Sport Scout head chamber design - suggestions, direction needed.

[AdminGuy]

I'm looking at casting a couple of heads to experiment with for a high compression 57 stroker engine, pop-up. Can anyone give me some direction or insight into chamber design or suggest reading material for this flat head project.

I have a pretty good idea of what needs to be done, but would very much like to talk with others that may have already been down this path.

Do you have any photos of modified cyclinder heads? Have you done any flow port work on such a thing? Have you dynoed such a thing? I'm curious.

Have you beefed up castings on standard 45 cases? Was it effective?

[AdminGuy]

Hey! That was timely. ibchief from Eureka CA just put one up on ebay. Thanks man. Much appreciated.

You can see the addition of material in a half moon shape in the top left area of the head. Pretty straight forward modification here.

So if I fill and shave it down for clearance of .050 TDC to top of crown. Maybe lap head to barrel and use industrial spray glue for a gasket, dowl pin lock in two spots. That may be a good start to rounding up the horses.

You stick clay in head, bolt it down and rotate. Squished clay can be read for clearance.

Now to figure out how to stop the bottom end from blowing out. Torque and twisting of wheels may crack bearing housing on case drive side. I'm open to suggestions here. Maybe TIGed on gussets?

[AdminGuy]

evo cycl head photo from cut-away eng

An interesting photo of the inside of a cyclinder and head mounted from an evo engine. Interesting I felt because of the use of a flat top piston. This photo from a cut-away engine shows very clearly the step or ledge of the cycl head that protrudes over the bore of the cycl to create turbulance in the mixture as it's compressed. This method creates a very efficient burn with the "low tech" introduction of additional turbulance.

Pop-up pistons/domed may not be as effient as I had originally thought. Nor the use of larger valves on a flat head. Does a ricardo head look like this?

Oh well.... interesting to me. Maybe to someone else also. It's not a real exacting science - so it interests me.

Again- many thanks to Donny Petersen. He's givin me some ideas.

[AdminGuy]

Yup- that looks pretty much like a Ricardo head. Mr Harry Ricardo - Shoreham England. WWI technology reborn in 1994. Wow..... or maybe rediscovered for OHV.

Interesting article here.
http://www.old-carburetors.com/1927-...-Dykes-083.htm

OK - so I'm learning.

I'm thinking in addition to tightening up the combustion chamber - adding a few lines or valleys to the barrel (running opposed to flow). Can these heads take maybe 8:1 compression? 10:1 ? Will they crack?

[AdminGuy]

Here's a shot scavanged off of ebay of some scout ricardo heads. Or are these called trench heads? Someone cast them up new looks like. Wonder who? They look pretty good. Note the absolute minimum camber size. ie the indents around the valves. Also the step or trench before the valves. I guess to give some swirl.

Visually compare this head to the modified one from ibchief. Big diff EH!
Who made these these heads? Maybe a woman cast them? Then we could say "she makes good head". Don't hear that very often.... What kind of alumium? Is it treated? I'd like to own these. I need good head.

[AdminGuy]

Hummm.... someone has informed me that real world experience has proven that 7:1 comp ratio is the magic number for a svfh. Not more, interesting eh! Lots of porting/breathing of course.

[AdminGuy]

I was thinking about this 7:1 today. If that held true in the late 40s -earily 50s. Would 8:1 be more efficient/doable with todays higher oxtane gas? I think stock svfh is 6:1 compression.

What's a good cam profile for a 57? Mid to high end power wanted. Should idle fairly normally also. So nothing over the top.