Thread: 360 Machining Questions

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Hey guys. I'm restoring my 75' f150. It's got the 360 FE which I am rebuilding and have stripped to the block. I know the easy thing would be to put a 390 crank and rods in it but I'm all about NOT always doing the easy thing and following in someone else s footsteps. Anyways I wanna build the 360 to be a nice mild running lil thumper(cause I've never seen it done). I want to zero deck the block to bring up my compression (hopefully 10:1) and get the quench a little more ideal (approx .040). I want to bore the block about .030 over cause there is a nasty little scratch in the #1 Cyl from a broken ring. My delima is that I need to install my new pistons to in order to get the exact deck clearance to know how far to deck the block. Problem with that is that I need to punch the holes out before I can temporarily install the pistons, I cant bore the holes before I deck the block because I want to use a torque plate cause if I did it would throw everything off. I'm open to any suggestions. Thanks!

If your going back with stock .030 over pistons why can't you just use the old ones for your measurements?? The only differance in the pistons should be the dia.? or am I missing somthing?

No i think you are right, I could do that I was just worried there might be slight differences from the old to new pistons but I guess I could always just measure the two and calculate the difference. Also I know some machine shops like to take over the entire engine build. would it be acceptable to measure my new pistons myself and then tell the machine shop the exact dimensions I want it bored to? or do they have to have pistons?

You'll need the new pistons in the block, the only really accurate way to get the deck height set correctly. The shop we use bores the block, fits the pistons to the pins and installs them without the rings to determine the amount of deck cut, then removes the rods and pistons, continues the machine work. Think I'd go with the measurements the shop comes up with as they are doing the machining rather then give them a predetermined set of measurements that may or may not be accurate to the actual dimensions of the new parts......

They can bore the block with the deck plates installed, take them off to set and cut the deck, then reinstall the plates to do the honing. Been awhile since I've worked an automotive machine shop, but I don't think the procedure has changed much.....

what all do u rekon they will need for this? crank, rods, and pistons? will they also need my new rod and main bearings?

how i do them is 1/2 the crank stroke length of rod then the new piston ch add this all up then deck the block with BHJ tru-deck to height i want then set the boring head off deck so all pistons bores are true to deck and deck is flat to tq plate hone this is the way i do it works the best for me

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.

Your right Barry_R. I'm not sure why i keep wasting my time chasing weird ideas. I now gotta try an find a 390 crank and rods. Its probably going to save me a lot of money going this route plus I learned that the 360 rods are somewhat weak. Should i use 360 pistons with the 390 crank and rods? I've heard it will bring the top of the pistons right up to the top of the deck giving me a good quench.

Originally Posted by jdonaldson

Your right Barry_R. I'm not sure why i keep wasting my time chasing weird ideas. I now gotta try an find a 390 crank and rods. Its probably going to save me a lot of money going this route plus I learned that the 360 rods are somewhat weak. Should i use 360 pistons with the 390 crank and rods? I've heard it will bring the top of the pistons right up to the top of the deck giving me a good quench.

I would offer, CALL Survival Motorsports and if possible, hire them!

Yea that would be the thing to do but I really have that kind of money.

Originally Posted by jdonaldson

Yea that would be the thing to do but I really have that kind of money.

I can appreciate that! Call him and try and pick his brain at a minimum!

how strong are 352/360 rods anyway? I dont see how they could be as weak as some people say since some models came with 350 horse from the factory.