Quote Originally Posted by jerry clayton View Post
a couple of questions-is your block cast iron or aluminum? Whats the stroke of the crank stock and of the one you want to use? Bore size now? Valve size and stem diameter?

You won't pick up much in cubic inches on small bore engines, even less if they are 4 or 6 cylinder

as for rpms, size of crank bearings make big differences-we are using Honda sized ( less than 2.0 vs over 2 inch rods and now are using 9 roller bearings on camshafts vs old 5 bushings, valve spring pressure is so high that the cams want to break------also valve lifts are near an inch where as stockers around 1/2 inch.

Problem of big bore size weakens block and its hard to save deck strength for head attachment, many blocks studs will go to bottom main area and attach load to same area as crankshaft bore.

Measure your block length for cylinder bore spacing-----maybe theres a head out there that can be adapted ---I'm thinking something maybe like the Nascar RO7 stuff

Sorry I didn't mean to leave you hanging I was on my lunch break when I replied to the threa yesterday afternoon, I didn't know this information off hand so I didn't want to post misleading or wrong information. Anyway, the block is cast iron and the bore is 3.43 and the stroke is 3.27. I would like to bore and stroke it out as much as reliably possible so I really don't know how far you can go with that particular block before the walls are too thin. The valve size and stem diameter are as follows on this chart because I really don't know what these all mean..

Diameter 35mm
Margin .050"
O/A Length 103.13mm
Seat Width .075"
Stem Diameter 6mm/.2362”
Tip Length 3.5mm
Top of Head 17° Dish
Underhead Angle/Radius x5/16"


what does machine work like this go for? Again sorry for the late reply