I want to build my first motor, but I need input

[moper]

Just my opinion but given what you have.. I'd get a 5.2L Magnum. It bascially drops in, same everything. It won't be as quick as the 5.9L with the same old nbolt ons, but it will be a bit better than any 273 combo. I can get them running around me for $200-300.

 

[273]

Is the car #'s matching and all that - if so, are you SURE you want to change everything? Not too sure on the rarity of your car - but it might be something to consider before you embark on your journey.. again, just thinking out loud here.

Maybe if it was 383/440 especially rag but even 340 A bodys are barely worth restoring to 100 % original.
My uncle bought a Super Bee recently its been 80s'd but running driving and decent shape for $16000 but it turns out it's a 69 1/2 M code car worth like $70000 he thinks he's hit the jackpot but it would take probably a $70000 plus restoration to make worth $70000, still good find and gonna make profit if sold as is to someone who want to restore.

 

[FrostyMopar]

Just my opinion but given what you have.. I'd get a 5.2L Magnum. It bascially drops in, same everything. It won't be as quick as the 5.9L with the same old nbolt ons, but it will be a bit better than any 273 combo. I can get them running around me for $200-300.

Is there any reason you recommend the 5.2 over the 5.9 other than the price difference?

I'd consider the extra torque to be well worth the small premium of $100-200, then again I live in Australia where 318's are abundant and cheap while a 360 that runs will sell for $2000 any day of the week and twice on Sunday.

 

[ScampMike]

yea maybe, but if I had a 340 rag top with matching #'s, I sure as hell would restore it...

Maybe if it was 383/440 especially rag but even 340 A bodys are barely worth restoring to 100 % original.
My uncle bought a Super Bee recently its been 80s'd but running driving and decent shape for $16000 but it turns out it's a 69 1/2 M code car worth like $70000 he thinks he's hit the jackpot but it would take probably a $70000 plus restoration to make worth $70000, still good find and gonna make profit if sold as is to someone who want to restore.

 

[Kevindc]

Don't even think twice about it. Whatever engine you choose rebuild it top to bottom yourself. You'll learn a lot, it will be interesting and fun. Any help or questions you have can easily be answered on this forum or any number of places. Everything from finding and working with a machine shop to choosing your parts will interesting.

A lot of what you read here is folks that have been doing this for a while so it gets very detailed with the planing, optimizing, science, and the back and forth debating. You need to concern yourself with pretty none of this part of it. Your first build should be kept fairly simple. Heck the biggest problem you might have is getting the pan and valve cover gaskets to seal.

Just please make sure you prime the oil pump and establish oil pressure before you even think about starting that engine!!

 

[FrostyMopar]

I know this thread is "I want to build my first motor" and a few people have suggested fitting a good used motor instead of building one, but please keep in mind this isn't because we want to discourage you from learning new things and experiencing the joys of putting together an exciting new engine. but rather a reflection of the information you've given is.

Namely, three things. firstly you made mention that you consider yourself a novice. time spent learning to remove and refit an engine is a logical starting point and will prove invaluable before getting carried away with the ins and outs of selecting an engine's internal components.

The second being your budget, Any time you build an engine from scratch the machining and parts costs often get pretty out of control rather quickly. You've mentioned you have a disposable budget of around 2.5k which needs to cover your engine, trans and rear end. That's super tight, trans rebuilds are usually pretty pricey.

Thirdly, your performance requirements are more-or-less attainable using a used late model 5.9 magnum engine without having to facilitate any of the above machining costs and while avoiding most of the expensive parts costs

(you shouldn't need new heads, aftermarket valvetrain components, cam, high compression pistons etc with a magnum 5.9, but with a 273 you probably would need these items and the machine work to make them fit to achieve the same desired result). you could realistically expect to achieve the kind of result you're looking for without removing the rocker covers!

I'm all for a project build, who doesn't love wrenching on a new monster donk? (aussie slang for engine) but it sounds like your money will go further if you don't go for a custom reconditioned 50 year old motor which is a little light on displacement. :burnout:

 

[Abodybomber]

Just my opinion but given what you have.. I'd get a 5.2L Magnum. It bascially drops in, same everything. It won't be as quick as the 5.9L with the same old nbolt ons, but it will be a bit better than any 273 combo. I can get them running around me for $200-300.

This, and a LOT BETTER than a 273 rebuilt for daily street/occasionally hot rod use.Some people don't understand bang for buck.

 

[FrostyMopar]

OP asked for a combination for around 300-325hp.

I'm seeing recommendations for the 5.2 magnum, but no suggestions on making the ponies with it.

 

[273]

OP asked for a combination for around 300-325hp.

I'm seeing recommendations for the 5.2 magnum, but no suggestions on making the ponies with it.

Depends on if your talking gross or net HP. The stock 5.9 was the same as the 300HP create which is said to make 320 with headers. And the 5.2 makes only 10 net hp less than the 5.9 .

 

[FrostyMopar]

Yes and no.

The standard 5.9L created 230 hp (170 kW) @ 4,000 rpm and 330 lb·ft (449 N·m) @ 3,250 rpm. It was upgraded in 1998 to 245 hp (183 kW) @ 4,000 rpm and 335 ft·lbs (454 N·m) @ 3,250 rpm.

At the time of its introduction, the 5.2L Magnum created 230 hp (170 kW) @ 4,100rpm and 295 lb-ft of torque (410 N-M) @ 3,000rpm

Both the 5.2 and 5.9 Magnum engines in truck format featured the "safely tow a heavy trailer all day long" conservative factory fuel and igintion tune, terrible kegger intake, tiny throttle body and restrictive cast manifolds. They made comparable horsepower and torque numbers per cubic inch.. 15hp and 40ft/lb difference over all.

But in reality once you get rid of those restrictions and "bolt-on" both magnums into "300hp crate motor" spec the difference is gonna be closer to about 35hp and 85ft/lb in favor of the 5.9, possibly more.

Notice even in truck format the 5.9 makes it's peak torque at a higher RPM of 3250RPM vs 3000RPM for the 5.2, despite the fact that it's breathing through the exact same cylinder heads and intake manifold as the smaller motor? ordinarily, Everything being equal except for displacement the smaller engine would create it's peak torque at a later RPM .

This suggests that the camshaft in the 5.9 actually has more duration and/or the motor has higher compression. IMO probably both if accurately measured.

If you want 300hp, I highly recommend you pick the 5.9

If you are happy enough with closer to 270hp. I highly recommend you pick the 5.2 instead and save yourself $250 or so.

 

[lil red]

the first 360 I built was basically stock e58 block with cast flattops, mopar 268 camshaft, ld340 intake, j heads, headers, duals, larger big block Thermoquad and it made good power with a ton of torque and the build cost about 2500-3000 (parts are a bit more expensive north of the border as well)
I had a couple of good reference books - one was how to build small block mopars, which had a good step by step checklist that was very handy and helped not missing some details along the way...

of course that was before FABO which helped on my last build, where I had a few questions that I could post and within minutes get some very good advise. I'd tackle the build if I was you, especially for the horsepower range your looking for, and especially with the help of this forum which has some very knowledgeable members

 

[67CudaBob]

This thread is very helpful guys - I know it is a bunch of different ideas, but that is exactly what I needed to hear.

The extra $250 estimate for a 360 over a 318 doesn't bother me - the little extra kick is "worth it" to me.

After reading all of this, and thinking things through, I am leaning toward the 360 Magnum swap - for a couple of reasons. It will get my feet wet. I will learn a lot and have a much higher chance of success without running out of money or patience.

My end goal is to have more than one classic Mopar, and I do want to build a motor - mostly for the pride factor to say I did it and that feeling one must get when you fire it up and everything works.

So I think I will find a 360 Magnum for the ragtop, and then I plan to read and learn more about building a higher performance motor for my next ride.

I really appreciate everyone's input - I am kind of a middle of the road thinking guy, so I can see most sides to every story so it really helps to hear everyones' ideas to help hone in what I should do.

 

[273]

Yes and no.

The standard 5.9L created 230 hp (170 kW) @ 4,000 rpm and 330 lb·ft (449 N·m) @ 3,250 rpm. It was upgraded in 1998 to 245 hp (183 kW) @ 4,000 rpm and 335 ft·lbs (454 N·m) @ 3,250 rpm.

At the time of its introduction, the 5.2L Magnum created 230 hp (170 kW) @ 4,100rpm and 295 lb-ft of torque (410 N-M) @ 3,000rpm

Both the 5.2 and 5.9 Magnum engines in truck format featured the "safely tow a heavy trailer all day long" conservative factory fuel and igintion tune, terrible kegger intake, tiny throttle body and restrictive cast manifolds. They made comparable horsepower and torque numbers per cubic inch.. 15hp and 40ft/lb difference over all.

But in reality once you get rid of those restrictions and "bolt-on" both magnums into "300hp crate motor" spec the difference is gonna be closer to about 35hp and 85ft/lb in favor of the 5.9, possibly more.

Notice even in truck format the 5.9 makes it's peak torque at a higher RPM of 3250RPM vs 3000RPM for the 5.2, despite the fact that it's breathing through the exact same cylinder heads and intake manifold as the smaller motor? ordinarily, Everything being equal except for displacement the smaller engine would create it's peak torque at a later RPM .

This suggests that the camshaft in the 5.9 actually has more duration and/or the motor has higher compression. IMO probably both if accurately measured.

If you want 300hp, I highly recommend you pick the 5.9

If you are happy enough with closer to 270hp. I highly recommend you pick the 5.2 instead and save yourself $250 or so.

I see it differently the hp power numbers are well documented but it seems the RPMs very from the source.

Since both are identical besides bore and stroke
The difference in power probably are from exhaust and tuning. I know my jeep and the R/T Dakota's make an extra 5 hp for 250 hp and that's cause the computer has a hotter setup. I have to run super over normal 5.9's.

I see it as proof that the cubic inch only really has effect on torque which is already well known. But that hp comes from top end which bore size is apart of that equation but at this power level the 5.2 shrouding has little effect.

For the torque difference for the 2 can be equalled out with gearing basically a 318 with 4.10 will equal a 360 with 3.55. But another way to look at it if gas mileage is more of a concern is a 360 would need around 2.85:1 to match a 318 with 3.23. But 9 times out of 10 I'd say go 360 unless deep gears don't bother you.

 

[Coyote Jack]

Rusty and Rumble are giving you good advice on the 5.9. If it was me I would be looking at the trucks on Copart to find a low mileage 5.9 in a yard near you. They will usually have a run and drive tag if they engine is any good. They are usually pretty cheap for a wrecked truck. Buying a truck this way for the engine may be the way to go as you can recoup some of your money by either parting the rest of the truck out or selling it as scrap.

Jack

 

[Abodybomber]

This thread is very helpful guys - I know it is a bunch of different ideas, but that is exactly what I needed to hear.

The extra $250 estimate for a 360 over a 318 doesn't bother me - the little extra kick is "worth it" to me.

After reading all of this, and thinking things through, I am leaning toward the 360 Magnum swap - for a couple of reasons. It will get my feet wet. I will learn a lot and have a much higher chance of success without running out of money or patience.

My end goal is to have more than one classic Mopar, and I do want to build a motor - mostly for the pride factor to say I did it and that feeling one must get when you fire it up and everything works.

So I think I will find a 360 Magnum for the ragtop, and then I plan to read and learn more about building a higher performance motor for my next ride.

I really appreciate everyone's input - I am kind of a middle of the road thinking guy, so I can see most sides to every story so it really helps to hear everyones' ideas to help hone in what I should do.

Best of luck,did this myself... Check out www.Magnumswap.com,read what they have there.A FABO member (LXguy..) assembled this website, & it's a good one.Also check out the Magnums forum here,post lots of questions. If you do the 5.9 Magnum right,you will love it.

 

[2 Darts]

Recommend that a machine shop be used for the heads and boring or planing of the block if needed. If the block is hot tanked (cleaned) at a machine shop be sure the cam oil gallery plug (Trelbig's post) is in place. Otherwise your day, and engine, will be wrecked.

You can pay someone else to build an engine to your specifications without much effort. If you decide to go this route, find a shop that has been around a while and has experience with small block Mopars. However, there's very little that replaces the satisfaction I get when I fire up an engine that I did most of the work on (all but the heads, usually) for the first time.

Recommend selling the LD4B and use a 360 for the new motor. The LD4B is configured for 273/318 small port heads. Put the $s towards an intake for the larger port heads of the 360.

 

[RedFish]

Is the car #'s matching and all that - if so, are you SURE you want to change everything? Not too sure on the rarity of your car - but it might be something to consider before you embark on your journey.. again, just thinking out loud here.

That was my line of thought. Hypothetical question for the 67 vert owner... If a previous owner had spent XXXX.xx to put a whole lot of incorrect later model drive line components in this car, Would you have paid XXXX.xx more for it, or even been interested in it at all ?
In my opinion, if a 67 came with a slant 6 and that engine finally died, a 273 or some other V8 would be a practical change. If it came with a 273, I wouldn't do more than get what happy moparing I could from that. Improved exhaust, ignition, the 8.75 rear with lower gear is correct enough for this car. Bottom line... if rebuilding a V8 engine is a burning desire, you do have one.

 

[magnumdart]

I' m surprised no one is really trying to convince you to do a 340. You can easily get your power requirements out of one. And it would hold its value,as long as you don't eject its internals. What would you consider to be too much for a complete 340?

And here is some food for thought. I got this out of an old thread. The post is from a respected member who has also commented here. You might even convince someone to give you one of these. Like one of my friends told me long ago, there aare some pretty nasty 318's running around.


RustyRatRod
09-21-2011, 09:39 PM
You have to work hard NOT to get 300 HP from a 318 with 9.5 compression a decent cam good induction and headers.

 

[ir3333]

...lot's of good info but your head must be spinning.
slow down a bit.Install that LD4B, a 600 eddy,those 3.55's and tune it sharply.
then see how you like it and where you might like to go next!

 

[67CudaBob]

That was my line of thought. Hypothetical question for the 67 vert owner... If a previous owner had spent XXXX.xx to put a whole lot of incorrect later model drive line components in this car, Would you have paid XXXX.xx more for it, or even been interested in it at all ?
In my opinion, if a 67 came with a slant 6 and that engine finally died, a 273 or some other V8 would be a practical change. If it came with a 273, I wouldn't do more than get what happy moparing I could from that. Improved exhaust, ignition, the 8.75 rear with lower gear is correct enough for this car. Bottom line... if rebuilding a V8 engine is a burning desire, you do have one.

I bought the car 2 years ago knowing that the 273 would be replaced at some point for something with some more zing to it. I bought that specific car because I loved the story behind it - lady had it 36 years - had every oil change receipt - Husband bought her the baby blue paint job in 1980 because it was her favorite color, etc, etc,. Neat people, neat car - she just needs a little more oooomph to her :glasses7:.

 

[67CudaBob]

...lot's of good info but your head must be spinning.
slow down a bit.Install that LD4B, a 600 eddy,those 3.55's and tune it sharply.
then see how you like it and where you might like to go next!

LOL - oh my head is indeed spinning! The LD4B and Eddy are installed currently. I was holding off on installing the rear end until I did the motor upgrade.

My biggest issue I think is that I sold a high performance 67 Cuda fastback to get a more family friendly drop-top - but since I have tasted that power the Cuda offered, it is hard to feel satisfied driving something with less than half the horses.

My Ex:
View attachment Cuda in Driveway - small.jpg

 

[ir3333]

if you are currently running 2.72 gears the 3.55 will be a dramatic change.
having said that,like most i'm in the 360 camp.

 

[ir3333]

...and that LD4B will work fine on a mild 360