318 or 360? That is my question...

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1974NYDart

1974NYDart

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Hey guys,
Here's a quick rundown... I have a 1974 Dart Custom (Daily Driver because I love it!) with a 318. I've had bearings go twice because of oil pump issues. Now I'm getting some nasty lifter chatter and power loss (already tried STP). I'm skeptical on pulling, fixing and reinstalling the same 318 a 3rd time, however, this is where I'd like some input. I had a local garage do the bearings last time and it hasn't run smooth since..

Do I tear apart the same motor and replace the lifters/heads (I've never done this in a Mopar) or do a swap? (Either another 318 or a 360).

Recap:

1. Bearings done twice
2. Oil Pump replaced
3. Really bad lifter chatter
4. Do I Repair or swap?
a. If I find a 360 out of a car first, is it an easy swap?

Any input would help... thanks guys!
 
Really it depends on "what you find" and "for how much."

So far as swap the big thing is the flywheel balance. You must use the 360 matching balancer, and you didn't say whether you have a stick or auto

If you have a stick you need a 360 weighted flywheel

If you have an auto you can buy aftermarket (BM) weighted flex plate for the 360 balance.

I cannot imagine, though, why you are having so much bottom end trouble.
 
I would probably build a 360, but I hate the external balance part of that...but it would cost around 400 to internally balance it...but a steel crank is only 600...hmm....yeah ;)
 
A 360 engine should fit where the 318 was, externally they are the same.

Early LA 360 engines have larger ports and valves than 318 engines.

Basically everything is interchangeable between a LA 318 and LA 360 engine EXCEPT engine block, crankshaft, main bearings, harmonic balancer and pistons.

If you need spend money on the block or crank it might be worth looking for a 360 engine to begin with. Your budget will probably decide for you!
 
thank you, that's what I've been reading. It's an auto. The bottom end seems to be fine now no noise/issues with the bearings. Is there anything special I should know about Mopar lifters?
 
Cam bearings have gone twice in the 318. in this case, I'm not a firm believer in "3rd time's the charm."
 
You could go to junkyard and pull a la 318 roller block and use that.
 
I just throw in a low mileage 5.9 mangnum
 
X2 ,on the Magnum. Takes some research, and time investigation wise. A Magnum 318,rocks as well. Need more information. What transmission? What is your expectations,and wrenching skills?
 
1974NYDart said:
thank you, that's what I've been reading. It's an auto. The bottom end seems to be fine now no noise/issues with the bearings. Is there anything special I should know about Mopar lifters?
Click to expand...
Not really. There are two types that you should be aware of. The LA engines that have a rocker shaft do not have an oil hole in the lifter, and hollow pushrods. The Magnum engines have the oil hole in the lifter that, with the hollow pushrods, provide oiling to the pedestal mounted rockers. The early LA can use the Magnum lifter, but not the other way around.

FWIW: The Magnum lifter is interchangeable with the late AMC V-8s.

Curious about what happened to quiet the bottom end. Usually when a bottom end makes noise it's because it's terminally ill. When it goes silent, it's because it has arrived at the terminal.
 
X2 ,on the Magnum. Takes some research, and time investigation wise. A Magnum 318,rocks as well. Need more information. What transmission? What is your expectations,and wrenching skills?
Click to expand...

I wouldn't mind a little more power. It's got the original TF-904. I want reliability more than anything. I assume its easier to swap an LA 360 rather than magnum? Magnum would require more parts? (I'm trying to keep on somewhat of a budget and get it done in a timely manner)
 
Curious about what happened to quiet the bottom end. Usually when a bottom end makes noise it's because it's terminally ill. When it goes silent, it's because it has arrived at the terminal.
Click to expand...

Haha. Having the bearings, cam and oil pump replaced TWICE silenced it.
 
As usual, I will dessent. I say remove and inspect the 318. If the block is not hurt and the crank can be turned, you can have a nice engine with what you have. Buying a whole nuther engine adds to the expense. It's always cheaper to use what you have. You can build a very streetable 350 HP 318 fairly easily. Sure, a bigger engine is nice, but is it in your budget? Do you have a 360 just layin around? If you do it yourself, you can be assured of what you have. You will know every nut and bolt. It's not hard. I say unless it's toast beyond repair, stick with the 318. It will be more cost effective in the long run.
 
I gave you my recommendadion in post #14.
 
On and don't use a fram filter they and garbage. Use a wix filter.
 
If your engine has lifter chatter, that would be the first place I would inspect.

If you're unsure about disassembling your engine, I highly recommend purchasing the book "how to rebuild small block mopar engines"

It's not terribly complicated as long as you read carefully and use a clean working environment.

At this point with having the same problems in the oiling system (all you mentioned is "issues"...that isn't very specific) I would say a full rebuild is probably ideal.

This way you can inspect all your block and crank's oil galleries with a long piece of flexible wire and make sure there are no blockages, the book covers this in some detail.

It will cost some money, but probably save a lot more than it costs in the long run.

Quite often when an engine is teared down the following things are best to be replaced.

Oil pump, fuel pump, water pump. gaskets, main bearings, big end bearings, cam bearings, piston rings, welsh plugs, hydraulic lifters, valve guides, valve guide seals

And often the valves should be lapped into the seats if the seats are in serviceable condition.

It is wise to have the block and cylinder heads surface ground at a machine shop to ensure they mate together properly, especially if the engine has overheated at some stage.

A regrind or aftermarket cam is also an option, depending on your budget.

If all these things are done, you essentially have a fully reconditioned engine.

Not only that but you will gain a ton of knowledge to go with your new motor, and you will have a blast building it.
 
Good book. I have built my first two engines with that book and great success has followed. Rebuilding what you have will be the cheapest route to take. It is still expensive to do. Also take the time to visit a machinists shop to have everything done rather than a local shop. This will save money in the long run.

Once the machinist has the engine parts, starting with the block, he will go through it and let you know exactly what the part may need or not. You must sit down with him and let him know exactly what you want from the engine performance wise. Tell him it is a daily driver that IS daily driven.

After the block is looked at, then move to the crank, then the connecting rods and then a piston choice can be made. Gather the crank, rods, pistons and rings to have it balanced. Once this is done, your ready to assemble the short block.

(Have bags (available through summit or Jegs) to wrap the parts in to a kid rust and other damage. Keep a clean work area!)

Then move onto the heads. Deliver them for inspection and rebuilding.
A stock type of rebuild can handle some cam shaft. The machinist will need to know what lift the cam is going to be and what spring will be used. A MoPar or Crane Cam's spring requires no machine work while a Comp Cam spring requires machine work to install.

A quick word on lifters, there are two style of Hyd. lifters. Both can be used. One is designed to oil through the pushrods. This can be used in non oiling pushrods without issue. The first .010 and last .010 of the plungers travel is useless and the pushrod should depress the lifters plunger at least that .010 downward apon installation and not beyond .090 into the last .010 of the total .100 plunger travel.

This is a fun and easy project to do when you have that book, a good machinist and of course, us for back up and tech. Share pictures and have at it.
 
I think, if the goal is daily driver status, and given the history - that I agree with moving on one way or another. The fact that this 318 has oil pressure history would make me nervous anyway. Good running (read as original condition) 318s are easy to find and buy cheaply and it's a afternoon of mild wrenching to replace with few parts needed. So I'd go that route if you have access to some hand tools. As soon as you take it apart you incur costs - even if what is discovered is not a fatal issue.
So I'd find another 318.
 
1974NYDart said:
I wouldn't mind a little more power. It's got the original TF-904. I want reliability more than anything. I assume its easier to swap an LA 360 rather than magnum? Magnum would require more parts? (I'm trying to keep on somewhat of a budget and get it done in a timely manner)
Click to expand...

The only reason I recommend the 5.9 Magnum there the second highest stock power SB you can get and low mileage ones can be found all over the place for $500ish around here you can dress it like an LA engine with parts from the 318 and you need a 360 oil pan the only tricky part I know on the swap is flex plate that needs to be modified a bit and a intake that will bolt to the magnum heads.
 
Really! $500 for a junkyard Magnum engine? Really!?!?!
That would make a trip into Canada worth the fuel if I could purchase a few for resale.
 
Did any of the shops look for why your bearings went? Obviously something was and probably still is wrong.
 
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