318 threads

[Cranky]

I'm too scared... all i see is money coming out the side of the block

What's strange is that I've run ALL of my cars hard and most of my daily drivers have been on the drag strip more than a few times and so far, knock on wood, never had an engine come apart.

 

[318willrun]

It seems like most mopar guys are afraid of the smaller bore. But really, how hard is it to notch a cylinder??? I mean the valve is only gonna be 0.045" closer to the cylinder wall.

Besides, a 2.08 intake valve will fit a 318 without a notch...

Too much analyzing things to death.

I love small block Mopars, 273- however big you can afford, or want to build.

yes, the dreadful small bore and valves. Hmm, wonder what size valves and bore the LS 5.3 have ???? Don't seem to bother the chebbie guys one bit.

 

[RustyRatRod]

You just defined yourself as a troll!

Indeed he did. lol

 

[273]

yes, the dreadful small bore and valves. Hmm, wonder what size valves and bore the LS 5.3 have ???? Don't seem to bother the chebbie guys one bit.

Most are running a 2.02 valve or less, a 318 bore is more than capable, is it costing you a few hp, more than likely but under 500 hp I wouldn't lose any sleep over it. And if rebuilding with a .030-.060" overbore your so close to being basically 4". If people really cared about bore size they would run big blocks, we really only got one V8 bore that's too small (273 3.625") and even that bore can make at least 400 hp without too much effort.

 

[Icetech]

What's strange is that I've run ALL of my cars hard and most of my daily drivers have been on the drag strip more than a few times and so far, knock on wood, never had an engine come apart.

Sadly my brain only sees the worst case scenario... my 408 (maybe 426) is going to all forged goodies and roller cam and will probably never go over 6500.

 

[toolmanmike]

Do ya know what kind of rpm it turns?

That I don't know.

 

[318willrun]

Most are running a 2.02 valve or less, a 318 bore is more than capable, is it costing you a few hp, more than likely but under 500 hp I wouldn't lose any sleep over it. And if rebuilding with a .030-.060" overbore your so close to being basically 4". If people really cared about bore size they would run big blocks, we really only got one V8 bore that's too small (273 3.625") and even that bore can make at least 400 hp without too much effort.

I see it differently than most. Bore cannot "cost you horsepower". If that was the case, then a 5" bore cost horsepower because it should be 5.5". You'll make the HP that you make on the entirety of the build. That includes every aspect of it. This is why we see 300+ HP V6's in family sedans these days, naturally aspirated too. Take the Pentastar. Less cubes than a 225 slant but 3x the power. Literally, 105 HP for a super six (net) vs 305 HP for the 3.6. Why? It's about the entirety of the build. More cubes = more opportunity. That's it. But opportunity is a word that can be spread from NY to LA. In short, the 318 has potential to make enough power to blow the block apart in finding it's weakness. Strength of the block. THAT is your limiting factor. Not bore.

 

[273]

Sadly my brain only sees the worst case scenario... my 408 (maybe 426) is going to all forged goodies and roller cam and will probably never go over 6500.

Shouldn't need to, say you squeeze 550 hp and make around 1.25 lbs-ft per cid and 90% of that torque at peak hp.

408 x 1.25 x 90% = 459 lbs-ft @ peak hp
426 x 1.25 x 90% = 479 lbs-ft @ peak hp

550 hp x 5252 / tq @ peak hp = peak hp rpm

408 = 550 hp @ 6,300 rpm and 510 lbs-ft @ 4300-5300 rpm
426 = 550 hp @ 6,000 rpm and 533 lbs-ft @ 4000-5000 rpm

Less hp and or more efficient = less rpm

More rpm obviously is the opposite.

 

[Mopar Sam]

I see it differently than most. Bore cannot "cost you horsepower". If that was the case, then a 5" bore cost horsepower because it should be 5.5". You'll make the HP that you make on the entirety of the build. That includes every aspect of it. This is why we see 300+ HP V6's in family sedans these days, naturally aspirated too. Take the Pentastar. Less cubes than a 225 slant but 3x the power. Literally, 105 HP for a super six (net) vs 305 HP for the 3.6. Why? It's about the entirety of the build. More cubes = more opportunity. That's it. But opportunity is a word that can be spread from NY to LA. In short, the 318 has potential to make enough power to blow the block apart in finding it's weakness. Strength of the block. THAT is your limiting factor. Not bore.

And, the old gasser guys had no problem running 283s, with a smaller bore than a 318.

 

[Icetech]

boost would fix a 273 right up

 

[318willrun]

And, the old gasser guys had no problem running 283s, with a smaller bore than a 318.

absolutely

 

[273]

And, the old gasser guys had no problem running 283s, with a smaller bore than a 318.

I showed a 500 hp 307 build in this thread, same bore as a 283 and wasn't too fancy pretty much what you would do making 500 hp with any other engine and size, just had too spin it up too 7,400 rpm.

 

[273]

boost would fix a 273 right up

My car was an original 273 car, thought about putting a turbo/blown 273 back in

 

[toolmanmike]

Shame on me, I posted a picture and description of a race 318. We weren't necessarily talking about maximum horsepower were we?

Here we go again.

 

[Cranky]

DTM #2

DTM can mean many different things.....

 

[toolmanmike]

DTM #2

DTM can mean many different things.....

Dan the Man and no it's not.

 

[RustyRatRod]

318 threads. So are they coarse threads or fine threads?

 

[One Bullet Barney]

yes, the dreadful small bore and valves. Hmm, wonder what size valves and bore the LS 5.3 have ???? Don't seem to bother the chebbie guys one bit.

The 302 z/28 chebby was nothing more then a 327 with a 283 crank.
Worked well.

 

[Cranky]

318 threads. So are they coarse threads or fine threads?

View attachment 1716426435

Semi course.....

 

[One Bullet Barney]

318 threads. So are they coarse threads or fine threads?

View attachment 1716426435

Metric.

 

[junkyardhero]

Shame on me, I posted a picture and description of a race 318. We weren't necessarily talking about maximum horsepower were we?

Here we go again.

and that's just the thing. all the 318 hater brigade jumps up and gets frothing at the mouth: it costs so much to make 500hp with a 318

well, Shirley Shanahan if you take off your rose colored drag race goggles, you'd see that if you're trying to make something more moderate and work within budgetary constraints that a 318 can be a perfectly cromulent piece to start with.

but nooooo all the slobbering masses cry out, gnashing of teeth, rending of garments. it won't rev like a 340! it won't have torque like a 360! the heads are ****! the pistons are a million miles in the hole! one time a 318 told me that i was ugly and my feet stink! i can't get good pistons for it! they should be $10 and a burrito, why does everybody want a bunch of money! a 318 took my mom to a nice seafood dinner and never called her again! the main caps are tiny! the rods aren't beefy enough! one time at sleep away camp a 318 touched me in my no-no zone!

and so on, and so forth.

but here's the dirty little secret: almost everything people hate on about 318's is EXACTLY the same for 360's. you have to do ALL the same work on a 70's 360 to make it kick *** just the same. at the end it'll make more power, because duh, it's got 50 more cubes.

 

[junkyardhero]

318 threads. So are they coarse threads or fine threads?

View attachment 1716426435

acme threads.

but not like, actual acme. more like Wile E Coyote ACME

 

[toolmanmike]

and that's just the thing. all the 318 hater brigade jumps up and gets frothing at the mouth: it costs so much to make 500hp with a 318

well, Shirley Shanahan if you take off your rose colored drag race goggles, you'd see that if you're trying to make something more moderate and work within budgetary constraints that a 318 can be a perfectly cromulent piece to start with.

but nooooo all the slobbering masses cry out, gnashing of teeth, rending of garments. it won't rev like a 340! it won't have torque like a 360! the heads are ****! the pistons are a million miles in the hole! one time a 318 told me that i was ugly and my feet stink! i can't get good pistons for it! they should be $10 and a burrito, why does everybody want a bunch of money! a 318 took my mom to a nice seafood dinner and never called her again! the main caps are tiny! the rods aren't beefy enough! one time at sleep away camp a 318 touched me in my no-no zone!

and so on, and so forth.

but here's the dirty little secret: almost everything people hate on about 318's is EXACTLY the same for 360's. you have to do ALL the same work on a 70's 360 to make it kick *** just the same. at the end it'll make more power, because duh, it's got 50 more cubes.

 

[340six]

Metric.

No not metric. Never metric is the devils tool.
I have 2 full draws of metric and almost never used.
I mumble metric and shake fist at stuff when SAE tools don't work.
Never give over to the dark side.
What's next left handed screwdrivers?
It's a plot I tell you..........

 

[Cranky]

and that's just the thing. all the 318 hater brigade jumps up and gets frothing at the mouth: it costs so much to make 500hp with a 318

well, Shirley Shanahan if you take off your rose colored drag race goggles, you'd see that if you're trying to make something more moderate and work within budgetary constraints that a 318 can be a perfectly cromulent piece to start with.

but nooooo all the slobbering masses cry out, gnashing of teeth, rending of garments. it won't rev like a 340! it won't have torque like a 360! the heads are ****! the pistons are a million miles in the hole! one time a 318 told me that i was ugly and my feet stink! i can't get good pistons for it! they should be $10 and a burrito, why does everybody want a bunch of money! a 318 took my mom to a nice seafood dinner and never called her again! the main caps are tiny! the rods aren't beefy enough! one time at sleep away camp a 318 touched me in my no-no zone!

and so on, and so forth.

but here's the dirty little secret: almost everything people hate on about 318's is EXACTLY the same for 360's. you have to do ALL the same work on a 70's 360 to make it kick *** just the same. at the end it'll make more power, because duh, it's got 50 more cubes.

Sounds like you are describing a /6 LOL