[CHARLIE YAPP]

Lion Speed Head: version 1, 2, 3, 3-A, 4
I offer this spec sheet for those that have a used or older Lion Speed Head.
IRON lion Speed heads are made from one set of patterns. Structurally all versions are the same on the outside and inside. The difference is in machining.

Version I ("I" was NOT cast into the head) was head cast with plugs on the driver’s side, a set of cast in spark plug positions over the valves (8 total) and with Combustion Chambers "as cast". The head could be machined for the second set of plugs at purchase time and, if not, a set of instructions were sent with the head. Version I ran and worked as planned using a "B" head gasket. The issue with VI was that cubic centimeter control of the chambers was difficult to hold as the cast iron process and use of cores to make the chambers had tendency to grow, expand and move a slight amount. I wanted better control over cc’s. These were offered in 6:1 (1/4" fly-cut) , 7:1 (1/8" fly-cut) and 8:1 CR (no fly cut).

V-II was identical in all ways except that I had the pattern maker add material to the chamber wall and roof, so that we could then machine the chambers and to control the cc’s to a much higher degree. This made the chamber gleam like diamonds. I doubt if performance improved much, perhaps a small amount, but the product was much more attractive and professional. AND it allowed even more control of compression ratio by the amount of material removed from the roof of the chamber. It was offered in 6 and 7:1 CR. A 1/16" fly-cut was found on the 7:1 cr and deeper cut was on 6:1 CR heads. These V-1 and V-2 heads are highly sought after by racers and collectors.

V-III (pattern change) was identical but the valve side plugs and corresponding interior core slugs were removed (Dyno showed a loss of HP with plugs used only at the valve side). These VIII heads can not be machined for 4 extra plugs. This reduced weight a bit and added greater water volume. However, I have never had complaints, from the field, about Lions running hot. "HOT" meaning boiling over in normal road conditions. This head has had the longer run of four years and was available only in 6.5:1, because after dyno testing, it was found to be more powerful than other 7:1 brand heads on the market and more powerful (HP and Torque) than any known production flathead made so far. There just wasn’t a need to make it stronger . . . keeping in mind that my #1 objective is to keep my customers on the road with a big grin on their faces and not in the shop.

V-III-A is identical to VIII with the exception that it will be (not on market yet) machined to accept 1-3/4" exhaust valves without machining required in the field. 6.5:1 CR.

V-IV is 356-T6 aluminum from new patterns. These nice heads are run in small quantities with 8 plugs capability and machined for big valves. I do not personally like aluminum for reasonable reasons already mentioned but there are some folks that need them for a variety of uses and it is my hope that offering these will help out that segment of the community. 6.1CR.

Issues: V-I has to be used with a "B" head gasket. There are 4 small areas where the gasket might overlap into chambers. With a "B" BEST brand head gasket this hasn’t been a running problem.

Heads weigh 42 pounds, which is uncommon but is proven as a HP and smoothness advantage.

Can be difficult to remove. Some guys have threaded a rear stud hole to accept an eye bolt to attach a sling for removal.

Head is sensitive to spark control (a good thing) and most old timers are not use to it. An electronic ignition and centrifugal advance distributor pretty much eliminates the issue. If using a hand advance lever do not fully advance until over about 50 mph.

CR is a bit of a misnomer: CR is dependant on chamber cc volume, which is controlled by piston shape, pop-up or under, cylinder overbore, gasket thickness . . so an advertised 6:5 CR may actually be higher. I shoot for 140 cc in a machined chamber for present production.

Production: I have not made any heads for about one year. I lost my prime machine shop and we are re tooling at another. I hope to have product back on the shelf in November 2011.

When it come to engines and performance "opinions", "gut feelings" and "doing it the way its always been done" will slow you down. C. Yapp