Edelbrock / RHS heads, or go BIG block and put it to bed!

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318 Engine Buildup & Dyno Test - A 318 Power Trip

A 318 Can Deliver Impressive Power At A Reasonable Cost
From the November, 2003 issue of Mopar Muscle
By Dave Emanuel
Photography by Dave Emanuel
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It's difficult to argue with the old adage, "There's no substitute for cubic inches." But, it's always fun to build an engine that performs like it has a larger displacement than it actually does. There are also practical benefits to upgrading the power-producing capabilities of a smaller engine. In the case of small-block Mopars, 340 and 360 engine cores are increasingly harder to find, and when one is located, it tends to be expensive.

That was the dilemma Mickey Hamilton faced when he began building a '67 Barracuda for street/strip use. "I started out intending to build a 360," Mickey says, "but I couldn't find one at a decent price. But, every time I went looking for one, I tripped over a 318. Finally, the light came on, and I figured since I was working with Andy Giles, who is a great engine builder, I could give up 42 cubic inches and still get an engine that would put the car into the 12s at the strip."

Andy is one of those engine builders who never attended a trick-of-the-week training class. He takes a straightforward approach and concentrates on refining proven techniques and components. He also has a knack for wringing amazing amounts of horsepower from engines built almost entirely from stock or stock-replacement-type components. As the dyno test figures demonstrate, his approach delivers high-dollar horsepower figures at low-dollar expense.

Since this engine was to be suitable for street driving as well as dragstrip use, Andy didn't set out to build a full-tilt race engine. Realizing many Mopar lovers would like to boost the output of the engines in their exclusively street-driven cars and pickups, he started with a stock rebuild to establish a baseline. Then, he developed a number of combinations, each of which raised the horsepower bar a bit higher. At the conclusion of the test series, maximum power had risen from 187 to 357 hp, and torque jumped from 305 to 388 lb-ft. The best part about the power increase is it was achieved with nothing more exotic than ported cast-iron heads and a custom-ground hydraulic-lifter camshaft.


Does this engine look like...

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Before the rebuild, Mickey's engine spent its life as the motorvational source for a '73 Dodge Dart. Despite its age, it had relatively low mileage and was in excellent running condition. Equipped with its original two-barrel carburetor, 151/48-inch Hedman A-Body headers, and 3-inch exhaust system with Random Technology PowerMax mufflers, the 318 displayed its plebeian ancestry, cranking out a maximum of 187 hp at a mere 3,750 rpm.

Andy's rebuild involved all the normal machining, including a .060-inch overbore and torque-plate hone. He also align-honed the main-bearing bores and deburred the block. After the machine work was completed and the block thoroughly cleaned, the short-block was assembled using reconditioned stock connecting rods, hypereutectic pistons (9.8:1 compression ratio), Hastings rings, Clevite bearings, Fel-Pro gaskets, and a Comp Cams hydraulic-lifter camshaft.

To start the testing, a Comp 270H cam with .224/.224 at .050 duration and .470/.470-inch lift was chosen. With intake and exhaust duration of .224 degrees at .050 lift, the camshaft was definitely on the aggressive side for a 318 (now 328 ci by virtue of the overbore). But, specific timing points and a lobe-separation angle of 110 degrees provided a relatively smooth idle and good low-speed torque.

The short-block was topped off with the original heads that were pocket-ported prior to installing Mopar Performance 1.78- and 1.50-inch valves. Andy also performed a multi-angle valve job and gasket-matched the port openings. Of course, the stock two-barrel carb and manifold were consigned to doorstop duty. In their place, he installed a 340 cast-iron manifold and topped it off with a 625-cfm AVS carburetor.


After removing the intake,...

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When removing the camshaft,...

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A good set of heads is essential...

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The amount of port work required...

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A "360" cast into the cylinder...

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The 2.02/1.60-inch valve combination...

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I posted the 318 build up only to show the power that i believe you have already have in your 360 but just haven't tuned it in.

This 318 is one of my favorite builds ever.

You have more gear plus 32 more cubic inches.

Your converter is a little tight but when a properly tuned carb is set on the engine and the car hooks at the line,the stall speed (converter flash) will go to a higher rpm off the line due to more power and resistance.
You 60 foot times will be way better.

A tuned carb will also give you more horse power getting your mph up where it should be.

Your dart should be running with this cuda for sure.

I would work on why it's not going this fast first and then buy the heads after you have tuned the engine in.
 
That engine should at least be 320 horse to the rear wheels and about 370 to the crank.
The torque should be over 400 foot pounds.

Your not making your max horse power.

That engines good for another 50 horses..........:thumbup:

I tend to agree with T67 and Moper that there's something missing in the existing build.

Is your builder checking the bottom end?
Was a leak down test done before the current heads were removed?
Was the cam installed correctly?
Was the timing chain holding time?
Were the electrics doing what they should?

Not saying you'll get 400 HP from your current combo - but no sense in buying RHS or Eddies if the short is a "wasted relic".
 
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