Hi just a bit of advice the most critical and overlooked thing about cylinder heads is making sure the valve guides aren’t worn and that if you get new inserts fitted to replace the worn guides that they are concentric to the valve seat it is super critical. Otherwise it won’t be long to the guides are shagged again and the valve and seats wear out and leak compression.
We are talking 0.01mm 6 times smaller than a human hair. 9 out of 10 machine shops won’t be able to cut valve seats concentric to the valve guides. So in many cases you will be paying a lot of money for something that’s worst off than what you gave to them without you realising. How many years has the business been open for how old is the machinery does it look antiquated if so everything will be poor fitment with no hope in hell in getting the seats cut bang in the centre of the valve guide.
As for improving the cylinder head you have no chance unless you do this as your job every day. Everything has to be correct size in Relation to each other.you open up the ports can be enough to slow the air speed down. Not what you want. Ion even you touch it there’s not much the experts can to do sort your handiwork. Touching any of the angles on the valve seat is disastrous the bottom angle from factory on modern heads is 70 deg many machine shops will cut a 60 deg angle because that’s what the cutter came with machine is. 70 outflows 60 by quite a margin. Smoothing the 3 angles on the valve seat hurts flow the actual sharp steps between the angles helps the air to shoot past the valve seat. Touching this area is going to make your car perform worse. There is a ton more information and precision equipment needed before going anywhere near a cylinder head. You want to have the head refreshed by a company that takes pride in their business that invests in their machinery to have the best equipmen
You can try looking through a Facebook posts to see their work.
https://www.facebook.com/Knight-Engine-Services-160553363962705/
https://www.facebook.com/Amac-Engineering-210475867317/
https://www.facebook.com/Veicomer/
https://www.facebook.com/energydynamics/
https://www.facebook.com/PortingSolutions/
Send me a pm when you finally get the head reworked Iam interested to know how you got on and who you went with.
Amac do engine work for Geoff steel racing and Bmw m3 kumho cup cars.
Other than these companies your looking at Neil roper, jondel race these are the old school guys that done touring cars ex formula 1 etc
