340 cid engine.. ??

[99ss]

340 cid engine.. ??

What can you do with a 340? How big can you stroke it? Is it a big block small block what? Dont know a thing about it but I see a few of the 71 Roadrunners I have been looking at have it in them. What can be done with it to emulate a 440 ?

 

[RustyRatRod]

This is just my personal opinion, so take it as such.

I would not stroke a 340. Either sell it to someone needin a 340 or throw it under the bench and save it. Find a 360 and build your stroker from that. This way, you assure nothing happens to the 340. It's not like they are growing on trees. Plus, the 4" bore size makes for cheaper rings and pistons. Just a thought.

Now, as to what you can do, no, you will never be able to make a small block run like a big block....all things equal. BUT, you can smoke moderate stock stroke big block with a well thought stroker small block.....and you can even compete with some stroked more aggressive big blocks.....but the small block will never be a big block. Never. 440 plus cubes are possible with the right part$$$.

 

[Cranky]

A 440 emulates a 440 pretty well....

 

[99ss]

This is just my personal opinion, so take it as such.

I would not stroke a 340. Either sell it to someone needin a 340 or throw it under the bench and save it. Find a 360 and build your stroker from that. This way, you assure nothing happens to the 340. It's not like they are growing on trees. Plus, the 4" bore size makes for cheaper rings and pistons. Just a thought.

Now, as to what you can do, no, you will never be able to make a small block run like a big block....all things equal. BUT, you can smoke moderate stock stroke big block with a well thought stroker small block.....and you can even compete with some stroked more aggressive big blocks.....but the small block will never be a big block. Never. 440 plus cubes are possible with the right part$$$.

Is a 340 desirable? I thought they were common back in the day... used in Dusters most of the time or pickups?

I don't know why but I like the big blocks...LOL we re-sleeved my LS2 and made it a 457 but thats aluminum and iron is a different story..LOL

Seems like the 71 Roadrunners I have been seeing are all 340 cars. I had a 71 Challenger w/318 and that was a real quick car but the 71 RR is a lot bigger/heavier

 

[Cranky]

340's were never used in any pickups. They were a high performance engine only and were never in a regular passenger car either. And no, they were not that common because of that reason. Yeah, there were a lot of 340 Dusters sold but not near as many as 383 road runners etc. Now there were probably 14 zillion 318's made....

 

[440roadrunner]

340's weren't THAT common. All you need to do is to look at the years they were manufactured. And where people like GM made 350's by the skads, in various performance levels, also true of 327s and other engines, Chev 350 were not all strictly a performance mill

This I think is the main difference between Mopar 340's and most other manufacturers. There WERE no medium performance 340s which might add to the "used later to be restored engine block pool."

In this day and age of "lots of aftermarket", IE stroker cranks, etc, I'd build a 360. If you're scared of cast cranks, don't be unless you are building a true monster. I don't know what the upper practical limit for such as a 360 cast crank, but I'd guess it's a lot higher than you think. The later (72?) 340s were cast cranks as well.

 

[daredevil]

340 with a little flow work and a hot cam put a lot of people on the trailer in their day.Quick revving little mill.

 

[Meep-Meep]

As mentioned, 340's are strictly business. Great engines and capable of mucho power, and I will agree with Rusty about the care and feeding of them. If you want a killer small block use the more common 360 as a base. A buddy of mine just built a 426 CI small block out of a 360 and stuffed it in an early Barracuda that weighs as much as a box of Kleenex. Should be fun.

 

[99ss]

Great info guys ! Thank you

 

[RustyRatRod]

A box of kleenex. Das a goodun.

 

[iraqivet01]

340 are great engines. Duster and cuda's are a screaming car

 

[PettyBlue72]

The 340 started in 68 and was used in the Dart GTS's and the Barracuda Formula S's and was the same for 69. In 70 the E-Bodies came along and the Duster was added to the plymouth line. The 340 was an available option in the Challenger, Cuda, Dart and Duster for 70. In 71 the 340 was the standard motor for the 71 RR and was also available in the Charger, Demon, Duster, Challenger and Cuda. The 340 was no longer available in US built Darts in 71 but some Canadian built cars got the 340. The models available with the 340 remained unchanged for 72. The only change for 73 was that the Demon was replaced with the Dart Sport but the 340 was still an available option. In 74 the 340 was replaced with the 360.

Joe

 

[bigredbird]

I traded a '71 383 Charger for a '71 340 Duster back in the day. The Duster was a screaming monster, with nothing done to the 340 except a valve cover change.

 

[Supershafts]

I got a 340 base that hammers big blocks....

It wouldn't be the best idea to use the smaller bore 360 for a stroker over the larger 340...

like i said my 340 base beats BB equipped cars.


Or of you want a BB i'll sell you my 6pk 73 RR for 6k.. it's not a 6pk car, it is a modified 6pk equipped motor in a RR