Small or Big block?

[Dodgy Dick]

Howdy, Is the small block 318 the same size block as the 383 ? Also do the big block? engines fit onto the same engine mounts/auto gearbox etc? What heads interchange?
Any discussion welcome !
R

 

[Turboomni]

I do not think so [small block / big block] . They are different but it is I believe possible to stroke a 318 to over a 360 or more with a different crank. That way you wouldn't need a different engine mounts and a different trans because of the bell housing is different between the small block and big blocks. But don't take my word for it and wait for the experts.

 

[Yatzee]

Howdy, Is the small block 318 the same size block as the 383 ? Also do the big block? engines fit onto the same engine mounts/auto gearbox etc? What heads interchange?
Any discussion welcome !
R

Mounts are different. But on the up side, a BB in your ride will be a bigger difference from a 318.

 

[Turboomni]

He would need a different trans for the big block yes?

 

[GJS]

Yes. 2 different 727s.

 

[Turboomni]

Thought so thanks.

 

[GJS]

318 is a sm block. 383 is a big block (the "b" variety of Chryslers big block) and the 440 is a big block (the "rb" variety of Chryslers big block). The b and rb engines used a beefier version of the 727 than the 318 so if swapping to big block, you'll need another tranny.

Obviously nothing interchanges between the 318 and either of the big blocks but I've never built either of the big blocks with anything other than what was made for either respectively.

Putting a big block into a small block car isn't much of an issue aside from the motor mounts themselves.

There's a whole wonderful world of things I can't answer but that's the skeleton answer to your question! Hope it helps a bit!

 

[MrMoparCHP]

This is a common question from the Chevy world as their 383 is a small block.

Small Block (A)
318 poly

Small Block (LA)
273, 318, 340, 360

Big Block (B)
361, 383, 400

Big Block (RB)
413, 426 wedge, 440

In general these do not crossover between the series and in some cases within the series.
Engine mount adapters are available for most combos.

Big block and small block automatic transmissions do not crossover.

Slant six transmissions are unique to the slant six.


This is a very general guide just to get you in the ballpark.


Alan

 

[e-440]

Do some good research. Nothing is the same. A big block will fit where a small block sits, but you will be changing and buying lots of parts. if you are going to change to a big block find a good running cheap donor car and take everything you can. It will be cheaper in the long run. If you have a good small block, get a stroker kit for it, if you are after HP and torque. You can even get a kit for the common 318. enjoy

 

[Dodgy Dick]

A STROKER KIT ?, I have considered these, but know very little about who or which one. Unfortunately the freight to Down Under will probably make them very expensive.??
Also I have been told 340 or 360 heads will fit the LA 318 for better breathing, is that correct?
What I like about the Stoker Kit idea is that your original engine number is retained!

 

[GJS]

Generally, the later 318 magnum heads will accomplish as much flow as you need. Couple that with a decent cam, 0 deck pistons, 4bbl intake/carb and a decent exhaust system, you can get an awful lot out of a 318.

Google 400 hp Chrysler 318 and check out any of the builds you find... they can be impressive mills without crazy money in parts or machining.

If I had any idea of this when I did my 440, I would have kept the original, numbers matching 318.

 

[e-440]

HUGHES ENGINES (309-745-9558)has 318 stroker kits that will take a 318 390ci. 340 and 360 heads will fit but if you uses heads that have a bigger combustion chamber you will actually drop you compression ratio. Use your 318 and save youself a lot of trouble.

 

[Welder guy]

just my opinion. go with a 383 they are everywhere which makes them cheap horsepower. You can buy a 383 4 door car with what it's going to cost you to stroke a 318 and everything including the transmission and it all bolts rite in and sell all the parts off the thing to pay for your build. Slap a purple Cam in it and a cheap set of built 906 heads. Then install a mild shift kit in the 727. You will have a high revving high torque Street screamer big block that only weighs 70 lbs more than the 318 for a LOT less money. Keep the 318 and it's small block if it's original.

 

[Turboomni]

I am looking forward to what he decides to do

 

[polara71]

Ive always been a pro small block guy. I currently dont have one in a C , I have a 383-2 a 383-4 and a 440-4. The 383-2 is a slug. No pep and when it does pull its because it has kicked down a gear and the engine is screaming.
My 383-4 is impressive. Pulls well , sounds great and is reliable. However when comparing these to the 440 there is no comparison. You simply easily feel the difference.... The torque and horsepower has it all over the the others. These are all sock engines.

I realize your in Australia but if I was going to do it Id go the full route and not be disappointed in the end result....

 

[PontiacJim]

The saying is that there is no substitute for cubic inches. As a "Pontiac" guy, this is true with the Pontiac engines. The larger 455CI engine has a larger bore and longer stroke which gives more torque. Torque is what moves the car. Now you can obviously build the more common Pontiac 400CI to give you plenty of power, but the trade off is that the 400CI has to spin at higher RPM's to get what the 455CI can do at lower RPM's. This is why many go with a stroker kit that turns the more readily available & cheaper 400CI into a torque pulling 461/467CI.

Basically, you are going to replace the old cast rods/pistons/rings with new forged pieces anyway, the supplied stroker crank is new so it replaces the 50 year old original crank w/bearings, and it is balanced which you will have to do even if you did not make your engine a stroker and simply replaced the pistons/rods for better pieces. So a complete stroker kit can be a good value.

As you build your engine, you have to also keep in mind that you want to think about upgrading the trans and rear end with some additional beefing up to handle the extra power and torque depending on your desired power level. You may have some trans problems if you built your small block into a 400HP killer and tried to use the stock transmission as is. Same goes for the rear end, you might find the original parts were not made for that level of HP.

My brother's 1973 Satellite had a 318CI. He wanted to install a Six Pack on the car, so I went with the more common LA 360CI (1977 engine) as the 340CI are hard to find and expensive when you do. Did what I would call a "standard" rebuild on the shortblock using forged rods & hypereutectic pistons. I did a basic gasket match porting on the intake/exhaust ports & some mild polishing. I had the machine shop add 2.02" intake valves with a 3-angle valve job, new valve springs, retainers, and seals. Used new stock style stamped rockers & shafts - nothing fancy. Cam was was Competition Cams .488" @ 274 duration intake/ .491" @ 286 duration exhaust on 110 LSA. Tamed the cam down for under 2,500 RPM operation/driving using Rhoads lifters - runs as smooth as a stock engine when you put it in Drive, but comes on like a bear once you nail the gas with its 2500 stall converter. Used stock cast iron exhaust for a stock appearing engine along with dual exhaust with low restriction mufflers and crossover pipe.

I used the 904 transmission which I had rebuilt to handle the extra power - lower first gear ratio added, HD clutches & bands, Trans-Go shift kit, along with a "tight" 2500 stall converter. Also added a trans cooler and needed to add a better aluminum radiator.

Installed all new bearings/seals on a 1977 donor 8 1/4" 3.23 posi rear.

The car will smoke the tires from a dead stop and pulls great through all the gears. My brother is very happy with the results. I don't think putting a 440 would have been worth all the changes to include suspension mods. Much easier in my opinion to stick with the LA engine/trans combo and build from there whether you go stroker with your 318 or go 360 LA as I did.

 

[Dodgy Dick]

Well I found a Hotrod publication how to rebuild Mopar small block's for performance but one article author contradicts the other, what a minefield!
I am at a lost, I want to stick with my original 318 numbers matching engine and modify it sensibly!
Next Please,???
A single plane, a dual plane, standard or 340/360 heads, a 600 Holley/ a what cam for streetable driving, standard or a what grind. Perhaps someone has the bits in the back of their shed, sorry BARN!!

 

[polara71]

That's a different story.....
If you want to keep the original engine then you're somewhat limited. You also have to walk a line before it doesn't matter

 

[PontiacJim]

Well I found a Hotrod publication how to rebuild Mopar small block's for performance but one article author contradicts the other, what a minefield!
I am at a lost, I want to stick with my original 318 numbers matching engine and modify it sensibly!
Next Please,???
A single plane, a dual plane, standard or 340/360 heads, a 600 Holley/ a what cam for streetable driving, standard or a what grind. Perhaps someone has the bits in the back of their shed, sorry BARN!!

This is not meant to be rude, but the questions you ask tend to make me believe you are not familiar with engine building?

That said, the first thing I suggest is to educate yourself on the assortment of parts/differences that you have choices in making AND your budget as rebuilding an engine can be from reasonable to deep pockets, with some mods producing greater results per dollar - Horsepower $$costs. Focus on what you want out of your engine and then build it based on that. For instance, dual plane or single plane intake? For a street engine, you want a dual plane, period.

I highly suggest you consider purchasing a few helpful books to add to your library and provide you with some knowledge that will channel your thoughts on what you want your engine/car to do. Knowledge is power and that power is in the information you will need to answer many of your questions and correctly select matching parts that will turn up the heat on the 318 versus putting together a bunch of costly mis-matched parts that will leave you disappointed in your engine's performance.

These books can be found on Amazon:

How to Rebuild the Small-Block Mopar by William Burt

How to Hot Rod Small-Block Mopar Engines by Larry Shepard

How to Build Big-Inch Mopar Small Blocks by Jim Szilagyi

 

[Dodgy Dick]

Thanks Pontiac Jim, I have rebuilt and modified many engines, including Jag, Triumph, Coventry Climax, early GM sixes, Peugot but never any Yankee V8 Iron. Hence my post to do the research you suggest.
As you know it not hard to get ripped off by an engine builder on price and/or workmanship,... and I have had my share !!
I.E Faulty bore liners, cams with mismatching lobes,blocks machined incorrectly, sub quality pistons fitted etc.
I will check out the books you recommend,
R