340 stroked?

[mastrdrver]

I am new to the board and the Mopar sence. I was wondering how far you can stroke a 340 or 360 affortably? Is one block better suited then the other?

Thanks
Jeremy

[jelsr]

Not a SB person but the 4" setup seems to be popular. 340's are difficult to come by, 360's are relatively plentiful and have larger mains than the 318/340. Costs should be comparable for the most part.

[c318cuin]

Well I have been pondering that exact issue my self. What I have come to realize is that the more dough the more go(to a point). Now I have seen 426cuin stroker kits for the 340 and that is about the biggest small block kit I have seen. Now affordable kits???!!!????? What is affordable and what are you wanting it to do???? 360 -408 and 340-416 kits are quite common and they are usually not too awfully expensive (of course that depends on what is expensive to you).

As far as which block is better is debateable. The 360 is not a rare block and should be able to handle everything a mild kit can bring. Now I have read articles that dis the the 360 large journals saying bearing speed is a down side. There are many 360 and 408 engines running today that say that bearing size is of little consiquence on the street. The 340 comes in two maybe three flavors that I know of. The first is the run of the mill block it is usually a High Nickel content piece that if you find one answers the bearing issue. However I have heard many people complain that it is starting to get difficult to find a good block. The second type is the ultra rare T/A block that is reported to be strong enough for anything. This is due to the stronger/thicker main webs and other internal enhancements done to make this motor capable of racing. The third type of 340 that I have read about may just be someones imagination but in one of the many mopar books I remember and article about a low nickel block that was produced at the end of the 340's lifetime.

For me I am going for the first 318 340 or 360 block i can find. As long as it sonic checks out good and I have all the oil system mods done i bet any block will work fine up to around 450+ hp. The thing is that 273 318 340 360 are all directly related and aside from the changes in Nickel content and the supposed switch to thin wall castings they should all make a good foundation for a stroker.

However if I can ever catch it again I have just about made up my mind to snatch up an R block next time they go on sale thru Mancini Racing again. The R block is the pure bred racing version of the A engine family.

Hope this helps. Post more details on your evil plan. I am sure that some one else on here with a stroker can either back me up or shoot me down. However it turns out inquring minds wanna know

[skankweirdall]

Siamese bore R3 block + 4.0" stroke crank at 4.22 bore = 448 cubes. You could also possibly get another .125 stroke out of that, but would need additional machine work and maybe even spacing the oil pump and pan some but would net you 462 cubes of rat killing small block Mope power.

[mastrdrver]

I was planning on going with the cheapest block I can find, probably a mopar 360 block, and go from there. I was going to stroke it, but didnt want to have to notch the pan rails or have to goto a small radius cam. Kind of like the chevy 383 or a ford 408W motor. Can you get away with putting a 4" stroke in a 360 without having to do the above mentioned? What is the deck hight of a small block anyway? I was hopping to get to as close to 400" as I could. Want kind of heads would anyone suggest for this? I saw some brodix heads in their cataloge that look nice.

[skankweirdall]

Originally posted by mastrdrver
I was planning on going with the cheapest block I can find, probably a mopar 360 block, and go from there. I was going to stroke it, but didnt want to have to notch the pan rails or have to goto a small radius cam. Kind of like the chevy 383 or a ford 408W motor. Can you get away with putting a 4" stroke in a 360 without having to do the above mentioned? What is the deck hight of a small block anyway? I was hopping to get to as close to 400" as I could. Want kind of heads would anyone suggest for this? I saw some brodix heads in their cataloge that look nice.

Yes you can get by without much ado with the 4 incher. The cam is high enough in the block and with a deck height of approx. 9.60 you won't need to machine much. Maybe some minor clearancing at the bottom of the bores for connecting rod clearance. Depends on the connecting rod you use. Stockers would have more clearance obviously than H beams or aluminum rods.

As for heads how radical do you want to get? W2's would work nicely as would some W5's if you can find some used. Other than that Brodix has the MC (moved centerline) head that looks very similiar to a W5 and looks very promising. I've got W5's on my car, they are an excellent head with just a little work but require long valves and all the W2 rocker type gear as well as an intake to match. They don't make low end torque on a smaller motor so you have to keep the velocity up, but they flow like a waterfall. That may not be a problem on a 400 incher though. Indy and B1 have heads also although I have no first hand knowledge of these.

let's see 360 + .030 + 4" stroke = 408

[mastrdrver]

What about the B1 BA heads from Brodix? It looks like those are pertty much like standard heads.

[FearThe4Doors]

Originally posted by c318cuin
The 340 comes in two maybe three flavors that I know of. The first is the run of the mill block it is usually a High Nickel content piece that if you find one answers the bearing issue. However I have heard many people complain that it is starting to get difficult to find a good block. The second type is the ultra rare T/A block that is reported to be strong enough for anything. This is due to the stronger/thicker main webs and other internal enhancements done to make this motor capable of racing. The third type of 340 that I have read about may just be someones imagination but in one of the many mopar books I remember and article about a low nickel block that was produced at the end of the 340's lifetime.

Theres been all aluminum 340 blocks on ebay from time to time for $1,000

[tsteiner61]

To stroke a 360 to 408 you WILL have to notch the block once at the bottom of each cylinder bore (8 total). This allows for rod clearance. Good news is the work can be done with a dremel and it isn't really near any water jacket area so a small screw up won't cost you the block.

Just assemble the crank and rods then turn it by hand until a rod hits, outline the mark and grind down to it. .060" of clearance between rod and block will be sufficient.

As far as budget goes, strokers are generally more expensive than non-stroked. On average, the pistons cost more because there are fewer varieties available. The 4" needs significant balancing work done. My balancing alone, not including the cost of the crank, was $525.