FI head. Choosing which direction I should go

[Syncro325is]

I'm getting my head refinished along with getting a IE cam for FI. I am looking to do a little bit of sprucing up on the head as well. I have three options of 1) getting a 5 angle valve job a resurface and a heat treat by the machinist that stickley only uses, for $350, 2) get 3 angle valve job, resurface done by my normal machinist for $265 or 3) get it done by my normal machinist and get the coolant channels in the head welded for an extra $75, a total of $340.

Soo what are the benefits of a 5 angle grind over a 3 angle grind? and would the heat treatment be better/stronger (for the money) than the welding.

[whiltebeitel]

From reading too many american V8 magazines, the 3-angle valve job will give you the majority of the benefit of a 5-angle at less cost. I wouldn't bother with a 5-angle job unless I wanted every last CFM out of the head, in which case, I'd probably have gone straight to ported/polished head.

Some tech from an import site here and here.

The coolant channel welding seems to be a reliable way to decrease the likelyhood of blown headgaskets from some casual reading on E30Tech. If it's pre-heated, and the mating sureface is machined flat afterwards, and all other factors are the same, the local guy seems like the safe bet. You could get marginally more flow with the 5-angle valve job, but without knowing the exact heat treating method, it's hard to say if it is really of a great benefit.

[Syncro325is]

Thank you! I think I will go the route of getting it welded and do the 3 angle with a resurface.

[whiltebeitel]

Note that not all machine shops do that same quality of work or do everything the same. If you trust your normal guy to do a good job, go with him, if not, have your normal guy weld and let Stickley's guy do a quality valve job, at least that's what I would do IF I didn't have confidence in the "normal" guy.

Just trying to remind that usually things aren't all equal like I assumed at first.

[Syncro325is]

well Zygmounts BMW first recommended him to me, but now they don't like using him so I don't know. I think its just because his prices went up. He did quality work on ricksloans m30 head's. So I'm gonna assume that he is consistent in his quality.