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Quote:Matt,

As you know, I was going to drop your emailed Packard engineering thoughts into the Wade's Workshop blog.
But your Biposto blog is a much more appropriate place to unveil them!

So for everyone, here are Matt's thoughts:

"......at the moment I am still hoping to use the 282 block that I picked up from the workshop the other week. I have pulled it down and the pitting in the bore of a couple of the cylinders on the 282 block is quite bad and I will need to look at how much material can be removed and possibly what sleeves are available, but I suspect it will be a minimum of 60thou oversize. This will also depend on what pistons I can locate to suit, as for a performance engine with supercharger the stock Packard units may be a little on the frail side. I am also looking at manufacturing a custom high compression head from solid billet alloy, but will need to do some design and flow modelling work on this first before getting too far down that track.

I also discussed with Wade the chance of using the senior motor that is still in the 34 chassis to look at some other development options. First would be to establish an easy conversion to standard type slipper bearings instead of the poured babbit type. I am also keen to look at the possibility of an overhead valve conversion head for these units and I wonder if such a thing might have a potential market in the US so that the development and tooling cost might be spread over a number of units. I am currently developing a special 2 piece high compression alloy head for the Willys side valve engines which we hope to market in Australia and the US, so this would become an extension of that enterprise."

Anyone interested in a high comp head for a 282, or an overhead valve head for 32?-39 Senior engines, or a Willys Four high comp head? The Packard projects are just gleams in Matt's eye at the moment but the Willys head is in development. So if you're interested in any of these please let Matt know.

Thank you Mal - you saved me from typing that again. Work is progressing with the Willys head, and given that we have developed what we believe to be about as good an upper chamber / head relief shape that we can, we are now looking at applying this to the Packard head. By machining the heads from solid billet aluminium alloy in 2 pieces we can create very high quality heads to very tight tolerances without the ever present issues that always seem to arise with castings - especially in small batches. We will also be able to adapt the design to the senior engines if there is some interest. Of course these heads may not be suitable for concourse cars as they will not appear exactly the same as the original and will feature cooling fins in the top surface of the head and other modifications.

Also tonight I received my new copy of "Fuerza Libre 1919-1942" by Guillermo Sanchez, a book on the cars and history of motor racing in Argentina during this period under similar rules to the European Formula Libre (which in the US was called the 'Junk Formula'). This formula was widely adopted in Argentina during this period and extremely popular with both designers and spectators with longer distance, multi stage road races seeming to be the preference. Argentina was a very sussessful and affluent country during this period and this was reflected in their racing. Much of their technical skills and knowhow came from Italian engineers and designers that emigrated to Argentina, but the machinery that was available for them to play with came from all over the world, including the USA. There are a number of pages in the book devoted to American marques - from Crysler to Duessenburg - including 3 or 4 Twin6 / V12 Packard based specials. An excellent book (written in both Spanish and English) for anyone interested in motor racing during this period and even though I have only just started reading I already highly recommend it.

Also after emailing the author, Guillermo, I have almost settled on a monicker for the biposto special. Cars of this type raced in Argentina up until the late 1930s were referred to locally 'baquets'. The road race in which these cars may have competed might also be known as 'carrera rutera' - a term which I also find very appealing. So for now I will be referring to the bipostos body style as baquet, despite the fact that this word had different meanings in different parts of the world.

Anyway, I have a book to read so I will rejoin you all again in the near future when we have a closer look at the possibly 'baquet bound' 282 engine now residing in the shed.

For reference material do a Google search on "ArDun" or ArDun head" for OHV conversions of fltaheads. HEre's one:

ardun.com/ardun_histrory.htm

One of the problems u'll run into is the increased compression will most likely cause very short rod and main bearing life but under racing conditions it doesn't matter.

My personal opinion is to avoid using aluminium for the head. If u can find a currently existing production OHV head that is close to fitting then there is a process known as oven brazing. A head can be cut in half or into cross sections and machined to fit a different block. THen it is oven brazed back together.

Oven brazing is very expensive and not many facilities available even in the detroit area to do it. Not sure it can be done on Al tho. I know it can be done on Cast Iron.

Yes the technology of the OHV conversion is well established and has been around for years, although fortunately for us the materials technolgy has come a long way and machining from a solid billet instead of casting gives us access to a far bigger range of alloys that we can use.

Of course I will keep you all up to date as this side project develops.

If you could make a high compression finned aluminum flathead to sell for a reasonable price I think you could sell a few.

Are you talking about milling one out of a solid slab or billet? How would you get the water passages in?

Yes, the water jacket. How is that going to be carved out of a soild billet???? Unless it's a 2 piece head of upper and lower halves.

Quote:Rusty & Keith,

I think this earlier post of Matt's explains it.

That is correct Mal, the heads are a two piece design allowing for the water jackets and webbing above the combustion chambers to be machined into each each half. The spark plug screws into the lower half while the plug hole in the top half is oversized to allow for use of a socket to remove the plug. The temptation is to reduce the machining and cost by trying to use a thinner piece of alloy for the top section, but differental expansion can cause problems in getting the water jacket to stay sealed.

Out of curiosity Rusty, what do you think would be a resonable price for a flathead HC finned alloy head as you describe? Knowing this would give us something to aim at and would control our batch sizes and hence capital outlay.

Thanks for the clarification. Sounds like a good plan. I'm sure it will be an excellent offering. Keep us posted.