On one of my recent trips to/from OK from Missouri, where I have way too much time to think about stuff like this, I came up with a few ideas for a low budget mini stroker. A basic 350 block, offset grinding the stock cast crank either .050 to standard small journal 5.7" rod size (.100" extra stroke), or even .080 to .030 under small journal rod size (.160" extra stroke). This would give anywhere from 360" (4" bore, 3.58" stroke) to 377" (4.060" bore, 3.64" stroke).
Using a set of dirt cheap rebuilder type dished or flat top pistons, either cast or hyper's that have a 1.54" compression height, and the deck height can work. 2 examples...the 350 in my 3/4 ton has a stock stroke, 5.7" rods, and cast federal-mogul flat top pistons. With an undecked block, they end up at .048" in the hole. I had a bare minimum decked off the block to correct a slight warpage issue (.008"), leaving me with the pistons .040" in the hole. By offset grinding the crank to standard small journal size (2.000"), this gives an extra .100" stroke, and moves the pistons up in the bore an extra .050", leaving the pistons .010" out of the hole. With a set of commonly available .050" or .051" head gaskets, quench still comes in around .040". I have another engine that also has some unknown .030 over cast flat tops in it that ended up .051-.053" in the hole with what I assumed to be a undecked factory block. Offset grinding the crank to small journal size gives an almost perfect 0 deck height...a .080" offset grind puts the pistons .015" out of the hole. With a .051" thick head gasket, there is still .036" quench. A setup like this, with my other spare 350 block which needs to go to .060" over, yields 377".
Now...my questions are...
1) where is a good source of rebuilt small journal sbc rods?
2) is it safe to offset grind a stock cast iron crank this far?
3) Silvolite, among others, lists "non performance" hypereutectic stock replacement type pistons. What is the advantage to a piston like this, compared to a regular cast piston? Do they use less silicon than the "performance" hypers?
4) am I completely crazy?
I have been playing around with this idea for a few days. The applications would be typical of what I mostly build...under 5500 rpm, pump gas grunt motors...not any serious performance application, in which case a Scat or Eagle stroker crank would make a lot more sense.
Using a set of dirt cheap rebuilder type dished or flat top pistons, either cast or hyper's that have a 1.54" compression height, and the deck height can work. 2 examples...the 350 in my 3/4 ton has a stock stroke, 5.7" rods, and cast federal-mogul flat top pistons. With an undecked block, they end up at .048" in the hole. I had a bare minimum decked off the block to correct a slight warpage issue (.008"), leaving me with the pistons .040" in the hole. By offset grinding the crank to standard small journal size (2.000"), this gives an extra .100" stroke, and moves the pistons up in the bore an extra .050", leaving the pistons .010" out of the hole. With a set of commonly available .050" or .051" head gaskets, quench still comes in around .040". I have another engine that also has some unknown .030 over cast flat tops in it that ended up .051-.053" in the hole with what I assumed to be a undecked factory block. Offset grinding the crank to small journal size gives an almost perfect 0 deck height...a .080" offset grind puts the pistons .015" out of the hole. With a .051" thick head gasket, there is still .036" quench. A setup like this, with my other spare 350 block which needs to go to .060" over, yields 377".
Now...my questions are...
1) where is a good source of rebuilt small journal sbc rods?
2) is it safe to offset grind a stock cast iron crank this far?
3) Silvolite, among others, lists "non performance" hypereutectic stock replacement type pistons. What is the advantage to a piston like this, compared to a regular cast piston? Do they use less silicon than the "performance" hypers?
4) am I completely crazy?
I have been playing around with this idea for a few days. The applications would be typical of what I mostly build...under 5500 rpm, pump gas grunt motors...not any serious performance application, in which case a Scat or Eagle stroker crank would make a lot more sense.