Touche. But a 260 cfm port like this needs some fill material. If I was grinding on a port and removed 4 cc of metal and my flow was basically unchanged, I would say that was a terrible porting mistake. I just put that metal back with clay.
SM Head Modifications on a budget
- Thread starter Earlie A
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PRH
Well-Known Member
But to be accurate here, I don’t think you removed 4cc worth of material from the area where you added it in.
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Honestly I don’t care what he does. I would never ever use that much epoxy in a port. For the type of heads I’m working on. Street, street strip, bracket racing it’s not the way to go.
I see nothing wrong with how you experiment, you seem more methodical than fly by the seat of your pants kind of guy, wrong/right that what your trying figure out.
Newbomb Turk
Well-Known Member
Unless I can’t get paid to do it, I fill in the back of every guide. That dead area back there is just that. Dead space.
I learned a few months after I bought my bench that some of the head manufacturers were leaving the material out from behind the guide to increase the volume a bit.
You won’t find many competitive heads without the guide being filled in.
Well with predictions of rain tomorrow I won’t be laying in the mud so since my new 120 and 80 flex hones came I guess I can tube a head tomorrow and try them out. Looking forward to trying this 80 grit out.
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gzig5
Well-Known Member
You are doing this to promote adhesion for the epoxy, correct? What size hole are you drilling? Something you may want to consider is running an undersize tap through such that it just forms a slight groove in the wall. That groove will provide a mechanical lock for the epoxy so that it will take significantly more force to shear the tube from the hole. We do this all the time when pillar bedding rifle stocks and its a common assembly technique in industry. The trick is finding a tap that is sized for what you need, though it isn't hard to grind one undersize or single point it in a milling machine. You still want to have the hole surface prepped properly using the hone or sand paper, but I always do the tap when I can for peace of mind.
PRH
Well-Known Member
And this is why I backed off. He will find out what it takes. I’ll graciously back away. Lol
No testing this morning. Saturday is work on my daughter's house day, so been playing carpenter all day.
As far as the posting, it is my sincere desire that no one backs off on the posting. We've had some good back and forth and exchanged a lot of good information. Sometimes we have different points of view. I'll stand up for mine as I expect others to do. No ill will here, just gratitude.
In fact, all the back and forth yesterday finally led to some aha moments. I've been searching for answers on 'why does flow stop increasing' and 'why does increasing the size of the pushrod pinch not always help'. Actually it was the conversation about clay, dead spots and Boosted's shirt that made a light bulb go off. More on that later. Time for some chicken casserole now.
As far as the posting, it is my sincere desire that no one backs off on the posting. We've had some good back and forth and exchanged a lot of good information. Sometimes we have different points of view. I'll stand up for mine as I expect others to do. No ill will here, just gratitude.
In fact, all the back and forth yesterday finally led to some aha moments. I've been searching for answers on 'why does flow stop increasing' and 'why does increasing the size of the pushrod pinch not always help'. Actually it was the conversation about clay, dead spots and Boosted's shirt that made a light bulb go off. More on that later. Time for some chicken casserole now.
I look forward to hearing the results. This could be a game changer over my method.
The chicken casserole is just going in the oven, so I had a few minutes to kill. Here you go @Yellow Duster. Tested the stock almost square corner 1.6" Edelbrock exhaust valve vs the Edelbrock exhaust valve with a 1/16" radius on the face. As often is the case, surprising results. I really thought the radius would help at low lifts and have no effect at high lift. I have no thoughts on an explanation for this.
Very interesting results. Thank you for testing and posting, I know it's time consuming!
PRH
Well-Known Member
I can visualize the radius being problematic, depending on its overall shape.
How about a side pic of that valve?
Newbomb Turk
Well-Known Member
You are playing in the grey area.
You are talking about a change of less than 2% at the most.
Flow the thing backwards and see what you find.
All this testing is dandy but not being able to hear the test makes it all the harder to see if the changes are actually going to produce the expected results.
Yeah. I haven’t learned much about analyzing sounds yet. The intake slurps and the exhaust is loud. I know both of those are bad, lol.
Newbomb Turk
Well-Known Member
lol. When you hear snapping and popping, especially in the exhaust ports you know you’ve got work to do.
PRH
Well-Known Member
Spy photo of EA’s lab as he’s getting ready to tackle Herman Munsters forehead…..
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