Engine rebuild

[mstrk]

Hi guys,

My 318 LA '68 Monaco is due for some engine restoration.
It has been running and driving from the moment i got it for years without any problem, but it now sputters and lacks power. (ever since July '23 as seen in my other threat)
I want to do a rebuild, but have a couple of questions that i cannot find the answer for or have found so much information that i'm lost again.
I have never seen the inside of a 318LA so this will be my first rebuild.

The one thing i am hoping for is to get some more spice out of it (300-350HP?) but it has to be reliable. With al the information i gathered this is what i came up with:
- Upgrade ignition. It's stock now, replace it all with a complete kit or only coil and module? and which one is best to buy?) I was thinking of a Petronix flamethrower with module OR a simple complete HEI distributor kit (as CBODY67 pointed out)
- new fuel tank, lines and pump. Holly sniper kits are too expensive for me.
- New carburator, the current one is held with tiwraps, but which one? Edelbrock?
- intake upgrade (stock 340 is impossible to find here, maybe also an Edelbrock performer? Anyone has a link or partnumber to buy?)
- The exhaustmanifold is also stock, time for headers or is that useless as some say? if yes, which one? I think i only have room for shortys. I already have a new stainless exhaust frond to back, no idea what diameter. (last owner put this in)
- other cam? everyone has a different opinion on this, if yes, which kit is best to take? Some point to this: https://www.hughesengines.com/Index...FtIEtpdHM=&searchmode=partnumber&partid=31310

I was advised to also upgrade to hardened valve seats because of LPG, going to look for a company that can do that for me.

 

[Jakter]

I'd figure out why it sputters and lacks power before doing anything else.

 

[mstrk]

I'd figure out why it sputters and lacks power before doing anything else.

Looks like an ignition problem.

 

[Welder guy]

A shop manual will go a long way in diagnosing your engine issues. It could be ignition , it could be carb . Do a compression check to see how healthy your engine is. Don’t fire the parts canon at it till you know what the issues are . It could save you thousands of $$

 

[mstrk]

A shop manual will go a long way in diagnosing your engine issues. It could be ignition , it could be carb . Do a compression check to see how healthy your engine is. Don’t fire the parts canon at it till you know what the issues are . It could save you thousands of $$

But then i would be back to stock.. i want to upgrade a bit and refresh the engine

 

[57fury440]

In my son's 74 Barracuda it has the 318. We put on a 340 intake manifold and an Edelbrock carb. It is a street only car so we left the cast iron exhaust manifolds. The timing chain and sprockets were changed to double roller and a cam and lifters were added too. I do not remember the specs on the cam, but they were similar to a 340 cam. A shop that does pipe bending put a nice set of duals on it. We changed the rear end gears to 3:55 sure grip. I also changed the advance springs in the distributor. It feels like a completely different car. It was not expensive to do and made a big difference. Adding headers would give more power too.

 

[CBODY67]

www.mymopar.com can be your friend as to downloading (free) factory parts books and service manuals.

The only real option for a stock-type aftermarket 4bbl upgrade is the Performer 318/360 Edelbrock intake. Buy the one "without EGR". Then add an approx 600cfm AVS2 to go on it. You'll need an adapter bracket (which Edelbrock sells) to interface with your throttle linkage.

On the YouTube channel "318 Can Run", the YT-er illustrates how to modify a later-model LA spreadbore intake so that a normal 4bbl will fit and work on it. Just takes some cut-off wheel and grinder action to remove the mounting flange areas. So simple how Chrysler just changed the mounting pad of an existing 4bbl LA intake! It appears that most of what this guy does is "low cost" and works, from what I've seen on there.

You can look on the Lunati cams website and look for a street-upgrade cam of about 210 degrees @ .050" lift, which should have a valve lift spec of about .440" or so. Much more than that with a street-driven/stock torque converter/2.94 rear axle ratio car might be a bit much for a good blend of performance and fuel economy, to me. I figured out that for a normal daily use car, building a torque-oriented motor "which will rpm" can be a better choice than shooting for "power numbers" which only work at 5000rpms or so. AND one that will work with a somewhat stock exhaust system.

Need to measure the OD of the exhaust lead pipes. Lets get the engine built and running before "headers" can be considered?

One issue with the 318 is its smaller valve sizes (than the earlier 340 and all 360s). But not much different than if you downsize the old 340 intake sizes for a 318 motor with the smaller 3.91" bore diameter. Later 340s had 1.88" intakes, IIRC? Of course, some casting flange port matching can happen, too. Everything in proportion.

In doing the rebuild, you do not need lots of "high dollar" stuff, just normal OEM-level parts from good suppliers which can last 100K miles or longer. These things, with a Cloyes roller timing chain, with normal maintenance and syn oils (SL API rating), can result in an engine which can last for 500K miles or more.

Remember, "torque" is what "burns the tires" as "horsepower" is what can help explore the upper end of the speedometer on the Autobahn.

Will you be running the car on CNG, gasoline, or both?

Enjoy!
CBODY67

 

[mstrk]

In my son's 74 Barracuda it has the 318. We put on a 340 intake manifold and an Edelbrock carb. It is a street only car so we left the cast iron exhaust manifolds. The timing chain and sprockets were changed to double roller and a cam and lifters were added too. I do not remember the specs on the cam, but they were similar to a 340 cam. A shop that does pipe bending put a nice set of duals on it. We changed the rear end gears to 3:55 sure grip. I also changed the advance springs in the distributor. It feels like a completely different car. It was not expensive to do and made a big difference. Adding headers would give more power too.

Sounds exactly what i want to do! As it is hard to find a 340 and with imports the costs fly up i think an edelbrock intake could be a better and easier option, wil put the rest on the list, i forgot about the advance when putting a hei module and coil in..

 

[1971 300 Alvah]

I thought I had a serious problem with my Alvah. It idled fine, had acceptable power under cruise, sputtered and hesitated under any load, turned out to be a failing ignition coil.

 

[mstrk]

www.mymopar.com can be your friend as to downloading (free) factory parts books and service manuals.

The only real option for a stock-type aftermarket 4bbl upgrade is the Performer 318/360 Edelbrock intake. Buy the one "without EGR". Then add an approx 600cfm AVS2 to go on it. You'll need an adapter bracket (which Edelbrock sells) to interface with your throttle linkage.

On the YouTube channel "318 Can Run", the YT-er illustrates how to modify a later-model LA spreadbore intake so that a normal 4bbl will fit and work on it. Just takes some cut-off wheel and grinder action to remove the mounting flange areas. So simple how Chrysler just changed the mounting pad of an existing 4bbl LA intake! It appears that most of what this guy does is "low cost" and works, from what I've seen on there.

You can look on the Lunati cams website and look for a street-upgrade cam of about 210 degrees @ .050" lift, which should have a valve lift spec of about .440" or so. Much more than that with a street-driven/stock torque converter/2.94 rear axle ratio car might be a bit much for a good blend of performance and fuel economy, to me. I figured out that for a normal daily use car, building a torque-oriented motor "which will rpm" can be a better choice than shooting for "power numbers" which only work at 5000rpms or so. AND one that will work with a somewhat stock exhaust system.

Need to measure the OD of the exhaust lead pipes. Lets get the engine built and running before "headers" can be considered?

One issue with the 318 is its smaller valve sizes (than the earlier 340 and all 360s). But not much different than if you downsize the old 340 intake sizes for a 318 motor with the smaller 3.91" bore diameter. Later 340s had 1.88" intakes, IIRC? Of course, some casting flange port matching can happen, too. Everything in proportion.

In doing the rebuild, you do not need lots of "high dollar" stuff, just normal OEM-level parts from good suppliers which can last 100K miles or longer. These things, with a Cloyes roller timing chain, with normal maintenance and syn oils (SL API rating), can result in an engine which can last for 500K miles or more.

Remember, "torque" is what "burns the tires" as "horsepower" is what can help explore the upper end of the speedometer on the Autobahn.

Will you be running the car on CNG, gasoline, or both?

Enjoy!
CBODY67

Thanks for the good reply! i’ll put the edelbrock intake on the list with the necessary parts.

Yeah i’ve seen that vid, looked promising but maybe one step beyond my current experience.

Putting headers at the bottom of the list.

It’s a toy for the weekend, so fuel economy is not really on top of my list, but cruising with the kids has to stay an option and gasoline is a little expensive nowadays here (11$ gallon), so CNG is preferred. Rather torque than HP. Enough to have fun, not to die.

Maybe a 3:55 shure grip as 57fury440 did?

Would you think changing out the valves and seals would be a must, or ‘if its good don’t change it’?

 

['66 Fury I]

Is this the original engine? What has been done to it in 56 years? Does it burn much oil?
Before tearing into it, Perform a dry/wet compression test to determine the health of the rings and valves. If the timing chain and gears are original, they should be upgraded. Loosing a few plastic timing gear teeth can spoil your day!. Next Find the source of the "sputtering". If you can remedy this, you may be surprised by the results! Have you looked into better ignition timing? Great improvements in driveability are possible.
I guess my bias is to fix what you know is wrong before chasing rabbits! I have saved a lot of time and money this way. Just my thoughts. Lindsay

 

[Just Carbs]

That's a lot of weight for a spin happy low torque small block to be moving around town without a very stiff rear gear. A 350 horse 318 is going to need a 3.55 or more to not border on being undrivable in town without a loose as a goose converter.
Your low compression motor with no headers means limited can choices. Limited cam choices mean limited RPM.

The four barrel with a long duration wide lobe center low overlap cam and a 3.23 gear will make for a car that's a lot more fun to drive with a lot more torque at the road. But the power band will stay the same.
The problem is not the motor or the car. The problem is that motor in that car.

 

[volksworld]

Hughes has a cam selection form where you list all your stuff...compression, gear ratio,etc etc etc ....and they'll recommend one to you...i have a Hughes cam in my big block...i did not go for a Whiplash as it seems to be more of a "sounds faster than it goes" grind...but if you are going to change the cam you are much better off having the carb and ignition issues sorted out ahead of time before the rebuild or you risk not breaking in the cam successfully

 

[MoPar~Man]

My 318 LA '68 Monaco is due for some engine restoration.

Welcome to the 60's-Monaco-with-318 group. Here's the original 318 polysphere in my '67 Monaco:

And then the new(er) LA replacement 318:

Photos are circa 1987. The new engine came from Ontario Reman (Chrysler engine rebuilder in Toronto). At this point I might have 10k miles on the engine, recent compression tests at 150-155 psi.

I think it's peppy enough, even with 2.95 gears. You might (or dare I say, you will?) get more info about rebuilding a 318 for power from the For A-Bodies Only forum?

 

[PurpleBeeper]

Hi guys,

My 318 LA '68 Monaco is due for some engine restoration.
It has been running and driving from the moment i got it for years without any problem, but it now sputters and lacks power. (ever since July '23 as seen in my other threat)
I want to do a rebuild, but have a couple of questions that i cannot find the answer for or have found so much information that i'm lost again.
I have never seen the inside of a 318LA so this will be my first rebuild.

The one thing i am hoping for is to get some more spice out of it (300-350HP?) but it has to be reliable. With al the information i gathered this is what i came up with:
- Upgrade ignition. It's stock now, replace it all with a complete kit or only coil and module? and which one is best to buy?) I was thinking of a Petronix flamethrower with module OR a simple complete HEI distributor kit (as CBODY67 pointed out)
- new fuel tank, lines and pump. Holly sniper kits are too expensive for me.
- New carburator, the current one is held with tiwraps, but which one? Edelbrock?
- intake upgrade (stock 340 is impossible to find here, maybe also an Edelbrock performer? Anyone has a link or partnumber to buy?)
- The exhaustmanifold is also stock, time for headers or is that useless as some say? if yes, which one? I think i only have room for shortys. I already have a new stainless exhaust frond to back, no idea what diameter. (last owner put this in)
- other cam? everyone has a different opinion on this, if yes, which kit is best to take? Some point to this: https://www.hughesengines.com/Index...FtIEtpdHM=&searchmode=partnumber&partid=31310

I was advised to also upgrade to hardened valve seats because of LPG, going to look for a company that can do that for me.

An engine builder once asked me, "How fast do you want to spend?" I will go on the assumption you have a "mid-size" budget and just want a peppier cruiser, so here's my advice.
1. Find a 360 engine. It bolts right in, costs the same to rebuild and starts off with 42 more cubic inches
2. Good set of heads in your price range. Iron 340/360 heads, aftermarket aluminum heads if you have the money, or I "think" some of the newer 318 heads flow really well.....I'm not up on small block heads.
3. 1-5/8" header primary tubes are a good choice, pick any brand BUT research how well they fit on your particular car, especially if you have power steering or a lower car (many small block headers have 3 pipes that hang really low)
4. A moderate hydraulic cam. Research what looks right, go down one size (seriously), and get a matched cam/lifter/spring/etc set
5. Any aluminum aftermarket intake manifold (some are a touch better than others - research) and a 600-650cfm carburetor (not a "double pumper") with a K&N air filter
6. Factory early 70's style chrylser electronic igntion kit, but stay away from the orange ignition boxes (pick another color box)

 

[mstrk]

An engine builder once asked me, "How fast do you want to spend?" I will go on the assumption you have a "mid-size" budget and just want a peppier cruiser, so here's my advice.
1. Find a 360 engine. It bolts right in, costs the same to rebuild and starts off with 42 more cubic inches
2. Good set of heads in your price range. Iron 340/360 heads, aftermarket aluminum heads if you have the money, or I "think" some of the newer 318 heads flow really well.....I'm not up on small block heads.
3. 1-5/8" header primary tubes are a good choice, pick any brand BUT research how well they fit on your particular car, especially if you have power steering or a lower car (many small block headers have 3 pipes that hang really low)
4. A moderate hydraulic cam. Research what looks right, go down one size (seriously), and get a matched cam/lifter/spring/etc set
5. Any aluminum aftermarket intake manifold (some are a touch better than others - research) and a 600-650cfm carburetor (not a "double pumper") with a K&N air filter
6. Factory early 70's style chrylser electronic igntion kit, but stay away from the orange ignition boxes (pick another color box)

I found a good 360 for 7100$ without manifolds etc, i think i’ll stick with the 318 as i know it’s good and has potential for my needs.

So you’re saying headers is more of a priority than cbody67 said?

 

[CBODY67]

In the quest for additional power, "better breathing" of the engine is always important. Headers are just ONE item in that mix. But are not necessary in just going from a 2bbl to a 4bbl. Your car already has dual exhaust, which is an improvement from stock. I'm suspecting the mufflers have a bit less restriction than stock mufflers, which can be good too.

Used to be that headers were troublesome. The flanges were not thick enough, so they could warp and cause leaks, but many took that to te "part of the landscape" and tolerated that as something of "normal maintenance". With time, the thicker flanges of the premium brands filtered down to normal brands. It was discovered that the premium brands also had thicker-gauge tubing, which was quieter. A plus! That also filtered to the lower-cost brands, over time and many header company combinations. That, plus reinforced high temp flange gaskets helped make things better, plus fancier retention bolts and nuts.

Any time the incoming air/fuel mixture is less-diluted by residual exhaust gasses which "have not left the space", power and efficiency can increase. Just normal situations. Which can mean just how much money is spent to get to those benefits. Is it worth the cost of new headers for 15 more horsepower at 5000 rpm on a smaller motor? Certainly, used headers can be found, which begs the question "Why were they removed?"

In how the individual header runners are arranged near the collector can increase the scavenging effect, for more power. The length of the individual runners can affect the power curve, too. Long tubes, mid-length tubes, shorty tubes, and block-huggers are the main variations.

The reason that most OEMs have transitioned into "tubular exhaust manifolds" is more about the cast iron manifolds not being a heat sink on a cold motor. The tubular manifolds absorb less exhaust heat so the cat converter(s) can get up to temp sooner for decreased cold-start emissions (in the first 2 minutes of run time). Plus being lighter in weight. Sizing of the tubing is important, too.

In many cases, the Chevy LS motor makes power with a common-looking exhaust manifold, as their Turbo 2.7L pickup truck motor makes over 300 horsepower with a single exhaust system. Intelligent design can be an issue in this, too, rather than what was considered "good" in the 1970s.

I grew up in the times when all of the "cheap headers" were around. I never owned any, but knew of many who did and endured all of their issues. Most usually needed some "re-forming of the tubes" on the popular Chevrolet applications just to get them to installed. Many claimed the additional "dimples" did not affect flow, but they were obviously poorly-designed in the first place. Not "plug 'n play", although they just "bolted-on". As these owners got older, the allure of headers seemed to dim somewhat, from their earlier times.

Can they help? Certainly. The are visible, can increase the underhood sound level some (especially when the flange gaskets fail), but to some, that is the "sound of power". BTAIM

Are they worth the cost of many $100 USD dollar bills? Plus shipping to Europe (provided they don't get damaged in the process, much less stolen)? For another possible 20 engine horsepower (of which only about 85% gets to the rear wheels)? Might the engine sound happier at WOT? Certainly. I would recommend to get the car running before making this addition. Get the engine paid for, save some more money in the bank, and then venture down that path, if desired.

Enjoy!
CBODY67

 

[commando1]

Get your 318 running like a Swiss watch.
At worst, it may be time for a rebuild but forget this nonsense of making it a high performer.
But you won't heed my advice. Too many people here will try to show you how smart they are and have you running in circles.

 

[57fury440]

With the mods made to my sons Barracuda, it runs nice and smooth and trouble free. It will make your car feel a lot more fun to drive.

 

[mstrk]

With the mods made to my sons Barracuda, it runs nice and smooth and trouble free. It will make your car feel a lot more fun to drive.

Thank you, i think my setup is going to look like that with changes pointed out by cbody67. Where did you find the suregrip?