Do you have to change the seats out when replacing stock valves on an E88 with new ones from an N42?

-e

Yup, gonna have to have the head milled so the larger valve seats will fit. Luckily that's all that is required.

hmmm

i see...

well we'll see what the quote from the machine shop is like...

i was looking at dimensions on the e88 vs n42 valves and while i did see a noticeable size difference on the intake side (almost 0.25"), the exhaust side difference is listed as being 0.08"

That's SO small... is it even worth it to do the EX side?

-e

You'll want to do both, no matter how small the increase is in the exhaust. You'll be allowing more air into the camber, and you'll want to make sure it gets out, especially if you are going to do any port matching etc.. which will allow even more flow through the combustion chamber. What goes in, must come out, right?

absolutely, of course i agree...

it's just that it's o.o8... damn that's small....

-e

Err, not sure if my memory is serving me correctly, but aren't the stock valves for the L24,42mm intake and 33mm exhaust, and the stock L28 valves are 44mm intake and 35mm exhaust?

I was under the impression that they increased the same 2mm difference for both intake and exhaust.