questions about boreing??

[pr3pg4lyfe]

i was wondering; does boreing your engine(like h22 to h27) does it give u alot of pull?? how do yo bore up your engine?? my boy was trying to sell me his h24 but i had no clue wat it was lol. can someone plz give me pros and cons about boreing?? thanks in advanced

[Flatline]

when you bore an engine, you make it bigger overall, like making an h22 and h23.

The problem with it is, you'll need oversized pistons, and you'll have to re-sleeve the block. In turn, boring out an engine too much can hurt it's reliability. Your going to make the space between outside and inside thinner.

You could gain more power in the low end, but you may sacrifice top end. the bigger the moving parts, the harder it is to safely turn them faster.

It would be a big, full build, but i can be worth it. but not a 2.7

[johnl]

You could gain more power in the low end, but you may sacrifice top end. the bigger the moving parts, the harder it is to safely turn them faster.

More like your trying to induct more air into a larger space through passageways that haven't been increased in size, which get more restrictive the higher the rpm and the more the cylinder has been 'bored'). As a result the power band may move lower in the rpm range, losing some top end but gaining some bottom end and mid range. I can imagine top end being affected to the point where it's not worthwhile to rev the engine as high as the un-bored engine.

I suspect it would be more economical / effective to leave the CCs alone and turbocharge it instead...

[93F22A6]

For one you would have to sleeve the block. Then have a machine shop bore and honw it to your specified piston size. Also you can not bore a stock H or F series(except a few but most have the FRM sleeves), this is due to the FRM(I think it stand for Fiber Reinforced Metal, not to sure about the metal part but the first part is right). Increasing the bore of the engine will give you more displacement, which will mean an increase in torque. In my opinion unless it's a full on build there is no need to bore an H22, there is plenty of power to be made with the top end of the motor. If you do want the increase in torque just get a stroker kit.

[deevergote]

I suspect it would be more economical / effective to leave the CCs alone and turbocharge it instead...

I couldn't agree more.

To totally redo an engine, especially when increasing bore and stroke, you're looking at a considerable amount of money. If you're going to do that much work, it'd make more sense to build the motor for a high boost turbo setup, unless you REALLY want to stick with NA.

To do it right, $10,000 or so will get you 280-300whp NA... and over 600whp turbo. Reliability will probably be about equal for both setups, and it will depend heavily on the quality of the parts, workmanship, and continued maintenance.

[wed3k]

i would only bore if im stroking as well.

otherwise leave the bottom end alone or hone the cylinders for an oversized piston to true the cylinders and work on the head aka camshaft and comrpession.

[deevergote]

You know what they always say... If you're bored... stroke it!

[johnl]

To do it right, $10,000 or so will get you 280-300whp NA... and over 600whp turbo.

Yes, but to get 280-300whp from a turbo set up should cost a lot less than $10,000, especially if you're starting with a sound / strong engine that doesn't really need to be rebuilt first.

[deevergote]

Most certainly. 280-300whp with a turbo setup can be done on a stock block.

I was simply saying that if you're going to invest in a full engine build, you can make twice as much power with a turbo. And, as you said, you can make as much power as a full NA build with a stock block and turbo!

Granted, NA has its charms and benefits... and if you're looking to race (which is the only real reason to put so much money into a motor anyway) then there are certain classes with certain limitations.

[johnl]

Deever,
I wasn't argueing, just pointing out that the potential within the constraint of a realistic budget (as opposed to a fantasy budget, at least for most of us) is far greater with forced induction than NA.

In the old days this wasn't the case, since the great majority of older engines weren't built to a particularly high standard or out of particularly good materials, so much of the engines internals needed to be upgraded for even relatively modest boost levels (by todays standards). So when substantially supercharging an older engine you might easily have been up for more cost than a NA build, i.e. many of the same costs as for an NA build just to bring the base engine up to scratch, + the supercharging hardware.

These days (last 20 years or so, ish...?) most engines from most manufacturers (particularly Honda) are much better designed / built / more robust in stock form, so you can get a lot from supercharging them before you need to start needing to look inside the engine itself.

You kids don't know how easy you have it these days... etc etc etc....

[deevergote]

I'm not so much arguing as just continuing to carry on the thought... I tend to do that!

But yeah, I've heard that. I've never worked on anything older (actually, I've never really gotten into ANYTHING other than F and H series Honda engines!) but everything I've heard and read has always said that if you want an older engine to last while making a lot of power, you need to address just about every part of it.

[johnl]

but everything I've heard and read has always said that if you want an older engine to last while making a lot of power, you need to address just about every part of it.

More or less, for most production engines. Of course there were exceptions, often homologation specials like the Cooper S Mini etc etc, but even some of these could be fragile when modded beyond factory spec.

Most modern engines are rather over engineered for their intended purpose (or at least the duty they'll actually see with most car owners), but it's a lot easier to build them that way with the advent of computer aided design and computer controlled production machinery.

[pr3pg4lyfe]

thanks everyone for the info