Hi again
Ebay item number 290269310059.
I saw this a while ago and it had a number of bids - but it doesnt look like it sold. Its not listed again so it may have sold privately.
Does anyone know about it? It says its a HP head. Ive not seen the lizard thing before - who made them?
Glenn

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ru=http%3A%2F%2Fsearch. ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26_trksid%3Dm37.l1313%26satitle %3D%2B290269310059%26category0%3D%26fvi%3D1&item=290269310059&viewitem=

Strange it never got a bid? Ok, it was taken off auction after less than 12 hours.

It's one of Charlie Yapp's Lizard heads, designed & cast only a few years ago. Design & production wasn't successful enough to keep it in production.
http://www.secretsofspeed.com/YAPPINC.htm
"The Lizard is "retired' waiting for a new day to dawn"

There has been some discussion on the forum - some were dissatisfied, but some of the heads preform good enough to stay in service.
http://www.mtfca.com/discus/messages/29/46264.html
http://www.mtfca.com/discus/messages/29/21936.html

Les Shubert's comment on another thread may explain some of why it failed, except for obvious production issues with water leaks due to core shifting during casting & bad machining:

"Several members locally bought Leaping Lizard heads. One of them was a novice owner and he asked me to test drive his car. On it, getting spark knock was really EASY. There was a.dull knock noise AND the car was really sluggish. Retard the spark and the noise went away and the car typically picked right up. There was not the rattling knock as you could get with a '60s car with too much spark advence. If you get a unusual noise from the engine and it goes away/reduces by backing off the throttle or reducing ignition advance you should observe and consider it. DON"T PANIC though. Perhaps solicit the ear of a experienced model T driver who has a nice quiet good running car. Most of the experienced T guys I know are more than willing to help a novice who honestly wants to learn!
Leaping Lizard Head;
I observed that it was REALLY REALLY sensitive to timing, so much so that you basically could NOT drive it well with a mag and coils as you do not have enough real spark adjustment.
Hope this helps.
Les"

Well there you go - thanks Roger.
I did find it again though - a new listing of the head was bought after 20 bids for $313.
Glenn

Mine worked fine, but the spark plug is on the wrong side of the chamber. The gas inside is ignited over the piston, so the flame travels towards the valves (a dead end trip) and towards the piston at the same time. Not the best bang for your buck. The 7:1 head I have works, but the 6:1 Z head I replaced it with really perked the car up. 7:1 is too high (102 psi) for babbitt bearings.

That head on ebay had many bids last time I saw it, and the description seems wrong to me. "Never been on the car" - so why are the plug holes and bolt surfaces rusty, and all that used looking copper gasket spray on the bottom? The chambers look clean, so maybe it was bolted on and sat without running, but never bolted onto an engine seems unlikely.

It probably leaked water out the spark plugs holes like mine did. YAPP CRAPP!!! You want one, I got one for sale. You can fix the leak. I bought two of them.

I also have one, but replaced it with a Z head on my 23 touring. I believe the power at lower speeds was the equal, possibly better than, the Z, but at higher rpm, I couldn't advance the spark without a knock. This limited me to about 40mph. I am contemplating trying it again on my 26 coupe with a vaporizer and running E-85 which should slow the flame front and maybe give me more room for spark advance. I've got it so I may as well play with it. There are no water leaks or sealing problems with mine.
Noel

I agree with Tim that the problem is the spark plug is in the wrong location.
Stan, I would be interested in aquiring one to experiment in relocating the spark plug to above the exhaust valve where it belongs. I have a idea on how to acomplish this using a "cup" type threaded insert through the water jacket. If it works I think it might make the lizard into a really nice head. Maybe if I can make it work I could fix it I could trade the fix for one of your heads.
Noel
On a flathead the flame is supposed to start in the large area of the combusion chamber and then "squish" above the piston just as it starts to go down. This squish slows doem the rate of burn because of the quenching action of all that relatively cold metal (piston and head) to give you a slightly longer burn time and much less sensitivity to spark timing. This was all learned back in the '20's and 30's and especially with tthe advent of "Ethyl" gas. Further refining of this knowledge was aquired in the 39-45 period.

The problem on the lizard is that it starts the flame in the narrow squish area and then burns too rapidly accoss to the verticle wall above the valves with a bang. With the timing very slightly to early all the combustion occurs before the piston has started down, very slightly to late and the flame becomes much to slow as the compression pressure falls off as the piston moves away from the spark plug and you much more rapidly lose power. It works just fine if you will adjust the spark to the vatying conditions as you drive. This becomes a chalenge for all but the most dedicated "gear head" and is unecessary if the spark plug is correctly located.
I hope my explanation makes sense to you

I go along with all you wrote, Les, and learned a few points, except for placement of the plug over the exhaust valve. I thought the idea was to get the spark nearest the intake valve, where the incoming mixture has more oxygen and is less lean.

I believe Ford put the spark in a good compromise location. To spark in lean air takes more voltage to jump, and, of course, air with little oxygen just won't hardly ignite, regardless of fuel to air ratio.

The early Dykes and Audel cover this. Shame that Yapp didn't read the stuff from the era.

rdr

I'd move it to the side of the head, between the intake and the exhaust valves (to ensure no interference). I thought about doing it with this one, but it's a lot of work! And it might ruin my otherwise o.k. head. Working with a leaky one sounds like a better idea. Let us know how it turns out. Do some "before and after" performance tests.

You know something, it looks like his Lion head has the plugs on the same side. I wonder why he prefers this?

Thank you, Les. Your explanation is most helpful. I would also be interrested in a means of relocating the spark plug over the valves. I used to run Kawasaki 2 strokes that had 2 plug holes and thought the tough part is locating the hole through the water jacket. My knowledge of engines is more as a prior mechanic than the engineering behind the mechanics. I understand some are having good luck with this head, but I can't get it to run without a ping even with the increased timing adjustment of battery only ignition.
Noel

If you think about it; the mixture comes through the space between the intake valve and the valve seat and so enters horizonatlly and swirls around the area above the exhaust valve as it is pulled down into the cylinder. This is further helped by any cam timing "overlap" that you have (the time when the exhaust valve is still open and the intake valve starts to open). The area above the intake valve is quite a "dead" area as far as swirl and flow is concerned. I will stand by my earlier statement as to the best plug location. If I relocated the plug I would use a 10mm spark plug thread and make sure that I could use various "reach" spark plugs to come up with a spark tip location that gave the best performance.
Noel
Now you know why you have the ping problems.
Tim
I agree in regards to the 7-1 if you are running unpressurized stock size crank
I think with a relocated plug this head might work almost as good a Sherman superfire which in my opinion has the BEST flathead cylinder head chamber shape available for T. Of course it just happens to ressemble a late model flathead V8 chamber shape, funny that!!!

Les, I have $445 hard earned US dollars invested in the one that leaks. As you know, Yapp's advice to me when I called him to complain about it leaking was to put it on ebay and get my money back or invest another 80 bucks in paying the shipping both ways to him so he could glue a washer in the hole to stop the leak. Make me an offer.

I sold the other Lizard after running it on one tour. I think it might run better with a distributor or single spark mag but I was running timer and coils and I didn't like the way it ran. IMHO it was nowhere as good as a Z head. When I bought the Yapp Crapp head I didn't have my Haibe High Power head. That's what I'll put on my next speedster engine.

I must admit that 4 or 5 years ago when they were still under development, I was attracted to the Lizard head.
Mainly because it was made of cast iron and not aluminium, thereby avoiding all those problems associated with water in both.
The other thing I liked was that you could choose the amount of compression best suited your situation, and because of these two reasons, I nearly bought one.
After reading this, BOY am I GLAD that I didnt. Instead, I stuck with a stock head. Someday I may trade up to a "Z".
Rob.

Stan
well i will probably be coming by you in January so we can talk then

Seems like somebody else has made high compression model T heads without researching much on what was learned about flathead combustion chamber design and spark plug placement back in the 20's-'40s?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:I T&item=160300875272

There is an obvious risk for water leaks with this design - the reason for doing like this must be the less complicated casting without cores.

I wonder who made it & if any of this type heads has been tested?

I'd vote for a new batch of Sherman Superfires, instead ;-)

Looks like you would have to use flat top pistons and there is not much room for the valves to open. Also there is not much "shape" to the area over the piston. Maybe why only a few were made. That and you would have to use two head gaskets(?) and seals around the spark plug holes plus how does the water get from the block back to the radiator?

Let me comment a bit about this design of head. I do not know the seller nor do I know who manufactured this head but I have used similarly designed heads for about a decade with great results including on the GreatRace for several years on Hudsons. Norm Frick from Colorado has used this same design for years making both flathead and overhead applications for all marques of vehicles. I have enclose a few pictures of a Model A/B head of mine that he did. He also manufactures Ardun overhead units for Model A/B using this design and also Riley, McDowell, and other OHVs.



Let me also say that while I am not an authority on combustion chamber design of 4 bangers, I have found that designs that I thought would make horsepower, ...did not, --and ones that I thought would be junk turned out to make power. Therefore, until this head has been tried (dyno-ed), I would not pass judgment on it.

2nd, I'm not so sure accurate determinations about piston clearance & valve shrouding can be made by looking at the pictures he has posted there on eBay. If you look at the picture I posted below of the combustion chamber, it is set up to allow a .400" lift intake valve. Not sure it looks like it in the picture though.

Finally, two head gaskets are likely not used. Generally the mating halves are lapped on a table and a thin layer of sealant is all that seals the upper and lower pieces. The head bolts keep all of it clamped just fine. Note the spark plugs seal to the lower plate. Look at the front view of my head and you will see the mating line all the way around including the water chamber area.

With regard to Mark's question about how does water get back to the radiator, the water enters the side of the block. I see for areas that water will enter the head from the block. Then it leaves the head out the upper tunnel that has a place to mount a water neck. This is really no different than a stock T design in terms of water flow. Also, I think one reason why you don't see many heads like this for T's is most T people would not spend the money. Going rate is about $125 per hole from Norm. In other words, you choose the combustion chamber design and shape of the head and Norm lets the chips fly. If you have a 4 banger, the price is $500, --if you have a 6 cylinder the price is $750 and a straight 8 is about a grand. Not bad in my eyes for a one-off head.

My Model A head...

That's cheaper than I'd do it. I think the one on T Bay is a great design. If I had the money right now....................................

I posted a question about the head to the seller. He responded:
"This was made by a friends father about 10 years ago. What I was told is that he made about 15 heads and he used one on his Speedster and had no problems. I got one for my speedster but never put it on then sold the car. I realy don't know any more info on it. It has never been on any car.
George"

I agree with Brent that it's not wise to completely dismiss a head design until it has been tested both on a dyno & in practical use - but I also have great respect for Les Schubert's experience & knowledge expressed earlier in the thread. according to Les posts & by looking at later designs of flathead engines, expectations should be held low for this particular head.

The Norm Frick heads seems to be fully machined billet heads, but this californian ebay head seems to be cast with only planing & drilling operations needed in the machine shop. Maybe that would be cheaper than Norm's method for short production runs, machining is expensive (as is pattern making for a core).

Besides the available Z head, what more designs could there be a market for in high comp heads for T:s?

Maybe a head that can be used on engines already equipped with high compression pistons?

Also a head with the low head exterior, but Z head combustion chamber design

And of course a Sherman Superfire (soon I'm starting to sound like that old roman guy, Cato)

---

quote:

Besides the available Z head, what more designs could there be a market for in high comp heads for T:s?

---

Thanks Roger, For posting the eBay link. I won the auction and have recived the head. Yes I would have liked to pay less but I got it at my max. Here are a few pictures.

Jerry, thanks for the pictures. Your max must have been about ten bucks more than mine. Mine was $404.00 =)

Glenn,Roger,Tim,Stan,Les,Rick,Noel,Rob,Mark,and Brent:
Regarding the 2 piece configuration of the model T head pictured in this thread (and the A as well):
The casting and pattern work look to be well done on the cast T head...Bolt holes are centered on the bolt towers and water passages are clean,chambers appear uniform and are also clean...overall i would rate the workmanship as very good ...
I have no idea how this head would preform,but these pictures serve to demonstrate how a prototype head or a copy of a known,proven design could be duplicated either by modern digitizing and CNC machining or by older technology tracing
mill...
I am inclined to suggest the use of tracing mill to duplicate chamber and water passage patterns ... a person could use a damaged performance cyl. head as a pattern ,or use bondo to fill and style a performance chamber in a stock cyl. head ...this is old technology that is able to duplicate 3D profiles using a sensitive hydraulic tracing stylus ...minor dimensional adjustments can be made by varying the stylus and cutter size...
Most of the tracing mills have been moved out of active service and put into storage or sold as scrap,however many are still around and operational...i sold my Gorton 1-22 with 360 Tru-trace attachment 8 years ago when i closed my tool shop...a 1/2" ball mill and stylus would trace the chamber and also water passages easily in this application...
This type of head can be produced and will function very well ...i built a "RED-HEAD" for my PB Plymouth powered 27 DB roadster ...this was fashioned after a 1933 Chrysler "RED_HEAD" chamber resized to match the 4 cyl. Plymouth block...this is a "Richardo chamber" that may serve as a great example for any flathead chamber...
The tracer mill may be a simple solution to the re-production of complex chamber profiles and water passages,without the expense of digitizing and programming of a CNC cutter path,or the expense of developeing foundry patterns...
just a thought...
Merry Christmas all
Gene K. French

It looks to me like this head is a casting but made without the expense/time/work involved in making a core box. The water jackets look cast to me (maybe just the photograph). Anyway it would be a much simpler pattern to make, not the right answer for production but to make a few test versions it would make sense.
As to the design of the combustion chamber I wouldn't copy it, but the method sure looks right!

Les:
This does look like a casting ...I don't see where vents or gates were trimed off,but these may have been incorporated in the bolt towers and were trimmed and machined clean ...also there seems to be signs of porosity in the chamber casting in the upper left corner in the photos ...
I was told that there were several companys that manufactured 2 piece cyl. heads years ago for air compressors and also performance applications ( A.O. Smith was one mentioned) ...
also regarding patterns ...possibly the top seal plate could be used without modification for any number of different heads ...the possible exception being the placement of spark plug ...maybe machine the spark plug opening and seal land as needed after chamber side is cast ...
Aluminum tooling plate worked well on my DB ...i sealed the top plate with o-rings and o-ring stock for the outside edge ,and used a normal head gasket at block ...i had an automotive machine shop straighten and surface the head on their belt sanding surfacer...considerable warpage occured after machining out the chambers and water passage due to stresses set up in machining process and clamping etc.(nearly .015" over length of head)
This process has a lot of intresting possibilities for developement applications...probably would not be suited for production in any quanity due to the the possibility of leakage on top plate and extra machining required etc ... the model A billet head seams to address the top plate leakage by using socket head screws to retain assembly in a sealed position rather than depend on achieving 2 positive seals during assembly...
Will be intresting to see what ideas develope from this post and the clear pictures ...
Merry Christmas All
Gene K. French

Les:
This does look like a casting ...I don't see where vents or gates were trimed off,but these may have been incorporated in the bolt towers and were trimmed and machined clean ...also there seems to be signs of porosity in the chamber casting in the upper left corner in the photos ...
I was told that there were several companys that manufactured 2 piece cyl. heads years ago for air compressors and also performance applications ( A.O. Smith was one mentioned) ...
also regarding patterns ...possibly the top seal plate could be used without modification for any number of different heads ...the possible exception being the placement of spark plug ...maybe machine the spark plug opening and seal land as needed after chamber side is cast ...
Aluminum tooling plate worked well on my DB ...i sealed the top plate with o-rings and o-ring stock for the outside edge ,and used a normal head gasket at block ...i had an automotive machine shop straighten and surface the head on their belt sanding surfacer...considerable warpage occured after machining out the chambers and water passage due to stresses set up in machining process and clamping etc.(nearly .015" over length of head)
This process has a lot of intresting possibilities for developement applications...probably would not be suited for production in any quanity due to the the possibility of leakage on top plate and extra machining required etc ... the model A billet head seams to address the top plate leakage by using socket head screws to retain assembly in a sealed position rather than depend on achieving 2 positive seals during assembly...
Will be intresting to see what ideas develope from this post and the clear pictures ...
Merry Christmas All
Gene K. French

More Pics. And yes it is a casting, and no the discoloring in the corner is just some rubbing. All sides should clean up nicely in the mill. In the next week I'll have an idea of the size of the area in the head and come close to a probably of the compression ratio. Jerry

Jerome:
very good pictures ...as i said in an earlier post ...the workmanship looks very good ...hope the chamber design yields good performance...
details show a lot of work went into the water passage pattern ...section thickness's appear uniform and all features blend with ample fillet...a lot of work went into this example...looks like a good buy and a great conversation piece ...congrats. and Merry Christmas
Gene French