59-ab pistons

Thanks for the answers guys. I'm going to get the right pistons and put it together right. I have always had a low power issue with this engine and now I know why.
 
I've got one of those 59 blocks, but it will hold a pencel on the front, the bore is 3-3/16 + .040 It's hard to figure out if original it was 3-1/16 or 3-3/16. I'm kind of scared to bore it 3-5/16, it's 3-3/16 + .040 now, I think I better try to clean it at .060. What do you think? Walt
 
Walt
If you know some one with a sonic test set, you might try that first but a lot of the early ones won't go much more than 3 3/16". If it's already .040" over that, it may be a 239 block anyway.
 
Yeah - I'd definitely sonic test the bores - at about 12 places per bore. That way, you'll know what you have to work with - along with any slight core shift in place. On a street engine, I like to not go much thinner than about .150 if I have a choice - others will push the envelope and be down around .100 to .120 (that is a bit thin for my liking).
 
Walt I have one of those odd blocks aswell in my pile. Has the pencil shelf has 59 rit big on the bell. It's 3 1/16" bore.
I've only had a rudimentary feel around with my fingers and thumbs, it definitely has a lot less heft than my 99A blocks, much more like my 81A and 21A blocks. A sonic test is needed I believe.
Martin.
Dale,
Just out of interest, I've seen Pete post his desired minimum wall thickness to be 0.090" this is after he's hogged um out to north of 3 3/8". I wounder what thickness they monkey motion engines have. I've seen folk get scared at 0.030" over on some of these things.
Martin.
 
scooder said:
Walt I have one of those odd blocks aswell in my pile. Has the pencil shelf has 59 rit big on the bell. It's 3 1/16" bore.
I've only had a rudimentary feel around with my fingers and thumbs, it definitely has a lot less heft than my 99A blocks, much more like my 81A and 21A blocks. A sonic test is needed I believe.
Martin.
Dale,
Just out of interest, I've seen Pete post his desired minimum wall thickness to be 0.090" this is after he's hogged um out to north of 3 3/8". I wounder what thickness they monkey motion engines have. I've seen folk get scared at 0.030" over on some of these things.
Martin.
Click to expand...

A lot of modern engines are thin-wall castings . . . great example a Ford 302 block (think roller motor from the 80's). I can pickup one of those blocks all day long by myself and not ruin my back. They reduced costs on material and lightened the cars - so they accomplished two things. On a 302, most folks don't like to bore much past .030. Tell you what - I have one that I'm putting together in the next couple of weeks - it is at .030. I will sonic test it for the Hell of it - just to see! Another thing that does come into play is the rod-length and bore thickness on the thrust side. Short rod motors will typically have more thrust pressure than long-rod motors - so another thing to think about.

When Pete is building a big-cube motor like this, it is an ALL OUT race deal - so consider that in the thickness numbers. The other problem with old blocks and thin walls is that you don't know where you might have a rust pocket or other thin spot. You can sonic test all you want, but the risk keeps going up - the more you bore.
 
Good stuff Dale,
I'd be really interested on what you find on that 302, just curiosity really, but cool to know.
Thanks,
Martin.
 
Sure will - heck, you have me interested as well! The block is what is known as a 'Mexican 302' - it is a 70's block that has bigger main caps - so a 'poor mans way' to build a fairly stout race engine. We'll be putting it into a SCCA/NASA road-race mustang that we have fun with. Nothing like 400 HP in a semi-light race car.
 
Bored&Stroked said:
Sure will - heck, you have me interested as well! The block is what is known as a 'Mexican 302' - it is a 70's block that has bigger main caps - so a 'poor mans way' to build a fairly stout race engine. We'll be putting it into a SCCA/NASA road-race mustang that we have fun with. Nothing like 400 HP in a semi-light race car.
Click to expand...

I always understood that the Mexican blocks had a bit higher nickel content than the standard 302's. Rumor had it that the cylinder walls were a bit thicker too but I have no way of confirming that.
 
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