Typical Machine Work

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Muad'Dib
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Typical Machine Work

Post by Muad'Dib »

Thanks to this thread and the huge help from RAPTORFAN85 we have come up with a list of the most common things to have done to your parts at the machine shop.

To make things easier to find and more organised .. i will make separate posts for each component.


!!IMPORTANT NOTE!!

The prices given in the following posts are for reference ONLY! They should be a baseline of the approx. cost you should expect to see. Some machinist charge more, others less. In my opinion, if the costs are way different then whats listed here than something is definitely not right!
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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Muad'Dib
Site Admin / Owner
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Posts: 1497
Joined: January 8th, 2008, 10:55 am
Stroker Displacement: 4.7L
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Bend, Oregon
Contact:

Typical Machine Work - Block

Post by Muad'Dib »

Block:
  • 1. hot tank or oven bake. (cleaning) $75 to clean, shot blast, and mag block
    2. shot blast.
    3. magnaflux. (check for cracks)
    4. line hone the main bearing bores if needed. (I would recommend this for bearing clearance) $150
    5. bore and hone to desired size. (I.E. over .030) $250
    6. check deck for flatness if not milling, if milling tell them how much. (I.E. have .030 decked off.) $75
    7. Install cam bearings. $25-$30
Additional Information:

Hot tanking the block is a better option for cleaning. Not all shops have a hot tank but most have a large oven they "cook" the parts in to burn off any grease, paint, oils, etc...
The shot blasting is to finish cleaning and literally blast away any remaining debris.
Magnafluxing the block is a good idea if the block is not familiar to you, also any engine that is suspect to have cracks should be mag'ed.
Line honing the main bearing bores will ensure that all the bearing journals line up and have adequate bearing clearance. Without adequate clearance the bearings could be tight and burn up. Not everyone thinks this is necessary but is good insurance.
The cam bearings are press fit and need to be installed in a certain order by size (smallest in the rear, largest in the front)

Another good "small" machining operation (you can do this one yourself with a drill motor and a large countersink) is to countersink the tops of all of the cylinder head screw holes slightly, in the block deck. Why? Because screws are retained by tensile preload ("stretch") when installed - that's what the torque wrench is for. Cylinder head screws are "stretched" more than most other screws in the engine. This stretch can also pull up the top thread of the threaded hole - which can interfere with head gasket sealing.

Countersinking each hole about 1/2 to/maybe/ on thread worth eliminates this. It's also not a bad idea to do it on main bearing cap screw holes at the bottom of the deck as well.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
User avatar
Muad'Dib
Site Admin / Owner
Site Admin / Owner
Posts: 1497
Joined: January 8th, 2008, 10:55 am
Stroker Displacement: 4.7L
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Bend, Oregon
Contact:

Typical Machine Work - Crankshaft

Post by Muad'Dib »

Crankshaft:
  • 1. hot tank or oven bake if dirty. $25
    2. grind mains and rods to desired size, or offset grind if desired. $125
    2a. Chamfer oil holes if desired. (better oiling) $25
    3. spin balance. (optional) $50
Additional Information:

Chamfering the oil holes isn't necessary but will allow better oil flow and volume threw the holes. Another nice thing about chamfering the oiling holes in the crank is minimising the risk of there being a "burr" that could arise from handling, which can just chew up main bearings.
Balancing is also not necessary but recommended. The cranks come some what balanced from the factory but can be made closer.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
User avatar
Muad'Dib
Site Admin / Owner
Site Admin / Owner
Posts: 1497
Joined: January 8th, 2008, 10:55 am
Stroker Displacement: 4.7L
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Bend, Oregon
Contact:

Re: Typical Machine Work - Connecting Rods

Post by Muad'Dib »

Connecting Rods:
  • 1. hot tank or oven bake if dirty. $25
    2. shot peen if desired. (for strength) $30
    3. check for straightness. $15
    4. install rod bolts if desired. $25
    5. resize bearing journals. $125
    6. weight balance. $20
    7. install pistons. $50
Additional Information:

Shot peening is not necessary but recommended. It will strengthen the rods by removing any stress in the metal, essentially returning it to an almost new state.
ARP rod bolts are recommended insurance for a stroker. They are a press fit and should be installed with proper tools by a machinist.
Resizing the bearing journals should be done after rod bolts are installed, the pressing of the bolts can distort the metal making the bearings tight and burning them up. It's a good idea to have them checked even if you don't install new bolts.
All the rods should be weight matched. Also have the pistons weight matched to the rods to try and get the rod/piston assemblies all as close as possible to help with internal balancing.
Stock Jeep pistons are press fit. If not done incorrectly You can break a piston or warp the rod.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
User avatar
Muad'Dib
Site Admin / Owner
Site Admin / Owner
Posts: 1497
Joined: January 8th, 2008, 10:55 am
Stroker Displacement: 4.7L
Vehicle Year: 1990
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Bend, Oregon
Contact:

Typical Machine Work - Cylinder Head

Post by Muad'Dib »

Cylinder Head:
  • 1. hot tank or oven bake if dirty and shot blast. $30
    2. magnaflux head. (check for cracks) $15
    3. port and polish. (optional performance upgrade) $600-$800 for pro, $25 for the Standard Abrasives kit and about 20 hours to do it yourself.
    4. valve job. $150
    4A. Install new seats if needed. $100 (for 12 seats)
    5. check for flatness. $15
    6. mill head if desired. (I.E. mill .010 off) $40
    7. assemble with new springs, retainers, and keepers. $50
Additional Information:

I would mag any head that is not new. It's not worth it to have money put into a head if it's cracked and only have problems down the road. Cheap insurance.
Porting and polishing will give good gains to a stroker. To have a pro do it will be big money but you will get the best possible job. It can be don by a DIY'er but if you screw up your head you can kill the power rather then help, thus making your head a boat anchor.
Most heads will benefit from a new valve job. Three angle jobs seem to be the new norm. I have seen five angle jobs but think that it may be overkill for a jeep. A new valve job is almost a must after a port and polish, especially if done at home. Also the three angle job will increase the flow of the head.
Assembling the head requires special tools like a spring compressor. if you don't have the right tools have the machinist do it. Usually only a small assembly fee around $50
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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