Someone start a new thread with tuning in mind please. Lets just switch topics on this one over to the rod again.
WD
Important KA Tuning Thread
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WDRacing
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Fiz, good to hear some informed opinions. I have actually never considered the block casting to be defective, but that makes a ton of sense. Did he mention a check for possible off center boring? Or anything at all we could check as tuners to keep every possibility down to a minimum.
Friggin bummer that the rods seem to unass themselves at a similar level to the pistons themselves, if not earlier in some cases. Since you were no where near peak torque or power correct?
Friggin bummer that the rods seem to unass themselves at a similar level to the pistons themselves, if not earlier in some cases. Since you were no where near peak torque or power correct?
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Ubernoober
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Core shift is definitely a problem in the old (70's era) Ford blocks I am familiar with. It is something that gets checked before an 0.030 overbore is even attempted. I was under the impression that newer tolerances and casting technologies had eliminated this problem. I would be very interested to find out if your block did have any significant core shift in it. Even if the wall didn't crack and suck in water, it is common for a thin wall to warp or go "out of round" putting a pinch on the piston.All this is conjecture and in the end it is probably just a case of a broken rod, but you know I am watching this all very carefully since I made a major investment in a KA rebuild and decided to go with the factory rods based on previous knowledge.
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deviousKA
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Re: (WDRacing)
Just fyi, the mexico cast truck blocks have much thicker cylinder walls. These mexico blocks come in both e and de form but the de's lack an upper cover distributor, all have sohc style oil pump and distributors.
These are the blocks of choice when using the ka24 for actual race use. There are other advantages as well but the cylinder walls are worth mentioning as it has come up.
I have had japan ka24e blocks sonic tested, there is enough material for me to be safe in NA form at 91.1mm bore. That is roughly .080" removed between cylinders, in total. The point at which the cylinder walls are the thinnest is about 1-1/2 inches down from the deck, where the diagonal coolant passages are. This is most likely not a problem area you KA-t may be suffering from, more likely to be lower in the bore. If this is truly the case the truck block is a substantial upgrade.
These are the blocks of choice when using the ka24 for actual race use. There are other advantages as well but the cylinder walls are worth mentioning as it has come up.
I have had japan ka24e blocks sonic tested, there is enough material for me to be safe in NA form at 91.1mm bore. That is roughly .080" removed between cylinders, in total. The point at which the cylinder walls are the thinnest is about 1-1/2 inches down from the deck, where the diagonal coolant passages are. This is most likely not a problem area you KA-t may be suffering from, more likely to be lower in the bore. If this is truly the case the truck block is a substantial upgrade.