Over bore vs longer stroke

[TexasNomad]

Can some body tell me what you over bore a engine for I know its to correct for a out of round cylinder but I was reading around online and also read that going with a bigger bore will give you more low end power with out going with a longer stroke.
I thought you get your low end power FROM a longer stroke?
So when I rebuild my engine should I go with a bigger bore only,longer stroker, Both?
can some body clear this up for me t
Thanks guys

 

[klatt_89]

Well, this being me. I'm gonna add some humor. It all depends on your engines limtations, and how long of a stroke ya can do! If ya prefer a tight bore or a loose bore is all up to you! I prefer tight......okay, now for me to be serious. I couldn't resist that.
In my understanding, overboring adds cubic inches, which also helps in power, although there are limitations to this. It's basically making a over square engine. Depending on how large you bore, you loose your high rpms depending on the engine and set up, but all depends on what you do and what power adders you have. Longer strokes also help as well. I'm not gonna go as indepth as i have on some things, but i'm sure i'll be corrected since i'm not known for being serious. Gernally having a larger bore then stroke is better, but it's a personal opinion on which you prefer.

 

[O'Rattlecan]

bores have some limitations from what I've heard. I've never done it myself but one of my more mechanically inclined friends told me that if you bore to a certain point you lose integrity in the block as you get nearer to the coolant passages. This makes for more erratic temperatures (there's less metal to warm/cool) and can make things more brittle more quickly.

Ryan

 

[klatt_89]

You bring up a very good point. It's important to have them do a test to see how think the walls are as well as if there was any core shift to where some walls are thinner than others.

 

[blacksnapon]

Most of the time its used to correct an out of round in the cylinders. You also increase the cubic inch displacement. If you need to, you can repair a damaged cylinder wall by over boring, then sleeving that cylinder. When boring, you must also replace the pistons and rings with oversized ones.

 

[SuperCab]

What engine do you want to bore/stroke?

Some engines (the 400ci chevy comes to mind) are maxed out from the factory, and can't be bored.

 

[Truckin4life]

boring and stroking both work as basically the same, they both have there limitations....

With a bigger bore and the stock stroke, you are allowing more air and fuel into the cylinder which will compress and ignite to create more power.

The more fuel and air you can get into a motor the more power you will get out.

A longer stroke will provide the same thing, you get more fuel and air into the cylinder and you likely get a little higher compression ratio.

Combine the 2 for maximum increases in tq and hp....

 

[TexasNomad]

What I want is a engine I can get the most low end power out of and not have to run high grade fuel..
So right now this is what I have on my plate keep my 302 and mod it out to get the best low end tq out of I have access to a 351M I want to do the same thing to that and what I would really like is a 400! But! if I can get the same low end power from stroking or boring my 302 then why not keep it..

 

[SuperCab]

work with the 302 rather than the 351. the 302 has more available aftermarket parts, the parts are cheaper and more widely available.

 

[Truckin4life]

bore it AND stroke it, but keep your compression ratio lower, so you dont have to run race fuel, i think like 10.5:1 is usually good, for premium gas, any kind of engine build i would suggest premium gas over standared unleaded.

 

[TexasNomad]

thanks guys.
As much as I would love to have a 351 or 400, I think it would be best in the long run to stay with my 302..

 

[Truckin4life]

Yea the 302 can be built to a respectable engine, but if your wanting the most power, it would be best to find a 351 and stroke it out. If your searching for the best bang for your buck.

 

[Bob Ayers]

The longer stroke will give you more low end torque, due to the higher mechanical advantage of the longer crank throw.

 

[TexasNomad]

I was thinking maybe stroking her out to about a 332 should do just fine for what I need.

 

[klatt_89]

Why not use ur 460 Just playing with ya man. You can have small blocks making some killer power, but some of those are high rpm engines as well

 

[blackhat620]

The longer stroke will give you more low end torque, due to the higher mechanical advantage of the longer crank throw.

General rule if you want more low end torque then stroke it.

 

[surewhynot]

Personally, I would find a 351w and stroke it. More cubes, more grunt.

 

[TexasNomad]

I think your right tony I talked to the guys at Performance Unlimited and come to find out.. you'll love this piggy, but they said the best thing to go with is a 393 stroker Once again the pig is all knowing..

 

[surewhynot]

I did a lot of research before building mine, and for the performance vs. price, a 393 beat a 347 (stroked 302) hands down.

 

[TexasNomad]

Yup should have just listened to you piggy
I'll never doubt the pig again...