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Had local guy port some heads for my TC 107 build. Not the results I expected, and buddy who had his done elsewhere was not impressed... Combustion chambers and exhaust ports are pretty rough, with dips and striations noticeable to touch. Am I being unreasonable? Opinions much appreciated!
Some of the best flowing heads I've ever seen weren't "pretty" do you have any flow bench numbers on them? That tells the story much more than pictures. The chambers are a little nicer looking than the ports but that doesn't mean much.
The air needs velocity and needs to tumble or "roll" through that port. A slick finished port doesn't usually give that very well. Another reason why even on CNC ported heads most leave the "witness marks" from the tool and dont polish them to a mirror finish.
On a 10K RPM, max effort track only kinda deal, yeah, spit shine those things for max port volume and flow but for a street build (or even F/I) it's not super critical.
Hard to tell in the pics but pretty mirror finishes do nothing but take time and cost $$$. Its the shape and size of the port that matters and I dont mean it needs to be big, just the right size to keep air speed up. The detail on the short side radius and the seat angles help low lift flow which is where the power is hidden. Testing them on a flow bench with a print out is really the only way to know exactly how good or bad the porting is.
I understand on the intake side you do not want a polished port and that imperfections can help with fuel atomization, though opinions vary on whether that's still a factor with fuel injection. Not aware of downside with a nicer finish on exhaust ports or combustion chambers...?
Likewise some say flowbench is not the be all/end all of determining factors, and I understand high flow numbers are more meaningful on high RPM race oriented applications and may have little to do with street performance. But polished combustion chambers should have some less propensity for detonation and carbon buildup. Polished exhaust ports ought to scavenge easier and also have less buildup.
And the question of polishing aside, the pics do poor job showing it but there are noticeable high and low spots.
This wasn't cheap either, and if heads didn't need to be ported any better than this, then why did I need new oversize valves??!!
Sorry don't mean to rant, but feel like I might've been taken.
Bottom line: do these look comparable to what other people have had done?
Does your guy do heads on a regular basis, does he have a flow bench,if the answer is no, then you have your answer
I believe he has quite a lot of experience and has been in the business a long time. Not sure about flow bench but also not sure if that ought to be looked at as definitive evidence as to whether they're done properly for street use.
I am concerned as he's in the process of relocating and I'm afraid job wasn't given usual time and attention it might have had otherwise. I didn't even get a chance to comment when I picked everything up as some boxes were thrust into my arms and I was shooed out the door.
I'm trying to meet up with machinist today to discuss, but wanted to make sure my concerns were legitimate before bringing anything up. The other issue I have is he gave me a Wiseco K2771 piston kit that I've been given to understand from another thread is older (out of production several years) version of piston that had some issues with oil rings that wiseco has corrected on later version(s).
Coming back to bottom line--do they look comparable to what you guys have seen from Big Boyz, Fuel Moto, Dunn Performance, Headquarters, Hillside, etc for a mid range 107 street build with Andrews 57 cams?
I'll offer up this..... from one of the best head porters in the business. Notice the guide too...
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Thats nice so the question is, what did that cost vs the OP's job and whats the output difference if any?
You'd probably be looking at $8-900, flow numbers I don't know.... didn't ask.
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Head porting job--opinions please!
