Achieving Rpk , Rk and Rvk numbers during honing

[joespanova]

Using my surface roughness gauge which measures Ra , Rmax , Rz and Ry...........which appears to be basically the same measurement samples as Rpk , Rk and Rvk...........the first thing I wondered was who changed the "terminology"?
The second thing I'm wondering is :
How difficult it is to actually ACHIEVE the combination of values you're shooting for?
Unless lots of data is collected and honing is done by CNC , I don't see how you can repeat or establish consistency.
Opinions?
Here's my reason for asking.........my engine is getting oil in the intake ports , piss poor oil rings , piss poor returns in piston , is my support rail in the way of proper return through holes. The guides are good , seals are always new , no issues with intake flange ( read that a gap a gasket wouldn't seal ).
These are typical .043/.043/3mm rings.
At this point I have to wonder if my " honer " has not been getting the finish requirement I should have. He stated he starts with a 250 and finishes with a 400 but has no clue as to the "values" of the roughness.

[Walter R. Malik]

If it was a ring, oiling issue there would be oil present everywhere, not just the intake ports.

In my opinion, getting those numbers exact is very difficult especially because almost every block material will require a different process to get there. Whatever can get great ring seal is fine; forget about all those numbers being exact.

[Frankshaft]

Using my surface roughness gauge which measures Ra , Rmax , Rz and Ry...........which appears to be basically the same measurement samples as Rpk , Rk and Rvk...........the first thing I wondered was who changed the "terminology"?
The second thing I'm wondering is :
How difficult it is to actually ACHIEVE the combination of values you're shooting for?
Unless lots of data is collected and honing is done by CNC , I don't see how you can repeat or establish consistency.
Opinions?
Here's my reason for asking.........my engine is getting oil in the intake ports , piss poor oil rings , piss poor returns in piston , is my support rail in the way of proper return through holes. The guides are good , seals are always new , no issues with intake flange ( read that a gap a gasket wouldn't seal ).
These are typical .043/.043/3mm rings.
At this point I have to wonder if my " honer " has not been getting the finish requirement I should have. He stated he starts with a 250 and finishes with a 400 but has no clue as to the "values" of the roughness.

Its possible to do, no cnc hone required. Not many use those. The easier terms to understand, Ra and Rz, you could call Keith Jones at Total Seal, that's all he used to talk about, and I think has since changed to Rvk, RK, and Rvk. I think your honer is starting to smooth. I think a lot of guys make the bores to smooth. Sometimes there is confusion on the stones, as they don't corralate to the grit. 220 grit, followed by 280, and sometimes a few swipes with 400 grit, or a brush. Were making peaks and valleys, you want a high Rz, deep valleys, and low Ra, peaks close together. If you start to smooth, or to fine of a grit, you never establish the deep valleys, and as you plateu to a smoother grit, you remove some of the valley, and it ends up to smooth. The engine will use oil and not seal. I am assuming you have a Dart block, Dart gives good recommendations on honing procedure. As will Total seal, although Total Seal usually gives you a range of values to target, Dart gives actual recommendations on the stone numbers, number of strokes, etc.

[joespanova]

Its possible to do, no cnc hone required. Not many use those. The easier terms to understand, Ra and Rz, you could call Keith Jones at Total Seal, that's all he used to talk about, and I think has since changed to Rvk, RK, and Rvk. I think your honer is starting to smooth. I think a lot of guys make the bores to smooth. Sometimes there is confusion on the stones, as they don't corralate to the grit. 220 grit, followed by 280, and sometimes a few swipes with 400 grit, or a brush. Were making peaks and valleys, you want a high Rz, deep valleys, and low Ra, peaks close together. If you start to smooth, or to fine of a grit, you never establish the deep valleys, and as you plateu to a smoother grit, you remove some of the valley, and it ends up to smooth. The engine will use oil and not seal. I am assuming you have a Dart block, Dart gives good recommendations on honing procedure. As will Total seal, although Total Seal usually gives you a range of values to target, Dart gives actual recommendations on the stone numbers, number of strokes, etc.

This stuff goes over the heads of most shops.........at least from my impression. That and they either are stuck in their "status quo" and wont change , or can't / don't know how /OR are not willing to invest the time and collect data.
My block is in fact a Dart ( little M ).

[joespanova]

If it was a ring, oiling issue there would be oil present everywhere, not just the intake ports.

I'll expand on this.
The plugs always look dry and indicate a good A/F ratio...or close anyway. The collectors are clean , primaries clean , exhausts normal and dry.
HOWEVER , at teardown , almost without exception , the intake ports have a light film of oil and oil is present on the top of the intake valves. Exhausts valves are always dry. This has "mystified" me , pun intended , for years.
Its as if the only "constant" that's followed me from block to block is the guy who did the honing?

[BillK]

What engine is it and has your combination been the same all along ?

[joespanova]

What engine is it and has your combination been the same all along ?

Just ordinary , garden variety gen 1 SBC . 377. For the most part its been the same yes.

[Walter R. Malik]

What engine is it and has your combination been the same all along ?

Just ordinary , garden variety gen 1 SBC . 377. For the most part its been the same yes.

I would suggest being absolutely certain that the intake rocker stud threads are completely sealed to any vacuum at all getting under the valve cover. through them.

[joespanova]

What engine is it and has your combination been the same all along ?

Just ordinary , garden variety gen 1 SBC . 377. For the most part its been the same yes.

I would suggest being absolutely certain that the intake rocker stud threads are completely sealed to any vacuum at all getting under the valve cover. through them.

I hear ya......and I thought I'd addressed that. Thread sealer and dry threads indicate I did , but , ya never know.

[Frankshaft]

Or, that your intake gaskets aren't sucking oil from the valley ever so slightly. If you don't use silicone around the intake gaskets on both sides, I have seen that happen.

[joespanova]

Or, that your intake gaskets aren't sucking oil from the valley ever so slightly. If you don't use silicone around the intake gaskets on both sides, I have seen that happen.

Makes perfect sense.The only thing that makes me question that is the gaskets have enough impression ( read that , you can see the compression seemed sufficient ) to make you think that wouldn't happen. I've never used RTV on a FeLPro 1010...........they already have the blue bead around the ports?

[Walter R. Malik]

Or, that your intake gaskets aren't sucking oil from the valley ever so slightly. If you don't use silicone around the intake gaskets on both sides, I have seen that happen.

Makes perfect sense.The only thing that makes me question that is the gaskets have enough impression ( read that , you can see the compression seemed sufficient ) to make you think that wouldn't happen. I've never used RTV on a FeLPro 1010...........they already have the blue bead around the ports?

Personally ... I think those black gaskets with the blue "printo-seal" around the ports are trashed after a month or so of being used.
They seem to seep and separate all the time with any brand engine.

Some people will swear by them ... not me.

[joespanova]

Or, that your intake gaskets aren't sucking oil from the valley ever so slightly. If you don't use silicone around the intake gaskets on both sides, I have seen that happen.

Makes perfect sense.The only thing that makes me question that is the gaskets have enough impression ( read that , you can see the compression seemed sufficient ) to make you think that wouldn't happen. I've never used RTV on a FeLPro 1010...........they already have the blue bead around the ports?

Personally ... I think those black gaskets with the blue "printo-seal" around the ports are trashed after a month or so of being used.
They seem to seep and separate all the time with any brand engine.

Some people will swear by them ... not me.

Hmmm , maybe I need to rethink that then................BTW I meant 1207 , not 1010 LOL.......those are my head gaskets.......

[MadBill]

An SBF-powered car I help on uses thick gaskets for proper intake alignment, and a loss of crankcase vacuum has twice been traced to the gasket sealing. We think we've got it licked now, but JIC we have a capped-off port on the front cover we can use lung power on to pressure test it. A wet sump engine can usually be checked with blocked off vents and a hose on the dipstick.

[JohnsnsFord2@aol.com]

Or, that your intake gaskets aren't sucking oil from the valley ever so slightly. If you don't use silicone around the intake gaskets on both sides, I have seen that happen.

Makes perfect sense.The only thing that makes me question that is the gaskets have enough impression ( read that , you can see the compression seemed sufficient ) to make you think that wouldn't happen. I've never used RTV on a FeLPro 1010...........they already have the blue bead around the ports?

Personally ... I think those black gaskets with the blue "printo-seal" around the ports are trashed after a month or so of being used.
They seem to seep and separate all the time with any brand engine.

Some people will swear by them ... not me.

I agree with you , I always use a sealant or rtv. I've seen that consumption of oil before because of the intake gaskets not seating