Estimate how much power this 345 cid Hemi will make

[ptuomov]

Wives' tale that repeatedly gets passed along on the forums. The stroke itself has no bearing on how high or quickly an engine can rev.

Really? No bearing?

[mag2555]

No bearing ! ? How about frictional HP loss?

[Krooser]

What year is the short block? The pre-09's had weaker PM rods and some say a crank that's a bit suspect... The oil pumps we're not up to the task so I think that is/was some of the problem.

I would think you'll see 500+ hp at the flywheel... Rwhp I don't have a clue.

I'm accumulating parts right now for a GIII build in a year or so... This one will be carbed and run on the MSD system they have for these. Using Eagle heads and a non VVT block I hope to see 700 hp for an endurance application.

This engine has a bad reputation for dropping valves and a poor oiling system...most of that was fixed after '08

Like in the 60's the dealers sell some good parts for these things at nice prices...engine internals and such... I'm hoping my local Dodge guy can help me out when the time comes.

[bigpoppapreston]

What year is the short block? The pre-09's had weaker PM rods and some say a crank that's a bit suspect... The oil pumps we're not up to the task so I think that is/was some of the problem.

I would think you'll see 500+ hp at the flywheel... Rwhp I don't have a clue.

I'm accumulating parts right now for a GIII build in a year or so... This one will be carbed and run on the MSD system they have for these. Using Eagle heads and a non VVT block I hope to see 700 hp for an endurance application.

This engine has a bad reputation for dropping valves and a poor oiling system...most of that was fixed after '08

Like in the 60's the dealers sell some good parts for these things at nice prices...engine internals and such... I'm hoping my local Dodge guy can help me out when the time comes.

Im using the 06 engine. The pistons are indeed different on the 09 up engines and i believe the rods has more material around the bolts but made out of the same steel as pre Eagles. I did however upgrade the bolts to ARP. I will likewise startgathering parts for an Apache headed 400 5.7 block stroker.
Thanks for playing the guess what horsepower game.hahahaha lol. I think it'll do better than 500hp at the flywheel also.
Its amazing that these new generation small blocks from the Big 3...Ford, general motors and Chrysler can make 500hp with stock bottom end short blocks, factory heads and intake. Technology
Good luck on your build.

[Krooser]

I have a "windowed" '04 block to use as mockup... I'm going to weld up the quench pads in the combustion chambers to try to get 13-1 or higher compression with the early style piston.

I also have a low mileage '14 take out that can donate the heads...might sell the short block or may look into machining the front of the block to allow the use of an earlier non VVT cam...

[blykins]

Wives' tale that repeatedly gets passed along on the forums. The stroke itself has no bearing on how high or quickly an engine can rev.

Really? No bearing?

You can't make a blanket statement and say that a long stroke engine won't rev or rev quickly. Case in point.....any mountain motor with a 5.5-5.75" stroke turning 8000 rpm.

Now, to fine tune that statement requires a lot more variables, but I've heard it way too many times that "a long stroke engine won't rev". That's completely false.

[ptuomov]

Wives' tale that repeatedly gets passed along on the forums. The stroke itself has no bearing on how high or quickly an engine can rev.

Really? No bearing?

You can't make a blanket statement and say that a long stroke engine won't rev or rev quickly. Case in point.....any mountain motor with a 5.5-5.75" stroke turning 8000 rpm.

Now, to fine tune that statement requires a lot more variables, but I've heard it way too many times that "a long stroke engine won't rev". That's completely false.

If you read what I wrote more carefully, my question was about reliability. And it wasn’t a blanket statement.

[blykins]

"I am wondering whether the rotating assembly with the relatively long stroke can spin very high?"

Sorry if I misunderstood your intent.

[ptuomov]

"I am wondering whether the rotating assembly with the relatively long stroke can spin very high?"

Sorry if I misunderstood your intent.

Cool. It wasn't very clearly written by me.

To be clear, in my (uneducated) opinion, that displacement, cam, and head flow combination could make a lot of power at high rpms. It will by my guess want to make power high up.

I didn't mean to say that this stroke would prevent power production. The intended question was what's the maximum safe redline rpm for the engine? There I think the stroke does matter.

As a reference, here's a magazine test with 6 degrees less camshaft duration and lower flowing heads, and it produces peak power at 6100 rpm and power looks like it's holding up very well as high as they run the engine:

http://www.powerperformancenews.com/tec ... -cam-swap/

[blykins]

I'm not familiar at all with late model Hemis, but as long as the rotating assembly is designed for higher rpms, the stroke should not have any bearing on the rpms. I'm of the Ford FE world where we routinely turn 4.250" cranks over 7000 rpm. I also have a customer who has two engines of mine, a Cleveland, and a Clevor.....both are drag raced and are routinely shifted at 7500 and have been shifted at 8000, both with 4" stroke cranks.

In the pulling truck world, the engines in the classes with 550-560 cubic inch rules, will turn 9000 rpm with a 4" (or a little larger) crankshaft.

I wouldn't throw a cast Eagle in there and turn up the wick, but a well-thought-out rotating assembly will turn very high rpms, regardless of the stroke.

I'll let you guys get back to regular scheduled programming as I have zero late Mopar experience. However, there are a couple of wives tales that float around the interweb that are completely false and that statement caught my eye. Again, I apologize if I misquoted you.