Bcz YT took my reply button away, I write this here: The swirl turns, bcz the swirl guide, the ridge inside the bowl creates a stationary vortex that fills the wall side of the bowl. This turns the flow towards the center and under the valve. Depending on your cam profile, this can bleed into your exhaust and if O2 sensor is used, give a false reading on your AFR (too rich). To get the escaped charge back inside your chamber, you need a back pulse from your header setup and the incoming mix from there is hot. All this may occur from a stationary valve, so it might not be as big of a deal in a live engine where the valve is moving, but you need your swirl to move across the spark plug before it hits the exhaust valve and not the other way around. On a traditional small block this means different cylinders need to swirl in different directions. Also when you have sideways angle in your valve setup, so your valve opens towards the center of the bore, this helps directing the swirl. To fix this particular port, the guide tail needs to be blended in and the leading edge smoothed out. It still has it's place inside the bowl, but the shape has to be massaged a little. Also the valve job and especially the blending are critical to keep the swirl in the right direction. EDIT: There is also a possibility for this setup to work as is, but it's very much cam profile dependent. That turn in swirl can fill the center low pressure area inside the chamber, but only if your exhaust is closed. Also, if you are using positive intake pressure i.e turbo or super charger, the swirl guide acts differently. In all motor setup, with a mild cam, this port will make good power. But when you modify the setup, this guide as it sits starts to create anomalies.

Appreciate the abbreviated videos!!

@WeingartnerRacing

2 ай бұрын

I will try them on some videos.

Thanks Eric just got the books love the info

@WeingartnerRacing

2 ай бұрын

Thanks

Thanks eric that was really cool

@WeingartnerRacing

2 ай бұрын

Thanks for watching

Thanks for more info on these heads! Looking to pull the trigger on a set but want to see which go best for my ls build

@WeingartnerRacing

2 ай бұрын

Should have dyno info in a couple of months.

Thanks Eric!

@WeingartnerRacing

2 ай бұрын

Thanks for watching

I remember a while back you realized that when the intake valve opens it is close to the chamber, how do those heads do in that respect? Good job man.

@WeingartnerRacing

2 ай бұрын

The valves are moved away from the bore so it really helps them.

Hi eric what you think of the new LMR SVE 170 cc with a 56 cc chamber sbf heads . I would think they would be great numbers for a 302 or 289 . I had never heard of them before . Thanks .

Love the flow test`s how much to flow test one-cylinder on a LS3 head. I want to test stock then after valve job

@WeingartnerRacing

2 ай бұрын

$40

Nice side by side flowing and and other stuff my guess since it is a 408 kinda bug engine not to big. But I think 3rd place will be stock head then 2nd place will be large bore yes is outflows small bore by a lot but the small bore already flows so much air probably engine doesn't need anymore so the small bore with way smaller cc that will make more compression I think small bore will take 1st

I have a twin turbo 403. Currently around 12-1300 with stock ls3 heads, but looking to make 1500. Would you recommend the small or large bore? How much would you charge to do whatever you recommend to them?

Hi Eric, can you explain why a multi angle valve job reduces the low lift flow? Thanks

@WeingartnerRacing

Ай бұрын

They don’t

Could the swirl change be caused by the valve moving past a backup in the chamber? maybe something affecting the air flow off the short side against the cylinder wall? I don't know just trying to understand the dramatic swirl drop / direction change at the same lift as peak CFM. Also, in your opinion is there a correlation between swirl and HP numbers. I get it for low flow low rpm Torque applications. But is there a point that it becomes Moot?

@WeingartnerRacing

2 ай бұрын

Maybe

Ur videos make coffee nervous

@WeingartnerRacing

2 ай бұрын

Can you explain

@rickyfulks889

2 ай бұрын

@@WeingartnerRacing disregard my rude comment Eric, thanx for sharing valuable info

Could you make or port the small bore so it wont fall off at higher lift. without increasing valve size?

@WeingartnerRacing

2 ай бұрын

Maybe. I haven’t ported them yet

Would cathedrals swirl more? Or maybe swirl less? It would be interesting to know just how the different port designs effects flow. Super interesting about the random reverse directions in swirling.

@WeingartnerRacing

2 ай бұрын

The ones I have tested swirl very little.

Good stuff for sure. The shorter video is fine but in this case it would have been nice if an explanation of swirl was given. The idea that the swirl reversed itself is really weird for sure but as a total novice when it comes to heads and porting I have no idea what a good or bad number might be. What I believe is swirl is good but is it always? Can there be too much?? Please keep up the great work and you must be some sort of superman to stay on top of all the irons you have in the fire.

@WeingartnerRacing

2 ай бұрын

I’m just trying to figure out if I need to change. My views are down

You do invest some flow energy into swirl, it can help and hurt you. The swirl has inertia, so it's good for transients at low to mid rpm, but creating the swirl takes some flow energy, which will affect flow numbers. Of course this isn't a hard and fast rule, different engines, and head designs make use of swirl differently. Diesels for instance benefit from swirl since they're low rpm engines and fuel mixing is very important. Their cylinder heads being flat, or nearly flat also help them generate effective swirl. On 2 valve engines, obviously, you know the swirl is built into the port and chamber geometry. On 4 valve pent roof heads swirl is very difficult to make work, so the focus is more on tumble. Of course every engine has both swirl and tumble, but again each engine is different and makes different use of flow rotation. Port flow is aided and hindered by hysteresis, the flow circulation stores energy, if you run out of flow, that inertia stored in the system will give you that last little gasp to keep the flow moving, or it can impede reversion. It can also hurt you because the energy stored in the flow inertia works both ways, if you have that recirculation and the flow needs to go against the direction of recirculation, you will need more flow energy to get the same mass flow than if that recirculation wasn't there. You made a video, where you blocked off the port of the head you were flowing and it didn't recover fully, that would be an example of hysteresis, in order to recover the flow you would have had to introduce more flow energy to overcome the energy stored in the circulation. kzread.info/dash/bejne/Z2p8r7ybopvJZ6g.html Using the concept magnetic hysteresis is a perfect analogy for understanding fluid hysteresis.

@arturozarate1752

2 ай бұрын

The "top hat" or "high hat" piston design in the diesel engine aids tremendously in developing the tumble to make the homogeneous mixture burn as efficiently as it can. With the new addition of dimples to diesel pistons, efficiency is greatly increased. I believe tumble occurs, mostly, in the 4 valve diesel combustion process due to the orientation of the 4 valves, and swirl is of little existence. The port recovery would occur with the next pulse of incoming air charge on a running engine. It along with a quarter of the initial pulse blocked and reflected at the valve closed event would not only recover, but if timed right, increase engine efficiency past 100%. So I don't see much in the flowbench incapable of recovering. It's only a flow bench. In reference to

@rolandotillit2867

2 ай бұрын

@@arturozarate1752 A diesel combustion chamber can induce a nice amount of swirl with poly-quad valve configuration. The flatness allows the offset valve size to induce swirl much better than a pent-roof chamber would otherwise. With such a setup you can have the ideal amount of tumble and swirl. Polyquad doesn't work as well on a pent-roof chamber, although it can be made to work with a semi-hemispherical chamber where the piston forms the quench pad, as Honda did with the F20C.

@arturozarate1752

2 ай бұрын

@@rolandotillit2867 with the valves rotated 45° off axis I can see swirl.

@rolandotillit2867

2 ай бұрын

@@arturozarate1752 intersting!

@arturozarate1752

2 ай бұрын

@@rolandotillit2867 I should have been more specific with the diesel engines I have experience with. The Ford 6.0, 6.4, and 6.7 and the Cummins 5.9 and 6.7. My comments and views pertain to thise specifically. Any others outside I'm ignorant of their piston and valve orientation. With both Automotive manufacturers their 4 valve orientation are rotated 45° off axis. The axis being parallel to the length of the cylinder head. That's how I can see that there would be swirl made in the cylinder. If the valves were oriented intake and exhaust valves parallel to the axis, I couldn't imagine much swirl but more tumble. That's what I see, or believe to occur, in gasoline 4 valve engines. I find it interesting that the fin of the valve guide be curved towards the wall of the cylinder. I bet it aids, a lot, more fresh air charge to remain in the cylinder than escape over and out the exhaust valve during overlap. Personally I have a few things that I do to my cylinder heads to deter low lift exhaust flow and reduce the fresh air charge escaping with the exhaust. I like to keep the exhaust valve smaller than what's offered on most gasoline V8 cylinder heads. When a 2 inch valve is used on the intake I'll use as small a 1.500 for example. I only like 1 angle on the valve and seat. Finally I don't any "machinist ridge" on the exhaust side of the chamber. The exhaust is under so much pressure and is forced out, at incredible speeds, before the valve ever reaches full lift. Deterring low lift flow as the valve return to the seat decreases the loss of charge. A tulip valve, back cut valve, and smoothed seat to chamber transition will increase air flow but also help the good air leave with the bad. In my book those are no good on the exhaust side.

So the combustion chamber is way smaller than advertised?

@WeingartnerRacing

2 ай бұрын

Or they gave me the 59cc by accident

Summit finally stopped selling speed master finally 😁

@Anthony77739

2 ай бұрын

To save their own ass.

@WeingartnerRacing

2 ай бұрын

Maybe

So the large bore actually has a slightly larger intake runner than stock.

@WeingartnerRacing

2 ай бұрын

Slightly

OK 91 octane testing is fine.

@WeingartnerRacing

2 ай бұрын

That’s what I typically run

woohoo first comment !

Looks like at the very least Promaxx has some quality control/tolerance issues they need to work on.

@WeingartnerRacing

2 ай бұрын

Every company makes mistakes

@nowayjose596

2 ай бұрын

@@WeingartnerRacing This is true - I'm sure the next set you come across will seal properly, have a 240cc intake runner instead of 250cc, a 63cc chamber instead of 57cc, and flow just as well as the first set did 😉 It's really the combustion chamber discrepancy that concerns me the most. Very few people are going to cc a brand new set of heads and on an LS1 going from an expected 63cc chamber to an actual 57cc chamber is going to raise your CR by ~0.8, and that could lead to some real tail chasing figuring out why you keep running into detonation on pump gas with what should be reasonable timing.

Large bore = supercharger. Small bore = turbo.😁