Had a good night on the flowbench(edited version)

[Dana]

There is nothing wrong with a stone valve job. My heads last valve job was stone, because the last two vj's before ...the fat *** on the machine leaned too hard and chartered the seats. Dressing the stones correctly and taking your time, that will yield great results, an expensive machine with an idiot at the helm....and you get shiny looking ****.

NOW THIS IS GOSPEL. In my opinion.

 

[Killer6]

Mopar specified a 15-45-70 3angle in their racing manual, for a reason, it worked & ran better. there are as many combos of angles, numbers of cuts, radius profiles-top only-
bottom only-or both sides of the seat as your brain has the imagination and the patience to try. I don't buy that "sharp edges" argument, sometimes sharp edges work better,
serdi/sunnen/goodson 3D, etc. offer some accuracy & consistancy but most of all efficiency.

 

[toolmanmike]

Toolmanmike listed 2different nonspecific seat profiles, then stated "vs Serdi" which is even more nonspecific, so I'm not
sure if he meant a radius profile that can really only be cut accurately w/that type of equipment or........................

Yes. It would be interesting to see the flow differences of 3 angle, vs, 5 angle, vs Serdi. Taking into consideration of course that some head designs respond differently to different procedures. What the Serdi does well is the smoothness of the transition in and out and it can all be done with one operation.

 

[MOPAROFFICIAL]

Mopar specified a 15-45-70 3angle in their racing manual, for a reason, it worked & ran better. there are as many combos of angles, numbers of cuts, radius profiles-top only-
bottom only-or both sides of the seat as your brain has the imagination and the patience to try. I don't buy that "sharp edges" argument, sometimes sharp edges work better,
serdi/sunnen/goodson 3D, etc. offer some accuracy & consistancy but most of all efficiency.

Agreed 70 is preferred, but the fps might dictate different angles to hold the air some more before going turbulent. It always depends on what that port needs. Not all heads are equal, some can take 5 and like this other builder says that I know ...7

 

[Dana]

My medium grit stones almost always chattered at 70, until that fella showed me i can lube them lightly.

 

[MOPAROFFICIAL]

Yes. It would be interesting to see the flow differences of 3 angle, vs, 5 angle, vs Serdi. Taking into consideration of course that some head designs respond differently to different different procedures. What the Serdi does well is the smoothness of the transition in and out and it can all be done with one operation.

Serdi will make you any cutter you'd like, for what each head necessitates.

 

[RAMM]

There is nothing wrong with a stone valve job. My heads last valve job was stone, because the last two vj's before ...the fat *** on the machine leaned too hard and chartered the seats. Dressing the stones correctly and taking your time, that will yield great results, an expensive machine with an idiot at the helm....and you get shiny looking ****.

He probably didn't apply enough pressure at the right time with spindle speed way too high. I have found varying the spindle speed as I cut yields the best results.

For the record a full radius intake valve seat may look like a hero on the flow bench but usually doesn't make more power than a real defined angular seat. I use my Sunnen VGS-20 and cutters to rough out , set seat heights and throat diameter then I finish with the stones--Nothing beats stones for surface finish and concentricity or run out. J.Rob

 

[RAMM]

Mopar specified a 15-45-70 3angle in their racing manual, for a reason, it worked & ran better. there are as many combos of angles, numbers of cuts, radius profiles-top only-
bottom only-or both sides of the seat as your brain has the imagination and the patience to try. I don't buy that "sharp edges" argument, sometimes sharp edges work better,
serdi/sunnen/goodson 3D, etc. offer some accuracy & consistancy but most of all efficiency.

Full radius didn't work in my case. J.Rob

 

[Dana]

The heads heads i'm running flow his peak by .400 lift. 215 @.300
His saturate/stall , I think he could fix that with some ssr adjusting, even it out and leave a lip at the top. Seeing what it looks like would be helpfull to visually determine.

i will get some pics, like i told the head guy i do want critiqued. and don't be easy on me. I'll listen to the good, the bad, and the ugly and meditate a while before i fire the air compressor back up. That being said, I've been reading and listening to mopar guys forever. It seems like just recently, and i don't know why, maybe the company i keep has changed or technology or something else. But the SSR was always Taboo " don't f@%k with it!" I'm having a hard time crawling out and shaking that off. Can someone please help. My brain is hungry!

 

[yellow rose]

Full radius didn't work in my case. J.Rob

I've seen a radius on the intake flow more air, and lose 30-40 HP, and it was dirty.

That's why I don't use a radius on the intake ever.

If the tooling is rigid you should be able to finish without a stone if you don't want to stone it.

The radius intake valve job is like the back cut. May look good on the flow bench but it's almost always a power killer.

 

[toolmanmike]

I've seen a radius on the intake flow more air, and lose 30-40 HP, and it was dirty.

That's why I don't use a radius on the intake ever.

If the tooling is rigid you should be able to finish without a stone if you don't want to stone it.

The radius intake valve job is like the back cut. May look good on the flow bench but it's almost always a power killer.

Interesting, any explanation?

 

[yellow rose]

Interesting, any explanation?

I got burned using radius intake cuts years ago. Flowed like jack the bear, but the engine was down on power, was hard to tune (finicky is a better way to say it) and it ran slower on the track then even the dyno numbers were showing. Lost my *** fixing it.

At this point, I no longer remember exactly how I figured it out but I started changing the way I flow tested heads.
The short of it is, I'm not in love with low lift flow numbers in particular or even flow numbers in general. The shape of the curve, air speed, cross section and how the port sounds is much more important to me. I no longer flow at just 28 inches. In fact, I only test there when I'm about done.

IMO, guys don't run enough lift, have too much low lift flow and the heads flow too much in the wrong direction. A mild street engine should net .525 and a good one should net .600

 

[toolmanmike]

Do you think a rough textured intake runner also helps break up the fuel mixture? If that's the case should the exhaust be smoother to be more efficient? I'm thinking about why the intake doesn't perform as well with smooth flow.

 

[Killer6]

Do you think a rough textured intake runner also helps break up the fuel mixture? If that's the case should the exhaust be smoother to be more efficient? I'm thinking about why the intake doesn't perform as well with smooth flow.

Yes. Also, sharp edges at transitions help flow break away cleanly & tumble in areas where it is preferable, You just have to find & know where........................
then there is the 2 way street, and you don't want that w/the intake now do you?.................................
I forget the site, but the gentleman was finishing his power calculating program &
was sharing some of his porting expertise. When he was done porting the heads, he
took a rough 6" shank carbide burr that he slightly bent the shaft on purpose, and
ran it all 'round the insides of the intake ports. Proved it's worth on the dyno & the
track....every time he did it........................

 

[yellow rose]

Do you think a rough textured intake runner also helps break up the fuel mixture? If that's the case should the exhaust be smoother to be more efficient? I'm thinking about why the intake doesn't perform as well with smooth flow.

There are two guys that come to mind when talk about port texturing comes up. Larry Meaux and Chad Spier.


I've had 2 phone calls with LM and several with CS. I personally have never been able to duplicate their results. Every time I do a burr finish the power is the same, but BSFC goes up.

IMO, the shapes and geometry of the surface is as much or more important than surface finish. I finish all my intake ports and manifolds at 60-80 grit and the exhaust port at 120 grit. Combustion chambers I do a mirror finish. That is how I get the lowest BSFC numbers.