First Build - Need Engine Recomendations

[SlyGuy]

Hey Everyone,
We are in the process of building a '72 Challenger (my two grown sons are helping me). We are getting close to needing to decide on an engine and transmission. It was a 318 car with an automatic transmission originally. I am NOT trying to build a show car, or a race car. I just want it to look good, and to be able to drive it on a fairly regular basis. However, I don't really want to put a 318 and auto trans back in either. Basically, I'm looking for good (economical) power.

I read thru another thread on this site where someone was trying to decide on a engine, and it looked like a popular choice among those responding was 87-92 LA 360 roller block? Please keep in mind that I have only ever helped build one engine in my life, and it was out of a 1943 2N Farm Tractor, so I really need guidance on where to start. A few questions that come to mind are:

Is an 87-92 LA 360 roller block really a good fit for my '72 Challenger? If I find one, does it matter what vehicle it comes from? Should it be EFI or carb? Will I need specific heads? Will my K-member work?

Any suggestions and/or opinions are welcome. Thanks!     

[70chall440]

Slyguy,

As I think you know, you have lots of choices here. Lets start by saying that your K member will support pretty much anything you want to put in, however if you were to go big block you would probably want to change out the torsion bars (you might want to regardless to improve handling and drivability).

As to which engine; You can go old school (318, 340, 360, 383, 400, 440), old/new school 5.9 (360) Magnum, or new school 5.7 Hemi. Each path has its advantages, issues and cost implications.

Old school - pretty straight forward, lots of support and knowledge online, huge after market, depending on the donor engine, its conditions, the options you choose, can be relatively inexpensive or very expensive.

Old/new school - much like "old school" its pretty straight forward. These engines are an improvement over the original LA engines in several ways not the least of which is the roller cam. That said, you can put a roller cam into anything, so there is that. The Magnum heads are reportedly better, but then you can buy new aluminum heads for old school engines where are as good or better.

New school - a few challenges here, specifically what transmission to use. You can use the old school trans (904 and 727) with an adapter plate so it isnt a huge issue unless you want to run really steep gears (4.10, 4.56, 4.88, etc), then you might want an overdrive. You can use a modern trans but you will have to cut the trans tunnel to make room for it. Another challenge here is the wiring, Mopar makes a stand alone harness to make this much easier, but you will have to mount the CPU some place.

Which ever path you choose, I would highly recommend going EFI. You can do so on any of the options to include old school. If you go with an aftermarket EFI system such as Fitech, its like 4 wires to hook up, if however you go with something like a Holley EFI, MSD, etc you will have to mount a CPU and run the harness. The benefits of EFI far outweigh the effort to install it; I ran carbs for many years and have or will convert every vehicle I have (5 vintage vehicles) to EFI. The other aspect of EFI that some don't like is that you need to install a commensurate fuel system; fortunately Tanks Inc. sells a bolt in tank and pump. You will need to run feed and return lines.

You can run a carb for sure, they have been used for many years and have served well. The down side traditionally is tuning and if you don't drive the vehicle frequently you can have issues getting the car started and running at times. Ethanol based fuel and carb gaskets don't get along, but if you can source Ethanol free fuel you can get past this easier.

As to cost, they all are pretty much the same depending on a wide variety of issues (where you start, where you want to go). Personally, I would recommend going with a newer Magnum engine at least, preferably from a running low mile vehicle. That said, if it were me I would go Gen III Hemi with a 904 or 727 trans (or better yet a manual). You can buy a brand new engine with a warranty for less than $5k, slightly used engine for $2500. the engine harness and CPU is like $1700 and lots of people have now done this so there is quite a lot of experience out there. There are some issues on which engine (year/model) to focus on which has to do with the accessory drives. The advantage here is that you get modern power, lots of parts available, modern reliability, etc. The next car I build (my 68 Cuda) will go this route.

Of course you can stay old school. The key here is to find a good donor engine. Do your homework and never take the seller's word as to what an engine is or what it represents. If the engine is purported to high speed and big HP, etc. get proof and try and find an engine you can hear run before buying. Keep in mind that if an engine is great, why is it being sold. Many people build engines with the wrong components that while they run are a nightmare (won't idle, low vacuum, lots of blow by, etc.). Try and get a guarantee if possible; can be difficult of course but at least try. Be very wary of the seller who says "I don't know anything about this engine".... those are code words for "this is probably a pile". 

Look hard at remanufacturerd engines, check your local O'Reillys or Autozone, you might be surprised at what you will find. You can buy a "reman" long block 5.9 360 from a 89-90 Ram 150 (1500) for like $2K; perhaps throw a cam in it (for fun), intake, valve covers, cam cover, oil pan, accessories, exhaust and you are there. You can probably find a short block as well and then go with some aftermarket heads if you are feeling froggy..  you get a warranty and don't have to wait on the machine shop.

This brings me to the next option, visit your local machine shops and see what they have. Every machine shop I have ever been in has a number of donor engines laying about. You might be able to score a deal.

Given your stated minimal experience with building an engine, I would recommend you stay away from engines laying in people's yards that seem like a great deal. Again, if the engine was a stump puller, high HP motor it wouldn't be laying in a yard. Of course they will all say "it ran when pulled", well in my experience that usually means "it was broken and we had to change it". Last engine I got like that had 4 bad cylinders with the piston ring lands completely broken yet the previous owner swore it "ran great".... Now, if the seller can start the engine for you, then I might entertain it if I needed something to drop in. Of course the best case scenario is to hear the engine running in a vehicle, actually drive it and access it. Do not forget to pull the dipstick and check the oil. If it is very clean, it could indicate that there is an issue he doesnt want you to see (as in a leaking/blown head gasket); no one changes the oil to sell an engine. Also look at the exhaust and see whats coming out; have someone rev it while you are behind it and listen to it, smell it and watch it. If you have the capability and intend to merely drop it in, you would be well advised to do a compression and a leak down test on it (or have someone do it for you).

Regardless of what you do, do not hesitate to post on here any questions you may have. We are happy to help.

[challengermaniac]

Best Response Ever 70Chall440! 

[70chall440]

Best Response Ever 70Chall440!

Thank you

[jimynick]

Great and fulsome advice and you'd be well advised to take it! 

[70chall440]

I just went back and corrected some of my misspellings and garbled thoughts, plus I added a little bit.

[SlyGuy]

Indeed! This is exactly what I needed. Once again, much appreciation to 70chall440 for the input.

Just to show you how "out in left field" I am, I work part time for O'Reilly's, and it hadn't even occurred to me to see what my employee cost would be on a block 

Part of my problem is that I don't know what kind of HP to shoot for. I'm not going to be racing. I want it to be a driver, but also let people know that it is a muscle car. Do I need 400HP for that, or is 275 to 300 enough?

One of my co-workers is an old school Mopar guy. He is convinced that I should go old school. I should buy an early '70's block for around $500.00, get it bored 30 over, add a few parts, and end up with nearly 400 HP (according to him). My son, however, is doing his best to convince me to go "old/new school". He thinks I should use a web site called "car-part.com" to find a relatively low mile engine and trany and drop them in.

I understand that all options have their own cost implications. I am trying to budget as much as possible, but don't want to let that be the determining factor (within reason). I'm not there yet on which way to go, but highly appreciate the input already given (thanks again 70Chall440). 

 

[70chall440]

SlyGuy - its my pleasure and I am happy to help. As to HP; this is of course an emotionally charged subject, but if we put some parameters around this it might help. For clarity, the HP levels listed here are at the flywheel, meaning they are what the engine produces.

250 - 275 HP: typical levels for the late 70's, will get you around town, won't do an impressive burn out, normally easy to maintain and reliable. Very easy to obtain.

275-300 HP: would represent the better or more high performance cars in the mid 70's and some modern cars. a peppy version of the first one but should support some spirited driving. Not difficult to obtain using easy to obtain parts.

300 - 350 HP: Would be similar to early to mid 70's muscle cars, fun to drive, relatively easy to obtain, requires a little more attention to detail and parts selection.

350 - 400 HP: Would be representative of some of the more HP cars of the 70's. Not terribly difficult to obtain but the parts selection needs to be a little more specific. Will offer some great fun in driving but may require some caution as it can get away from you. Depending on the platform, could require a little more maintenance to keep at optimal performance. Cost to obtain will be higher. FYI this is where new Challenger RT, Charger RT, Ram trucks, etc are now (375-395).  This level starts to affect drive train components.

400 - 450 HP: Starting to require more $$ and specific parts selection. Will typically roast the tires without a lot of effort. Should carefully consider good quality drive train components (clutch, trans, U joints)

450 - 500 HP: Starting to get expensive and require specific parts that work together to achieve the goal. Also really starts to hit the drive train significantly (i.e. breaks parts).

500 - 550 HP: Requires detailed planning and specialty parts. Start to get expensive. Definitely will affect drive train components.

I am sure this isn't super clear and there is lots of misinformation out there not the least of which is flawed memories. So many people (car people) will say "i had such and such car that had 500+ HP with factory parts" etc. In pretty much every instance of this type of talk, there isn't any dyno results or 1/4 mile time slips to support it.

300 HP is a good target for a street car that is going to be driven. 300 HP can be made to 350 or more without a huge amount of effort and can be done incrementally.

The one thing you need to think about is building a good foundation, meaning the short block. Need a good crank, rods and pistons. Once you have that, you can do whatever you like to make whatever HP you like (within reason).

Last thing and as I said previously, I would focus on a Magnum motor if you want that old school look (for the most part), they are plentiful and will deliver decent reliable power.

[challengermaniac]

Last thing and as I said previously, I would focus on a Magnum motor if you want that old school look (for the most part), they are plentiful and will deliver decent reliable power.
[/quote]

Agreed.  While I am addicted to 340's (see my car list), they are very expensive to buy and build.  The Magnum motors will get you a lot more these days for a lot less money.

[70chall440]

 

[SlyGuy]

All I can say guys is great minds think alike! Just brought it home yesterday. It's a 360 out of a 2001 pick up with 131,000 miles. Now we just need to decide how deep we want to get into it. I "had" decided to shoot for 300 HP, but my boys are nudging me to up the ante a little, and shoot for closer to 400 

[70chall440]

Excellent.. now you start down the slippery slope of power...  Obviously there are a number of options, 131K isnt horrible so long as it was maintained.

Here is how I visualize the options

A. Clean it up, change out the oil pan (from truck to car) and drop it in. Pros - quick and won't cost a lot / Cons - you have a motor with 131K miles, power will not be superb that might be leaky.

B. Clean it up, change the pan, regasket it completely, change the cam out, add headers. Pros - doesnt cost much, will at least look like a new engine, will have a little more power, should serve you well. Cons - still have a 131K motor in there

C. Same as B except throw on a new set of heads (many magnums suffer from cracked heads, I have an 01 and it does as well), Id go aluminum at this point. Between the heads, the cam and the headers your power should be decent, probably somewhere around 350-400. Pros - good running motor that doesnt leak. Cons - not many.

You will have to resist the urge to put in new bearings which leads to polishing the crank which leads to new rings which leads to punching out the motor 30 over.... (otherwise known as a complete rebuild).

You haven't mentioned what you are going to do with intake/fuel. I would highly recommend EFI. Go with something like Fitech, cheap and easy to install but will require a EFI fuel system.

[SlyGuy]

Definitely leaning toward option "C" (350-400 HP).

I know that you have recommended EFI on a couple of occasions now, but I am still struggling with that decision. If I go EFI, you mentioned that I wold need an EFI fuel system? Can you give me a little insight on what that would involve? Would I need a special wiring harness and/or an ECU of some sort? Should I buy the stock replacement fuel tank, or is there something better for EFI?     

[jimynick]

Yes, you'll need a special engine wiring harness and a ECU. If you go efi, then don't buy the stock tank as you'll need one able to mount the in-tank pump and you'll need a return style fuel line setup. While wonderful to be able to reach in the window and turn the key and have the car start and run, it's NOT cheap nor easily accomplished. Many have done it, but if you're not either well versed in efi and/or fabricating/tuning then the sad old carb begins to show her virtues, eh? Oh, did I mention the 1000's of $ you'll also need before you're done? Your car, your call. Have fun! 

[70chall440]

Just to give you the complete picture, I will give you a pile of information but in the end give you some very specific examples to help you decide.

Let's break this down into 3 areas;

1. the EFI system itself (intake, throttle body/s)
2. the EFI controlling system
3. the fuel system

For #1 you need to understand that there are 2 distinct types; throttle body injection (where the injectors are inside the throttle body and direct port injection (where the injectors are installed in the intake and squirt fuel directly int the intake valve/cylinder), this is what every modern car uses now. Within these 2 types of EFI there are a wide range of systems that offer all sorts of attributes, however the more things do (or say they will do, the more they cost). As an example, you could purchase a complete direct port injection system from any number of sources to include the factory system used by Mopar on Magnum engines, or you could just use a 4 barrel intake an bur a bolt on throttle body system like a Fitech, MSD, etc.

For #2; in order for the EFI system to work correctly it needs a controller (basically a computer) which takes in input from various sensors, analyzes that data and makes adjustments in the system (what adjustments depends on how complex the system is). Of course with any computer system there are connections and senors that need to be installed and connected; at the most basic you will need a O2 sensor, coolant temp sensor, inlet air temp and throttle position sensor. In the simple systems everything but the O2 and coolant temp are contained in the unit itself, so installation is very simple, however because its simple it can only do so much. In a complex system you would need all of the previously mentioned senors along with a crank signal and cam signal.

For #3; in most cases a EFI needs to be able to return unused fuel to the tank, thus they need a return line. Additionally EFI operates at a much higher pressure than a carb system (EfI 30-60, Carb 7-16). Therefore a EFI system needs a high pressure pump and very tight connections unlike a carbureted system which can get by with hose clamps and run of the mill rubber hose. As to the lines, you can get pre-bent lines that look like factory lines or you can bend your own. Another option is to run braided lines (I prefer the nylon braided over stainless steel and normally use Fragola series 8000 line and fittings). One very important aspect is filtration; EFI is very sensitive to dirt and debris (small injectors and such), therefore you must install the correct filters in the fuel system. It normally requires 2, a 100 micron and a 10 micron; generally one in the tank and one somewhere along the feed line. You may also opt for a fuel regulator (put onto the return side) and perhaps a fuel pressure gauge (mounted onto the regulator). Some of the basic systems have built in regulators.

So, where does this leave us? Well, here is the simplest and easiest way to put EFI on a car (that I know of)

1. install a throttle body system like a Fitech go street, MSD atomic or Holley sniper
2. buy and install a new tank from Tanks Inc. along with one of their EFI pumps and a new sending unit
3. buy or make new fuel lines (feed and return)

I cannot speak for the MSD or the Holley system but the Fitech connects using 4 wires, very simple and it comes with everything you need. It even comes with a plate system so that that you do not have to weld in an O2 bung (you drill a hole in the exhaust or header, lay the plate over the hole, clamp it in place, screw in the O2 sensor).

You can use the factory sending unit wire. You will need to run a wire for the pump to the EFI system (it controls the pump).

The down side (if you want to call it that) to this system is that you will have to adjust and set your timing as you would with a carbureted vehicle as the EFI does not control timing. Additionally, you have very limited control over the system, you can make some small adjustments but not a lot. The best thing here is that the system "learns" as you drive it, so you really do not need to make a lot of adjustments usually.

This type system is really for a daily driver type vehicle, meaning not a race car or a high HP vehicle. Once you have an air cleaner on you can barely tell its there.

Now, if you are adventurous, have a big HP motor and want to control everything, you can go go with a direct port injection system, a full on CPU and harness. You would need the same fuel system (probably a bigger pump). The advantage of this system is that it controls timing as well as fuel based on the information from the sensors. The down side it requires you to do a little more tuning than with a basic system. You don't have to get knee deep on a laptop and tune every little thing, these systems also self learn, but they let you make corrections manually (which I have found to be very helpful).

So, all said, you can get a very basic system and still enjoy EFI. Yes, installing the fuel system is a little more work however it is well worth the effort.

Hope this is helpful.