[RatONaStick]

As a machinist myself and having read these posts it appears to me that you can achieve comparable results either way......I say this noting that the shop that I use does not have any sophisticated equipment, but, bores to either close to (prior to hone) or possibly finish size ,depending on the circumstances and I will check DH with a rod and piston on all four corners to determine cut depth for decking. I'm not too concerned about the consistency or quality of the parts I use because they come from good sources (quality). As far as I know the last operation is the deck cut but even if its not the deck ends up parallel to the crank C/L anyway whether its cut first or last , correct? As far as bore spacing

im out of my league here, but from what i read decking the block last using the method you described might not leave the deck parallel to the crank C/L. the reason being is different tolerances between the crank, rods and pistons.

plus it was mentioned that if the engine was ever rebuilt using different crank/rods etc you could end up with some pistons out or down the hole.

i believe it was Carl that mentioned this.

i guess that if you're doing it this way it might be wise not to go all the way to zero deck to possibly save yourself from trouble in the future? the reason i ask is the machine shop in my area doesnt have the expensive cnc machines, so i would assume they would be decking the block last.

 

[GOSFAST]

As a machinist myself and having read these posts it appears to me that you can achieve comparable results either way......I say this noting that the shop that I use does not have any sophisticated equipment, but, bores to either close to (prior to hone) or possibly finish size ,depending on the circumstances and I will check DH with a rod and piston on all four corners to determine cut depth for decking. I'm not too concerned about the consistency or quality of the parts I use because they come from good sources (quality). As far as I know the last operation is the deck cut but even if its not the deck ends up parallel to the crank C/L anyway whether its cut first or last , correct? As far as bore spacing, I would imagine a competent guy can make the corrections ( if theres limited core shift)with conventional equipment anyway .......I think Gary may have finally given himself some legitimacy with the pics(?)Let me just say in my rambling that I dont question Mike or CNC blocks in their proceedure or philosophy I'm only sharing my thoughts here and it sounds to me that you all have very nice shops and equipment............my .02 worth

Hi Joe, you're 100% right. Whether it's CNC'd or not, the final result is all that matters. The SB 468" we posted about earlier in the year (Highest HP, N/A/ SB in the Country), had not one piece CNC'd inside, and yet performed flawlessly. We use absolutely no CNC'd heads (any ones brand) and yet they flow where we need them to attain our goals. Having the CNC's handy though is an added plus in the overall picture. Having all this equipment, is simply not a guarantee that you'll be able to produce reliable units, and this goes for our units as well. Thanks, Gary in N.Y.
P.S. I'll add here, the "quench" was an extremely critical number on this 468". And if you look at the unit in the picture, the one with the motor-plate, and the P/Steering, and all the other components, you'll have a little further insight as to what we are able to do. "March" pulleys actually didn't want to sell us the pulleys because of the motor-plate, we were guaranteed "they'll never go on" by March themselves. This is one example why we don't take many mfr's. at their word.

 

[joespanova]

im out of my league here, but from what i read decking the block last using the method you described might not leave the deck parallel to the crank C/L. the reason being is different tolerances between the crank, rods and pistons.]


The block locates off a mandrel through the crank C/L.......It is the responsibility of the builder to insure that
A) Comp. dist. is equal on all pistons
B) rod center to center dist is equal
C) crank is index and stroke correct
I dont see a connection between bad parts and deck height.....you would never average your parts tolerance stack up and come up with a compromise deck height (unless you plan on doing a rebuilder special). So that being said you can do the math with your parts , rod c/c , compression dist. and 1/2 stroke to get your deck before you do anything and add your required running clearance or preassemble and verify........

 

[RatONaStick]

Joe

that clears it up, ive never had a block decked so i wasnt sure.

thanks

 

[CNC BLOCKS N/E]

I don't think these pics are legit as if you had a shop like that wouldn't the Sunnen rep no about you and from what I have heard about your shop this is not what I pictured at all.

Still no address or phone number and you still have not ansered a few of my posts.

 

[79943]

this is entertaining stuff. i find this very interesting and i wish i knew more about engine block machining. my problem is i know a little bit about everything but not enough about any one thing. therefore, by definition i can never be an expert. a point was made that there may be more than one way to achieve acceptable results and i would agree that as a general rule that may be true. however, i have found that, like fred taylor discovered many years ago, there is usually one best way to do anything. working in quality in a variety of industries i have seen countless processing methods and a lot of machining operations. i would say strictly as a general rule, and this may not always be the case, but when machining a complex component like an engine block it is best to select one starting point datum, make a qualifying cut on it to create a register to work from and relate as many of the features back to that as is possible to minimize variation in those features. using that as a general "rule" i have to like the decking the block first. i would tell you that the vast majority of machining follows that principal. that doesnt mean you have to do it that way. sometimes "stackups" are used to control critical features but when i see that being done i tend to increase the "sample size" so to speak in the qc world. and by the way i have two large, programable, zeiss cmm's at work to keep an eye on things such as that

 

[1968 hot rod]

Gary,
looking at that Matsuura twin spindle& control it was built around 1980 or so
and is painted Methods machine green.

 

[JimM]

Bill, the common datum is always the main line. First thing you do, if you have to, is any main cap stuff, line bore or hone. From there, all modern machines register off the mains. It really don't matter much which you do when, as long as every machine is registered off the main line.

Exception would be if the boring bar registers off the deck, then you would have to deck before you bore.

 

[79943]

Bill, the common datum is always the main line. First thing you do, if you have to, is any main cap stuff, line bore or hone. From there, all modern machines register off the mains. It really don't matter much which you do when, as long as every machine is registered off the main line.

Exception would be if the boring bar registers off the deck, then you would have to deck before you bore.

of course that makes sense that everything needs to be controlled in relation to the mains. i told you i wish i knew more about machining blocks supposing you measure the mains and find them out of alignment alot. how do you determine what the eventual centerline is going to be? i assume you need to align it parallel to the cam bores and on the same centerline as them? i'm just curious as to what would be the backup datum if the mains are out of whack and you have to reestablish them.

 

[cody]

And if you look at the unit in the picture, the one with the motor-plate, and the P/Steering, and all the other components, you'll have a little further insight as to what we are able to do. "March" pulleys actually didn't want to sell us the pulleys because of the motor-plate, we were guaranteed "they'll never go on" by March themselves. This is one example why we don't take many mfr's. at their word.

Doesnt' look like any march pulley system I have ever seen??? They don't use that alternator bracket or alt pullye, and the water pump pulley looks suspicious too

 

[musclecarjohn]

carl, yeah i read the writing on the wall, this guy hasn't built a motor ever,

harsh...but funny!

 

[Rowdy]

First of all, these Novelesque threads are a lesson in anxiety, you read a post that stirs your juices, maybe you have a valid opinion, know the answer to a question, whatever it is that prompts a response, but the moment is lost by the time you browse through the rest of the replies. I hate when that happens.

That said,

Considering my earlier post (Mexican Mill), my level of expertise has already been established.

My rationalization of "optimal" order comes down to a matter of symmetry. It all starts at the mains (Thanks for stealing my thunder Jim M, I had my rebuttal to Bill's deck post. Now it seems so watered down). It seems to me that if you started with the deck, the inherent problem is that you actually have to start with one or the other.

Think of it like this;
When you trim your mustache, the first side thats cut is perfect. No matter how many times you turn back and forth or open the medicine cabinet for a double reflection side view, the other side just doesn't match. Pretty soon you've whacked your way into looking like Hitlers twin (can't go out looking like Hitler, regardless of his character flaws, he was an ugly dude with a bad shave). Next thing you know your I.D. is cut in half by the clerk at the Liquor Barn and you and your pasty white lip are thrown in the hooscow for identity theft. You cellmate is a 270lb cross dresser whose been on an Enzyte and Viagra binge for three days straight.

Now do you see what I mean. If you start with the deck, don't expect to be able to sit down the day after. I hope this clears everything up.

 

[Wolfplace]

of course that makes sense that everything needs to be controlled in relation to the mains. i told you i wish i knew more about machining blocks supposing you measure the mains and find them out of alignment alot. how do you determine what the eventual centerline is going to be? i assume you need to align it parallel to the cam bores and on the same centerline as them? i'm just curious as to what would be the backup datum if the mains are out of whack and you have to reestablish them.

=
Hey Bill
Glad you posted from a precision machinists perspective.

The above post by Jim is partially correct.
The mains & cam set the Y axis & the mains are a starting point for height (Z)
You still need a datum for X
This can be the thrust in the case of BHJ equipment with regard to bores & the factory datum or front of the block for lifter bores.

We use the factory datum or front face of the block in the case of the CNC machines
But, the very first thing even BHJ tells you is you have to have a straight & square DECK for their fixture to be accurate.

Just to be clear, I do not disagree with using a single piston/rod assembly to check the deck but there is no reason to do this & most shops that have the capability of measuring accurately from the main centerline do not use this until it is time for preassembly any longer.
At this time of course you would use this as a final check

It is just not necessary assuming you can measure a piston & a rod & the crank throw.
Then of course you have the problem of correcting any of this if there is an issue which is another story,,,,

You do not need a CNC machine to get the decks correct, any boring mill will do an excellent job & I used one for many years & before that I used a Kwik-Way stand to do boring off the mains & a Storm 85B to do decking again off the mains.
And before that a boring bar after squaring the decks that bolted to the block but this was 35+ years ago,,,
Point is there are many ways to machine a block & it can be done with reasonable accuracy with all of them.

Now, anyone that tells you that it is not more accurate to set as many dimensions in one machine from a single set-up by probing the block in the X Y Z dimensions without moving it from that single setup is either very misinformed or is not capable of doing it but I can guarantee as soon as this shop invests the equipment capable of doing this their answers will change.
I have in the short time I have had the capability to measure finished blocks from a single point / setup found out exactly how inaccurate some very hi end machining work is.
Carl has been doing this for a number of years & I am sure he can attest to the accuracy as he has had the opportunity to probe out some of the best machined block in existence, the ones done in the NASCAR cup shops.
There is absolutely no way to accurately measure a block when using different set up fixtures & machines short of a CMM without trusting to a few "assumptions" & as I posted earlier this is beyond the scope of all but the best funded places like the cup guys.
As you know a CMM big enough to measure a block is worth probably 5 or 6 of my machining centers

I have read the above posts about shops pre-boring so you can use a piston/rod for deck measurement & if you can't accurately measure from the main center this is certainly a viable option but you should also square the decks at least in the Y axis so they are 90 degrees from one another to do this too.
Now you are pre-boring, pre-decking, Pre-honing, inducing a myriad of chances to screw something up.

And any one who tells you that using two or three fixtures, no matter how accurate they are is more accurate than the new generation of block machining centers that will hold the bores & decks & lifter bore location to tenths is well for lack of a more politically correct term,,, full of $hit.

This in not a knock on the older ways of doing blocks, I did them about every way conceivable over the years & feel they were as accurate as you could make them given the equipment used & some of the very best stuff out there for this was & is the BHJ featuring
Wanna buy some

But to come on here & tell you that the CNC centers will not do a more accurate job is just plain ludicrous.

On your question of the cam/ main tunnel, the most accurate way of correcting this is still the BHJ fixturing that Carl has posted pics of a few times.
They also have fixturing that can be used in a standard line boring machine that is every bit as accurate if you already happen to have a line bore.
Both use your finished main bore & fixture for height & either the front or rear cam bore for the Y axis depending on which is closer to what it should be.
You do not want to move the rear one much as this brings you another can of worms,,,

If you read this post along with my first couple I think it covers most of the questions without too much "fluff'..

 

[musclecarjohn]

All I can say is...watch out World when Gary get's this whole CNC "science" down pat!He really hasn't needed it yet because his 468 SB currently makes more power than a top fueler.Wait until the CNC comes on-line...I'll be able to hear it run here in CA.He'll be on the cover of every performance magazine known to man.

Seriously though...Gary,no one is listening to you (and I'm not saying you don't know some stuff) because you won't answer direct questions and you won't post your number or website.Can't be bothered to answer phones but you have 80 motors lined up?Who do you think you're trying to kid?I know of a guy who builds vintage T-A motors that cost a gazillion dollars (Tony Oddo) and at least HE (or his son) will take the time to talk to you on the phone.

I'm still sort of an outsider here but I can tell you I would certainly lean towards the views and advice these two experienced builders have offered before I'd believe a single word you've said.

You gotta back up the words Gary and whether you think you're being "helpful" or not,no one gives a rats ass unless you uncloak the whole mystery bs.

And cut out the PS part...will you?

 

[kirkwoodken]

I was standing next to the boss one day watching the new CNC machine and he commented on what a great finish you got with CNC. I explained to him it produced a good finish because it was a new machine, not old junk. New is good.

And for Gary: I called Smokey Yunick 6 times and he answered the phone every time. Guess he didn't have as many irons in the fire.

 

[GOSFAST]

Doesnt' look like any march pulley system I have ever seen??? They don't use that alternator bracket or alt pullye, and the water pump pulley looks suspicious too

Hi Cody, you also are a doubter, but with a sharp eye. So here, Damper pulley, March #7731, W/Pump Pulley=March #7512, P/Steering Pump=March #513, Alternator Pulley, Moroso=#64800 (the reason I chose this pulley over the March is due to the fact I'm not using a Serpentine and the belt spans being somewhat lengthy, had a high element of risk as to "spitting" the belt, the Moroso has the "extra" deep groove, we merely had it's polished to match the others), Alternator & P/Steering risers, Street-Perf. #N.A., P/Steering bracket, Zoop #808, the Alternator adjusting arm is a Mr.Gasket, it's the only one available that had the correct "arc", etc. I haven't posted any prices up for a reason, it's no ones business but mine and the customer. I can tell you doing this fitting AND all the machining to maintain the critical alignment was extremely time consuming. We actually fabricated one one tool (2 ft. long) to bank off the crank pulley and maintain the alignment up to the alternator. There's less than a .005" difference from any one pulley to the next. If I told you what the owner of the vehicle (not Chris at Island Musclecars) paid for this operation alone, I know for sure you wouldn't believe it. Chris wanted no part of setting up pulleys after installation. This unit is from the same shop as Tracey's (TSM5150) 1972 Chevelle LS-5. This part of this job, including parts AND labor equaled the price an entire decent "stock" build on a SB unit. Thanks Gary in N.Y.
P.S. If you wait a day or two, I'll see if I can "twist" Tracey's arm to post some more details about us, I just balanced his clutch and am waiting to see him. He's been with us through the entire build, even in the dyno room (the first time), he'll explain that statement, as his unit was on 2 times and I believe there may a pending lawsuit involving the original builder. I know some of you hate these PS's, but that's my choice, and we're not going back to the tools.

 

[CNC BLOCKS N/E]

I want to see the picks of the Sunnen hone, 2 dynos and 3 flow benches and the Serdi had a blanket whats that about, line boring equip. and boring bar. and go back and anser the post I asked you about.

Thanks carl

 

[GOSFAST]

But to come on here & tell you that the CNC centers will not do a more accurate job is just plain ludicrous. [/QUOTE]

I know we have our differences up here, but that statement says it all. I personally don't run ANY CNC equipment and have no plans to run it with my own hands. Don't read this as not having it available, read it as me not touching it. We're far from the "original" post here. Every operation we're involved in is pretty much scienced out (I know both Mike and Carl and other builders are gonna be in total agreement here) to maximize the available time spent on each job. In order to have money left over in business you keep a close watch on "time & charges". It's bad enough having to reboil a unit up to five times, caustic, electric, cabinet wear & tear, labor, etc., so back to milling the decks for a moment, IF you "chase" a piston/deck specific number, it makes more sense (from a business perspective) to do the ENTIRE measuring at the same time, deck hgt., p/v, pushrod length., any "component interferences", etc., intake port fit & alignment (with head and intake gaskets in place), everything) and milling the decks ONCE, flat, to the desired hgt., and square. I'm in the process of "weeding out" equipment at this time, we just got rid of one crank grinder, mainly due to the fact with all the new shafts on the market, we decided we had one too many. More (equipment) will be going. If you run a grinder you'll see my point, we used one machine for "mains only", another for "rods only". For the number of shafts ground (0/1 a week) now we'll do a double set-up. Not everyone in the field can premeasure crank stroke, rod length, pin hgt, etc., so there's an advantage to using those pieces (in place) to accomplish the job. (No P.S.'s here) Thanks, Gary in N.Y.

 

[jbird]

I think Gary just has trouble communicating EXACTLY what he means sometimes. If you truly think this guy has no machining experience, or has never built an engine, I will have to say you are just dead wrong. Most of what he says about machining processes makes sense to me. May not agree with all of it but it does make sense to the point I can see where he is coming from. As far as the "CNC is more accurate" vs the "you don't need CNC to be accurate" thing. Millions of very good quality race motors have been machined just the way Gary is describing. ALL of the shops in my area do it just like he is describing. Is it better than using the CNC? Nope. Is it adequate? Yes. Would any bracket racer, hot rodder, street racer ever know the difference in a block machined the "old way" vs one machined on a CNC? I don't see how, if done correctly. Would the machine shop owner know the difference? Yes, they would. I think the number one thing the owner would notice is how much faster you can machine a block,(with excellent accuracy) and as Mike has said, you can walk away and work on other things while the CNC does it's thing. To me, the biggest reason for a shop to own one is the time factor, and less margin for error once you know how to use it. Just my opinion, I'm sure someone will tell me where I'm wrong.
PS: There is no place on this board for name calling. I'm referring to the "Gay" thing. Again, just my opinion.