Big turbo build engine internal questions.

[BSTD_B7]

Hey guys, planning on a full internal build on the 2.0t running a pretty sizable turbo with an aggressive tune. obviously to do this i'll end up doing valves. However, i'm not the type who likes to send out my parts to be installed and then slap it together. I would much prefer to do the head work myself aside from maybe having the head resurfaced as i don't have the machinery for doing so.

What does everyone use for a valve seat cutting tool set?

Is it recommended to have your head resurfaced even if it has no issues when pulled?

I'm 100% sure i'll have more questions down the road as i go, any help/advice would be much appreciated!

(I'm aware that builds like these are usually best left to those with more experience, but you can't be someone with more experience without attempting things. Not looking for criticism unless it's constructive. Thank you.)

[Seerlah]

Most people on here leave valve seat cutting to the professionals when oversizing, but would lap valves themselves with standard sized valves.

When it comes to milling surfaces, that is always the best route yet not necessary at all. Rule of thumb is if the head and block are original of each other's, then cleaning the surfaces would suffice. If either the head or block are not originals of each other's, then at least one needs to be milled (ie my current head is from a different block and I had that surfaced milled, then just cleaned the block surfaces with a 3M roloc disc).

Majority of us on here are DIY guys, so we are all for people doing it themselves. If you post a thread in the B7 A4 subforum, you will get much more responses and support. My advice, make the thread when you actually start building it and document it as you go along.

[BSTD_B7]

Most people on here leave valve seat cutting to the professionals when oversizing, but would lap valves themselves with standard sized valves.

When it comes to milling surfaces, that is always the best route yet not necessary at all. Rule of thumb is if the head and block are original of each other's, then cleaning the surfaces would suffice. If either the head or block are not originals of each other's, then at least one needs to be milled (ie my current head is from a different block and I had that surfaced milled, then just cleaned the block surfaces with a 3M roloc disc).

Majority of us on here are DIY guys, so we are all for people doing it themselves. If you post a thread in the B7 A4 subforum, you will get much more responses and support. My advice, make the thread when you actually start building it and document it as you go along.

Good info, I intended to cut the new seats a couple turns at a time until I got (from what I understand) a perfect contact patch of 1mm right in the center of the 45 degree cut, using "blue stuff" to check it. Then lap the valves for a nice fit.

I'm undecided yet if i'd like to go with oversized valves, as i haven't really read anything or heard from anyone on how big of a difference it makes on a big turbo build. Obviously the more airflow you can get in the time of an intake stroke the better, i'm just unsure/undecided if it's something i need.

But if i do decide to stay stock valve size you think just lapping the valves will be fine? i've already got the majority of my parts for this build, just don't want to skip any additional steps and wish i hadn't later.


Owner/Chief Operating Officer
Euros of New England

[Seerlah]

If putting in new valves, lapping them in would be fine. Just make sure they move up and down the guides without getting hung up.

[BSTD_B7]

If putting in new valves, lapping them in would be fine. Just make sure they move up and down the guides without getting hung up.

Yeah, I plan on doing valve guides, springs and retainers and everything, the whole 9 yards, so I’ll definitely be making sure of that.


Owner/Chief Operating Officer
Euros of New England