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Discussion Starter · #1 · (Edited)
Anyone gone to this site: MotoTune USA ?

There's his articles on some controversial stuff...like smaller ports being better, and using a HARD break in, as opposed to a gentle break in.

His logic makes sense though, although probably not every engine needs smaller ports. I've heard ours are limited by small ports that can't be enlarged much. I assume there are dyno numbers to prove there's an increase with P&P work?

I was curious because I'm gathering tools now for my head gasket/ piston ring project, and came across his site.

BTW the link doesn't subscribe you to anything...I bookmarked the page and posted the link. I subscribed several times at work, because my computer was acting up...if there's a [email protected] out there, YOU'VE GOT MAIL!
 
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Hard Break in = Good, though don't tell any oldschool V8 mechanic that.

Small Ports? As far as my understanding goes, that only applies to a 2-stroke engine.
 

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no first hand knowledge, but what I've picked up from reading is that you want to have the highest velocity of the intake charge, ie you want the air to be moving as fast as possible. By reducing the size of the ports you can increase the speed. But as with anything, it's a trade off, smaller ports mean less total airflow, less air means less power.

As such, the idea is control the size and shape of the ports to get the highest velocity for a particular flow rate.... sometimes you can do that by decreasing the port size.
 

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Think!

FlySwat said:
Hard Break in = Good, though don't tell any oldschool V8 mechanic that.
I don't think John Force could subscribe to any "baby-it-for-the-first=xxxmiles" nonsense. But I kinda think of him as old school V-8 kinda guy.

My opinion on break-in is that you must constantly vary speed and load. Some hard miles, some easy, some fast, some slow.

moebius said:
you want to have the highest velocity of the intake charge, ie you want the air to be moving as fast as possible. By reducing the size of the ports you can increase the speed.
To increase volumetric efficiency (i.e. to better fill the cylinder) on a NA engine you leave the exhaust valve open longer past BDC. The air flowing into the engine has inertia and it keeps right on a-comin', even though the piston has passed BDC and is starting to come back up. The faster the air is flowing, the longer it can overcome the the force of the rising piston in the cylinder and the higher the volumetric efficiency.

This phenomenon is less apparent (non-existent?) when you push air into the engine, rather than pull.

moebius said:
But as with anything, it's a trade off, smaller ports mean less total airflow, less air means less power.
Not quite that black and white. Volumetric efficiency varies with RPM -- a smaller port can equate to less power in one RPM range and more power in a different RPM range.

moebius said:
As such, the idea is control the size and shape of the ports to get the highest velocity for a particular flow rate.... sometimes you can do that by decreasing the port size.
Not sometimes, all the time (for a particular flow rate).
 

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word!

yes!! we have signs of intelligence!!

you guys are good! :D bringing forth the truth to us mx6ers.
the way i see it is, every aspect of an engine is all part of an equilibrium. to make one mod effective, the design aspects of the engine have to be considered.

})
 

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Re: word!

veltpak6 said:

the way i see it is, every aspect of an engine is all part of an equilibrium. to make one mod effective, the design aspects of the engine have to be considered. })
Critical analysis. What a novel concept!!!
 

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If you want a high revving 4 stroke... large, extremely large ports and short runners are the key because Vm.Ec. is higher (optimal). To make high rpm power youre engine doesnt want to breathe through an extremely long passage as it is harder to induce the fuel charge into the cylinder; Therefore ports must be larger.
Granted the intake needs to hold 'x' amount of cc's to create enough free air flow. Too many CCs and the engine will not make enough torque to keep the power curve climbing; Too small and the HP curve will be on the downslope at 'n' desired RPM because the intake is not supplying enough fuel.

the 2.2L is designed for moderately quick scooting around with good accelleration. Therefore it is not set up for high rpm and 3" exhuasts unless you increase the port size and decrease the intake CC.
 

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critical analysis or horsefluff?

pud said:
If you want a high revving 4 stroke... large, extremely large ports and short runners are the key because Vm.Ec. is higher (optimal). To make high rpm power youre engine doesnt want to breathe through an extremely long passage as it is harder to induce the fuel charge into the cylinder; Therefore ports must be larger.
This guy is saying the ports must be smaller. Of course he's only talking about 14,000 RPM, not the kind of Rs a Mustang makes. He's also talking (primarily) about multiple intake valves per cylinder, something the Mustang seems not to have.

But don't let any of that interfere with your lecture.

pud said:
Granted the intake needs to hold 'x' amount of cc's to create enough free air flow. Too many CCs and the engine will not make enough torque to keep the power curve climbing; Too small and the HP curve will be on the downslope at 'n' desired RPM because the intake is not supplying enough fuel.
What's "free air flow"?

pud said:
the 2.2L is designed for moderately quick scooting around with good accelleration. Therefore it is not set up for high rpm and 3" exhuasts unless you increase the port size and decrease the intake CC.
Nonsense. There are 2 different 2.2L engines. N/A responds quite differently from turbocharged. V8 Fords should be discussed in the "other cars" area, not here
 

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smaller ports=less CC=longer runner to compensate=high torque+low shift point

yay small ports, everybody should have them.
Custom grind. Im sure you could drastically reducethe base of the lobe to extremely increase lift and duration (needed for high rpm power). Yeah now you think im a dumbass, so this is where I say do some research and find your valve dimensions (diameter and stem length) add the amount of base circle you took off the lobe to the length of the pushrod, over size your valves a step up and then come tell me you cant make power up to at least 5500 rpm with a hybrid turbo....can you say 12 second 1/4s?
 

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spaceman

pud said:
Yeah now you think im a dumbass, so this is where I say do some research and find your valve dimensions (diameter and stem length) add the amount of base circle you took off the lobe to the length of the pushrod, over size your valves a step up and then come tell me you cant make power up to at least 5500 rpm with a hybrid turbo....can you say 12 second 1/4s?
Yup, I think yer a dumbass.

I did some research and couldn't for the life of me find the length of the pushrods in the 2.2 -- do you wear your baseball cap with the peak to the rear, by chance?

V8 Fords should be discussed in the "other cars" area, not here.
 

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yet i still think your ignorance is the cause of youre weak ass car. It probably sounds like ass noises. Ooh no I said pushrod, so that means you can automaticall disgregard my post...jackass. I made it obviously clear that I was talking about valve length and diameter. If you have 0.45" of cam lift stock, and you want 0.7" lift (this is purely hypothetical lift specs). To get that 0.7" of lift, you need to grind 0.25" inch off of the base circle (please dont attck that statement, it will prove to be a futile attack). if youre missing 1/4" off the base of your cam then youll have rockers that float, and possibly valves that slam hard, too hard against the head and break. So now you need longer valves, 1/4" longer. Putting new valves in? might as well unshroud, oversize, and do some bowl work.

On topic again, smaller ports would work better for a truck.
 

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FlySwat said:
Hard Break in = Good, though don't tell any oldschool V8 mechanic that.

Small Ports? As far as my understanding goes, that only applies to a 2-stroke engine.
A guy I know builds 2-stroke racing engines for quads. He has always told me break it in like a ***** and it will run like a *****. Break it in like a beast and it will run like a beast. You get the idea. He says this is the same for both 2 and 4 stroke motors. I'll see what he says about the ports.
 

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my dog can beat your dog

pud said:
yet i still think your ignorance is the cause of youre weak ass car. It probably sounds like ass noises. Ooh no I said pushrod, so that means you can automaticall disgregard my post...jackass.
Ad hominem, ad hominem, ad hominem (look it up).

Name-calling is the last resort of the intellectually bankrupt.

I was trying to explain that just because you can copy paragraphs from a V8 site and paste them here, doesn't mean you understand the 4 stroke cycle and internal combustion process.


pud said:
I made it obviously clear that I was talking about valve length and diameter. If you have 0.45" of cam lift stock, and you want 0.7" lift (this is purely hypothetical lift specs). To get that 0.7" of lift, you need to grind 0.25" inch off of the base circle
Umm, that's unadulterated horsefluff, pud. You have no idea whatsoever what you're talking about. That would only be true if your rocker ratio was 1:1. Which it isn't.

Think before you post, pud.

pud said:
(please dont attck that statement, it will prove to be a futile attack).
Oops, looks like I already did.

The attack would be futile if your rocker ratio was 1:1. Which it isn't.

Think before you post, pud.

pud said:
if youre missing 1/4" off the base of your cam then youll have rockers that float, and possibly valves that slam hard, too hard against the head and break. So now you need longer valves, 1/4" longer.
Do you even know what "base circle" means, pud? Have you ever seen a rocker arm? If so, have you ever noticed that the part that pushes on the end of the valve stem (HLA end) is longer (~1½ times longer) than the end that follows the cam profile (follower end).

Think before you post, pud.

If you're "missing" (as you call it) ¼" from your cam base circle, with a rocker ratio of 1:1.5, you would need .375" (3/8) longer valve stem to avoid "rockers that float", not .250" (1/4).

Think, pud, think.

All that would be meaningless, however, because your rocker geometry would be so funked up that your HLA would be pushing valves sideways, wearing away valve guides with vast amounts of side thrust which also uses up mucho horsepower and creates heat (assuming it doesn't just bend that longer valve stem. Lousy idea, all in all.

Think about the difference between your stock cam with the long end of your rocker arm moving between 2 o'clock and 4 o'clock position (assuming a vertical valve stem). Now let's check out pud's modified cam/valve. The HLA end of your rocker is now moving between 1 o'clock and 3 o'clock position -- all that extra lift has been translated into much, much more side thrust.

Think first, then post.

pud said:
Putting new valves in? might as well unshroud, oversize, and do some bowl work.
How much would you charge to do my head, pud? Sounds like you've really got your text editor together, even if you lack a die grinder.

pud said:
On topic again, smaller ports would work better for a truck.
Or (as the author of the website cited above found) a sport bike. But what does he know? Betcha he hasn't ported as many heads as you, right pud? How many heads have you ported, pud?

Oh yeah, I almost forgot. V8 Fords should be discussed in the "other cars" area, not here.
 

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Discussion Starter · #14 ·
So um, my original question was mainly if anyone's read the site there before.

And all that crap from the last few posts...WHOOOSH!!!...right over my head. :shrug:
 

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critical analysis (seldom) spoken here

Illswyn said:
So um, my original question was mainly if anyone's read the site there before.
I hadn't read it before, but appreciate you posting the link here. It seems to encourage people to "think for themselves" rather than just follow the leader and parrot nonsense spouted by others.

I notice that no one seems to have responded to your statement in your first post that says: "I've heard ours are limited by small ports that can't be enlarged much. I assume there are dyno numbers to prove there's an increase with P&P work?"

I would take that lack of response to your statement to indicate that there are no dyno numbers to confirm any HP increase after head work on the 2.2. Since the tuner on the website you showed us does have dyno numbers to confirm his "small ports" theory, we seem to be faced with a decision:
  • subscribe to the mototune theory which has been researched and tested, or
  • subscribe to pud's bluster consisting of half-understood (or misunderstood) half-baked theories cribbed from other websites (catering to 2-valve-per-cylinder pushrod V8s!) where they were posted by folks who seem similarly disinclined to test their theories on a dyno.

I happen to think the mototune guy makes a lot of sense (and seems to have a fair bit of support around here, at least in the break-in theory area). I also happen to think that pud's rantings make very little sense (attributing pushrods :confused: and 1:1 rockers :confused: to our 2.2).


Illswyn said:
And all that crap from the last few posts...WHOOOSH!!!...right over my head. :shrug:
Not certain that it was all "crap", but I do consider it imperative to look at those kind of factors when modifying an engine. I think that people who fail to understand the implications of, say, smaller base circle on their cam lobes can be causing themselves many other problems without even knowing about it. Pud's beloved SB Ford V8 is famous for devouring its own valve guides, even before pud starts doing his "longer valve stem" mods. That's why I encourage him to "think".

If I thought vector diagrams might help others understand the concepts, I might create some, but my perception is that most people here just want someone (anyone who seems to speak authouratatively will do, whether they understand the words they're using or not) to tell them who makes the best camshaft for the 2.2, don't bother me with details like lift, duration, overlap, valve acceleration, spring rates, etc.

To many hereabouts seem to think speed is achieved by mindlessly writing checks.

Speed is achieved by having all the parts in your machine working in harmony to complement one another. To understand how they can work in harmony, you must understand how they work.
 

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I didnt cut and paste, I thought that up completely on my own, that would be why you could find so much error in the posts. Anyways, I was just throwing an idea out there that might help squeeze a bit more cfm's through there
 

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ad hominem<>idea

pud said:
I didnt cut and paste, I thought that up completely on my own, that would be why you could find so much error in the posts. Anyways, I was just throwing an idea out there that might help squeeze a bit more cfm's through there
How many heads have you ported, pud?
 

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Discussion Starter · #18 ·
I certainly wasn't meaning the info was crap...just my way of saying all that stuff went over my head.

And it's not only pud, or anyone else on here, that gets their head ported and polished, assuming it is going to make an improvement. The problem is that they get that done as a side job, when they get an array of other things done. If there's no evidence that it alone improves performance, then maybe it should be questioned.

And I'm not sure on the hard break-in. What about all the other seals and gaskets that are being broken-in? Should they be stressed that much in the first 20 or so miles? I assume it's not a problem, because to do the rings, you have to change the gaskets. So anyone doing a hard break-in would be doing a hard break-in on the gaskets as well.
 

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i just made the ports on my car smaller, and the power increase in the 9000 rpm range is amazing!! thanks

JK, this is interesting though. i'm really wondering right now how much of a HP increase would we get if did make the exhaust ports bigger. Makes more sense now to have the intake (compressed air from turbo) side have the dual valves, while the free flowing exhuast side ahve single valves.

that page has some good info
 

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el norm said:
Makes more sense now to have the intake (compressed air from turbo) side have the dual valves, while the free flowing exhuast side ahve single valves.
Actually more the opposite, norm, unless I'm misreading your post.

The compressed air from the turbo is only at 7 psi (stock) to maybe 18 psi (modified) above atmospheric.

On the other hand, when that exhaust valve starts to open, there's still lots of residual pressure (between 400 and 600 psi) in the cylinder.

Stick your finger in a spark plug hole and have someone crank your engine. The pressure that blows your finder outta the spark plug hole (let's say, for sake of argument, 125 psi) would be something like 16 times as strong as what your stock RBH5 is pushing past the intake valves at best of times. But it would still be only a quarter of what's trying to get past that exhaust valve once it starts opening.

The two intake valves provide more port/throat area than the single exhaust valve. You need a bigger orifice to move low-pressure (intake) air than high-pressure (exhaust) air.

Just not as big as pud thinks. :D
 
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