unshrouding intake valve near cylinder

[CantedTexan]

wideopen231,

On a 351C the job is basically laid-out by what the head gasket will allow.

FelPro offers 1013 & 8347 part numbers ......however the 1013 is factory defective in that the relief for the exhaust valve is "Clocked" incorrectly. I elect to use the 8347 even though it is .006" thicker.....the valve reliefs are correctly located.

I relieve all I can..... to within .050" of the sealing ring of the gasket.....and depth to within .080" from the top of the top ring. On my Fords, the gasket also allows a nice radius around the perimeter of the valve head.

The finished product is.... multiples larger.... than the factory reliefs.

If these eyebrows were on a woman's face.....she would want them plucked!

If your Hemi application will be an o-ringed / copper gasket installation......I would relieve the gasket to suit the eyebrow's desired configuration and then relieve the cylinders accordingly..... using your gasket as a template.

Looking at the proximity of your valve to cylinder........it appears to be a no-brainer.

Go for it Big Guy........." Intake is King "

Intake reversion is immensely more of a product..... relating to other variables.........not an eyebrow !



Quote: "One of my most impressive attributes is that .......a lot of people don't like me.......or the horse I rode in on"

[lada ok]

" If these eyebrows were on a woman's face.....she would want them plucked! " LOL

[quickd100]

What do the heads flow and at what lift??? and what do the intake ports cc at?? If they were used on a boosted motor making a lot of power a non boosted motor may not be the best choice. They may be a dog until the rpm is in the stratosphere.Dave

[CantedTexan]

quickd100,

The original post is concerning cylinder wall relief eyebrows.......

Making this Hemi crisp on the street..... as a non-supercharged configuration.....is....

Excellent subject matter for a new thread

That new thread might indeed create.... a 60mph wind-driven West Texas Grass Fire

As a Tumble Port Hemi @ low RPM ....with big aftermarket flow numbers....

It will definitely have it's challenges

even if it is mounted to a...."Lean-to-Steer".... 4 Caster'd Aluminum Yard Chair........



Quote: "One of my most impressive attributes is that.......a lot of people don't like me.......or the horse I rode in on"

[quickd100]

I have nothing against you or your horse , just making an observation . I have the opposite problem my heads are to small for the motor they're on. I hope you get everything worked out.Dave

[wideopen231]

Not sure about the street comment this dragstrip only motor.Leave 6600 shift 7800 and finish line around 8500. Flows are decent 528 at .900 and425 at .900. While they sound big most BBCs with 540 to 600 ci run similar numbers. AS for port cc's I do not have those with me. Have run similar heads on smaller hemi and ran fine. Larger bore but shorter stroke,Ports are bigger than factory hemi but then motor is 100 ci bigger also. Also very lite car 1500 on starting line with 4.30 gears. Crisp is not a issue the injection will have it crisp.Only been tuning injected and blown injected engines for 28 years I am starting to get idea how they work though.

Thinks for info on 351c Canted Texas. Pretty much same ideas I have on this engine.

Got with friend that has superflow, We are going to setup ficture using sleave and test before and after in cpl weeks. Most I have to loose is one sleave and I have 10 or 12 extra's sitting here.

[CantedTexan]

wideopen231,

My apologies.....

I mistakenly thought your application for this Hemi ....was for street use.

Naturally.......HUGE difference!

The results of your eyebrow flow bench testing will be interesting.....please let us know.

Your results will serve as some data to help compare a tumble flow port "vs" a swirl flow wedge port......and the effects of eyebrows.

I will be doing some similar eyebrow testing on a canted valve sbf soon to learn the difference of a 4.030 bore / 2.19" valve "vs" a 3.830 bore / 2.04" valve as applied to a 2 barrel circle track engine.......and the effects of eyebrows.

Are you limited somewhat about the size of your potential eyebrows due to the location of your O rings?

It sound like your project's configuration has no choice....it has to be fast!

Best wishes



Quote "One of my most impressive attributes is that.......a lot of people don't like me.......or the horse I rode in on"

[wideopen231]

I am limited on cutting them outwards. I have about .030 to .04 I can cut till I get to point of being uncomfortable,This is already the weak area in seal.GAsket will have to worked some also. I have two intake seat that are being replaced now.Seems my last runs with the blower deal on my TA/D was too close and hammered head up enough to blow gaskets on 5 and 7. Temps looked fine and these where richest 2 cylinders at idle.Whipple charger has rear delta hole discharge and also pushes toward those cylindres.Have to run extra fuel during run. Sorry back to regular program.

I will be testing 4.250 untoched,4.310 untouched and 4.250 modified. Right now I am checking ring hight with different pistons I have that will work with several crank rod combos in this block. Trying to see max depth I can work eyebrow downward and try to get as much opening as quick as I can. Bad part I do not have access to dyno to see how much power it gains. I can run numbers thru desktop dyno and change flows to see what it says. for what its worth.

Will also be testing heads to see how much flow we picked up with valve job and backcutting valves. Again if born rich instead of so good looking I could just play with this stuff in my fully equiped machine and engine building warehouse.

May not be super fast but not going to be from lack of trying

[jsgarage]

WO231, stock Cleveland eyebrows (4.000" bore) are small enough that a common 0.030"-overbore makes them disappear. No one to my knowledge puts them back in after an overbore, either. So it may not take as much as you think to make a small flow difference in your race motor. I'd be interested in any results + or -. Good luck.

[wideopen231]

jsgarage,

Hope your correct.I am not expecting huge gains but a gain is a gain and to make extra 100 hp you have to make the first cpl to get started. While I am building bracket car(mostly) I see no reason not to go after every HP I can get especailly when its basically free.Kind of like the kickout oilpan on my Hemi block.May not add anything but can not see it hurting either.

I bet first guy to cut angle open back of valve had someone tell him was useless and that little cut could not gain anything. Sure not first but any means just making point about trying it.

[CantedTexan]

Very interesting....conflicting experiences.

I hand relieved a .030 overbore 351c less than two weeks ago. MOST of the factory eyebrow remained before my procedure for intake and exhaust locations. This has consistently been the case for me.... for decades.

It is possible.... that I am the only nut case that would do so....

Just as wideopen 231eluded.... many small increases from many efforts will accumulatively produce significant additions.

My theory....is.... since head flow data is tremendously affected by bore diameter....Why would eyebrows not cause a similar effect in a swirl fed environment?

It is at present a theory....I have no flow bench data....yet

When personal experiential data is available....I will report.

I also have an interest to test the same theory on an inline valve head......Why not?


Quote "One of my most impressive attributes is that.......a lot of people don't like me.......or the horse I rode in on"

[wideopen231]

First I know your not only nut case, According some friends anyway. But us nut cases never pass up a chance for more power and that normally means we are finding something that makes more power.How many times before Edison came up with working light bulb? Sometimes you make more sometimes you learn it did not work that way.

[twl]

If your short turn is working real well, you might get something out of the eyebrow cut.
If the short turn is not working, and you are flowing mostly out the long side, then you probably won't see much, if anything, from the cut.

[wideopen231]

Well getting started earlier than expected. Going to set flow bench up with new fixture so we can swap cylinders and test heads.Should have some info by end of weekend.

[wideopen231]

Did not get all test done this weekend. We did get to test in as is form.

With 4.310 and 4.250 cylinders.
The 4.310 had .025 more clearance at valve and cylinder.
Heads on his regular 4.400 tube.
.100 105 cfm
.200 148
.300 .209
.400 282
.500 349
.600 428
.700 462
.800 509
.900 519

These are roughly 2 to 3 % below what we where hoping for from published numbers. They are well used heads.

Next we went to the 4.310. To keep it short we saw very little change except in the .100 and .200 lifts we had about 5% loss. .100 was 96 and .200 was 140 the rest where maybe 1% low not sure that enough to qualify as loss or reading accuracy.

Next the 4.250 cylinder
.100 98
.200 142
,300 207
.400 281
.500 350 and pretty much repeat from .300 an up. While we only had 6 or 7 cfm loss it is a loss. Not sure how much power that is in real world.On desktop dyno it showed loss of 4 to 6 hp in rpm range I care about 6000 to 8500.Again this is dragcar and thats pretty much my operating range.

Next we will test with backcut on valves .Then rerun all test.I am thinking the backcuts will pickup flow,but the shrouding will steal most of it back at low lifts. I will also test with cylinders I have ground reliefes into.If I can regain half or more of my loss from 4.40 to 4.250 pipe I will be tickled . Tune in after next weekend for results.