The Dodge Challenger Message Board

Hi,
Whom here are good on older engines? I like to know which yera the 318 A and the 318 LA engines was produced. What is the difference and what parts are interchangeble?

318 "A" Engine
1957-66 • 3.91" bore x 3.31" stroke

First produced in 1957, the first 318 employed "thickwall" casting techniques that, while very strong, handicapped it with excess weight. It was economical to operate and was reliable as a stone, making it perfect for its use as the base V8 engine of its time.
Very hard to find parts for them these days.

318 "LA" Engine
1967-and-later • 3.91" bore x 3.31" stroke

The 1967 318 "LA" V8 shared little more than bore and stroke dimensions with the earlier "A" Engine. It was a completely new design using a much lighter block (LA = Light 'A' engine).

I really would not reccomened you using the early heavy 318 unless you are restoring a car that came with it. You would be taking a large backwards step if you put one in a Challenger.

No I will not use an old A engine in any Challenger!!!!!
I'm a very much a spokesman for to keep cars in factory spec an genuine condition.
I just came across a guy that liked to get some more power out of his 318 A engine, but my advice was to use a newer and a biger engine instead of spending all money on this old one. I have look on different web pages to find the diffence between them.

On http://www.allpar.com/mopar/318.html I could read "The LA family was introduced in 1964 with the 273; the primary difference between the A and the LA was the new lightweight casting technique, which saved a great deal of weight (and was ahead of its time)." and

"Parts interchange: A to LA (Bill Watson)As for internals, the 273 used the poly (A) 318 crankshaft, bearings, bearing caps, vibration damper, and conecting rods. The 273 and 318 both had a 3.31" stroke. Pistons were different, though, as the bores were different while camshafts could not be shared due to the different valve arrangements.
The sharing of parts was one of the things Chrysler bragged about when the 273 was introduced. But little on the 273 LA was shared with the earlier 277/301. The LA 273 had a longer stroke and smaller bore than the 277/301."
but this I don't get a clear picture of the interchangebility between 318 A and LA.[/u]

You were right to advise him not to try and get more power out of the A engine. There are no speed parts that will fit that I know of?

Yes the 273 was the first LA engine. But the 318 came in 1967.
The 273 did have the same stroke as both types of 318 but what has that got to do with anything?

Both versions of the 318 had the same bore and stroke and possibly used the same crank and bearings. But that is about it as far as I know.

If he wants a performance small block he should find a 340 or 360. Even a stock one will out perform the old 318 'A' by miles. The new crate 360s are a good price and work well. Plus he can put his original 318 to one side in case he ever wanted to restor the car to original.

Here is a list of parts that interchange between the polyspherical A 318 and the LA series of motors (318, 273, 360, 340).

Thermostat
Thermostat housing
Internally balanced 273-318-340 harmonic balancers
Valve springs, retainers and keepers
Main bearings (NOT 360 though)
Rod bearings
Crankshafts (reground 360's included)
Flywheel
Starter, both standard and high torque
318 LA ring set
timing chain and sprocket
fuel pump
oil pump
oil pan (not 360)
distributor pump drive gear
distributor, standard points or electronic

Here is how to modify one for power. You learn something new every day!

http://www.1962to1965mopar.ornocar.com/poly318.html

Thanks Dave,
It's always nice to see "new" pages (I haven't seen this before).
The guy with 318A engines was convinced to make engine swap instead (no Challenger).