Head CFM vs. HP per c.i.?

[thumper 823]

I think it's great Thumper that you are out there, testing, testing, testing and more testing stuff. Fail, succeed, fail, succeed-No Dyno, no problem. Sure it would be a lot easier to evaluate changes but, "Potty mouth", Just take it out on the open road or a track and rip it-you will learn what works, and what doesn't. BTW, there was an AHDRA pro stock champ who never put his bike on the Dyno during his championship year run...
You are actually exploring the possibilities and potential of your motor, not playing keyboard commando and never doing anything.
Depends on many factors how long they last, but my current street bike motor lasted about 30k hard core miles till it needed a rebuild....must have been all the "shows" the bike was in that wore it out-

I do have AFR gauge ....it is almost a dyno..LOL
The two dyno people sort of close to me have given me a bunch of shet..I was going to dyno it last summer.....
But one operator thought the twin plugs were a novel idea and great for emissions.
No clue.
Both operators wanted it to come off the rack with a tune of 13.5
I am not the smartest there is...but not the dumbest either.
There is no way I could run this thing that lean.
So no it was not dynoed

[thumper 823]

I will run right out and measure it for ya...
LOL
Actually Just took it apart and I can give you just a couple number cause I can't remember everything.
I believe the seats are 2/32  way at the top.
Cam is DM 530 with his spring set.
  I measure it about 2.5 years ago..  Brain farts
I am now going to a 50 deg seat angle with perhaps a 3/32 seat..I will not know until a few other items are solved here.
(I need the rockers back from Basily )
Like i said
Don't do what I do if you want a 5oK (mile ) engine.

Well your doing something wrong if it cant make 50k. Tell us more so we don't make the same mistakes....Bob

No not at all , you just are not understanding the subject matter.
If I was shooting for long, longevity I would do like the diesel and most aircraft engines do, a 35 deg seats.
Hvy sodium valves.
Aunt tillies 3o lb ring pack, cheap cast slugs .
And a few other mods.
Harley comes to you with a detuned engine and then wants to sell you stuff to bring it to par.
Rule of thumb  -one cubic inch per hp, is way safe, too safe, considering some crotch rockets are upwards and past 3 HP per cube.
However, they have no internal RPM governor.
I am hoping i am in the 1.3 Hp per cube area.
With as much as I have done I think that is a conservative guess.
But it is just a guess without the papers.

[1FSTRK]

I will run right out and measure it for ya...
LOL
Actually Just took it apart and I can give you just a couple number cause I can't remember everything.
I believe the seats are 2/32  way at the top.
Cam is DM 530 with his spring set.
  I measure it about 2.5 years ago..  Brain farts
I am now going to a 50 deg seat angle with perhaps a 3/32 seat..I will not know until a few other items are solved here.
(I need the rockers back from Basily )
Like i said
Don't do what I do if you want a 5oK (mile ) engine.

Well your doing something wrong if it cant make 50k. Tell us more so we don't make the same mistakes....Bob

No not at all , you just are not understanding the subject matter.
If I was shooting for long, longevity I would do like the diesel and most aircraft engines do, a 35 deg seats.
Hvy sodium valves.
Aunt tillies 3o lb ring pack, cheap cast slugs .
And a few other mods.
Harley comes to you with a detuned engine and then wants to sell you stuff to bring it to par.
Rule of thumb  -one cubic inch per hp, is way safe, too safe, considering some crotch rockets are upwards and past 3 HP per cube.
However, they have no internal RPM governor.
I am hoping i am in the 1.3 Hp per cube area.
With as much as I have done I think that is a conservative guess.
But it is just a guess without the papers.

My guess is you read a lot and talk to a lot of knowledgeable people.
If you stay away from flow benches, dynos, as well as professionally built engines and components your projected hp will continue to go up and up. You will continue to happily work on your bike all winter and ride with a smile all summer long.

[Matt C]

There's a guy on youtube, Tatro Machine. You should check him out (he doesn't believe in Dyno and Flowbench testing) Uses his 'fingers' to predict airflow patterns. I don't know why some Nascar team hasn't snapped up this
genius. 

[1FSTRK]

There's a guy on youtube, Tatro Machine. You should check him out (he doesn't believe in Dyno and Flowbench testing) Uses his 'fingers' to predict airflow patterns. I don't know why some Nascar team hasn't snapped up this
genius. 

Don't knock it if you have not tried it, your finger is very sensitive to air flow and is invaluable when picking which direction to face when peeing outdoors.

[Matt C]

The BIG Picture-
Textbook answers are ok .
But the devil is always in the details.
I have worked very hard at discovering more then what is says on say page 93.
The guy that has applied all of that and 1000 other pages in details will win.
I am not sure what he will win, It is just personal satisfaction for me.
Everything (all most) that will make your engine perform better will never make it last longer.
The novice wants a hi-performance guaranteed to go hundred thousand mile engine.
That is upside down and not going to happen.
Narrow seats, steeper angles, shorter narrowed guides, will outperform the textbook answers.
I have arrived at the 20K mark .
By this I mean I will sell out miles for performance if it will make it 20K mark.
That is about two years for me and just long enough to make me forget all the frustrations last time.
So, guys and gals pick your poisons.

Narrow seats, steeper angles, shorter narrowed guides? (That stuff is in text books, if you look for it).

That crap is for unlimited budget racers *Nascar for example*. We don't need any of that crap for
these low RPM street driven engines. Keep it simple, ride it sanely and they'll last a long time.   

[Matt C]

Anything that increases the efficiency of the engine will make it last longer. It's when you start raising
the engine's operating RPM range that potentially shortens its life.

Engine blueprint, quality parts, break-in and good maintenance all will extend it's life. Along with riding
it sanely. I have 25,000 on my Dyna and it's never been into. Just oil changes and routine maintenance.

I do plan on going into it before I ride it this year b/c it's probably due (lol). And, since I'm going to be in
there; better heads, cams, gear drives and BB kit are going on it. It will last another 40K at least after that.
 

[thumper 823]

The subjects seem to get turned around here.
Sort of into insults, and I in no way have tried to do that to anyone...
So whatever makes you all happy.
Nothing I have done has not been done others, somewhere else.
I am no genius, just rather predictably always looking for better.
I do study a lot, Smokey Yunick should be on everyone's shelf.
The saying I use is "it is VERY hard to bolt on horsepower ".
I think I may have stolen that too from perhaps Corky Bell.
To the point-
We all want more power, it comes with cost .
Like I said B4, - 20K miles is a good number for me, it allows ideas outside the box of conformity.
No one is going to do anything different by repeating the stuff over and over.Again .
Shaving heads 50 thou, 10.5 CR, bigger carbs and pipes.........sending heads out for thousand dollar port jobs
Is all stuff that can be done at home.

[thumper 823]

Anything that increases the efficiency of the engine will make it last longer. It's when you start raising
the engine's operating RPM range that potentially shortens its life.

Engine blueprint, quality parts, break-in and good maintenance all will extend it's life. Along with riding
it sanely. I have 25,000 on my Dyna and it's never been into. Just oil changes and routine maintenance.

I do plan on going into it before I ride it this year b/c it's probably due (lol). And, since I'm going to be in
there; better heads, cams, gear drives and BB kit are going on it. It will last another 40K at least after that.

I cannot agree with that, as a IC engine is about 20% efficient.
Example-Drain the water out of your car and will be more efficient, but will not last very long.
Everything is a trade-off. Compromise.
That is why all the R&D has been going into ceramic engines-no liquid cooling just hotter.
If we ask more from most anything we get it but the time ticks away faster on the other end.

[build it]

Thumper, I applaud what you're doing and encourage you to go further with each succcessive build. Make sure those seats are concentric and vacuum test the head. You're on the right path and just might be surprised upon freshen if you follow good principles.

[thumper 823]

Thanx !
The  Devil is in the details.
No production shop will ever treat your heads like their own.
Simple.
That is why I encourage everyone to buy a hard seat grinder and needed pilots /stones.
Used is cheap on eBay.
Do your own work and this will no longer baffle you.
Then, one is willing to try some other stuff. Like narrow short guides.
Its just no big deal along with whatever other tricks might be applied.

[Matt C]

The subjects seem to get turned around here.
Sort of into insults, and I in no way have tried to do that to anyone...
So whatever makes you all happy.
Nothing I have done has not been done others, somewhere else.
I am no genius, just rather predictably always looking for better.
I do study a lot, Smokey Yunick should be on everyone's shelf.
The saying I use is "it is VERY hard to bolt on horsepower ".
I think I may have stolen that too from perhaps Corky Bell.
To the point-
We all want more power, it comes with cost .
Like I said B4, - 20K miles is a good number for me, it allows ideas outside the box of conformity.
No one is going to do anything different by repeating the stuff over and over.Again .
Shaving heads 50 thou, 10.5 CR, bigger carbs and pipes.........sending heads out for thousand dollar port jobs
Is all stuff that can be done at home.

I wasn't insulting anyone, sorry if you took it that way. Just trying to add common sense perspective.
If you can do a "$1000" port job yourself, more "power" to ya.

Power comes with cost, yes. But allot of ppl operate under a false assumption that if it costs more, it has
to be better.

I spend 80% of my time doing R&D because it's what I'm into. I'm not in it for money. I'm retired and have
that covered. I do it b/c I enjoy the challenge. A Flowbench and a Dyno is what I use to develop cylinder
heads.

If you think you can to a "$1000 port job" with stones and no flowbench, that's great. You're smarter than
99% of the people out there.

Have a nice new year.

[No Cents]

   so...your saying no head porters are needed like wfolarry, J Sachs, Jim Libo, or even Dave Ward...just to name a few off the top of my head. 
Just do it yourself huh?
  You say these guys won't show you their best work. That's a pretty bold statement...and I have to disagree with you. They will give you their best work...but you have to pay for it. Horsepower doesn't come cheap or free. I leave things like head porting to the professionals. Tell them what your after...and set back and let them do their thing. These guys got to where they are today by hard work and constantly experimenting to find more. I'd rather pay them for their knowledge and expertise, rather than me ruin a good set of heads by me trying to improve the velocity and flow with no way to test it besides bolting it together and running it down the road to see if I felt an improvement. I guess if it was a full time drag bike you could tune it according to results your seeing off the strip. But a bike ran on the street I'd want it on a dyno for break in while it's being monitored. Too lean, or too rich can be destroying your engine without you even knowing it.
   I know Nascar teams use high dollar wet flow bench's to actually see what's going on inside the heads. They will make very small changes, one at a time, and then re-evaluate after seeing the results. It's a never ending process they do to try to gain more power. They have full time design engineers and machinist working on this every day.

[thumper 823]

More money should get more power.
But more often than not it dont!
for instance-
The 400.00 dollar air cleaners .....
I wish I could tell people......what a waste

[thumper 823]

   so...your saying no head porters are needed like wfolarry, J Sachs, Jim Libo, or even Dave Ward...just to name a few off the top of my head. 
Just do it yourself huh?
  You say these guys won't show you their best work. That's a pretty bold statement...and I have to disagree with you. They will give you their best work...but you have to pay for it. Horsepower doesn't come cheap or free. I leave things like head porting to the professionals. Tell them what your after...and set back and let them do their thing. These guys got to where they are today by hard work and constantly experimenting to find more. I'd rather pay them for their knowledge and expertise, rather than me ruin a good set of heads by me trying to improve the velocity and flow with no way to test it besides bolting it together and running it down the road to see if I felt an improvement. I guess if it was a full time drag bike you could tune it according to results your seeing off the strip. But a bike ran on the street I'd want it on a dyno for break in while it's being monitored. Too lean, or too rich can be destroying your engine without you even knowing it.
   I know Nascar teams use high dollar wet flow bench's to actually see what's going on inside the heads. They will make very small changes, one at a time, and then re-evaluate after seeing the results. It's a never ending process they do to try to gain more power. They have full time design engineers and machinist working on this every day.

you read more into that then I actually said.

I have raced a couple people that had Brand X  do their heads.
They were quite pissed.
All i am saying is most people can do a lot of the work for a lot less. (if they put their mind to it)
They might not do as well  as Mondello, but they are off to some satisfaction.

[Matt C]

   so...your saying no head porters are needed like wfolarry, J Sachs, Jim Libo, or even Dave Ward...just to name a few off the top of my head. 
Just do it yourself huh?
  You say these guys won't show you their best work. That's a pretty bold statement...and I have to disagree with you. They will give you their best work...but you have to pay for it. Horsepower doesn't come cheap or free. I leave things like head porting to the professionals. Tell them what your after...and set back and let them do their thing. These guys got to where they are today by hard work and constantly experimenting to find more. I'd rather pay them for their knowledge and expertise, rather than me ruin a good set of heads by me trying to improve the velocity and flow with no way to test it besides bolting it together and running it down the road to see if I felt an improvement. I guess if it was a full time drag bike you could tune it according to results your seeing off the strip. But a bike ran on the street I'd want it on a dyno for break in while it's being monitored. Too lean, or too rich can be destroying your engine without you even knowing it.
   I know Nascar teams use high dollar wet flow bench's to actually see what's going on inside the heads. They will make very small changes, one at a time, and then re-evaluate after seeing the results. It's a never ending process they do to try to gain more power. They have full time design engineers and machinist working on this every day.

Yeah Ray, that's the way I read it.

I sometimes spend 40-50 hours a week, flowbench testing (on one port). Trying very small incremental
changes. Seat profiles, short side shapes, valve shapes wet flow, etc & so-on...

I think if you told Smokey he didn't need a flowbench, he would have laughed you out of his shop. Smokey was
one of the pioneers of flowbenches. Very sharp guy and ahead of his time. He held many many patents as well.

His books are very good too.

Joe Mondello was another one, he was a good friend and a mentor to me.

[thumper 823]

Where did I say "No flow bench needed?"
You all hung over?
I have seen some hacks with flow benches too.
Snake oil comes in various containers.

[No Cents]

     Matt...I wasn't fortunate enough to ever meet Joe Mondello...but I did get the chance to talk to him on the phone once. He impressed the hell out of me after he took the time out to talk to a nobody like me. I was humbled. He was a very smart man. 

[Matt C]

     Matt...I wasn't fortunate enough to ever meet Joe Mondello...but I did get the chance to talk to him on the phone once. He impressed the hell out of me after he took the time out to talk to a nobody like me. I was humbled. He was a very smart man. 

He was awesome, (I was devastated when he passed). The really good ones, will take the time to pass their
knowledge on willfully. I went to a couple of his classes/seminars, that was a chance of a lifetime.

I had the honor of meeting Darin Morgan last year, and I managed to get into his advanced induction system
design course.

He's allot like Joe. Very down to earth and will show you everything and anything you want to know and stuff
you didn't think you wanted/needed to know. Highly recommend that one, if you can get in.

[kd]

Thumper, you can't compare what happens in a race based solely on how the heads turned out (no matter who did them). There are too many other parts to the equation like compression, cam specs, intake, pipe, tune yadda yadda yadda.

If anyone can get some book learnin on how to pull air around a short side, how long to cut the seat angles and how many if any, what and where the CSA should be, (and on and on) ..... then pull out their Harbour Freight grinder and produce a set of heads that are even close to the same as WFO, Dan Baisley, Don or any of the others considered worthy professionals you should be on stage telling jokes. Seriously, I can't get my head around that any one can believe that. Valve jobs .... OK. Change guides ..... sure, follow the instructions.  To know by appearance (through experience) how to pull up the torque #'s when that is the riding style or get the most out of a certain cam spec to get that 1/10 of a second in 1320 does not happen in your first or even 10th set of heads.  All I can see here is a bin full of aluminum castings on the way to the recyclers. That is of course unless what you are really talking about is cleaning up the port castings and doing typical valve jobs.  That is doable.

I hope that no one starts thinking they can do head work better than "Brand X" (if they are a proven porter) because they read somewhere there is nothing to it. Having said all that, I am only trying to say THERE IS NO SUBSTITUTE for a set of heads custom ported and massaged by one of the top porters who's names we generally throw around here. The money is ALWAYS well spent when you are trying to pull 1.25 or there about out of a build. Top tier engines require top tier work. That's a well known fact.

If you have read and studied head porting techniques you will likely be able to have a well educated discussion with a top porter and subsequently get more of what you are after in the end from that porter. That's about it. Doing the work involves a huge amount of learning hands on and testing to confirm success or failure.   My 2 cents 

[build it]

Thanx !
The  Devil is in the details.
No production shop will ever treat your heads like their own.
Simple.
That is why I encourage everyone to buy a hard seat grinder and needed pilots /stones.
Used is cheap on eBay.
Do your own work and this will no longer baffle you.
Then, one is willing to try some other stuff. Like narrow short guides.
Its just no big deal along with whatever other tricks might be applied.

You’re doing guide work first, correct?

I dig that you’re using stones plenty to be said about that, all positive.

If you have a good foundation and principles no reason you can’t go as far as you want to go. In my experience a lot of people especially on forums make port work sound like magic, it isn’t, all it is is area scheduling.

That’s my last post in this thread.

[kd]

     Matt...I wasn't fortunate enough to ever meet Joe Mondello...but I did get the chance to talk to him on the phone once. He impressed the hell out of me after he took the time out to talk to a nobody like me. I was humbled. He was a very smart man. 

He was awesome, (I was devastated when he passed). The really good ones, will take the time to pass their
knowledge on willfully. I went to a couple of his classes/seminars, that was a chance of a lifetime.

I had the honor of meeting Darin Morgan last year, and I managed to get into his advanced induction system
design course.

He's allot like Joe. Very down to earth and will show you everything and anything you want to know and stuff
you didn't think you wanted/needed to know. Highly recommend that one, if you can get in.

I had a similar experience with Dan Baisley over a period of phone calls looking for head work. Once he found my level of understanding, he explained what he would do to satisfy my needs and qualified it with examples. He then delivered in spades. Best money I spent on my 120 as far as I am concerned.

[Matt C]

Thanx !
The  Devil is in the details.
No production shop will ever treat your heads like their own.
Simple.
That is why I encourage everyone to buy a hard seat grinder and needed pilots /stones.
Used is cheap on eBay.
Do your own work and this will no longer baffle you.
Then, one is willing to try some other stuff. Like narrow short guides.
Its just no big deal along with whatever other tricks might be applied.

You're doing guide work first, correct?

I dig that you're using stones plenty to be said about that, all positive.

If you have a good foundation and principles no reason you can't go as far as you want to go. In my experience a lot of people especially on forums make port work sound like magic, it isn't, all it is is area scheduling.

That's my last lost in this thread.

There's nothing wrong with stones, I still have the set I bought in 1973. The only downside(s) I can think of,
is they can't do radius seats, and it takes a little longer. Other than that they're fine. I still use them on quickie passenger car heads if the guides are good.

If I have to heave the damn thing on the machine for guides, then I'll do the seats too while its on there.
car heads

[Hossamania]

For me, I pay someone else for their knowledge and skill, and I do all the small things I can. I do not chase all the horsepower anymore, just enough to beat my friends.
I don't have the time, patience, or money to practice all the little details to squeeze every horse out of an engine, but I sure appreciate the guys that do.

A friend of mine got his kid into go-cart racing. We are talking the low end of the carting ladder. But, he wanted his kid to be competitive (not even close at the beginning), and asked for a little help from some of the other fathers. He got the coldest shoulder possible. He couldn't believe it.
He asked me what to do, so I said to start talking to others in the industry, search the net, and he and I talked often about theory and actual specs.
One of my favorite contributions was clutch mods, shaving it to the minimum spec (using a cordless drill, a vise, and some sandpaper!) to help with the starting line launch. So many other small mods. One of the best things he did was take it to a guy to set up the chassis, and learn how to adjust it himself, keeping tight notes.
Long story short, by the end of the year, he was starting to win races, and the next three years his kid was series champ and traveling out of state to compete nationally. I was proud of him, and a little proud myself that I could make some contribution to his kid's success.
Beating those dicks that wouldn't help at the beginning was the best reward.

Now he wants to get back into riding, and Harleys especially. He already is asking me how to make more horsepower before he even has a bike.
And so it continues!!

[thumper 823]

I use a combination of stones/cutters and other stuff., like most anyone
Depending what I am doing.
The Porsche stuff is very exacting.