Dimpling a LS port

[dannobee]

Here's a video of Kinsler injection from above. https://www.youtube.com/watch?v=RaN165eLgYU Although on methanol, the fuel just runs into the intake at low speed, using the sharp edge of the throttle valve to help atomize the fuel. This same effect can be seen on the sharp edges of the valve and seat angles on a wet flow bench. Radius on intake seats or valves, bad. Sharp angles, good. Use the dykem trick and you can see it atomizing on the valve angles when you look at the chamber side.

Higher fuel pressure helps create better atomization. Look at the current crop of diesels, fuel pressure is now above 30,000psi. GDI fuel pressure is trending up for the same reason.

My SWAG regarding why carbs hung around so long on race cars. Pro Stock and nascar Cup carbs were at the absolute pinnacle of their evolutionary chain and were much better than anything available to us mere mortals over the counter. When the sanctioning bodies forced them to switch, they had to relearn a whole new system (and were, as mentioned before, limited by rules). They were reluctant to switch because back to back testing revealed they were down 50hp or more from their best carb setups. Evolution takes time.

With respect to intake plenums with carbs, I don't think it's a secret that fuel is washing and sloshing around the floor. A smooth surface tends to keep it there. A rough surface tends to put it all back in suspension (analogous, I suppose, to comparing the ocean on a calm day and a stormy day). I was helping out a friend with a Super Stocker and he noticed the exhaust temps all over the place (varied by over 150deg, IIRC), on a couple of cylinders and he thought if he could get them equal, he'd find the holy grail. I had my suspicions. Knowing what I knew, a little grinding and welding at the bottom of the plenum got the EGT's to within 20defF of each other and guess what, no power gain within the margin of error.

[Fatman]

Larry, were these tests A-B tests with the same pair of heads. So dynoed, pulled off, dimpled, put back on and dynoed again?

Yes sort of , one Pair made in 1080's , sent to BES for dimpling , back on the Dyno 1103 HP
the other pair brand new dimpled same Brodix 3 Extas CNC'd+ dimpled -vs- same Heads no dimples just CNC'd
that Engine was in the 1090's HP , then made 1104 HP

some Dyno text data is still there at this Link :
Post Subject : BBC 501cid 1104HP at 8500 RPM new Golf Ball Dimple finish Brodix 3 Extra
https://maxracesoftware.com/bulletinboa ... =70&t=1598

Larry, did you see anything in the Non dimpled heads that you thought needed fixing? Anything that the dimples may have fixed?

[GARY C]

same thing with Craig's B/ND ... injector placement and as much important is Injector "spray direction" inside Cyl Head Intake Port
was worth a lot of HP

i told Craig about F1 with Injectors at the top of Bellmouths ... he's said he's going to see if he can get something fabricated to Dyno test
and then see if Rules would allow something like that in B/ND if it ended up making more HP

Nitrous guys have found similar issues with nozzle placement, I had the idea of putting the nozzle in the head because it eliminated reversion in the runner when tested on the flow bench vs traditional nozzle position but It lost 75 hp on the dyno.

Messed with that idea myself on BBCs as a 4th stage.
You probably screwed around with the jetting thinking that was the issue and got nowhere, yes?
Probably what happens is that you lost the cooling charge effect upstream.

Crower used to market one of their stack injectors with high port nozzle placement was something to be considered. I seem to recall there was one above the butterflies. No loggers, killer tracks or tires in those days so it didn't get explored much by we, the great unwashed.

In short it was secondary test for this engine, I talked to David Vizard before hand about the testing he did with Mike Thermos of NOS and the problems they ran into when using large nitrous shots, their testing showed that the initial cylinder pressure should have returned more power then what they were seeing, the thought was that at a certain point the cooling effect in the cylinder hinders the burn and causes diminishing power gains, DV felt this could be addressed to some extent with a fuel designed specifically for the cold atmosphere of nitrous but none of the fuel company's were interested.

I was told ahead of time by DV and guys that have tested nozzel placement higher in the runner that my test would cool the cylinder to much causing a rich condition which is what I experienced and not having enough experience or money I didn't want to risk destroying a fairly expensive engine. I only tested the same 225 hp jetting that I used in the traditional runner location and also tested 150 and 300 hp shots on a plate.

The other possible flaw with my test was that I only injected nitrous at the head and kept the fuel at the nitrous nozzle in the runner so it could have had an atomization issue although the air speed at the traditional placement is fast.

If the test had shown any promise I was going to try to use the stud girdle as nitrous and fuel rails to feed fogger nozzles but then you also have the same issues that under manifold hidden system suffer with heat soak so I never perused it.

[NewbVetteGuy]

High Injector Placement vs. Water / Meth injection:

As much of the later parts of this thread have already focused on the performance benefits of injection earlier in the air intake path to aid charge cooling and air density, I have to ask about whether water / meth injection in an NA engine would potentially be an alternative solution and one that may provide even greater evaporative cooling capability...

(Doesn't water / meth evaporation involve a greater cooling capacity vs. gasoline?)

And if you're using water / meth for this purpose, what's the ideal location of the injection for max performance? -Would moving even further upstream to the throttle body or even cold air intake tubing provide any more benefit (greater air density through the entire air intake tract)?



-If evaporative cooling = power and earlier = power, then why not go super early and with water / meth instead of gasoline for your early-in-the-intake-tract cooling? (although I could see wet flow in a shared plenum or CAI tubing and cylinder-to-cylinder distribution of the water/meth to potentially get terrible with some intake designs -if you don't need the fuel flow and only the cooling??...)


Adam

[Rowdy Yates]

Sharing is Caring...

Posted the link and Videos on both Ls1tech and my Luv YB



Keep up the good Work ....

Chad and a Burr/Rough finish

[BLSTIC]

Water itself is pretty crap at evaporating compared to hydrocarbons, even though it provides fantastic cooling when it actually does evaporate. But with modern high pressure injectors it could work for that purpose vs the in cylinder purpose it mainly serves now.

The thing about that vs high fuel injector placement is that you already need to evaporate the fuel anyway. And water evaporation is ambient humidity dependent and presumably limited to cooling to the dew point. Fantastic in Death Valley with zero humidity and high ambient temps, not so good in the Australian tropics where I'm from.

[GARY C]

High Injector Placement vs. Water / Meth injection:

As much of the later parts of this thread have already focused on the performance benefits of injection earlier in the air intake path to aid charge cooling and air density, I have to ask about whether water / meth injection in an NA engine would potentially be an alternative solution and one that may provide even greater evaporative cooling capability...

(Doesn't water / meth evaporation involve a greater cooling capacity vs. gasoline?)

And if you're using water / meth for this purpose, what's the ideal location of the injection for max performance? -Would moving even further upstream to the throttle body or even cold air intake tubing provide any more benefit (greater air density through the entire air intake tract)?



-If evaporative cooling = power and earlier = power, then why not go super early and with water / meth instead of gasoline for your early-in-the-intake-tract cooling? (although I could see wet flow in a shared plenum or CAI tubing and cylinder-to-cylinder distribution of the water/meth to potentially get terrible with some intake designs -if you don't need the fuel flow and only the cooling??...)


Adam

All of the tests I have seen published on Water/Meth for N/A engines showed it prevented detonation if you were running a compression ratio higher than your fuel could support but I don't recall it ever showing a power increase unless it was a boosted application, in most cases on an N/A engine the power was the same or less with Water/Meth injection.

[Dave Koehler]

Nitrous guys have found similar issues with nozzle placement, I had the idea of putting the nozzle in the head because it eliminated reversion in the runner when tested on the flow bench vs traditional nozzle position but It lost 75 hp on the dyno.

Messed with that idea myself on BBCs as a 4th stage.
You probably screwed around with the jetting thinking that was the issue and got nowhere, yes?
Probably what happens is that you lost the cooling charge effect upstream.

Crower used to market one of their stack injectors with high port nozzle placement was something to be considered. I seem to recall there was one above the butterflies. No loggers, killer tracks or tires in those days so it didn't get explored much by we, the great unwashed.

In short it was secondary test for this engine, I talked to David Vizard before hand about the testing he did with Mike Thermos of NOS and the problems they ran into when using large nitrous shots, their testing showed that the initial cylinder pressure should have returned more power then what they were seeing, the thought was that at a certain point the cooling effect in the cylinder hinders the burn and causes diminishing power gains, DV felt this could be addressed to some extent with a fuel designed specifically for the cold atmosphere of nitrous but none of the fuel company's were interested.

I was told ahead of time by DV and guys that have tested nozzel placement higher in the runner that my test would cool the cylinder to much causing a rich condition which is what I experienced and not having enough experience or money I didn't want to risk destroying a fairly expensive engine. I only tested the same 225 hp jetting that I used in the traditional runner location and also tested 150 and 300 hp shots on a plate.

The other possible flaw with my test was that I only injected nitrous at the head and kept the fuel at the nitrous nozzle in the runner so it could have had an atomization issue although the air speed at the traditional placement is fast.

If the test had shown any promise I was going to try to use the stud girdle as nitrous and fuel rails to feed fogger nozzles but then you also have the same issues that under manifold hidden system suffer with heat soak so I never perused it.

I've also heard the high equals rich theory from Mike. No one could explain to me where this "rich" came from. Colder, dense air should have required more fuel to clean it up, not less. Willing to listen.

Too bad you didn't have time to tinker with fuel low and nitrous high.

[GARY C]

Messed with that idea myself on BBCs as a 4th stage.
You probably screwed around with the jetting thinking that was the issue and got nowhere, yes?
Probably what happens is that you lost the cooling charge effect upstream.

Crower used to market one of their stack injectors with high port nozzle placement was something to be considered. I seem to recall there was one above the butterflies. No loggers, killer tracks or tires in those days so it didn't get explored much by we, the great unwashed.

In short it was secondary test for this engine, I talked to David Vizard before hand about the testing he did with Mike Thermos of NOS and the problems they ran into when using large nitrous shots, their testing showed that the initial cylinder pressure should have returned more power then what they were seeing, the thought was that at a certain point the cooling effect in the cylinder hinders the burn and causes diminishing power gains, DV felt this could be addressed to some extent with a fuel designed specifically for the cold atmosphere of nitrous but none of the fuel company's were interested.

I was told ahead of time by DV and guys that have tested nozzel placement higher in the runner that my test would cool the cylinder to much causing a rich condition which is what I experienced and not having enough experience or money I didn't want to risk destroying a fairly expensive engine. I only tested the same 225 hp jetting that I used in the traditional runner location and also tested 150 and 300 hp shots on a plate.

The other possible flaw with my test was that I only injected nitrous at the head and kept the fuel at the nitrous nozzle in the runner so it could have had an atomization issue although the air speed at the traditional placement is fast.

If the test had shown any promise I was going to try to use the stud girdle as nitrous and fuel rails to feed fogger nozzles but then you also have the same issues that under manifold hidden system suffer with heat soak so I never perused it.

I've also heard the high equals rich theory from Mike. No one could explain to me where this "rich" came from. Colder, dense air should have required more fuel to clean it up, not less. Willing to listen.

Too bad you didn't have time to tinker with fuel low and nitrous high.

My understanding on the high point is the nitrous has more time to turn to gas and creates a cooler dense charge as you said and is just better all around. Rich or lean is only a problem if it can't be tuned but you already know that.

My concern on my test was trying to tune a system that I made up.

I think I may have spoke too soon about my results (going off memory from 2005) I thought the EGT's spiked but after digging out my dyno sheets they actually dropped 200+ degrees. We only did one test hit and one pull and with power down and EGT's low and all over the place, even with coated parts and piston squirters I wasn't willing to risk it, probably need 8 O2's

Not to mention I was doing this on a production 2 bolt 350 block and had already seen 700 ft lbs on the 300 plate system.

[NewbVetteGuy]

High Injector Placement vs. Water / Meth injection:

As much of the later parts of this thread have already focused on the performance benefits of injection earlier in the air intake path to aid charge cooling and air density, I have to ask about whether water / meth injection in an NA engine would potentially be an alternative solution and one that may provide even greater evaporative cooling capability...

(Doesn't water / meth evaporation involve a greater cooling capacity vs. gasoline?)

And if you're using water / meth for this purpose, what's the ideal location of the injection for max performance? -Would moving even further upstream to the throttle body or even cold air intake tubing provide any more benefit (greater air density through the entire air intake tract)?



-If evaporative cooling = power and earlier = power, then why not go super early and with water / meth instead of gasoline for your early-in-the-intake-tract cooling? (although I could see wet flow in a shared plenum or CAI tubing and cylinder-to-cylinder distribution of the water/meth to potentially get terrible with some intake designs -if you don't need the fuel flow and only the cooling??...)


Adam

All of the tests I have seen published on Water/Meth for N/A engines showed it prevented detonation if you were running a compression ratio higher than your fuel could support but I don't recall it ever showing a power increase unless it was a boosted application, in most cases on an N/A engine the power was the same or less with Water/Meth injection.

Gary: WHY does high injector placement show a power increase vs low injector placement?

If it’s because higher injector placement sees more fuel evaporation / evaporation in more of the intake tract and that evaporation cools the intake air charge making it more dense so that more oxygen enters the cylinder, then doesn’t injecting a fuel / “air coolant” with a higher latent heat of vaporization / evaporation mean that MORE COOLING and therefore a denser air charge with more oxygen and slightly more power via the same mechanism?

-Water meth can also be injected even further up the air intake track or in the cold air intake safely while a high injector cannot; meth injection retrofits are simple compared to adding a 2nd injector too.


If evaporative cooling increases power when a high injector does it, then it has to increase power when water / meth does it. No?

(I THINK water / meth evaporating cools more than a typical gasoline blend too, IF you can get it to evaporate, which I think is harder with water / meth vs fuel, but high pressure and fine atomization at the nozzle and a long TIME / distance between the point of injection should help.)


Adam

[GARY C]

High Injector Placement vs. Water / Meth injection:

As much of the later parts of this thread have already focused on the performance benefits of injection earlier in the air intake path to aid charge cooling and air density, I have to ask about whether water / meth injection in an NA engine would potentially be an alternative solution and one that may provide even greater evaporative cooling capability...

(Doesn't water / meth evaporation involve a greater cooling capacity vs. gasoline?)

And if you're using water / meth for this purpose, what's the ideal location of the injection for max performance? -Would moving even further upstream to the throttle body or even cold air intake tubing provide any more benefit (greater air density through the entire air intake tract)?



-If evaporative cooling = power and earlier = power, then why not go super early and with water / meth instead of gasoline for your early-in-the-intake-tract cooling? (although I could see wet flow in a shared plenum or CAI tubing and cylinder-to-cylinder distribution of the water/meth to potentially get terrible with some intake designs -if you don't need the fuel flow and only the cooling??...)


Adam

All of the tests I have seen published on Water/Meth for N/A engines showed it prevented detonation if you were running a compression ratio higher than your fuel could support but I don't recall it ever showing a power increase unless it was a boosted application, in most cases on an N/A engine the power was the same or less with Water/Meth injection.

Gary: WHY does high injector placement show a power increase vs low injector placement?

If it’s because higher injector placement sees more fuel evaporation / evaporation in more of the intake tract and that evaporation cools the intake air charge making it more dense so that more oxygen enters the cylinder, then doesn’t injecting a fuel / “air coolant” with a higher latent heat of vaporization / evaporation mean that MORE COOLING and therefore a denser air charge with more oxygen and slightly more power via the same mechanism?

-Water meth can also be injected even further up the air intake track or in the cold air intake safely while a high injector cannot; meth injection retrofits are simple compared to adding a 2nd injector too.


If evaporative cooling increases power when a high injector does it, then it has to increase power when water / meth does it. No?

(I THINK water / meth evaporating cools more than a typical gasoline blend too, IF you can get it to evaporate, which I think is harder with water / meth vs fuel, but high pressure and fine atomization at the nozzle and a long TIME / distance between the point of injection should help.)


Adam

If you have a combination that will benefit from it then you would see some gain, you would just have to get a kit and test it.

My personal experience has not shown enough to justify the cost for an N/A engine although it does keep your chambers and pistons clean as new.

For the money I would cobble together a few used nitrous pieces and run it like a sneaky pete system, you get both cooling and added oxygen, but thats just me.

[induction apprentice]

https://youtu.be/LqFpBzBLvWY By Eric

He should flow each port several times and take the average for comparison sake, especially since the largest difference between them all is only 1.5%.

This is SOP in laboratories when weighing things.

I still think golf ball dimples are misunderstood by most laymen and a conduit / duct is not where they belong.

I actually have it set up to take 15 readings at each lift point then it averages them. That is the numbers on the flow sheets.

[induction apprentice]

For the record I’m going to test many things on this head many of which come from commenters. I will revisit the dimpling and wet flow with spray and velocities. I don’t know that it will answer any or all of your questions but it will give you info. You can do what you want with it.

I have things i would like him to try as well. like a 60 deg seat no top cut. But he is just one guy. So we will get what we get. I appreciate his efforts. I have my own flowlab and am just exploring a wetflow situation my self. I am super looking forward to when Eric gets back to this wetflow stage in his vids.

[GARY C]

For the record I’m going to test many things on this head many of which come from commenters. I will revisit the dimpling and wet flow with spray and velocities. I don’t know that it will answer any or all of your questions but it will give you info. You can do what you want with it.

I have things i would like him to try as well. like a 60 deg seat no top cut. But he is just one guy. So we will get what we get. I appreciate his efforts. I have my own flowlab and am just exploring a wetflow situation my self. I am super looking forward to when Eric gets back to this wetflow stage in his vids.

What do you think any of this will show if the different changes are never tested on an actual engine?

[In-Tech]

For the record I’m going to test many things on this head many of which come from commenters. I will revisit the dimpling and wet flow with spray and velocities. I don’t know that it will answer any or all of your questions but it will give you info. You can do what you want with it.

I have things i would like him to try as well. like a 60 deg seat no top cut. But he is just one guy. So we will get what we get. I appreciate his efforts. I have my own flowlab and am just exploring a wetflow situation my self. I am super looking forward to when Eric gets back to this wetflow stage in his vids.

What do you think any of this will show if the different changes are never tested on an actual engine?

The sadness and beauty is that without enough money to ever complete your diagnosis of dimpling or sharp edge, everything is still unknown. Dimpling and ball effect on the bottom of a boat has been shown to have advantages to learn about sheer and laminar flow. Many things are still hidden in the airplane industry about all of this since it is very NDA stuff. It is probably well known to high level engineers in the airplane industry. They have to fly in wet and dry environments as well as different barometric pressures.