AJ's Opinion; Just for you 318 streeters

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A lot of books written here. Here is my finding. I had a low mileage 1973 318 auto out of a Charger.

I pulled the 408 out of this Duster and needed a motor and trans to stuff in the car for resale. So I used the 318. I didn't want a 2 bbl because I wanted to use all the 340 parts on the motor such as valve covers. and air cleaner and throttle pressure.

I installed a Weiand intake and a 750 comp series carb. 273 single point distributor. After the front end alignment I had a buyer for the car. Took him for a ride and I could not believe the way the car performed neither could he. Rolling along with the factory 904 high stall used from 71-73. 323 suregrip. and 275 15 goodyear eagles. It turned the tires from a 5 mile an hour kick through low and about 5 foot in second. The motor never fell of in RPM's.

So you can write three books. It never equates to the real world. What I can tell you is some motors just work and some with the same modifications don't work at all.

The most important part of building a motor is Balance. Pressure balance and weight balance. Several grams out can't be felt in the car in vibration. But very noticable in performance. That is why some run and some don't. We just got a BB Pro balanced stroker crank from Scat it was 18 grams out. We had some here that were out even more from race motors that were here for refresh . They were run with cranks out of the box. Very Very big difference after balanced.

Some 318 motors make power. Cut reciprocating weight everywhere you can. Pencils and papers can only suggest opinions

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Nothing wrong with the 273/318. Good combo. The 273 2bl came with 8.8cr. Run a.028 felpro and bump that CR up a bit. That intake carb combo is great for the 273. Just need a little gear in the *** to get it going.
 
dart4forte said:
Nothing wrong with the 273/318. Good combo. The 273 2bl came with 8.8cr. Run a.028 felpro and bump that CR up a bit. That intake carb combo is great for the 273. Just need a little gear in the *** to get it going.
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Stock steel shim gaskets were around .024 compressed. A Fel Pro won't do you much good other than seal the head to the block. Also the newly made gaskets are over 4" bore which doesn't help. Cometic can make you some the right diameter but they are still .030 thick or more.
 
I had Cometic make me a pair of .028 thick X 4.04 head gasket.
 
rumblefish360 said:
Or calculators…….
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I agree that the true test of engine selection and mods is really known once the engine is in the car and running. However, I also think that all the combos and mods initially start on a piece of paper on some engineer's desk surrounded by, you guessed it... paper , calculators and computers. I'm very sure Rouch , Ma Mopar, Ray Barton, etc.. start every engine mod that way. What's really great here is that we have enough owners on here to comment on a variety of these mods and how they actually worked out.
To give A/J , 318willrun and Rusty some props, I watched the videos ,followed some advice they posted and played around with my ignition/timing this year. Hooking up the vac advance , finding proper TDC and setting timing differently picked me up about 6mpg. I'm delighted with both the fuel savings and the power levels as I now know my engine is running much more efficiently.
Hats off to you guys for taking the time to share invaluable knowledge!!

Cheers!!
 
I’ll just say that calculators are 100% perfect in dictating what should be, which is impossible in a world of imperfections.

Calculating a perfect cam can be done but finding that perfectly calculated cam is another story. For sure, if your going to try and get the best cam possible, do the homework and go for it. If not, your now subject to ridicule just because you didn’t use a calculator.
(So much for having fun with car parts huh?! But that’s OK.)

Ive gone down this road so many times in the past here it’s stupid and won’t bother anymore. I’ll just try and help topically with combos.
On my Rouch, Barton and Ma’Mopar, I say;
Probably so, maybe, no way in that order.
Rouch probably did sit with a calculator, Barton might have, Ma’MoPar just went with there off the shelf purple cams and called it good.
 
rumblefish360 said:
I’ll just say that calculators are 100% perfect in dictating what should be, which is impossible in a world of imperfections.

Calculating a perfect cam can be done but finding that perfectly calculated cam is another story. For sure, if your going to try and get the best cam possible, do the homework and go for it. If not, your now subject to ridicule just because you didn’t use a calculator.
(So much for having fun with car parts huh?! But that’s OK.)

Ive gone down this road so many times in the past here it’s stupid and won’t bother anymore. I’ll just try and help topically with combos.
On my Rouch, Barton and Ma’Mopar, I say;
Probably so, maybe, no way in that order.
Rouch probably did sit with a calculator, Barton might have, Ma’MoPar just went with there off the shelf purple cams and called it good.
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I can't speak for anyone else here but the help and advice given here is very much appreciated.
Keep posting!
Some of us do listen!!
 
The biggest mistake many make is Cam shaft choice . They read the description characteristics and think to themselves how they want their motor to sound . Thumper cams were designed for them.
 
Yeah alot of idiots in my area with trucks either remove or put loud mufflers on, and they move S-L-O-W so I have to hear the noise of a half or 3/4 ton truck, be it chevy/Dodge or Ford from the 90s extra long as it lumbers down the road making way too much noise for how fast it is actually going...I dunno when trucks became hot rods but im sick and GD tired of it...:).
 
Over the weekend my 318 Duster went 8.35 1/8 mile which is its best thus far. It KB flat tops and J-heads, works great and takes 87 octane.
 
AustinGriggs said:
Over the weekend my 318 Duster went 8.35 1/8 mile which is its best thus far. It KB flat tops and J-heads, works great and takes 87 octane.
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Where do the pistons sit in the hole and what head gasket thickness was used?
 
Darter6 said:
And I raced 20+ years a Slant six in the 12's,Normal Aspirated, I got Why ? and "Can't be done !"
Sorry....It Can. There is a thing called "IT won't work on Paper" Well you don't race on paper.
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Good point. You can draw an *** hole on paper , But You can't make it fart.
 
A lot of usefully info here. Thanks for everyone's contributions.
Currently building a street 318.
All this info has been very helpfully :thumbsup:
 
Oldmanmopar said:
A lot of books written here. Here is my finding. I had a low mileage 1973 318 auto out of a Charger.

I pulled the 408 out of this Duster and needed a motor and trans to stuff in the car for resale. So I used the 318. I didn't want a 2 bbl because I wanted to use all the 340 parts on the motor such as valve covers. and air cleaner and throttle pressure.

I installed a Weiand intake and a 750 comp series carb. 273 single point distributor. After the front end alignment I had a buyer for the car. Took him for a ride and I could not believe the way the car performed neither could he. Rolling along with the factory 904 high stall used from 71-73. 323 suregrip. and 275 15 goodyear eagles. It turned the tires from a 5 mile an hour kick through low and about 5 foot in second. The motor never fell of in RPM's.

So you can write three books. It never equates to the real world. What I can tell you is some motors just work and some with the same modifications don't work at all.

The most important part of building a motor is Balance. Pressure balance and weight balance. Several grams out can't be felt in the car in vibration. But very noticable in performance. That is why some run and some don't. We just got a BB Pro balanced stroker crank from Scat it was 18 grams out. We had some here that were out even more from race motors that were here for refresh . They were run with cranks out of the box. Very Very big difference after balanced.

Some 318 motors make power. Cut reciprocating weight everywhere you can. Pencils and papers can only suggest opinions...
Click to expand...

What combo of heads, pistons, and cam did you use? If you don't mind sharing.
 
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