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DOHC 4.6L V8 build

main cap bolts

The inner and outer bolt heads on the main bearing caps appear to be the same size on the Coyote. On my 4.6L they are different sizes but that doesn't mean the cranks are different. I'll check to see if the main bearing inserts are interchangeable.

Edit: Coyote main journal dia. = 2.652", rod journal dia. = 2.082", 4.6L main journal dia. = 2.657", rod journal dia. = 2.086". So I can't use the Coyote crank unless I can decrease the 4.6L diameter of the main bearings by .005" and the rod bearings by .004". One way would be to purchase 4.6L .010" undersize bearings and then machine the Coyote crank journals to fit. However, I still don't know if the width of the bearings is the same. Also, the thrust bearing might be a different configuration.

MMR has a 4.75L 900 hp all forged stroker kit (crank, rods, pistons) with rings, rod and main bearings, oil pump with pickup tube, and ARP main and balancer bolts. It's currently on sale for $2000 ($300 off).
 



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The Coyote crank sounds like an interesting way to go if it'll work. Given the cost of the stroker kit, even some machine work for the OEM parts will be more feasible.
 






crankshaft information

The crankshaft in the 2003-2004 Mach 1 with manual transmission (PN 2R3Z-6303-BA) was forged due to the higher engine rev limit. It has been discontinued by Ford. I suspect the same crankshaft was used in the 1999-2001 SVT Cobra and should survive at least 750 bhp. I think these crankshafts have an 8 bolt flange.

The crankshaft in my 2003 Aviator (PN 2C5Z6303BA) is cast and the same as used in the Mach 1 with automatic transmission and numerous other 4.6L vehicles. It is still available from Ford ($275) and should survive 500 bhp. This crankshaft has a 6 bolt flange. I can purchase a low mileage (under 50K miles) stock cast crank for $150 plus shipping. mmr sells an aftermarket cast equivalent crank for $340 and a forged Kellog crank for $1600. ModMax sells a remanufactured stock cast crank with medium performance undersize bearings for $300 or with high performance bearings for $350. ModMax sells a remanufactured Cobra forged crank with undersize bearings for $800 and an Eagle forged crank for $850. I just can't justify the additional cost of a forged crank since a cast crank will probably handle more power than my block can stand.

I'm inclined to go with a stock stroke cast crank, forged pistons and rods.

Edit: list of 4.6L vehicles with PN 2C5Z6303BA cast cranks:
2007-2011 Ford Crown Victoria
2005-2013 Ford Econoline
2003-2004 Ford Expedition
2002-2010 Ford Explorer
2007-2010 Ford Explorer Sport Trac
2004-2010 Ford F-150
2002-2010 Ford Mustang
2003-2005 Lincoln Aviator
2005-2008 Lincoln Mark LT
2004-2011 Lincoln Town Car
2007-2011 Mercury Grand Marquis
2002-2010 Mercury Mountaineer
 






Ford has always been good about making strong cranks etc, in general. There are some weak items the big power levels discover, like the 302 blocks. The power being made these days is way past what was a lot 25 years ago. So me saying the cranks were good may not apply to as much as when we thought it 20+ years back.

That 550hp level is probably about the right place to shoot for with limits for the parts. Find stuff that will survive that, and it should work out.
 






flexplate

Most (maybe all) of the forged crankshafts have 8 bolt flanges. The 2002-2003 Explorer with the 5R55W/S transmission comes with a 6 bolt flexplate. So if I purchase a forged crankshaft I would also need to purchase an 8 bolt flexplate that will mate to the 5R55W/S and is compatible with the 4.6L starter. The 5.4L Expedition and Navigator have 8 bolt flexplates but the early Navigator came with a 4R100 transmission that may have a different bolt circle. I can purchase an aftermarket 8 bolt universal flexplate with 3 different bolt circles for around $150. The uncertainty of compatibility and the additional expense of an 8 both flexplate is additional rationale for using a cast 6 bolt crankshaft even if I could purchase a remanufactured forged crank for the same cost.
 






This is an outstanding reference document that is now at 65 posts and I can visualize it growing to hundreds.

Here is a link to a thread structure that provides an easily accessible index format all within the same thread.

http://forums.turbobricks.com/showthread.php?t=271886

Post a profound bit of information . . . put a link to that post in the index.
 






thanks for suggestion

Tom, thanks for the suggestion and link to an example. I must admit that I am rather unorganized when it comes to filing and lax when it comes to backing up data. So for the past several years I have posted things I want to keep track of on the forum. Forum threads organize my data and I can count on Rick (forum owner) to back it up on a frequent basis at the reasonable rate of $20 per year. I'll probably add some links in the first post to various topics in this thread to help me and others quickly find things.
 






cylinder bores

One of the gifts I received for Christmas was a 6 inch digital caliper. Today I purchased an inexpensive telescoping gauge set to start measuring cylinder diameters.
TelescopingGauges.jpg

It's going to take some practicing using the tools before I can get accurate, repeatable measurements. First the telescoping gauge is inserted into the bore with the axis of the handle on the centerline of the bore. Then the handle is rotated to lock the spring loaded sliding, perpendicular pistons in position. Then the handle is slanted to remove tension between the cylinder wall and the pistons and the gauge is retracted. The final step is to measure the distance between piston ends with the caliper. The hardest part is getting the gauge centered in the bore and then locking the pistons without disturbing them.

The measurements pertinent to each cylinder are taper and out-of-round. Taper is determined by measuring the top, middle and bottom of piston ring travel in the direction parallel to the crankshaft axis and perpendicular to it. Out-of-round is determined by making one measurement and another perpendicular to it. A minimum of 6 measurements are required per cylinder for the results.

According to the shop manual the bore is 90.2 mm or 3.55 inch. However, 90.2 mm is actually 3.5512 inches. I suspect that the factory uses mm instead of inches when boring the blocks so I'm using 3.5512. There are three categorized cylinder bores:
Red: 90.200-90.213 mm
Blue: 90.213-90.226 mm
Yellow: 90.226-90.239 mm
I don't know if the categories relate to piston diameters or to cylinder diameters but I think the factory uses the categories to match pistons to cylinders.

The cylinder specifications are:
Cylinder bore dia., surface finish (RMS): 0.2-0.6 microns
Cylinder bore dia., out-of-round limit: 0.015 mm (0.0006 in.)
Cylinder bore dia., out-of-round service limit: 0.020 mm (0.0008 in.)
Cylinder bore dia., taper service limit: 0.006 mm (0.0002 in.)
Cylinder bore max. taper: 0.006 mm (0.0002 in.)
Cylinder bore max. out-of-round: 0.015 mm (0.0006 in.)

I am not yet proficient enough to get repeatable measurements accurate to less than 0.0005 inch but it appears that cylinders 6 and 7 (the ones with the spinning rod bearings) exceed the out-of-round tolerance. I'll do more practicing and measuring but I suspect I'll need oversize pistons and the block bored and honed. The only forged oversize pistons I recall seeing listed are +0.020 inches which is the max overbore for my WAP aluminum block with boost.
 






To measure with the snap (telescoping) gauges:
-Insert the gauge into the cylinder at a slight angle and release the ends. (So it is measuring larger than the cylinder.)
-Snug down the tension (while still angled, one tip deeper in than the other) -- not all the way down hard, but enough for the gauge to hold its position.
-Pull down on the handle in a sweeping motion. It will pivot on the tip that is closer to the opening, and sweep the tip that is deeper in across the diameter. The gauge will automatically find the largest diameter. The tip will push in to the correct diameter, then hold position once you have passed the full diameter and reach an angle in the other direction. You have to have the right amount of tension for this to work.
-Remove the gauge from the bore and measure it with a micrometer.
-Repeat if desired for confidence in the measurement.

I have several sets of low and medium quality telescoping gauge sets. It's hard to get consistent results with cheap gauges because they don't slide smoothly. If they feel crunchy when you push them in, they may be hard to deal with.

I would strongly suggest you get an appropriately sized micrometer (even a cheap one) to measure your telescoping gauges instead of a digital caliper. Calipers are for approximate measurements, not precision.
 






thanks for the advice

I realize that the caliper is not very accurate but I was hoping that the measurements (even if inaccurate) would be repeatable. Then I could compare cylinder bores to each other and for taper and out-of-round. Probably the only significant cost difference between standard and oversize pistons and rings is the machine shop labor to bore the block. I plan to take the block to the machine shop in January and get an estimate. I probably won't spend any money on the block or the rotating assembly until I purchase an Explorer and determine the state of its engine. If the Explorer engine is in good condition I may use its crank and block and possibly keep the Aviator block as a spare. Or I could sell the Explorer long block to help pay for another cast crank, and forged pistons and rods for the Aviator block.
 






crankshaft journals

I measured the diameter of the crankshaft journals today using the caliper.

Specified main bearing journal dia. is 2.657 inch.
5 = 2.653 1,2,3 = 2.652 4 = 2.651

Specified rod journal dia. is 2.086 inch.
8 = 2.095 1,5 = 2.091 2,3 = 2.090 4 = 2.085 7 = 2.070 6 = 2.026

I wasn't very careful making the measurements since I was mainly interested in how badly worn rod journal 6 was. It was 0.069 inch smaller than the largest one - one of the worst I've ever heard of.
 






CXRacing connecting rods?

Does anyone know about CXRacing connecting rods? I can purchase locally a complete new balanced rotating assembly with Manley forged pistons (+0.020) with rings & pins, mmr stock stroke cast crank, bearings, and CXRacing forged rods for about $1100-$1200. According to Amazon the rods are H beam, 4340 steel and support 600 hp. I think they are made in China. I don't know the dish volume on the pistons yet to be able to determine compression ratio on my 4 valve heads.
 






Rejected CXRacing rods

After doing more research I've rejected the CXRacing connecting rods in a locally available rotating assembly. Right now my rod preference are those by Manley that came stock in the 2003 supercharged Cobra. These "economy" forged H beam rods (PN 14042-8) are rated to 700 hp @ 8,000 rpm. They are the same weight (602 grams) as Manley's Pro Series I beam rods and a little heavier than the Sportsmaster I beam rods (571 grams).
 






One of the gifts I received for Christmas was a 6 inch digital caliper. Today I purchased an inexpensive telescoping gauge set to start measuring cylinder diameters.
View attachment 81857
It's going to take some practicing using the tools before I can get accurate, repeatable measurements. First the telescoping gauge is inserted into the bore with the axis of the handle on the centerline of the bore. Then the handle is rotated to lock the spring loaded sliding, perpendicular pistons in position. Then the handle is slanted to remove tension between the cylinder wall and the pistons and the gauge is retracted. The final step is to measure the distance between piston ends with the caliper. The hardest part is getting the gauge centered in the bore and then locking the pistons without disturbing them.

The measurements pertinent to each cylinder are taper and out-of-round. Taper is determined by measuring the top, middle and bottom of piston ring travel in the direction parallel to the crankshaft axis and perpendicular to it. Out-of-round is determined by making one measurement and another perpendicular to it. A minimum of 6 measurements are required per cylinder for the results.

According to the shop manual the bore is 90.2 mm or 3.55 inch. However, 90.2 mm is actually 3.5512 inches. I suspect that the factory uses mm instead of inches when boring the blocks so I'm using 3.5512. There are three categorized cylinder bores:
Red: 90.200-90.213 mm
Blue: 90.213-90.226 mm
Yellow: 90.226-90.239 mm
I don't know if the categories relate to piston diameters or to cylinder diameters but I think the factory uses the categories to match pistons to cylinders.

The cylinder specifications are:
Cylinder bore dia., surface finish (RMS): 0.2-0.6 microns
Cylinder bore dia., out-of-round limit: 0.015 mm (0.0006 in.)
Cylinder bore dia., out-of-round service limit: 0.020 mm (0.0008 in.)
Cylinder bore dia., taper service limit: 0.006 mm (0.0002 in.)
Cylinder bore max. taper: 0.006 mm (0.0002 in.)
Cylinder bore max. out-of-round: 0.015 mm (0.0006 in.)

I am not yet proficient enough to get repeatable measurements accurate to less than 0.0005 inch but it appears that cylinders 6 and 7 (the ones with the spinning rod bearings) exceed the out-of-round tolerance. I'll do more practicing and measuring but I suspect I'll need oversize pistons and the block bored and honed. The only forged oversize pistons I recall seeing listed are +0.020 inches which is the max overbore for my WAP aluminum block with boost.

are those measurements taken using a torque plate?
 






no mention of torque plate

The shop manual does not list or show a torque plate as a special tool. Nor does it mention or show one in the procedure for measuring cylinder bore out-of-round or taper.

I don't know if the factory uses a torque plate when the stock engine is bored but I doubt it. I'm guessing that the change in bore due to compression from the torque plate may be about .0005 inch for my aluminum block. As I recall the specified max piston diameter to cylinder bore clearance is about .001 inch.
 






Definitely use a torque plate for engine machine work, it cannot hurt and it always helps.
 






subscribed
 






There's some great info here, I keep coming back to this thread.

The crank bearing side bolts are actually 1/2" for some reason. A 13 impact will knock the corners off but a 1/2" will pull it out without any fuss. Well, at least on the Romeo blocks found in Explorers anyways.

As for a budget performance mod I have always wondered about about just going 40thou" over to achieve 4.7 litre displacement, buying the pistons straight off the shelf at RockAuto. Then milling the heads to the limit so you're cramming 4.7 litres of air into an even smaller space inside the heads, increasing compression to possibly 10:1? This combined with premium unleaded gasoline should bring about a noticeable difference but just how noticeable remains to be seen.
 






4 valve heads

According to the 2004 Aviator shop manual the combustion chamber on the 4 valve heads has a volume of 53 cc although I've seen it listed in some aftermarket catalogs as 52.4 cc. One of the auto magazines did a review of the 2003 Aviator and listed the compression ratio as 10:1 requiring premium fuel. It crept up eventually to around 10.2:1 in 2005 as I recall. I think my stock pistons have a 3 cc dish top: 4600/8/(53+3) = 10.27:1

The 2 valve heads on the Explorer have a smaller volume so dish on the pistons is significantly deeper.

I've decided to bore the Aviator block 0.020 inch oversize and purchase an all new rotating assembly and get it balanced locally. I'm trying to find a seller willing to substitute the Arias pistons (-17 cc, 8.2:1) that come in the Eagle rotating assembly 16420 with JE pistons 257545 (-10 cc, 9.2:1).
JE257545.jpg

It has valve reliefs for high lift cams. If the block deck and heads get milled to flatten then the compression ratio could easily increase to 9.5:1 which is about what I want - good enough for NA performance and not too high for 8 psi boost. I'd end up with a cast crank, forged rods & pistons good to 500 fhp.
 



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Are there many choices for head gaskets? The thickness of the gasket makes a noteworthy difference in compression ratio. With many engines you can find anywhere between .027 to .45 thick gaskets, which is a few cc's change. I'd wait to buy those last, when you know better what the chambers and deck heights will be.
 






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