318 hp estimate??

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440valiant

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hey there ,

i have a pretty much stock 318 from my 69 cuda, i just bought it so i dont no much about it, all's i can see is it has a four barrel intake with a Carter AFB carb, electronic ingntion and coil. thats pretty much it, also if i was a ricer how much more hp would chrome valve covers give me?

thanks
 
I would say 250 whp is on the optimistic side of a stock CR/Headed 318. :cheers:
 
The engine is rated at 230 HP stock. It should respond quite well to any mods.
250 hp sounds good.
 
I would say you would be right around 225-235 at the crank, which is not bad power at all.

Remember, Chrysler was overzealous about compression and more than likely wasnt the advertised 9:1, more like 8:5:1.

Although, you got to keep on eye on these 318s. I have seen a dart dynoed with an internally stock well worn 318 with only a eddie 4bbl. It made 194 hp at the wheels. Thats about 260 or so at the crank, which is excellent power for any small cube small block.
 
I found some old timeslips and an ET calculator and this is what I came up with.

My old 318 dart weighed 3460 and ran 18.1 bone stock. RWHP 116
(140 crank).

I put headers on it and a holly 600, it then ran a best of 16.4. RWHP 155.
(186 crank)

My 318 Duster weighs about the same and has a 600 Eddie through stock exhaust and an performer intake. 16.9 with a "one tire fire" through the 60'.
RWHP 140. (168 crank)

Granted, this is only approximate and there are some variables, but it will give you a good place to start.
 
340 Dart said:
I found some old timeslips and an ET calculator and this is what I came up with.

My old 318 dart weighed 3460 and ran 18.1 bone stock. RWHP 116
(140 crank).

I put headers on it and a holly 600, it then ran a best of 16.4. RWHP 155.
(186 crank)

My 318 Duster weighs about the same and has a 600 Eddie through stock exhaust and an performer intake. 16.9 with a "one tire fire" through the 60'.
RWHP 140. (168 crank)

Granted, this is only approximate and there are some variables, but it will give you a good place to start.
Click to expand...


Man.... those numbers are low.

Are you sure about that?:scratch:
 
Got the time slips right here. 60's were all about 1.9-1.8.

Again, it is only an estimate. Traction is a huge issue, and I was going through the traps still in 2nd. (245 gears). If I had 4.10's a suregrip and a set of slicks, I am sure it would have done alot better.

Granted, this is only approximate and there are some variables, but it will give you a good place to start.
Click to expand...
 
Man.... those numbers are low.

Are you sure about that?:scratch:
Click to expand...

You made me rethink it and I made a mistake. I the number the calculator gave me was ALREADY RWHP and then I subtracted 20% from that.
Here is a corrected version.

I found some old timeslips and an ET calculator and this is what I came up with.

My old 318 dart weighed 3460 and ran 18.1 bone stock. RWHP 140
(168 crank).

I put headers on it and a holly 600, it then ran a best of 16.4. RWHP 186.
(223 crank)

My 318 Duster weighs about the same and has a 600 Eddie through stock exhaust and an performer intake. 16.9 with a "one tire fire" through the 60'.
RWHP 168. (201 crank)

Granted, this is only approximate and there are some variables, but it will give you a good place to start.

Thanks mullinax95!

02-21-2008 11:48 AM
 
sorry to piggy back but what is the main killer of crank to wheel hp? the drive shaft, gears, ...?
 
440valiant said:
hey there ,

, also if i was a ricer how much more hp would chrome valve covers give me?

thanks
Click to expand...

If you were a ricer, chrome valve covers would give you an additional 30HP, but the 5 inch exhaust tip would be good for at least another 35HP-40HP, at least in a ricers mind. :-D
 
n00blike said:
sorry to piggy back but what is the main killer of crank to wheel hp? the drive shaft, gears, ...?
Click to expand...

I don't know for sure but I would guess the transmission would be the main killer. The gears and such on a manual transmission and the torque convertor on a automatic.
 
n00blike said:
sorry to piggy back but what is the main killer of crank to wheel hp? the drive shaft, gears, ...?
Click to expand...

Actualy, that's an excellent question and makes sense to add on to this discussion.


mullinax95 hit it on the head. After the trannys, the propshafts (Driveshaft) length has a play, though minor and then the rear end size has a play, again, minor, then axle length, minor and then tire size. Tire size is the next main problem is performance or race cars. To big (Tall) and theres not enough released from the engine. You may run short of RPM's or have a hard time getting to the power band quickly.
Theres alot to overcome in a tire that is to tall in it's mass as well.

I seen once on Hot Rod TV, they dyno'd the HP useage of a couple of rear ends. The 9 inch Ford used 5 hp to turn. So to me, rear end size never mattered as long as it was big enough to handle the power output of the engine. The only other consideration to rear end size is weight, being unsprung weight. Small potatos IMO.
 
340 Dart said:
You made me rethink it and I made a mistake. I the number the calculator gave me was ALREADY RWHP and then I subtracted 20% from that.
Here is a corrected version.

I found some old timeslips and an ET calculator and this is what I came up with.

My old 318 dart weighed 3460 and ran 18.1 bone stock. RWHP 140
(168 crank).

I put headers on it and a holly 600, it then ran a best of 16.4. RWHP 186.
(223 crank)

My 318 Duster weighs about the same and has a 600 Eddie through stock exhaust and an performer intake. 16.9 with a "one tire fire" through the 60'.
RWHP 168. (201 crank)

Granted, this is only approximate and there are some variables, but it will give you a good place to start.

Thanks mullinax95!

02-21-2008 11:48 AM
Click to expand...

Wow,thats it..no wonder why everyone uses them for "boat anchors"..lol...
 
340 Dart said:
You made me rethink it and I made a mistake. I the number the calculator gave me was ALREADY RWHP and then I subtracted 20% from that.
Here is a corrected version.

I found some old timeslips and an ET calculator and this is what I came up with.

My old 318 dart weighed 3460 and ran 18.1 bone stock. RWHP 140
(168 crank).

I put headers on it and a holly 600, it then ran a best of 16.4. RWHP 186.
(223 crank)

My 318 Duster weighs about the same and has a 600 Eddie through stock exhaust and an performer intake. 16.9 with a "one tire fire" through the 60'.
RWHP 168. (201 crank)

Granted, this is only approximate and there are some variables, but it will give you a good place to start.

Thanks mullinax95!

02-21-2008 11:48 AM
Click to expand...


Still low!

Look at this: http://www.mopar1.us/engines.html

There is a 318 making 230 HP with a 2 bbl!

You've got to making more power than that.
 
... go to a dyno, or the track, guesstimations can very, as you can see.

A dyno sheet will be another one to add to the stack of 'this guy pulled this with a _____' :D
 
Ummmm, he did write crank, but I just assumed he ment "At rear tire." Which would be equal approx; like to the amount of power lose through an automatic tranny. Right???

At what percentage is a auto trans useing power?
 
I always thought my 318 made good power... I'm sure a dual exhaust and 4-barrel would really wake it up. ARRGH, I need cash!!!
 
My 1st car was a 1968 Dodge coronet. Had the 230hp 318 w/ a Holley 4bbl (changed it to a Carter AFB). The car kicked butt on a lot of cars it shouldn't have (V8 Vega w/ a 4oo small block, Pontiac Grand Prix w/ a 455, 350 Buick Skylark and a bunch of others) the 4bbl really woke it up. I liked the carter better on the car though. Probably worked better as it was smaller than the Holley.:toothy10:
 
340 Dart said:
I always heard that 20% was a safe estimate. Most are a little more efficient than that though.
Click to expand...

And thats what I heard. Give or take some, but thats what I heard.

250 HP minus 20% is 200 HP. Now take into account the days weather, alt. of track, minus a few 10's of thousands miles and maybe not a perfect state of tune........

Power is dropin fast. Added weight to the car just makes the car slower and if exact weight isn't known, it makes the power seen lower. If he had a full tank of gas one race and a 1/8 last race, he calcs the first race at a much lower power level than the last race. But all calc's were made at list weight, AKA lighter than weight as raced.

How much does a gallon of gas weigh? Spare tire and jacks? Tools in trunk?

The equation of cars weight/et= est. HP is a general rule of thumb that can get you in the ball park preety good, but matching that aganst a actuall dyno is a no o and just another way to race dynos.

340 Dart's numbers are good enuff and have merit.
 
My a&% !!. This boat anchor in my 72 Duster eats stock 396's for lunch and then goes looking for a snack. I didn't say mine was stock.

That post or HP loss needs to be posted on its own so we can really keep an eye on it. That is good. Go up and start a new topic please.
 
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