cheaper 904 trans. It's not as beefy as a 727, but it also takes far less power to operate and works very well with a shift kit and slightly looser converter. In a light car such as your typical hot rod coupe or roadster, it's all the trans you'll need. Be very carefull to insure that you set the throttle valve adjustment correctly, though...or you'll waste the tranny faster than shit! The 'kickdown cable' as most folks call it is essential to proper operation and long life on a Chrysler auto tranny. You can eliminate the need for it by going to a full manual valve body, but that's beyond reasonable for a low buck rod. If you're going to go full manual, run a stick shift!
In closing, the rock solid 360 Mopar engine will run strong and provide you with relaible power for a relatively low investment. They are still easy to find and service parts are available at any auto parts store. Consider one for your next low buck hot rod project...those die-hard Mopar fanatics out there will love you for it...and you'll dig being different while burning rubber!
I'm going to make a bold suggestion here, based on my personal experience and observations. If you're going to dive into a Mopar small block, you will be best off to start with a 360 cubich inch variant. Yes, the 318 and 273 can be made to run well, but the 360 has the better heads and more cubes to begin with...not to mention, there are thousands of them out there in larger cars and trucks built through the 70s and into the 80s! The 340 is a legendary performer in it's own right, but it was only offered as a performance engine in selected models, and thus...it is harder to find and a little more expensive as a result. Still, if you can score one cheap enough...the 340 is a strong runner!
The 360 Mopar isn't as light as it's Chevy and Ford companions, but it's not a monster, either. They tend to fit pretty well in most chassis designs, and share some superficial characteristics with the Chevy mills...as far as the distributor being in back, the basic layout and such. The oil filters are usually angled, and they can use the small block Ford longer FL1A style filter if there is room. The starter is on the driver's side and is the famous Chrysler gear-reduction type. Headers resemble small block Chevy offerings with the center two cylinders together, but they will not interchange with Chevy units!
On to making some more power! Chrysler always had an excellent factory performance parts program, and there are some great street/strip cam grinds available through them for your little Mopar. The "purple" cams and the 340 four barrel spec cams make dynamite hydraulic choices for the typical street engine. In addition, the Isky Mega Cams are available for small block Mopars, and Edelbrock offers several optional cam kits engineered to work with their intake manifolds, too. Keep the duration @.050" lift specs at or below 224 degrees, and you'll be okay!
Mopar engines use non-adjustable shaft-mounted rocker arms from the factory. This set-up will work fine with most mild hydraulic cams, but if you're drifting into more radical specs, you may have to look into adjustable pushrods or aftermarket rocker arms. Just a thought. I'd stick with a mild grind and just torque the shafts per spec.
Mopar 360s LOVE the basic Edelbrock Performer and Performer RPM intake manifolds! I had an older version of the Performer on a big 1974 Roadrunner, and it hauled ass...with a stock cam and duals with no headers! The single plane Torker 340 works okay, too...at the cost of some low rpm torque. The Torker might be a good choice for a lighter car with more gear, but the Performer RPM is probably better for the majority of mild rods out there.
The factory "six pack" induction systems really rock on a small Mopar...and if you can afford to go that way...it's a dynamite way to make power and look cool, too! Dual quad tunnel rams also seem to work very well on Mopar small blocks. From what I've read and seen people use, two 450 or 600cfm Holleys run strong on an Edelbrock tunnel ram with a decent cam and headers. Surprisingly, torque and midrange power levels actually seem to be boosted on a tunnel rammed 360, in addition to upper rpm power! That might make for a cool visual and performance upgrade if running a small block Chrysler in a rod where the engine is fully exposed. They will run on a stock engine with bolt-on speed parts, but don't push a stock 360 short block much over 5500-6000 rpm!
For carb choices on a single four barrel engine, I like the Holley 750cfm vacuum secondaries as a balance between power and economy. Lighten up the secondary spring and give it a little healthier pump shot to really make the 360 go! Also, a properly built and dialed in Thermoquad works wonders on a 360! They kind of have a bad image, but that comes mainly from confusion and lack of knowledge. They DO work great, but are not as familiar to the masses as the Holley is. I'm so used to tuning Holleys that I tend to put them on everything...but if you have a Thermoquad, you may want to give it a whirl before pitching it!
The Chrysler electronic ignition systems for small block Mopars is really hard to beat. You can get all of the components by buying the electronic ignition conversion kit right from Mopar through your dealer or speed shop. You'll get a brand new distributor, an electronic ignition control module, the proper ballast resistor, and the wiring you'll need. Nothing wrong with points distributors...but the factory Mopar dizzies had a habit of freezing up the advance units and running like crap! For my money, I go with the whole conversion kit! There are three different performance modules for the Chrysler electronic ignition....orange, chrome and gold. The orange box is the best all-around choice for most rods, with the chrome box being a slightly hotter upgrade. The gold box is a racing oriented unit. Use the orange or chrome one for your street/strip Mopar.
Be aware of the fact that there are different ohms ratings on Chrsler ballast resistors! Use the right one for your set-up...either for a points style distributor, or an electronic one. That's another advantage of buying the conversion kit...you get all the right components in one handy package!
From there, a good set of headers is all you'll really need to round out a budget-built 360 Mopar! Run one of these engines in a T-bucket or a Model A, and you'll have an interesting alternative to the typical small Chevy. Carefull shopping can yield you one of these engines for next to nothing...just buy a rusty old van or big ol' Chrysler land yacht and you have a source for other incidentals as well as your engine!
A word on trannys....there are 727 Torqueflites available with the small block Chrysler bolt pattern, but personally I'd recommend the lighter and cheaper 904 trans. It's not as beefy as a 727, but it also takes far less power to operate and works very well with a shift kit and slightly looser converter. In a light car such as your typical hot rod coupe or roadster, it's all the trans you'll need. Be very carefull to insure that you set the throttle valve adjustment correctly, though...or you'll waste the tranny faster than shit! The 'kickdown cable' as most folks call it is essential to proper operation and long life on a Chrysler auto tranny. You can eliminate the need for it by going to a full manual valve body, but that's beyond reasonable for a low buck rod. If you're going to go full manual, run a stick shift!
In closing, the rock solid 360 Mopar engine will run strong and provide you with relaible power for a relatively low investment. They are still easy to find and service parts are available at any auto parts store. Consider one for your next low buck hot rod project...those die-hard Mopar fanatics out there will love you for it...and you'll dig being different while burning rubber!