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318 upgrade power gains?

TAZZ

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Out of necessity I’m having the 318 engine in my 72 charger rebuilt. Using this cam kit Xtreme Energy 218/224 Hydraulic Flat Cam K-Kit for Chrysler 273-360 - COMP Cams® It’s gonna be bored .030 over has 340/360 heads, Edelbrock Performer 318/360 intake, headers and choice of Edelbrock carbs. I know it’s not an exact science but what kind of gains can I expect?
You might get 300 horse out of that. Might. I haven't tried it but some say the 340/360 heads work good on the 318's but I don't like loosing a half point or more of compression by using a open chambered head. The stock ratio is supposed to be 8.8-1 and a large open chamber may get you down around 8-1. Just sayin.
 
I would bump up the compression and shoot for as much as possible, solid lifter cam and 273 adjustable rockers good heads and intake will help. They respond to improvements like a 340...
 
Probably around 50-70 hp, most of that coming above 3000 RPM, depending on where you end up with the CR. You can't say that headers are worth 40 hp, manifold is 50, and the cam is good for 40. They all have to work together, or you may have problems/poor performance.
When figureing power gains, think of a dyno curve, a hemi doesn't make 500 hp until 5000 rpm, performance parts work the same way.

Mark
 
Agree with above. If it made 230, plus 70 is 300.
Should be 20 horse down from a similar 340.
 
As mentioned..... pick taller pistons to keep your compression ratio up since you're boring the block anyway. I've run 340/360 heads on 318's and the motors ran well. No idea on hp numbers though
 
I know it’s not an exact science but what kind of gains can I expect?
Rough guess but I'd say $3,000 in debt easily.

I'm just kidding, BUT I gotta wonder since you did'nt present any money numbers and you are asking about power gains, How much do you spend before you wish you had just picked up a 360 and gone that route??
Don't get me wrong I'm not one to knock the 318's or even 273's, but it's not the motor I look to for decent power.
 
Rough guess but I'd say $3,000 in debt easily.

I'm just kidding, BUT I gotta wonder since you did'nt present any money numbers and you are asking about power gains, How much do you spend before you wish had just picked up a 360 Magnum and gone that route??
Don't get me wrong I'm not one to knock the 318's or even 273's, but it's not the motor I look to for decent power.
or better yet........................Fixed!
 
Rough guess but I'd say $3,000 in debt easily.

I'm just kidding, BUT I gotta wonder since you did'nt present any money numbers and you are asking about power gains, How much do you spend before you wish you had just picked up a 360 and gone that route??
Don't get me wrong I'm not one to knock the 318's or even 273's, but it's not the motor I look to for decent power.
We've got a raggedy 72 with a 360 for fun. Wanted to leave the 318 in this one. Why would I need to "present any money numbers" when asking about power gains with the combination?
 
Why would I need to "present any money numbers"


Myself I tend to think about everything like an accountant first....just how I am of course. If it were a nice numbers matching car, I'd leave it alone... otherwise I'd go for cheap displacement because it's a very good power adder.
Like I said, just jerkin your chain a bit. If it makes you happy, I'm happy for you....really.
 
We've got a raggedy 72 with a 360 for fun. Wanted to leave the 318 in this one. Why would I need to "present any money numbers" when asking about power gains with the combination?
It doesn't have to be like that lol. I'm a 383 guy at heart in a world full of strokers.
If you want to get serious you could probably pull 450 horse out of a 318. But you have to commit
 
Good choice of parts for a noticeable power increase, while keeping in mind that it is a small-ish engine in a heavy car. I think some of the power increase #s are a bit optimistic.
A Edel 650 AVS2 carb would be the best carb choice.
 
Something to think about would be a gear and TQ change, one of the cheaper mods that will have a noticeable affect. For that combination (small engine/heavy car) some more gear and a looser TQ can really add to the response/ fun factor.
This will really apply if your current setup is the 2.76 gear that alot of the 318 cars came with.

Mark
 
Something to think about would be a gear and TQ change, one of the cheaper mods that will have a noticeable affect. For that combination (small engine/heavy car) some more gear and a looser TQ can really add to the response/ fun factor.
This will really apply if your current setup is the 2.76 gear that alot of the 318 cars came with.

Mark
Rear gear is on the wish list. Thanks
 
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