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Thread: OST-037: Under Pressure

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Posts: 111-120 of 128
2016-02-19 23:17:09
#111
OMFG...... 2 weeks to get valve seats, and install them......

anyway.... the head is back in my possession, and the new seats has been opened to the size of all the other seats... they have also been blended into the surrounding chamber :thumbup:

The head is mounted on the flowbench again, this time with stock intake valves to see how the intake side flows with the stock valves.... now just waiting for my associate to stop and lend a hand.... with any luck I should have new numbers by Monday....
Last edited by oldeskewltoy on 2016-02-19 at 23-19-00.
2016-02-24 09:18:17
#112
this is a great read.

read in multiple places the sr20ve combustion chamber is 41.8cc.

also that the oem metal headgasket compresses to 1.1mm. few threads on here about this.
2016-02-24 17:58:47
#113
Originally Posted by oldeskewltoy

The head is mounted on the flowbench again, this time with stock intake valves to see how the intake side flows with the stock valves.... now just waiting for my associate to stop and lend a hand.... with any luck I should have new numbers by Monday....


It was a "wash".... the stock valves flowed very close to the Supertech valves in the ported head. They did flow marginally less, but they were close. What I found out when I checked Supertech valves in a 4AGE head (ported vs unported)... the valves made a bigger difference in an unported head.

With discussions with my client I'm going to have the radius removed from the intake side valve job and add a more conventional throat cut to try and improve high lift flow. One additional thing, when I brought it back to have the throat cut added, it was decided a small "breaking" of the ridge at the edge of the seat of the exhaust valve would also improve flow. "Breaking" - will be only about .020" wide.




I expect to have the head back by next week, and I'll get new intake numbers and then finish the heads assembly.



more to come..........
2016-02-26 02:26:11
#114
please keep this thread updated very nice work. very interested in how shimming the head is done

I will be using the 10mm ktm hotshot kit
2016-03-10 22:11:01
#115
Originally Posted by oldeskewltoy


With discussions with my client I'm going to have the radius removed from the intake side valve job and add a more conventional throat cut to try and improve high lift flow.

I expect to have the head back by next week, and I'll get new intake numbers and then finish the heads assembly.


2 weeks.....


So with the new valve job the numbers didn't improve.... until I added a clay radius at ports edge.



The numbers grew substantially @ the higher lifts .350" flow went from 229 to 235, at .400" flowed went from 240, to 249, and .500" went from 255, to 265.

Flow @:
.050" is 42
.100 is 85
.150" is 122
.200" is 159
.250" is 190
.300" is 217
.350" is 235
.400" is 249
.450" is 257
.500" is 265


Why is this relevant? Simple, the ports will have a manifold attached, there will not be a flat surface.


So now comes assembly, with the new Supertech hardware(springs, retainers, etc.) Once assembly is complete we move to checking valve clearances.


More to come......
2016-03-14 15:37:09
#116
Originally Posted by oldeskewltoy
Once assembly is complete.....


Prior to assembly... all the parts, and tools laid out




Now one of the careful touches I do is when assembly the valve, springs seats, springs, retainer, and keepers, is to space the keeperss so they don't touch each other. As an example of this here is a recent Miata head showing the difference




and a view of how the Nissan looks




By spacing them with room between them, when they go through heat cycles, the 2 keepers don't expand against each other causing possible galling to the titanium retainers, or excess stress on the valve stem


The Supertech valves, along with the Supertech hardware has now been installed. Next step is to measure the gap between each valve stem, and each retainers edge so I can determine the minimum shim usable (remember Harley shims to be used)







more to come........
Last edited by oldeskewltoy on 2016-03-14 at 15-39-01.
2016-03-14 23:32:17
#117
So today was a lot of measuring. Remember, there isn't a spec for the valve protrusion, so I had to do some checking/measuring.

First thing I checked was valve tip to top edge of the retainer to determine the thinnest shim that could possibly fit.



This measurement varied a fair amount from a low of .066", to a high of .089". .089" = 2.27mm. So the absolute minimum I can go on the shim would be 2.27mm. I'm hoping there will not be a problem here, if you remember back in December I picked up a couple of 2.55mm "test" shims





and they finally are getting used...





A quick view showing where I'll be measuring



Quick sidebar...

correct assembly is important, note the holes on this rocker shaft are pointing in, that is so the oil can get routed through the rocker to directly oil the lobe to rocker contact zones. If you were to use the incorrect shaft, these oiling ports would be facing away.


So getting back to measuring....



Wanting to be as exact here as possible (time and money) I'm use only one shim, and measure each valve independently. This removes any chance of a mis-measure based on any influence the other valve might have had on the VVL rocker assembly. The feeler gauges are laid out, from .0015"(.038mm) to .026" (.660mm).


The good(great) news... is the protrusion appears to be within shim specs, now all that is needed is a set of valve clearances.

As of now the gap between valve tip and rocker pad
1E - 3.090mm
2E - 3.050
3E - 3.025
4E - 3.050
5E - 3.060
6E - 3.070
7E - 3.085
8E - 3.100

1I - 2.935mm
2I - 2.955
3I - 2.980
4I - 3.000
5I - 2.960
6I - 2.875
7I - 2.810
8I - 2.980

Now it is just a matter of math... and getting the appropriate shim from Harley.......


A brain teaser for you..... Which valve am I checking the clearance on?? (valve number as well as intake or exhaust)




More to come........
2016-03-15 09:39:02
#118
arrows point to the cam gears. centre rocker cover screw hole is present. big clearance gap. exhaust side, 2nd pot?
2016-03-15 16:36:25
#119
Originally Posted by sss4me
arrows point to the cam gears. centre rocker cover screw hole is present. big clearance gap. exhaust side, 2nd pot?


assuming you mean #2 cyl/piston, then yes... but WHICH valve #3, or #4?? (should be simple at this point )

Although the current clearance is HUGE... What I did was make sure that a 2.55mm shim would clear the retainer (minimum) and with the shim fitted there is more than enough room for corrected clearences, which there is....



Current clearances in discussion are: 1) stock .20mm/.008"(intake) and .37mm/.0145"(exhaust), or those suggested by Franklin .010"(.25mm) for both. I would normally just accept a cam makers clearances, but as you (sss4me) have kind of pointed out, bigger clearances are usually on the exhaust side... equal clearances COULD/MIGHT cause a situation where the exhaust valve stays open just a tiny bit... leading to a burnt valve... So because of that reason is why I'm, not setting to Franklin's specs..... just yet.........


edit - Just heard back from my client, we are using the OEM specs...... Its time for math... and then a checking if any of the shims that came out can be re-used... then its off to Harley.....



more to come.......
Last edited by oldeskewltoy on 2016-03-15 at 16-42-04.
2016-03-17 16:07:11
#120
Intakes clearances are now all between .20mm(.008") and .23mm(.009").


Exhaust clearances to come.......
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