stock head cc 1984 318 M body 2bbl

Opticon77 said:

Note: If you are actually serious about a turbo you are going to want to think about how you intend to fuel it now. AND the pistons you're sticking in it.

Scenario 1: MPFI with forged pistons and ethanol blends? You'll have enough accuracy and resistance to preignition for decent boost levels near 10:1 base compression. Expensive.

Scenario 2: A sloppy blow thru carb and stockish hypereutectic pistons on clear gasoline? Better just throw on some 360 heads, tank your base compression, run it rich, and use a good intercooler for insurance. Cheap... at least until you melt the pistons a few times.

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If I do turbo it later on it would most likely be draw through carb setup and only like 5psi. Running a little rich and setting up a timing controller on pump 91 gas. I know there's some guys running 10 psi on the stock bottom end 318s on some of the turbo forums with good luck and they are doing it with a carb and locked dizzy.
It's a thought not something that's 100% going to happen. For the time being just wanting to get close to 300 hp out of the mostly stock 318.

Ask those guys what their compression is. Usually stock or lower (due to a head swap). I'd be surprised if those setups can make 250hp off boost as they usually make around 400 with the 10psi boost.

I say you just commit to all motor and get that compression up there.

OR

Commit to the turbo setup now have fun and save the rebuilding for when the stock engine pops.

Maybe this could help.
A spreadsheet that provides insight into the power and boost needed. Import imperial units, and imperial and metric results.

I built a 300+ 318 back over 15 years ago. Got most of my parts from Jeg's and Summit Racing. I took an '86 police 318 two barrel, and built it up. Put a regular hydraulic Competition Cams .444 lift cam and lifters. Double roller timing set. New oil pump. Spent 3 days porting and matching the heads and stock Thermoquad intake. Made my own recurved distributor by welding the advance slots a third of the way. Then just used two stock light advance springs. Replaced every gasket and seal. Got headers from Jeg's, and ran straight 3" exhaust back to two turbo mufflers. Never put tailpipes on. Ran an 825 cfm Thermoquad and 3" air filter. Put new mechanical fuel pump on, plus ran a Purolator 5-7 pound electric pump near the tank to feed the fuel. When i got done, she had over 300 horsepower. Put a 2.94 Sure Grip out back.Not a drag racer, but no slouch around town either.

84Furyus said:

Looking for info. I have an 84 Fury 318 2bbl and was trying to find out what the combination chamber cc is on stock heads.

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I recently rebuilt the 318 in my 1980 Mirada, the heads cc'd @ 67cc per chamber, the factory manual says my engine was suppose to be 8.5:1
static comp. but when I ran the numbers and it was really only 7:1.
casting # 4027593
So I wouldn't trust what the comp ratio is by the book.
The motors manual I have states 8.6:1 comp ratio for 1984 318 2v. 130 hp.
and 235 tq.

Gadsden said:

I recently rebuilt the 318 in my 1980 Mirada, the heads cc'd @ 67cc per chamber, the factory manual says my engine was suppose to be 8.5:1
static comp. but when I ran the numbers
it was really only 7:1. So I wouldn't trust what the comp ratio is by the book.
The motors manual I have states 8.6:1 comp ratio for 1984 318 2v. 130 hp.
and 235 tq.

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Wow that's crazy the compression was that off. How far down the bore was the pistons.

I went 20 over and used Keith Black pistons, moved the ratio to 9.1:1.
I also used 360 truck heads from an 84 360, I had to shave them .040
to get them down to 67 cc chambers and have the stock 360 4bbl manifold
cut .040 as well to match. So it has a 360 top end. The hp #s I ran on my
desktop dyno program is claiming 273 hp and 331 tq with the elgin cam
and dual exhaust I'm using on stock 360 manifolds. The best part is the
engine looks completely stock, but you can tell it's not, even with the
stock 245 rear gears.

84Furyus said:

Wow that's crazy the compression was that off. How far down the bore was the pistons.

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The pistons were .143 from the top of the deck.

Gadsden said:

The pistons were .143 from the top of the deck.

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That's unreal.

84Furyus said:

That's unreal.

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I didn't have the block zero decked, so the Keith Back pistons were
still .008 from the deck. No complaints though. The power difference
from the stock configuration was substantial.

I'm going to toss another opinion in just to muddy the waters.

Your goals:

• Budget conscious
• Street friendly for DD usage
• 300HP

Stay away from boost. You mentioned staying with a carb for simplicity and cost - this is not going to end well as far as reliable street manors are concerned. Tuning boosted applications with a carb is a pain in the ass and is only compounded if you're daily driving it.

Overdrive and fuel injection are easily the biggest contributors for street manors. With a low power goal of 300HP a simple 5.9L Magnum swap utilizing the factory fuel injection and headers will get you there. Additional displacement of the motor will make for a better bottom end and a far more enjoyable ride than a 5.2L. This is a fairly easy and upfront swap if you use a motor and harness from the early 90's as it's all self contained. Find a low mileage motor, or even a high mileage one - you only need a factory build, so it'll be cheap.

For the transmission use an a500 for the lower first gear and the overdrive. If you don't want to do the fabrication to make it fit, the motor will bolt to your existing transmission.

Honestly, I would replicate this guys build with a 5.9L instead of the 5.2L he used:



That's a 1994 engine in his 1984 Fifth Avenue.



To give you an idea of how self contained the electronics are.



Shake down video.



Looks to be a six second 0-60. Not bad at all!

OEM reliability to boot.