Wow Bret!

That's about the angriest I've ever read you.

Have you considered counseling for this problem?

A trip to the lake, some fishing and beer is my prescription..... and I'm about to follow my own advice for once......

-Mindgame

 

Ace and Game got me chuckling again.

Anyhoo, the difference in coefficient of expansion between Nickle-Chrome-Moly (8620) steel and cast iron is minor... about 10%, where aluminum is about double that of cast iron. If we are talking 250*F operating temp in the mains, that's maybe a 180*F temp change from shop temp. Using a 2.7 inch dia hole, that's about .0003 difference in expansion.

Riddle me this: Why do aluminum block engines, like the LSx car engines use steel main caps on alum blocks?

As far as the description of the Bowtie Block, the caps are 8620, which IS machined from a bar ('billet'). These are probably the strongest caps you'll find in any block. Many 'steel billet' caps are 1018, low carbon ('mild') steel. Non-heat treated 8620 is about 50% stronger, and a LOT stronger than cast iron especially in tension.

If you think about the loads a block takes, most of them are compressive loads. The caps take the tension loads which are trying to pull them apart. That's why steel caps work so well. It's about STRENGTH and type of load.

Nope, no fuel pump boss. These blocks aren't used in Cup, so electric fuel pumps are the norm almost everywhere else.

I kinda thought block accuarcy, strength, oiling, and suitablilty for big hp and rpm was the topic here.

I'm thinking of a little Pappy Van Winkle 20-yr. Family Reserve and a splash of branch water later on today. Nectar!

 

Like Bret said, I have had the best experiance with the blocks from the people who originally designed them, the Bowtie blocks are second to none.

The gen VI blocks do not have provisions for mech pump or clutch ball pivot, but I made one out of some plate and an older ball stud for a 489 motor we built last month, it takes about 30 min.

 

OK, obviously no problem there.


Yeah, let's move on to oiling. Are there any ways to improve a stock Mark IV oiling system? What about a priority-main oiling system?

 

That might be harder to do than replumbing you from a male to a female.

I believe PO has to be built internally into the block. Another reason for an aftermarket block, IMO.

Most of the things covered in the block prep references noted earlier apply. Again it depends on how much time and money you are willling to spend.

You are never going to make the silk pocketbook from the pig's ear, but you can make one expensive pig's ear.

 

Would someone please give me some ballpark figures and the proper machinist terms for:

• align boring
• align honing
• boring the cylinders so they're where they're supposed to be
• indexing the lifter bores
• square and equal decking

 

Those are basically the right terms...

Now when it comes to a BBC getting a block to be perfect in all of those aspects costs almost as much as a CNC machined Bowtie Block, but the block is now stronger and can have a much larger bore which BBC heads love.

Bret

 

So the prices would be about $500 each?

 

Not necessarily. Each procedure involves a different amount of work and different fixtures. I'd guess the costs, in descending order would be 4, 1, 3,5,2.

To put what has been said in other words:

By the time you had all the procedures done, in addition to all the other things you should do to make a nearly perfect block, you could spend as much on your present production block as a new Bowtie CNC block costs. You would then have a well prepared, but weaker, less well oiled and less durable hunk of cast iron...but it might have a fuel pump boss.

In OTHER words: You could buy a new Bowtie block, finish off the bores, and have the basis for an earthmoving BBC capable of over 600 cubes, for about the same $ as nearly completely remanufacturing your production block of lesser strength, and you'd still have the complete production engine which you could sell or use elsewhere.

There are a number of ways to accomplish most tasks. Some folks usually choose the hard way. I've never been able to understand that.

 

I understand that, but why is it like pulling teeth with a Vise-grip to get someone to give me some ballpark figures and the proper machinist terms for the machining operations necessary to make a block perfect? Do I need to be a member of some secret club or association? Is it classified information? Does it have to do with national security? Are there copyright issues involved? Would you like some money in exchange for these secret terms and costs? It's like this info is stored in a 50,000 ton safe with a timelock on it on an undisclosed island in the middle of the ocean with embassy-style razor wire on top of 50ft tall 10ft thick concrete walls around the perimeter and big, angry guys inside the compound with .50-cal machine guns! What if I want to build a Super Stocker or a FAST/Pure Stock racer someday? This info would be VERY USEFUL!

 

Got your point. I'm a sucker for subtlety, aka the "velvet covered bludgeon".

Prices vary from shop to shop and from one part of the country to another. Not every shop can do all the operations: some might sub-contract one or more of the operations and do the others in-house.

If you want numbers, try these in the 4, 1, 3, 5, 2 order suggested previously. Your terms are pretty good.

Indexing lifter bores and bronze bushing them (necessary when you bore them out): $600 and up. The fixturing isn't cheap, and the operator needs to be conscientious in all portions of the operation. The bushings can be made from various materials, and the higher-end bronzes ain't cheap.

Align boring of main saddles because you have changed caps: $200 and WAY up, depending on the caps, their hardness, preparation required to install them, like squaring them up or fitting them in the block recess. You might hear this described as "line boring" but align boring (and honing) better describes the process; you want the bores to be aligned with each other.

Boring the cylinders at a true 45* to main bore/cam bore centerline, at the correct bore spacing and perpendicular to the main saddles: $200 and WAY up depending on how exact you want things to be. The easy way is to square up the decks to the main and cam bores and locate off the decks, but that won't always get you as close as a CNC block.

Squaring the decks(aka decking the block): $100 up depending on the accuracy you demand. Be advised not everyone can accurately measure deck angular alignment with the main/cam bores in both longitudinal and lateral planes. More than likely you might get decks parallel to the main bores within a thou (.001) or two, and 90* between them within a degree or so. It would be nice if the 90* was centered so the now correct lifter bores made the cam timing on both banks what it was designed to be.

Align honing: Probably the least costly operation, and done after line boring, but you want the size to be correct within about .0002 and consistent along all 5 bores within .0002. $100 and up.

These numbers could be 50% (or more) higher depending on what you demand for accuracy. Remember, your results may vary!

Add to all this a complete cleaning of the block, sonic testing of bore wall thicknesses in multliple places in every bore, checking for cracks, retapping all holes, clearancing for larger stroke if necessary, modifying oil passages, etc. and you may easily reach the cost of a Bowtie or equivalent block. Or you might scrap the block if it fails a sonic or crack test, but you still paid for cleaning and checking.

As in almost everything, you may not always get what you pay for, but you rarely get something you don't pay for. Of course your results/costs may vary.

FWIW, even if you pay the high-end $ for all of the operations, you, as a consumer probably can't measure the block to assure everything was done correctly. Sure, the main, cam and cylinder bores are fairly easily measured, but their geometric locations aren't. The best thing a consumer can do is choose his engine builder or block machine shop(s) VERY carefully.

Your chances of getting things fairly close is better with a CNC Bowtie block, but there are tolerances in every machining operation, and $2600 doesn't get you a +/- .000 block. Neither will it get you that accuracy in an automotive machine shop. There is no such thng as a "perfect" block.

Nextel Cup teams may start with this block and then do many $1000s of more work on it, but not too much of it is correcting major machining errors. Then again, +/- .001 might be WAY off for a very **** Cup block guy. "How fast do your want to go?"

If you want to build a SS or FAST Pure Stocker someday, the best advice I can offer is spend LOTS of time choosing your engine builder, discuss your expectations and your budget with him, and let him design the engine. If you can come to an agreement, belly up with the $, and get the heck out of his way. The decent engine builders I know of will be happy to keep you informed of the progress, but most of them won't tolerate micromanaging or day-by-day progress reports. If you can't trust your chosen builder to do as he says he will, you chose the wrong guy! If you attempt to micromanage, you'll probably get the parts handed to you in a basket, and any "unused" $ refunded. I can't stress that enough. If it has to be your way or the highway, it will be the highway, at least with any engine builder worth his stuff. I've not met a good one yet who wants his name on an engine that isn't going to perform well, or eats camshafts because the owner insisted on doing things HIS way rather than the pro's way. Good engine builders just don't need that "5%" of the customers who are that way. It's true in almost any business. Some folks call it the "5% Rule", but it might be the "1% or 2% Rule", but it's still the same thing. Sometimes the $ just aren't worth all the hassle! The trick for the customer is to not be the "5 percenter".

FWIW, Vol 2: It was George Bernard Shaw who was reported to have said:, "Reasonable people adapt themselves to the world. Unreasonable people attempt to adapt the world to themselves. All progress, therefore, depends on unreasonable people. "

GBS also said: "Beware of false knowledge; it is more dangerous than ignorance."

Shaw never built an engine. He had them all built by experts.
My highly opinionated $.02

 

Thanks, that's exactly what I was looking for.

 

Nova you really gotta fix your sig now. Let me know how much you spend getting the block perfect... cause last time I checked a Bowtie did it cheaper and more accurately.

Bret

 

Cubic inches = Cubic dollars

 

Good info all around here, I'm not new to this site at all but have been trolling around this forum in particular the last few weeks.

Intelligent discussion that really only applys to the wants of that 5% as Stroker said. Good to see, I think I'll start becoming a fixture here.