Richard , Z, Lizzard or simular like find a nice H/C head
You most likely do not want a Lizard head. Except for a few, they had problems. Even those that didn't leak were not good performers.
So knowing a Lizard sucks, what would the going rate be for one just to hang on the wall?
Lizard also needs some combustion chamber work, rounding off sharp edges etc. Can not be run with a stock ignition. Plug placement not the best either.
Quite a few years ago at Hershey I was privy to a discussion regarding the (then) recently introduced Lizard head. No one had anything good to say about it. The condemnation "Another piece of Yapp crap" was uttered. One disgruntled purchaser had pulled the Lizard off his T and threw it into his scrap pile to spare some other poor unfortunate from suffering the disappointment and indignation of possessing a Lizard head.
Tim, why would you wish to have one on your shop wall and be subject to ridicule and shame?
AN interesting head to run is a Metz, there is two bolt holes that are off a little nothing a good machinist could deal with but the compression ratio is great, better have a good bottom end for it.
There are a few issues of note, one, being the horrendous quality of the cc. all those edges are pre-ignition events waiting to happen. This can be cured with a 6 pack and lots of time with a high speed ball file.
The placement of the spark plug has been proven to be a horrible idea since the dawn of the flatmotor. Out side of that, i still plan on giving one a go.
Ok I have to ask; why can't you use the stock ignition with the Lizard Head?
I had bought one when C Yapp first made them mibe was from the 1st casting run.
I was told it needed run distributer
Mark, the stock ignition when run on magneto can only be advanced "from coil to coil" so to say, on bat it's a little different, more sensitive to the lever position - but not enough advance on 6V, so 12V bat might actually work with the Lizard head.
It's the odd placement of the spark plugs that makes it more sensitive to timing - you'll have to adjust the timing lever more than usually needed in a T to avoid pinging = pre ignition.
Bob, A good choice is a Ricardo-Waukesha head. It has the combustion chamber design by Sir H. Ricardo that does not increase the compression ratio but improves performance noticeably. This is much easier on your bottom end. Harley Davidson paid royalties to Ricardo for years to use his design - seems to have worked for them.
The preignition issues are mostly like caused (exacerbated) by all the sharp edges in the cc. Everyone of those hard angles has the opportunity to become red hot and cause an ignition event.
Typically accepted locations for a spark plug on a flat motor is directly over the exhaust valve or in between the intake/exhaust valves. The space over the exhaust valve will have the highest temperature for the best combustion.
Had some good heads being offered but realy want find a head close in price to the Z head
Z-heads are listed by all of our regular suppliers (Lang's, Chaffin's, Snyder's, Texas Model T, etc.) They appear to be $375-$380 which is pretty close to the price of a Z-head. The Z-heads are good stuff, run by many people here (including me) and have very predictable and documented performance increases.
Sherman heads are also listed on most of those sites for $400. Another good head, although not as widely installed as the Z-heads. It's my understanding the the 8:1 Sherman head, as delivered, works out to be about 6:1 compression, which puts it closer to the other "traditional" HC heads.
Is your request here a result of lack of inventory from our vendors, or something else?
Just seeing what out there befor i buy one from a vendor
Douglas - the preignition issues was something I saw discussed here at the forum by those who bought Lizards back when new, I haven't any first hand experience - but I think those who said they needed more spark adjustment ability than what the magneto coil system can do already had rounded off the offending sharp edges inside.
Eric D - the head sold for $400 from the vendors is the Prus head. It's a great head with better quality and a slight power increase over the Z head, but it doesn't have 8:1 and it isn't a Sherman - it's false advertising. The Prus is about 5:1 just like the Z. The real finned Sherman was reproduced recently with a true 8:1 compression - I saw one here at the classifieds cheap, but it would be overkill for most touring T's with std bottom ends.
Pris or Z head makers have web site
Kevin Prus can be reached through his profile here: http://www.mtfca.com/cgi-bin/discus/board-profile.cgi?action=view_profile&profil e=racer_22-users
Sometimes he has cast iron versions of his head available too.
Hi From Iowa! I have one of the cast iron Prus heads & it is Great Quality! I have not used it yet, but from all everything I see it I think it will do very well!! Thanks John