Thread: 360 Machining Questions

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Can you elaborate a little? I'm a bit slow

You are working/thinking too hard.

As the other gentleman mentioned, the compression height of the pistons, the rod length, and the stroke are all publish/known dimensions. We'll deck the block to a nominal value to get "close" based on those. We'll rough bore referencing the deck and print cylinder center to center specs, and leave material for honing. Honing is done with a torque plate and most often with pistons in hand for measurement. On inexpensive rebuilder quality stuff you're better off having pistons, but on higher quality race stuff the diametrical dimensions are normally pretty darn good these days.

If you want to zero deck or hit a perfect target you will need a trial assembly and a subsequent decking operation. Particularly when using stock and inexpensive replacement parts - rods, reground crank, pistons - you will be mix/matching them to equalize heights before you cut the block for the second time. Simply way too many variables to "nail it" on the first go 'round - stroke variance, block variance, rod variance, piston variance....

All of this is way over the top for any 360 FE build. A 390 crank and rods will get you a far bigger gain than anything you'll do to the 360 and will not cost any much more by the time you're done. Some battles ain't worth fighting.

Originally Posted by Barry_R

You are working/thinking too hard.

As the other gentleman mentioned, the compression height of the pistons, the rod length, and the stroke are all publish/known dimensions. We'll deck the block to a nominal value to get "close" based on those. We'll rough bore referencing the deck and print cylinder center to center specs, and leave material for honing. Honing is done with a torque plate and most often with pistons in hand for measurement. On inexpensive rebuilder quality stuff you're better off having pistons, but on higher quality race stuff the diametrical dimensions are normally pretty darn good these days.

If you want to zero deck or hit a perfect target you will need a trial assembly and a subsequent decking operation. Particularly when using stock and inexpensive replacement parts - rods, reground crank, pistons - you will be mix/matching them to equalize heights before you cut the block for the second time. Simply way too many variables to "nail it" on the first go 'round - stroke variance, block variance, rod variance, piston variance....

All of this is way over the top for any 360 FE build. A 390 crank and rods will get you a far bigger gain than anything you'll do to the 360 and will not cost any much more by the time you're done. Some battles ain't worth fighting.

Barry,
I had not put 2&2 together with you & Survival Motorsports. Aren't you guy's one of the becoming one of the big sources for lots of trick FE stuff at least in the mid-west?

Originally Posted by Barry_R

You are working/thinking too hard. All of this is way over the top for any 360 FE build. A 390 crank and rods will get you a far bigger gain than anything you'll do to the 360 and will not cost any much more by the time you're done. Some battles ain't worth fighting.

Barry, It's good to see you here again! To gain any of your wisdom I have to go to the other site. It is good to have you back! I don't remember if you published a winner for guessing the horsepower output of that SOHC motor. I guess that shows how long it's been since I've touched base....

And thanks for the great explaination and the common sense approach.