In need of an education..340 vs 360.

-
I think you should look at this question differently. 340 vs 360 what does it take a 340 to run say a 360 in say an 11.00 drag race. Stock stroke both engines iron heads not w2. I run 340s because thats what i have. Iknow obviously that the 340 will need more gear and rev alot higher. Im interested in this as I would like to pic up another 1/2 second on my current combo.
 
jerry6 said:
Do you have a 71 340 or a 73 340 ? I the original post you say you picked up a 1971 340 , 73 has cast low compression pistons , cast crank , not that the factory forged cranks were all good . some were some were not .
Mahle has some good pistons here is page put in the year it will spit out the replacement pistons available from tem . I'm using the 10.5 coated pistons , so far 10,000 miles and all is well

And Stroker , WGAF about Herb , what you got ? When it stops being fun , it's work , I'm retired , f work . I bought the car to have fun with my son , not to be competitive , been there done that in business .

http://catalog.mahleclevite.com/lv/search.php
Click to expand...


The OP said he had a 71. I bought a 73 for the engine swap in my 73 Duster Twister. The heads are from a 73 (I think) 360. I'll have to check the catalog. Thanks.
 
My fish had a 340 in it when I bot the thing. I think it is a stock 69 with a purple 508 cam and a victor 340 intake. It was a 8.4 1/8 car. Before that engine the guy had a 360 in it. I may have that motor cause I got a almost complete 360 as well as a 71 360 long block (and others). Anyways, the car ran 7.80 on open headers and a tad slower after he put on mufflers with the 360. Size matters.

7.25 with the 416 so gimme a stroker every time!
 
Screw it all and throw in a 572 Hemi with twin turbo chargers, bet it will out do a stock/stroked 340/360 any day of the week :twisted:
 
This started out as a 340 vs 360 mild build now its full blown money pit.
Well for that instance My brothers step-father is a huge a body guy,he must have 8 or more swingers and some coronets and a few belvederes,anyways his race buddy has a 318 that dyno'ed at 713 or 723 HP(cant remember which one).Nothing stock but the block.So is the 318 in this bench race now?
 
jerry6 said:
2700 Ito the 360 and it has 380 hp ? My 340 makes 413 hp 398 tq built to stock specs . All that was done was a bit of cleaning up the heads ,new stock spec pistons and a mild cam . So the op can have a 400hp 340 without putting in the money he would need to get the 360 to 400hp . How can spending close to 3 grand to make less hp and tq be advised ?
Click to expand...
Like I said it was all brand new. I didn't have an engine lying around to use. Not sure you can build a brand new 340 for the same price. My 340 MP block was $2600 bare.
 
moparmanestock said:
Like I said it was all brand new. I didn't have an engine lying around to use. Not sure you can build a brand new 340 for the same price. My 340 MP block was $2600 bare.
Click to expand...
I was including the carb, ignition, roller rockers, Aerohead 340 heads, MP 380/360 roller shortblock, oil pan, oil pump, bolts,etc. All new, no rebuild.
 
Joes68340s I think the question should be how much HP is needed to power an average weight an A-Body to 11 seconds from the argument were getting here bigger engines need less power to do it over smaller ones. Which I'm pretty sure is wrong? Think of engine size as a powerband selector say you want 400hp a 273 gonna be at around 6800rpms and 340 gonna be 5800rpms and 408 gonna be like 4800rpm, now 273 gonna make less torque than the 408 but if geared proper the torque to the ground is gonna be about the same through gear multiplication but if everyone ran 3.55:1 the 408 gonna walk away from the other two.
 
dartcuda1 said:
There is a point hear and of course you missed it.And yes you are making ridiculous comments hear.biuld your 360 and go 340 hunting you will get your nuts handed to you sooner then you think. Mark
Click to expand...
Perhaps you could state your point more clearly then. Maybe try proof reading & spell checking first too. And if my nuts ever get handed to me by anyone, I'm sure it won't be by you! Especially if you are as good with a wrench as you are eloquent!
 
To the original poster. The EQ heads are better than the original heads, although leave much to be desired. Anything you can use on a 360 will work on the 340 excluding the crank and pistons, and the bushed rods. This I'm sure you're aware of. The drilled crank for the pilot doesn't mean it's a forged crank, you would need to look for a wide rib on the throws of the crank, and the drilled front and rear throws.
Unless you have your heart set on owning a 340, there is no good reason not to build your 360 for the street.
To the other 4 pages of useless pablum, I offer this. I build competition engines for a living. I am a member of the Society of Automotive Engineers, so I have the credentials to back up my statements.

A 360 with the same compression ratio and cylinder heads, cam, manifold etc will ALWAYS make more torque and horsepower than a 340. Don't believe me, Mopar rated the '72 340 at 10 hp less than the '74 360. Same compression, same cam specs, carburetor etc. NHRA rates the low compression 340 at less hp than the 360 4bbl. 360 Darts run on a quicker class index than the '72 340's do.
Small stroke engines don't rev faster. They have to rev higher to make power because they are just smaller air pumps. People gear them so that they can get into the useable RPM range sooner, but the engine by itself does not rev faster under load.
In building Stock, and Super Stock engines, one thing remains true. The 327 and 350 Chevy engines make more power in legal S/SS trim than the 340 and 360's. The heads simply flow much better than the horrible X and J castings.
340's are cool, I have owned a few '68 -'72's. but to build a small block Mopar I wouldn't hesitate to start with a 360. After all 273's also had forged cranks and floating pins and solid lifter and some even high compression, but nobody is raving about them beating up on 318's are they.
 
My point was made early in the post.To bad you missed it.One I do have a 340 that I could build a car around to hand you your nuts.I wonder what kind of wrench you hold.My guess is none dady handed everything to you witch is why you can only type on a computer with stuiped comments you make.Sorry I didn't make it through collage and my poor spelling bothers you.Maybe you can come to my house and teach me. Mark
Lonewolf3165 said:
Perhaps you could state your point more clearly then. Maybe try proof reading & spell checking first too. And if my nuts ever get handed to me by anyone, I'm sure it won't be by you! Especially if you are as good with a wrench as you are eloquent!
Click to expand...
 
SuperStock1489 so 360 Quicker than 340 cause it's bigger but slower to 327/350 but there smaller. I have a hard time believing Chev head out flows mopars my cousin runs late model up here in Canada and they use stock block, crank and heads and Chevy didn't catch up in power until they let them use vortec heads which are pretty the same ports as ported out old school stocker and he still has a power advantage just smaller now.
 
There is about a 20 cfm difference between the chevy heads and the X/J mopars. The mopar heads fall off right after .500" lift and start backing up above .550" where the chevy heads (461, 041, 462) will not lose as much. The exhaust post are even worse on the mopar heads.
 
I'll have to take your word for it I'm just an armchair expert but from what I've read X/J heads flow 200-210 cfms so Chevy flows 220-230cfms so Chevy heads are good for 450hp OOTB ?
 
A friend of mine has a 1974 360 Duster and he pulled the crank from the engine. He said it was the same crank as the 340. I don't know enough about either, but my friend has owned 340s in the past and has a few now. He also noticed that the pulleys were different on the 360.
 
Palmetto 340 has 4.04 bore 2.5 main bearings 3.31 stroke
360 has 4. Bore 2.8 main bearings 3.58 stroke
 
dartcuda1 said:
My point was made early in the post.To bad you missed it.One I do have a 340 that I could build a car around to hand you your nuts.I wonder what kind of wrench you hold.My guess is none dady handed everything to you witch is why you can only type on a computer with stuiped comments you make.Sorry I didn't make it through collage and my poor spelling bothers you.Maybe you can come to my house and teach me. Mark
Click to expand...
Your poor spelling doesn't bother me nearly as much as your ignorance & refusal to acknowledge the facts does.
Maybe you could take a 1/2 hour ride & stop by MY shop & watch what I do as a professional. I doubt a pigheaded mental midget like you is capable of learning anything so I won't offer you a lesson. And for your information nobody has ever given me anything. I work hard & have earned everything I've got.
Second thought, don't bother. You're not worth another moment of my time.
Don't go away mad... Just go away! :finga:
 
SuperStock1489 said:
To the original poster. The EQ heads are better than the original heads, although leave much to be desired. Anything you can use on a 360 will work on the 340 excluding the crank and pistons, and the bushed rods. This I'm sure you're aware of. The drilled crank for the pilot doesn't mean it's a forged crank, you would need to look for a wide rib on the throws of the crank, and the drilled front and rear throws.
Unless you have your heart set on owning a 340, there is no good reason not to build your 360 for the street.
To the other 4 pages of useless pablum, I offer this. I build competition engines for a living. I am a member of the Society of Automotive Engineers, so I have the credentials to back up my statements.

A 360 with the same compression ratio and cylinder heads, cam, manifold etc will ALWAYS make more torque and horsepower than a 340. Don't believe me, Mopar rated the '72 340 at 10 hp less than the '74 360. Same compression, same cam specs, carburetor etc. NHRA rates the low compression 340 at less hp than the 360 4bbl. 360 Darts run on a quicker class index than the '72 340's do.
Small stroke engines don't rev faster. They have to rev higher to make power because they are just smaller air pumps. People gear them so that they can get into the useable RPM range sooner, but the engine by itself does not rev faster under load.
In building Stock, and Super Stock engines, one thing remains true. The 327 and 350 Chevy engines make more power in legal S/SS trim than the 340 and 360's. The heads simply flow much better than the horrible X and J castings.
340's are cool, I have owned a few '68 -'72's. but to build a small block Mopar I wouldn't hesitate to start with a 360. After all 273's also had forged cranks and floating pins and solid lifter and some even high compression, but nobody is raving about them beating up on 318's are they.
Click to expand...
Very good points here Super Stock! Perhaps the most intelligent thing said so far. Very valid points about the HP ratings of the later 340s v 360s. :blah5:
 
Yes if mopar drop 340 when the 360 debut in 1971 and built the 360 to 71 340 spec's the 360 would be the legend, 340 would be the 327 of our story. But if 20 CID means that much than throw all small blocks to the trash heap put a 440 between the fender wells how can a small block compare when there 80+ CID shy. So when I get my 400Hp 273 built what's the quarter mile time gonna be 18's 17's HaHaHa. 340 is the best block to start with 360 close 2nd but cheaper so makes the best deal plus if using stock cranks 360 gonna be more street able and have more torque 3rd don't count out the 318 can be a fun engine and leave the 273 to sucker like me who like to do things the hard way trying to prove everyone wrong. Unless you competive racing a well built and setup car with any of these engines will put a smile on your face.
 
""A 360 with the same compression ratio and cylinder heads, cam, manifold etc will ALWAYS make more torque and horsepower than a 340. Don't believe me, Mopar rated the '72 340 at 10 hp less than the '74 360. Same compression, same cam specs, carburetor etc. NHRA rates the low compression 340 at less hp than the 360 4bbl. 360 Darts run on a quicker class index than the '72 340's do. ""

Right but the op said he had a 1971 340 , not a 1972 , so higher compression , better cam , crank etc . If he just wants to go out and have fun , not run for money then just freshen up the 340 would be a less expensive option . Does not take much to hit 400 hp with a 340 as is . Unless the shop I had mine built at rigged the dyno or somehow found a block and heads with the same serial numbers to trick me into thinking I had a 340 with 413 hp . All that I had done was put in pistons , Mahle 10.5 replacements , new cam , and the shop worked a bit on the heads , so basically stock . Now if I had to go out and get a 360 to make 400+ how much would I have to spend , and what parts ? Not arguing that you CAN make more with the 360 , hell my 440 made much more , but for just cruising around without spending much and you had the 71 340 what would you do ?
 
273 said:
Yes if mopar drop 340 when the 360 debut in 1971 and built the 360 to 71 340 spec's the 360 would be the legend, 340 would be the 327 of our story. But if 20 CID means that much than throw all small blocks to the trash heap put a 440 between the fender wells how can a small block compare when there 80+ CID shy. So when I get my 400Hp 273 built what's the quarter mile time gonna be 18's 17's HaHaHa. 340 is the best block to start with 360 close 2nd but cheaper so makes the best deal plus if using stock cranks 360 gonna be more street able and have more torque 3rd don't count out the 318 can be a fun engine and leave the 273 to sucker like me who like to do things the hard way trying to prove everyone wrong. Unless you competive racing a well built and setup car with any of these engines will put a smile on your face.
Click to expand...
Hey if you can build a 273 to scream & it puts a smile on your face I say go for it! Nothing wrong with that at all! I actually think it's cool. I'll smile with you!
 
I've got a ways to go before I decide what type of 360 to swap into my 68 Barracuda (slant six original car)and your posts got me thinking. In general, what is the cost differential between a built 360 and a stroker 360? (I plan to drive mine to work if that helps). Can you recommend any crate engines and suppliers? I've seen them in Mancini, Summit Racing, and a few others for around $5000+. I live east (thank God) of Kansas City. Would you know of any builder/suppliers in this general area? I have no block or transmission so I'll need everything. Thanks for great posts. I learned a great deal from this discussion. I certainlly would like a 340 but the cost...
 
You must log in or register to reply here.
-

Back
Top