Is there a 318 "Big Block"?

[MSN Member]

From: Wasserhaus1
Sent: 3/21/2005

I was told by the PO that my 1968 D22 had a Dodge 318 "Big Block" Engine.

How do I tell that it is a "Big Block"

[Slantsixness]

Sent: 3/21/2005

Jim,
If it is, it might be a 318 "wideblock"

There was never a "big block" 318. The wideblock is based off the same 318 block that is in the standard LA 318 engine.

The "wideblock" used to be known as the "semi-hemi" as the wedge shaped area is 'almost' hemispherical.
The history of this motor started in the 50's as the 331 hemi, which was brought to Chrysler from GM's Zora Arkus Duntov (the GM genius who gave us the Corvette and Camaro) the idea originated as the ARDUN60, a 60 cu inch Hemi Zora made for go-carts he had for his house guests....kinda weird, that the GM genius invented the Hemi concept that gave Chrysler it's big edge, huh! The "hemi" people talk about  is a completely different motor, though and only the hemispherical chamber concept carried over to the B series engines, starting with the 392, then the 426 later around 1956.
The original 331, 348 and 355 hemis are all based of the 318 block!

The semi-hemi came from a need to reduce the amount of space the motor took up in the engine compartment, so Chrysler could have clearance on the lower profile car hoods in the sleek 60's, much the same as why the slant six is slanted, and not straight like the old 220 L6.

Back to the heads: the wide block has "wedge" heads, and a pretty good design, but the valve covers were always a problem, and the configuration was changed and the head got even smaller for the a bodied cars so they mad the 273 V8, these heads were even smaller in size  and became the standard for 273/318/340/355/360 LA engines by 1968.

Now they went and brought back the "hemi" small block, like it's some kind of "new" thing, when the concept and production of an almost identical motor is really over 40 years old!

You can bolt on standard 318 heads and an intake, along with exhaust manifolds. The oil pump is different, so watch out for that!
These motors are actually damn good running motors, with the exception of valve cover oil leaks. The performance and power is about the same as a standard 318-3.
Four barrel manifolds are very hard to find, but I might have a lead on one for you if you want one....


Tom

[MSN Member]

From: Wasserhaus1
Sent: 3/23/2005 10:16 AM

Tom -

Wow, thanks for the information.  I just have to wait for the rain/snow to let up and I can check it out and see if mine truly is a "wide block".  Right now Winnie is snugged down with a tarp as I've begun working on the roof and the A/C has been removed.

With regards to the lead to the 4 barrel manifolds, I may be interested - I just need to make sure I know what I've got first.  I will let you know either way.

- Jim

[DanielTBolger]

I've been looking for a 318 wide block 4barrel intake. Lot of the old timers here said to me they never made one for it. Mine is in a Dodge 500 truck, and it runs great! Just kind of bad fuel mileage with it. Its a stump puller motor.

[Clyde9]

I had a friend that had 318 wide block in his 1970 Challenger. It really did have a lot of pull to it. He replaced it with a 68 440 block. It then had even more pull. lol. Had to eventually replace the font end. The weight was too much for the stock front end. Fun car though.

Jack

[Slantsixness]

Yep. there are, in fact 4 barrel manifolds for a "Wideblock" 318.
Good luck finding one, but they did make them. Weiand made one that was aluminum... but most of what I've seen are the cast iron factory manifolds. Kind of rare, and really really hard to find...