Hey everyone! I’m new here and this is my first post so here goes. I’ve got a really dumb idea for a custom engine build that I’ll be starting to work on hopefully around Christmas time so I’m using the specs on the parts that I find on the internet to kind of theoretically blueprint everything out ahead of time. Ive been looking around and gathering some specs on parts I think I’ll use and I plan on running the parts/numbers by a knowledgeable source when it’s closer to when I’ll start gathering parts, but there’s some info I’m struggling to find.

I’d like to do something custom for the top end of the engine involving the four-valve head found in the Milwaukee Eight (M8), so I’ve done a fair bit of internet reading into the engine. I came across an article some time last week that I thought had the specs on the valve angle (I believe) relative to the face of the piston, but now I can’t find it. It took me a few days just to find the valve specs, which I found on an aftermarket site (Kibblewhite Precision Machining to be accurate) so it could be wrong and I’m not finding anything to verify it anywhere, so I’m lost as to where to go from there to find the specs I’m looking for. The specs I did find were:

Intake Valve
1.571” valve diameter
0.2347” stem diameter
4.015” stem length

Exhaust Valve
1.264” valve diameter
0.2342” stem diameter
4.050” stem length

I believe I also read that the stock head chamber was 88cc but again I’m not completely sure.

If anyone knows if the above is correct as far as size of the valve is concerned, and also what the valve angle is relative to the piston face I’d be really grateful for the help. Thanks for letting me hang around.

(Bold for simplifying/emphasis. I write a lot sorry.)

I’ve got a thing for the Shovelheads. I was reading online one night and came across the article about the M8, and the concept of a M8 chamber/valve setup in a Shovelhead package appeals to my problem-solving side. Maybe work the angles out on paper then model it in Solidworks or some other 3D modelling/printing program, then get it CNC’d. Can’t find the article anywhere anymore though. I think it’d be a good challenge to try and stuff it in that package somehow. Set the whole thing up with an Ultima bolt pattern that’ll match the case/cylinder combo I have in mind and see if it works. It’s dumb, I know, but it’d be a cool one-off and hey, I figured if the specs are here it’ll help someone else who might be curious too.

Definitely an option. I’ve seen the four-valve Shovel replacement mentioned in an article I read and I’ll take a closer read into it. The case and cylinders I’d be putting them on would be the Ultima case (part no. 206-49) Evo-style with the Ultima pattern which has the through-studs and 4.250” bore, so if they meshed it’s an idea to chase.

I could just go with the Sorenson Performance head which has the big-bore space to match but it’s five bolt and I’d like to take advantage of the through-stud four bolt setup that comes with the Ultima case. Cylinders would obviously be something with the four-stud run through. I’d have to get the heads undrilled if I went that route and drill my own bolt holes to match them, and I’m not sure if that’s a possibility. The chamber’s pretty big too and I’d rather run flat pistons with less skirting and height on a shallower chamber than a taller domed piston with taller skirts and a hemi chamber, mostly to cut down on heat soak into the head and a personal distaste for domed pistons.

The four-valve idea using the M8 setup appealed to me on a few different fronts. If it broke or went bad, stock or aftermarket parts could be used because hopefully the geometry would be the same and make it easier to source the moving parts. The second was valve area, which I’m probably wrong but should be bigger than a SP head as the two valves together should allow more area than the single valve while cutting down on chamber surface area for heat soak. The chamber shape I also liked because it would allow a flat piston or even the dished piston from Wiseco (part no. 40182PS) and, again, the logic behind limiting heat-soak into the head from an article I had read made sense. Finally, it was something for me to think about and work on making work, which is never a bad thing in my opinion, and when I had trouble finding the information I joined the forum so hopefully if anyone else was curious the information would be out there.

I’m totally self-taught so there’s probably lots I’ve screwed up in my line of thinking, but if nothing else it gives me an important opportunity to learn and maybe come up with something really cool. I mean, why do the normal when you can make something unique and learn while doing it?

Okay, for the sake of the initial intent of the thread I’ll concede that it’s just a shiny stupid idea and it’ll go nowhere. Just a thought exercise I guess, or a one-off project. Always was anyway. It’s what I think about when I’m bored.

Going back to the initial intent of the thread, then, all I wanted to know was if anyone had the data on the head itself and what the numbers were i.e.: valve stem angle, valve diameter, chamber volume. Figured it’d help someone somewhere to have the data in one spot. I really appreciate the help, everyone.

Haha thanks. Its been six years and this project idea of mine isn’t dead yet, just evolving. Think I’ll ask the MoCo via the service line today and cross my fingers. Otherwise I eyeball a photo from the press release and start guessing!

New year, same old shenanigans. I’ve acquired a Shovelhead head and just purchased an M8 oil-cooled head. Once it arrives I’ll measure everything that it strikes me should be measured on the M8 head and post it here. I also stumbled onto a couple images online from the service manual concerning oil flow through the heads so that’s a bonus. I’ll pick up an angle finder, machinists rule, and a dial caliper in a week or two as well.

If all goes well measurements should be here in a month or two. Then the fun begins.