A local machinist just purchased a 3-axis CNC machine for doing engine work. Mains, Decks, Cylinders, relieving for stroker cranks, just about anything except honing cylinders. Once the machine is programmed, all you have to do is correctly mount the block, enter the program for the job to be done, and insert the correct tool-head. He claims that the main-line machining has 10% of the variance that the Sunnen line-hone does (he has one of those too). It also indexes the cylinders and decks so that they are truly at 90* from each other and truly indexed with the crankshaft centerline. For instance, he recently bored a virgin 454 block, and it had to go .060" before the cylinders could be re-indexed correctly with the crankshaft centerline :eek2: . I realize that even the very best equipment is only as good as its operator (and/or programmer). In this case, I don't particularly agree with this machinist's cylinder wall honing method, but believe that he has by far the best machine-equipment for correctly preparing a block. Anyway, my question is how many of you guys in the big cities get your work done on this type of equipment?
There is a new cyl. head shop in my area (Pro Flow) that is looking into purchasing just such a machine, plus the honing machine. They're not cheap at over $80k - but, they sure are slick machines!!:TU: :bglasses: You can also correct the lifter bores and line bore each cap one at a time (cuts first main bore, lifts back out, moves on to the next). Once he gets those.....there's a good chance I'll be getting back into doing heads, etc.!!:bglasses: :TU:
I used to run CNC machines. I don't know if I like that idea.....computer controlled machines are very accurrate, but if the operator makes a mistake.......OUCH! You could ruin a block quite quickly by just missing one decimal point. I prefer the old tried, true, and trusted method of doing things the old fashioned way.:bglasses:
I'd be interested in knowing who makes this machine and how he's going to do mill work as easy as he believes he's going to... There are still issues with fixtures, and tooling just to get started. And CNC or not the job is only as good as the operator / programmer. Would like to know a manufacturers name on this machine if anyone knows... thanx
The machine I am speaking of is a Rottler F65A For those of you that think CNC is goofy, NASCAR and the like use them exclusively I am told. The machine is programmed once for a given task, then the program is run each time the task is to be repeated. So obviously the programming must be done VERY carefully!
More Boring Equipment Anthony Usher of Rottler Mfg. in Kent, WA, says Rottler has two machine models for line boring automotive and diesel engines: the F80 and F65 series multipurpose machining centers. The F80 machines can handle blocks up to large earth moving and natural gas compression engines such as CAT and Waukesha, while the F65 machines are designed for smaller automotive engines and ideal for performance racing work," Usher explains. "Boring is easier compared to honing as the boring tool is set to final size and all the main bores can be machined in one automatic cycle, tolerance and repeatability is within .0001 to .0002 maximum, explains Usher. The alignment of the bores is perfect, eliminating errors such as bar sag associated with bar type machines. The cutting tool is supported by precision roller bearings resulting in excellent surface finish and round holes." Usher says one thing that is great with Rottlers system is that every bore is the exact same size and perfectly round, "so when the customer measures his block, he is always very happy with the accuracy and quality." "Large diesel blocks such as a CAT3516 V16, which is nearly 100 inches long, can be set up and line bored complete in less than 2 hours, floor-to-floor," says Usher. "This type of job can take one to two days on conventional manual operated machines. And to further help the whole process, the machine works unattended while boring the complete line allowing the operator to walk away and attend to other work while the machine completes the automatic cycle. When line boring performance blocks, the crankshaft to camshaft center-to-center distance can be accurately controlled and actually measured and set on the machine as high performance timing chains and belt drive conversions require precise distances. Rottler recently introduced a new design set-up fixture which can handle OHC and in-line blocks. Usher says some customers are using this set up so that they can line bore the main and cam lines in one set up resulting in perfect parallelism between both lines. Speed-O-Motive uses this system to main line bore and machine clearance for stroker crankshafts in one set up. The F65 system allows line bore jobs to be completed in less than 30 minutes floor-to-floor.
The rottler F65 is not all that its cracked up to be when they came out with that machine they sold it as the next coming of christ. The machines they use in Winston cup are the hass CNC machines.Far better machine.You really have to be on your toes with the F65. mike
That's good to know..How does it compare to the old fasioned boring machine and line-hone in your opinion?
In my opinion line boreing should always be followed up by line honeing the main saddels afterwards.When boreing any hole weather it be a cylinder or main saddles in the crank it leaves peaks and valleys the bearing as in this case would sit on top of these peaks and the heat would not transfer to the block that is genorated by the crank.By line honeing the main saddels after words we reduce these peaks which in turn would allow the bearing to sit more flat to transfer its heat better.Same thing go,s for ring sealing .
So even though in theory the runout is 10x greater with the line-hone than with the CNC, it should be honed? Would the best compromise be to use the CNC and follow it with a light line-honing?
Supposedly the runout, or out-of-true between the main bores is 10x more when using a line-hone than with the CNC. (hope that makes sense)
Not sure what you mean but will take a stab at it.Sunnen line honing equipment which most shops have work on an accentric. now when you line hone a main you will have a hole that is bigger at the parting line then you would vertical same as rods(is this what you mean about out of round).You don,t want the hole perfectly round because it will pull in at the parting line under stress.When you look at bearings there are to kind,s concentric wall and eccentric wall.The eccentric wall bearing is heaver at the crown then the parting line this is built into the bearing.Some years back they use to put shims between the rods before they were honed in order to keep the rods from pinching the crank and seizing i don,t know if they still use this practice. I tryed to do my best with out getting to far off the topic. mike
I understand what you are saying, but that's not what I meant. I'm not a machinist, so I don't know the right terminology.... What I meant was the alignment between each individual main sadlle. (#'s 1,2,3,4,5) is not as good when using a hone. Since you mentioned the actual journal machining, you are also supposed to be able to cut the main journals so that so much meat isn't removed between the cam and crank journals. I'm not a Rottler salesman, but the guy that just bought this machine sure is (I would be too if I'd spent that much $$). That is why I am wondering about the ins and outs of this piece of equipment. So thanks for your replies, and keep them coming.
Ok i think i know what you are talking about now.The stones and shoes must be kept straight this is helped by cutting the same amount off each main cap they have a fixture for checking that.Now when you take a 2 bolt main block and convert it to a 4 bolt yes you must aligh bore the block first to remove most of the materal from the new caps.You leave the housing bores under size by .0015 to hone them out. At that point it is very rare to end up with any kind of housing bore misalignment.If you have a block that has had a spun bearing and you have to remove .005 or more from the cap then yes i would align bore the block first. ps.Don,t take this as being the machine is junk its the way they are selling to us in the bisness.For the money you pay for this machine i much rather have a more versatel machine that can do more like the HASS.Rottler makes a dam good product. mike
OK. so you're saying it's not the best thing since holes in doughnuts, as it's being marketed. It still requires lots of attention to detail and careful setup like any other machining operation. (not to put words in your mouth).
Adam/Mike-- Back to Adams original comment about how "far off from square" that BBC was--I would be interested in hearing comments from you and others on this particular machining operation. I was discussing "square decking" with a machinist here also and got a similar response---basically it was "good luck" if you want to try that--likely you will have to remove so much material to get it square it will ruin the block. In essence he was saying that these old factory blocks are typically so far from square and/or have so much core shift that most of them cannot be brought to a perfectly square configuration. I am not talking about "decking" the block so please don't tell me you had your block "square decked" when all they did was deck the block to just make sure the deck was flat---these are two different things in my book (I am not a machinist but I think this is correct) I also realize that each block can be different--some w/more core shift than others, etc. I am looking for real world feedback from anyone that has actually square decked these old blocks---and what kind of luck they have had----Mike, you are a machinist--have you done any of this to these old blocks and what has been your experience in how "out of square" these things are? and have you been able to bring them back to truly square condition without having to excessively overbore the cylinders? Thnx for any input--this is a great thread! Patton
