Today, dollar for dollar, is the 318 faster than the 340 ???

[ch1ll]

You have to put more than a few hundred dollars into a 318 before it can even get close to a stock 340 with headers so there's that it's funny how the 340 is still the measuring stick of all Mopar small blocks! And there's a good reason for that actually it seems really simple. A 318 will never have the reputation nor the mystique or history of the 340 no matter what kind of lipstick and money you throw at it great little motor it will never be a street legend. 340s took down some of the biggest baddest small block combos actually pretty much all of them on the streets and the track in the day, people love that about the 340. Not so much how cheap you can build horsepower. If that was all there was to it everyone would build LS's. When the 340 hit the track and Street in 1968 it was a dominating motor that 80% street big blocks couldn't even handle. that's what people love about a 340.

THIS IS TRUE!

 

[justinp61]

Everyone is on a different journey !!!
I have more money in these ( Relics) than new Brodix set up but its what I wanted & they also are going on a LA with 318 stamped on the side ( 90 over partial fill ) with 3.20 stroke photos very soon !

Does it also have a X cast on the front? Should be a fun little screamer.

 

[66fs]

Yep but a friend just spent $$$$ for a running 262 Hemi

What is a 262 Hemi?

 

[SS Lancer]

Does it also have a X cast on the front? Should be a fun little screamer.

No sir
1968 oem block

 

[justinp61]

No sir
1968 oem block

 

[Dave_J]

What is a 262 Hemi?

I am sorry, I was off by 3CI. Its a 265CI 6 cylinder Hemi. With shipping it was upwards of $7,000 Aus$.
He has a 71 Australian Charger that had a blown up 265

Wiki
"The top of the line performance engine in the E49 Chargers produced 302 hp (225 kW) at 5600 rpm and 320 lb⋅ft (434 N⋅m) of torque at 4400 rpm. The increased power is due mainly to a more aggressive camshaft, high-load valve springs, triple 45 mm (1.8 in) DCOE sidedraught Weber carburetors, tuned-length exhaust headers and a higher compression ratio of 10.0:1."

 

[Nat]

where the hell can you find alu heads these days , put an order for pro max heads , not shipping until november wtf

 

[66fs]

I am sorry, I was off by 3CI. Its a 265CI 6 cylinder Hemi. With shipping it was upwards of $7,000 Aus$.
He has a 71 Australian Charger that had a blown up 265

Wiki
"The top of the line performance engine in the E49 Chargers produced 302 hp (225 kW) at 5600 rpm and 320 lb⋅ft (434 N⋅m) of torque at 4400 rpm. The increased power is due mainly to a more aggressive camshaft, high-load valve springs, triple 45 mm (1.8 in) DCOE sidedraught Weber carburetors, tuned-length exhaust headers and a higher compression ratio of 10.0:1."

I am into early Dodge, Desoto, and Chrysler Hemis. The numbers did not ring a bell. Now it makes sense. Thanks

 

[HankRearden]

This has been my argument for decades but mostly for the other LA that this thread is not about. Around here 340's are pricey. Hell i was just at Carlisle and I didn't see any affordable 340's.
so the extra grand or so dropped on a 340 core put into a sub 100 dollar 318 goes a long way.
If you don't have three grand to spend and need to go as fast as you can as cheaply as you can ,which is the situation I've been in most of my life, you just sort of forget 340's exist as they are way too pricey.
Go to car shows and talk to some of the boomers who just spend money and don't really build anything. They think there is something magical about a 340 and will argue all day long that no other small black build can touch it.Yet they are quick to idle into their enclosed trailer when its time to put up or shut up.
Objectivity never enters into it. Quarter mile times and dyno sheets are considered blasphemy.

 

[SS Lancer]

This has been my argument for decades but mostly for the other LA that this thread is not about. Around here 340's are pricey. Hell i was just at Carlisle and I didn't see any affordable 340's.
so the extra grand or so dropped on a 340 core put into a sub 100 dollar 318 goes a long way.
If you don't have three grand to spend and need to go as fast as you can as cheaply as you can ,which is the situation I've been in most of my life, you just sort of forget 340's exist as they are way too pricey.
Go to car shows and talk to some of the boomers who just spend money and don't really build anything. They think there is something magical about a 340 and will argue all day long that no other small black build can touch it.Yet they are quick to idle into their enclosed trailer when its time to put up or shut up.
Objectivity never enters into it. Quarter mile times and dyno sheets are considered blasphemy.

Everyone is on a different journey save those 340s for restorations and build those 318s and 360s and be happy u can do such !!!

 

[pishta]

So many posts...one formula: take your 340, divide the money spent by the HP (or ET, or ft/lb) and then do the same for the 318. The OPs question was Dollar per dollar, which motor is faster. Faster would mean a time slip i guess or if HP wins races per some famous author, fo HP. Another famous one said" Torque wins races, HP sells cars" so do torque. Let the math begin. I got no 340 in this game and don't own a 318, in just lurking with my 318 vote.

 

[318willrun]

So many posts...one formula: take your 340, divide the money spent by the HP (or ET, or ft/lb) and then do the same for the 318. The OPs question was Dollar per dollar, which motor is faster. Faster would mean a time slip i guess or if HP wins races per some famous author, fo HP. Another famous one said" Torque wins races, HP sells cars" so do torque. Let the math begin. I got no 340 in this game and don't own a 318, in just lurking with my 318 vote.

And most of this is driven by the rising cost of 340's.

 

[Dave_J]

As far as shrouding the valves between a 318 and a 340, how much is 3.2% less bore diameter really in effect?

If the compression ratio, heads, valve size, cam, intake, exhaust were all the same exactly:
A 340 with 22 more cubic inches at 85% volumetric efficiency is 18.7 HP.

This is based on a 318 Police 4bb @ 165 HP. The 340 with higher CR, bigger valves and hotter cam makes 275 HP, 110 more horses. But, this is NOT an equal comparison.
Many of us have built a 318 with 9.5:1, 2.02 X heads, 340 resto cam, larger 340 size intake and headers.
Except the headers, 'WORKED' iron logs, my 65 B-Cuda 318 (0.030 over) 9.5:1 CR, with ported X heads, a DC Purple 272 cam, Sanborn Oil mods, a 904 (2800 stall and shift kit) and 3.55 SG would slowly walk on my friends stock 340 Duster with 4 speed and 3.55 SG. I'd have him by a door in the 1/4 mile time after time.
My B-Cuda weighed 100 more pounds.

YEPPER, a 340 is FAR superior to a teen. I will leave them to their cult followers.

 

[318willrun]

As far as shrouding the valves between a 318 and a 340, how much is 3.2% less bore diameter really in effect?

If the compression ratio, heads, valve size, cam, intake, exhaust were all the same exactly:
A 340 with 22 more cubic inches at 85% volumetric efficiency is 18.7 HP.

This is based on a 318 Police 4bb @ 165 HP. The 340 with higher CR, bigger valves and hotter cam makes 275 HP, 110 more horses. But, this is NOT an equal comparison.
Many of us have built a 318 with 9.5:1, 2.02 X heads, 340 resto cam, larger 340 size intake and headers.
Except the headers, 'WORKED' iron logs, my 65 B-Cuda 318 (0.030 over) with ported X heads, a DC Purple 272 cam, Sanborn Oil mods, a 904 (2800 stall and shift kit) and 3.55 SG would slowly walk on my friends stock 340 Duster with 4 speed and 3.55 SG. I'd have him by a door in the 1/4 mile time after time.
My B-Cuda weighed 100 more pounds.

YEPPER, a 340 is FAR superior to a teen. I will leave them to their cult followers.

Also, that 165 hp was net, the 275 was gross... that in itself is a big difference.

 

[pittsburghracer]

Most of the guys on here aren’t balls out go fast racer type guys so at your local street cruise it doesn’t matter. Give me a grinder and some JB Weld and I can turn a 318 block into a 340 block in about 15 minutes. Lol

 

[Dave_J]

I wonder if any 340 owner would do a $3000 limit 'buy the block' and build from scratch then do a heads up 'Claimer' race with a $3000 scratch 318 build?

No 'RINGERS' like an R block sitting in the garage, both must acquire a new to them, fair market price block and NO free'bees.

 

[rumblefish360]

Factory OE passenger vehicle production use blocks need only apply then. Sounds like the 340 guys are in the hole for a grand plus to start & then the machine work to check if it is a good unit to start with.

 

[Dave_J]

I wonder if any 340 owner would do a $3000 limit 'buy the block' and build from scratch then do a heads up 'Claimer' race with a $3000 scratch 318 build?

No 'RINGERS' like an R block sitting in the garage, both must acquire a new to them, fair market price block and NO free'bees.

But then if the 340 dude or the 318 dude spends $50,000 on chassis build this race becomes moot. The person that can get the 450 HP to hook wins in most races.

I'd bet a highly tuned 273 stuck in a current 'PRO Stock' chassis and body would spank this $3000 340 in a 1972 Duster with stock suspension......

 

[fishmens67]

I think a 400 block is the answer. lol

 

[Jadaharabi]

As far as shrouding the valves between a 318 and a 340, how much is 3.2% less bore diameter really in effect?

If the compression ratio, heads, valve size, cam, intake, exhaust were all the same exactly:
A 340 with 22 more cubic inches at 85% volumetric efficiency is 18.7 HP.

This is based on a 318 Police 4bb @ 165 HP. The 340 with higher CR, bigger valves and hotter cam makes 275 HP, 110 more horses. But, this is NOT an equal comparison.
Many of us have built a 318 with 9.5:1, 2.02 X heads, 340 resto cam, larger 340 size intake and headers.
Except the headers, 'WORKED' iron logs, my 65 B-Cuda 318 (0.030 over) 9.5:1 CR, with ported X heads, a DC Purple 272 cam, Sanborn Oil mods, a 904 (2800 stall and shift kit) and 3.55 SG would slowly walk on my friends stock 340 Duster with 4 speed and 3.55 SG. I'd have him by a door in the 1/4 mile time after time.
My B-Cuda weighed 100 more pounds.

YEPPER, a 340 is FAR superior to a teen. I will leave them to their cult followers.

.
A modified 318 Beats a Stock 340. I can see that happening.
Rework the 340 heads and put the same cam in it that you put in the 318 and I guarantee the 340 will walk the dog on the 318.
Cost would be the same between the two Motors. I'm talking about the cost to do the heads in to put a cam in it.

Yes it's fun to modify a 318 and see if it will outperform a 340. But in the end you want the 340 even if it cost a little more. So keep looking for those 340 blocks.
Personally I think the 360 or the 5.9 Magnum is the way to go nowadays.

 

[pishta]

Take a 68 318 with about a zero deck height....~210HP. Put in a 340's cam, 4bbl cop intake....compare that to a equal compression 72 340. Check out this crude "road simulation" dyno result from the Mopar family. 5HP? I think Ehrenberg passed out seeing this.

 

[Jadaharabi]

Take a 68 318 with about a zero deck height....~210HP. Put in a 340's cam, 4bbl cop intake....compare that to a equal compression 72 340. Check out this crude "road simulation" dyno result from the Mopar family. 5HP? I think Ehrenberg passed out seeing this.
View attachment 1715772763
View attachment 1715772764

.
A 70 318 2 Barrel Duster against a 73 340 Duster.
Tell me there's five horsepower difference at the rear wheels. BS

The chart left out the 383 hp from the RR and Chargers and the 440 6pac and the 426 8 hemi

 

[Dave_J]

.
A modified 318 Beats a Stock 340. I can see that happening.
Rework the 340 heads and put the same cam in it that you put in the 318 and I guarantee the 340 will walk the dog on the 318.
Cost would be the same between the two Motors. I'm talking about the cost to do the heads in to put a cam in it.

Yes it's fun to modify a 318 and see if it will outperform at 340. But in the end you want the 340 even if it cost a little more. So keep looking for those 340 blocks.
Personally I think the 360 or the 5.9 Magnum is the way to go nowadays.

Keeping this in the $3000 range. I would not be using many stock parts on the 318 build as I will be far ahead in block purchase $$$. My son will sell, not give, me his 1978 LeBarron's 318 for $50. So I still have $2950 to spend on parts.

Speedmaster Cast Aluminum Cylinder Head Small Block Mopar 318/340/360 w/Hydraulic Flat Tappet Cam. Jegs $1713.70

I'd still have $1236.50 for Intake, Cam and Pistons.


I still would not spend the money on a 318 OR a 340. Stroker 5.9 or stroker 400. But this is not the topic.....

 

[318willrun]

.
A modified 318 Beats a Stock 340. I can see that happening.
Rework the 340 heads and put the same cam in it that you put in the 318 and I guarantee the 340 will walk the dog on the 318.
Cost would be the same between the two Motors. I'm talking about the cost to do the heads in to put a cam in it.

Yes it's fun to modify a 318 and see if it will outperform a 340. But in the end you want the 340 even if it cost a little more. So keep looking for those 340 blocks.
Personally I think the 360 or the 5.9 Magnum is the way to go nowadays.

It isn't if the 340 is faster, because we all prefer the 340 if both are free. It's about you having 3k to spend and you don't have a motor. Is the 318 (members claim good running 318's are free) a better choice if performance is your only goal. Will 3k put into a 318 beat a 340 that you had to spend 1500 to get and only 1500 to put into it. That's the point. On a low budget, is the 318 the better choice for your lowest ET .... It has NOTHING to do with "318 just to be different".

 

[Jadaharabi]

It isn't if the 340 is faster, because we all prefer the 340 if both are free. It's about you having 3k to spend and you don't have a motor. Is the 318 (members claim good running 318's are free) a better choice if performance is your only goal. Will 3k put into a 318 beat a 340 that you had to spend 1500 to get and only 1500 to put into it. That's the point. On a low budget, is the 318 the better choice for your lowest ET .... It has NOTHING to do with "318 just to be different".

.
I was replying to his statements about the modified 318 beating a stock 340.