Harley Singh Grooves

[t120r]

Sorry I haven't updated this... I had the heads shaved 0.030", radiused the edges and polished the chamber to a mirror finish. I still haven't put in the grooves as I don't have access to a mill anymore so I'm trying to figure a good way to do it accurately.

[daves66nova]

I used a dremel tool with a ball tip to groove the heads.

[octfifty]

Ball mill with 1/4 inch shank will fit in a routermake a router template using bolt holes for reference. Slow and easy does it works on aluminium cann't say on iron.

[t120r]

Update: SO my heads are shaved 0.030". The edges are radiused and the chamber is polished. I took out my new powerlynze tools and started at it. All I have left to do is cut the Singh Grooves. I'm kind of nervous about it, but what the heck:) Give it a go. I have a 1/16" ball mill and a dremel... Pics will follow when I finish it. Hopefully done tonight.

[Pinhead]

Don't forget pics of the ports! I want as many pictures to compare my work to!!!

[smitty]

What did you decide on the squish dimension? I would have thought you'd have set that first, before shaving the heads, so that you would know where the cc's and static c.r. are going to come out.

Mike, I don't get why a loose squish would (as I read on Singh's site) do anything to help the effect of grooving. Seems like it be just the opposite. In the old days, before Singh, before fire-slots, et al, tight (cautiously tight!) squishbands went a long way toward doing what the grooves now do somewhat better. Why not tight squish with grooves? Has anybody actually isolated and tested this variable?

[mpgmike]

About 2 years ago someone was doing extensive testing on a Geo Metro 3-cyl engine. Apparently, he was equipped with some pretty sophisticated equipment to see what goes on. I don't remember his name, but a search of the site might bring the subject up. If anybody did that sort of testing it would either be him or Automotive Breath.

Mike

[Pinhead]

About 2 years ago someone was doing extensive testing on a Geo Metro 3-cyl engine. Apparently, he was equipped with some pretty sophisticated equipment to see what goes on. I don't remember his name, but a search of the site might bring the subject up. If anybody did that sort of testing it would either be him or Automotive Breath.

Mike

threepiston perhaps?

[threepiston]

Not me, but that's where my username comes from....


Squish is pretty cool too though. 305 heads on a 350 raise the compression some, but it also has a few other benefits. It provides about an 1/8" squish band around the perimeter of the bore due to the bore difference, and the valves and ports are slightly smaller which increases velocity. That mod really wakes up a stock 350.

[smitty]

Where is Automotive Breath these days? I e-mailed him a month ago, but heard nothing back.