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Advanced Cast Iron Machining Q's


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I've got some questions for you advanced engine builders or experienced engine builders about removing casting flash, radiusing oil holes, radiusing corners, etc. in a cast iron block. In a normal engine rebuild according to Sunnen's Complete Cylinder Head and Engine Rebuilding Handbook your process would be something similar to this:

 

Engine Dis-assembly

Bore Cylinders

Hone Cylinders

Hot-Tank (Caustic)

Wash Thoroughly then immediatly Oil Cylinder walls to prevent rust

Engine Re-assembly

 

I know that this is very simplified, but I'm curious as to where in these stages do you do the thermal coating in the lifter/oil valley, remove the casting flash, etc.? Most of the cleaning processes that I have seen all use water/caustic solution to clean the block before final assembly, what I'm concerned about is having rust form on the freshly machined surfaces and removing the thermal coatings. Also for smoothing out cast iron am I better off to leave it to a competent engine shop or is it something that can be done at home, is there anything that one should be concerned about with these processes?

 

Thanks,

 

Tyson

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Last time I posted a response on this BB having to do with machining I was told I absolutely had no idea what I was talking about but I'll risk it again...

 

Disassemble engine,

Deburr all the stuff you wish at home. You COULD have it hot tanked first for a cleaner environment but it isn't necessary.

 

Thermal coating could be done at several stages along the way. I would do it before final machining.

 

The machine shop will:

Remove cam bearings, gallery plugs, freeze plugs.

Visually inspect,

Clean the block in either a caustic solution or a "shake-n-bake", which is a thermal and shot peening process. Makes it look like new cast iron.

It is now clean and ready for further inspection and machining.

Magnaflux, sonic check as necessary.

Add block fill as necessary.

The first machining operation if needed or wanted would be to align hone or bore the main line.

Then the next operation is decking as necessary.

Then you would bore,

at this point I would do the thermal coating.

then hone, preferably with torque plates.

Then the block would be jet washed in a hot detergent solution, final rinsed, passages cleaned, pressurized air blown, and oiled.

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Well, your right about deburring, do it before you send it out as best you can. When they deck they'll have to chamfer the head bolt holes so don't waste time doing that.

 

IMO your wrong about block fill though, it should be last, and when you fill it you intall the head and torque it to distort the block. Of couse the mains should also be torqued. I actually do it on final assembly with all the pistons and rods in it but that's my preference. It takes 28 days for it to cure so don't be in a rush. You can do one side and then the next day do the other. But I recommend waiting the 28 days befor eyou start it cause cement won't reach peak strength until then and you don't want to be flexing the cylinder walls too early.

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Well' date=' your right about deburring, do it before you send it out as best you can. When they deck they'll have to chamfer the head bolt holes so don't waste time doing that.

 

IMO your wrong about block fill though, it should be last, and when you fill it you intall the head and torque it to distort the block. Of couse the mains should also be torqued. I actually do it on final assembly with all the pistons and rods in it but that's my preference. It takes 28 days for it to cure so don't be in a rush. You can do one side and then the next day do the other. But I recommend waiting the 28 days befor eyou start it cause cement won't reach peak strength until then and you don't want to be flexing the cylinder walls too early.[/quote']

 

And again,

That's why you are not a machinist...

You want the block filled and cured for at least a week prior to honing with torque plates.

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Jake, I'm not biting. If you have usefull information great, if your going to talk smack, go over to zcar. Your attitude is less than what the standards are here at hybridz.

 

Just bring your tech knowhow big motor z to sez and get yourself an buttwhoopin'! Do you even own a z?... Oh well, bring whatever you got and come play. The only thing you'll ever see of the ol' black z is the *** end. That is if you show up! End of story!

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http://www.hardblok.com/info.html

 

Also go download page 2 of their info.

 

In all instances they speak of filling BEFORE machining. Their insructions allow quicker work times.

 

I still usually wait a week prior to machining.

 

Other reasons you fill BEFORE machining or assembly are:

Sometimes on an extreme stroker motor you may break through or hit porosity. You want the filler in place before you grind so that worst case scenario you hit it. Instead of trying to pour it into a block with a hole later...

 

And another good one...

Why would you want to be dealing with concrete (dirt and water, more or less) on an assembled block... :icon56:

 

 

I prefer to do cleaner work than that.

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Jake' date=' I'm not biting. If you have usefull information great, if your going to talk smack, go over to zcar. Your attitude is less than what the standards are here at hybridz.

 

Just bring your tech knowhow big motor z to sez and get yourself an buttwhoopin'! Do you even own a z?... Oh well, bring whatever you got and come play. The only thing you'll ever see of the ol' black z is the *** end. That is if you show up! End of story![/quote']

 

Yes I own a Z,

74 260Z. Freshly installed 408 cid SBC. I installed the motor about 2 weeks ago after returning from Iraq.

It is currently sitting on 4 jackstands receiving the 300ZX rear diff.

I race at the Texas Motorplex occasionally. Maybe we will run into each other at some point in time.

 

It's simple....

If you are going to put out incorrect info, I will correct it.

 

Too many enthusiasts have their time and money wasted by false info.

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http://www.hardblok.com/info.html

 

Also go download page 2 of their info.

 

In all instances they speak of filling BEFORE machining. Their insructions allow quicker work times.

 

I still usually wait a week prior to machining.

 

Other reasons you fill BEFORE machining or assembly are:

Sometimes on an extreme stroker motor you may break through or hit porosity. You want the filler in place before you grind so that worst case scenario you hit it. Instead of trying to pour it into a block with a hole later...

 

And another good one...

Why would you want to be dealing with concrete (dirt and water' date=' more or less) on an assembled block... :icon56:

 

 

I prefer to do cleaner work than that.[/quote']

 

Actually they talk about installation before final honing not maching.

 

Quote from Hardblok.

 

"Ample working time to pour and install torque plates." This is required so that the cylinder walls are pre-distorted prior to setting of the filler otherwise that distortion can cause separation of the cylinder wall from the filler material. You can also do the same thing just use cylinder heads for those that are home builders and don't have torque plates laying around.

 

 

I said cement not concrete. Cement and Concrete are two different things. Cement is a mixture of burned lime and clay is an ingredient of concrete. Concrete is a mixture of cement, stone and sand mixed with water. Hardblok is a mixture of cement and iron particles.

 

Quote from Hardblok

 

"cement-based product" It has to be since cement is the only chemical process I know of that can't be undone. All block fillers are cement based with iron additives to mimick the thermal expansion properties of Cast Iron.

 

I'm not sure what kind of performance gains are to be had, haven't seen a side by side dyno comparison. But Corky bells book mentions the advantages of stiff cylinder walls in boosted applications and it only makes sense in terms of ring seal. I also haven't read anything about the minimum cylinder wall thickness required for the portions of a filled block that aren't backed by the cement material.

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Typical minimum cyilinder wall thickness desirable on the thrust side is .180", obviously more is better especially in high cylinder pressure apps.

 

It is desirable to fill before ANY machining operation because if it does cause any distortion, it could also affect the main line.

 

 

Also,

If you are bolting a torque plate or head on to simulate stresses, you need to having decking done prior to this.

 

Unless you are completely filling the block to the deck (very unusual), or it is an engine that the head bolts go into the main webbing (Caddy Northstar) a partial fill can be done without worry of the torque plates. The distrotion of torque plates is in the upper cylinder, the filler doesn't get into this area.

 

I SERIOUSLY doubt it would be a problem for the mains but it CAN be a problem for the hone.

 

The honing is the critical procedure because you typically leave ~.005-.007" to hone, You could put the filler in before or after boring it doesn't really matter, as long as it is BEFORE honing. Not after engine assembly.

 

The order of machining varies depending on procedure.

Years past, you would true up the mains, then square the deck, THEN bore. Nowadays the boring and decking can be done alternately but the decking needs to be done before honing to use torque plates effectively.

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What is SEZ?

 

Car is a 74 260Z, JTR V8 conversion, TH350 with 2800 converter for the moment, possible 200-4R with similar converter later (stealing it from the Chevelle when it gets the 4L80-E), 300ZX R200 LSD rear diff.

 

408 SBC, Trick Flow 23* heads, Air Gap intake, 800 Demon, block hugger headers, ~11.5-1 comp, solid flat tappet 256/260@.050 on a 108 LSA.

 

Pretty basic strip/street SBC for a weekend fun car.

 

Long story but I bought the car on a whim last August, went from north TX to MO to pick it up, very rust free body, locked up I-6, $575 off Ebay.

 

Plan was to get it going over a 2 week leave but the scheduling of picking up the car from the seller caused me to barely be able to go get it before returning to my job in Iraq.

 

I also bought the 400 from a member on another message board I frequent, it was hurt (Eagle crank) but had all the new parts to fix it.

 

Got the heads from another member, etc.. Pieced it together vie the internet from 9K miles away :)

 

Finally got home, final assembled the 400, but needed it out of the way so I can work on a LSx motor swap on my dad's '55 Chevy car in his garage until my shop gets finished. (Approx 10 more days WOOHOO!)

 

So I brought the 400 home one evening to just set in the car to more or less store it until I got back to it...

 

Well the '55 has been on the backburner since...

 

Very difficult to manuever the motor around when the garage isn't big enough, hoist is half in garage, half on the sloped drive, etc..

 

So anyway,

I fired the 400 about a week ago for cam break-in, but it's been sitting since.

 

My house has a small poor driveway that I am working on the 260Z in for the moment (although there is a helluva nice 30x50 slab about 150 ft away :) )

 

It makes for slow going, that and I went and spent a day pulling the rear mustache bar, axles, etc. from a 280Z to use and then attempted to change the halfshaft U-joints, 30 yr old u-joints. First one went easy, 2nd one wouldn't move even with heat, etc.. trying to do it without a vise or press...

After smacking my hand a couple of times trying to drive them out I took them to my local driveline shop. $10 a piece to change is WAY cheaper than an ER bill.

 

Ordered axle nuts today for it.

 

I have some work to do to get it moving under it's own power yet, finish installing the axles, shifter, tidy up the wiring (it's all over the place), hook up the tach, etc..

 

Also need to get a real ignition system. My main goal at the moment is to have it propel itself into the shop here in about 2 weeks.

Then it will probably sit for a few weeks while I get the LSx motor into the '55, so I can disassemble it and have it media blasted. Once I get the mechanical done on it I will turn my dad loose on the bodywork. He likes to do it for a hobby, I am good at it but it gets tedious.

 

WAY too many projects right now. I have to wire the shop, hang lights, build the bathroom, run water lines, install air lines, etc.. when it gets up.

Then the '55, 260Z, couple of trans I need to build for buddies and the 4l80 for myself, my '69 Chevelle needs some TLC, and I have a bunch of parts to customize the new Harley (gotta save gas right :) )

 

 

400Z.JPG

 

400 in the way..

 

260zmotor.JPG

400 out of the way

 

260z.jpg

The Z

 

55chev.jpg

 

My oldest daughter and dad sanding on the '55.

 

5.3trial.JPG

 

5.3 motor for the '55.

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Are you two at it again? Why can't we just be friends?.........lol j/k

You guys sound like two highly intelligent people, instead of matching wits, maybe combine your ideas, thoughts, etc. You guys take care, and get those Z's going!!!!

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Man, that 55, always wanted one, that and a 67-69 camaro. That's cool. I was thinking of selling the Monte and getting a camaro to play with. We'll see what happens, the monte is a complete garage kept rust free car, I bought it in '93 with only 16K original miles on it, new interior, still has factory seats that are pristine, new glass, new paint and soon to be TT powered for awhile. Considering selling it with the TT powerplant in it and then using the new white z to go TT with an all tubular chassis.

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