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[nshaffer2001]

I'm not an idiot, but I don't know much about the mechanical details. I know you can bore over a 350 to a 383, make a stroker engine with a bigger cam, but I hear it's better if you down stroke the engine with a smaller cam to reach higher rpms. In theory, can the same thing be accomplished with say a 400 or 427? what about adding Hemi heads? I am aware that all this will take a lot of machining, just wondering if it is possible?

[brads70]

I'm not an idiot, but I don't know much about the mechanical details. I know you can bore over a 350 to a 383, make a stroker engine with a bigger cam, but I hear it's better if you down stroke the engine with a smaller cam to reach higher rpms. In theory, can the same thing be accomplished with say a 400 or 427? what about adding Hemi heads? I am aware that all this will take a lot of machining, just wondering if it is possible?

Welcome It's not just the bore  that makes the bigger cubes it's the longer stroke of the crank. Eg. in the 350/383 combo you mentioned it's a 350 block , bored the standard .030" over but with a 400 crankshaft. a 350 stroke is 3.480" and 400 stroke is 3.750"
These days you can buy a stroker kit for darn near any V-8 engine. No Hemi heads have/need extra head bolts that require a Hemi block, but countless crank combo's are available.
Hope that helped!
Brad

[nshaffer2001]

Thanks, brads70, but I'm kinda focusing on a "daily driver monster miata" kinda deal. I am aware that there are endless possibilities to drop a 350 in a miata, but it's the concept I'm after. Basically, you get more HP and more torque from installing a bigger cam, but is it more reliable to insert a smaller cam, "tune" the engine, and add hemi heads.

[nshaffer2001]

Thanks, brads70, but I'm kinda focusing on a "daily driver monster miata" kinda deal. I am aware that there are endless possibilities to drop a 350 in a miata, but it's the concept I'm after. Basically, you get more HP and more torque from installing a bigger cam, but is it more reliable to insert a smaller cam, "tune" the engine, and add hemi heads.

all that on a higher displacement engine to get the same (more or less) power as  you get from a 383 stroker with a higher rpm range?

[brads70]

all that on a higher displacement engine to get the same (more or less) power as  you get from a 383 stroker with a higher rpm range?

Generally you lose RPM but gain torque with more stroke.

[nshaffer2001]

Ok, lets clear this up.. Two cars, one bored over with a larger cam vs one bored over, smaller cam, hemi heads. Granted, torque being the transition of horsepower to the road, the larger cam would be more powerful. But, with this increase of the rpm range, who would win in a quarter mile, half mile,

[ChallengerHK]

Ok, lets clear this up.. Two cars, one bored over with a larger cam vs one bored over, smaller cam, hemi heads. Granted, torque being the transition of horsepower to the road, the larger cam would be more powerful. But, with this increase of the rpm range, who would win in a quarter mile, half mile,

I won't really clear it up; in fact, Ill probably muddy it a little more. But I think these are two important distinctions.

First, overboring will result in a very small increase in cubes, and therefore power. As Brad said, overboring PLUS stroking will result in a much bigger increase.

Second, I would be more inclined to think of torque as power and horsepower as the rate at which torque is applied.

[brads70]

If your looking to see what kind of V-8 to stuff in a Miata and old school Hemi would not be my choice. It's too big and too heavy and way to expencive! Unless its a race only car never to see the road. I'd look into a new school Hemi preferably with an aluminum block for a weight advantage. Then later add a supercharger or turbo , nitrous, etc...
Don't get suck on the Hemi head thing. While I've never had one my understanding is the old school Hemi was not all that great on the street in stock trim. They really shine when built for racing , high RPM's etc...
All a camshaft does is determine at what time the valve opens( in relation to the crankshaft) and for how long. Shoving the biggest cam you can find in any engine is not the way to go. It will most likley run terrible, won't idle, low on power, use too much fuel, etc...
A cam has to be selected that matches the total combination or poor/disapointing results will result. Bigger is not always better.

[72cudamaan]

Is everyone talking about the same thing here. The OP seems to be using the word camshaft and everyone else is saying stroker.
OP, a camshaft is different than a crankshaft. Each will give completely different results when changed. I just wanna
make sure everyone is talking the same lingo so we can answer your questions properly.