How to assemble a shortblock

[MalcolmV8]

OK I repeated the whole procedure from cleaning to ring size checking on cylinder #7 and this time I got different results. The machine shop told me torque plates actually open up the top of the cylinder but maybe that's just a general rule because I got different results.
At the very top of the cylinder I could slide the 0.016 in and the 0.017 could barely start to get in. About an inch and a half down or so the 0.014 slid in fine and the 0.015 got in about 3/4 of the way. Just like cylinder #5 was all the way. The rest of the way down cylinder #7 was consistent with what I got about an inch and a half down.
I found if I just pushed the ring down the depth of the piston I'm good. That appears to be all I need to do in order to gap rings with out torque plates.

 

[Silverboost]

Good thread.

Definitely looking forward to updates and post up some pics of what you are doing. At least host them on a photo website.

 

[MalcolmV8]

Oh yeah I have a few pics here and there, will get more tomorrow and get them up. I found the difference between stock and diamond pistons alone to be quite interesting

 

[MalcolmV8]

A couple pics I already have. I'll get more tomorrow.

Block and heads loaded up going to the machine shop. Valve covers on to keep dirt out although I ended up wrapping it all in plastic too.

Block back from machine shop. They used main studs for NON factory windage tray 4v motors but left them in for the ride home. I then pulled them and returned to shop.

Another shot of the block. The difference in cylinder walls is just reflection from the flash.

My heads back from the machine shop. They pulled the cams and checked things out. Decked it 4 thousands to get it straight.

The only pic I have of the pistons so far. I'll get more.

 

[03SVTCOBRA10TH]

#5 and & #7 don't sound right.... this is and iron block correct??

I usually bore match each cylinder to a specific piston and leave 0.003" of material left from final pistion to wall values for plateau honing. Here are the steps I use.


FORD 4.6L V8 PLATEAU HONING RECOMMENDATIONS

Ford has developed a specific procedure that engine rebuilders can use to duplicate the OEM plateau cylinder bore finish in Ford 4.6L V8 engine blocks (which are diamond honed at the factory). The honing equipment specifications are for a Sunnen CV-616 with Sunnen MB-30 honing oil as a lubricant, but the basic procedure can be adapted to any honing equipment.

Prior to honing, Ford recommends cleaning the block (if heat is used, the temperature must not exceed 750 degrees F) and inspecting the block for any defects.

The "semi-finish" operation is performed after boring or rough honing the cylinder bores to within .003 inch of final oversize.

Spindle speed 170 rpm

Feed rate setting #4

Stroke length 5.250 inch

Stroke speed 57 SPM

Top over stroke 3/8 inch

Hone head CK-3005A

Stones C30-A45-81

Stone length 2-3/4 inch

Stock removal .003 inch

Once the semi-finish step is complete, the plateau operation is performed with the following settings. Ford recommends hand feeding the stones using the crown wheel to maintain a load reading on the load meter of between 20% and 30% (30% is optimum). The load must be maintained for 30 seconds.

Spindle speed 170 rpm

Feed rate setting #1

Stroke length 5.250 inch

Stroke speed 57 SPM

Top over stroke 3/8 inch

Hone head CK-3005A

Stones C30-C03-81

Stone length 2-3/4 inch

Stock removal .0001 inch




Did they match each bore to a specific pistion??

 

[MalcolmV8]

#5 and & #7 don't sound right.... this is and iron block correct??

Did they match each bore to a specific pistion??

Yes it's an iron block. The factory block the car came with. No they did not match each bore to a specific piston. I asked when I picked it up and he said any piston could go in any bore. I figured that must mean every piston is exactly the same diameter.

Here's the chart I got from the machine shop.

 

[SlowSVT]

Malcolm

Sounds like you are being very careful and asking the right questions. There is a lot going on here but something tells me you are in unfamiliar territory. The .0035 - .004 PWC which is almost 4X the factory clearance which is safe up to 550-600ish HP seems a bit loose where I would probably opt to keep it in between .0025 - .003 depending on your power level you are trying to achieve. A torque plate severs no purpose when setting ring gap especially when the head bolts reach down into the block which is done to minimize cylinder distortion at the top of the block. Having a little too much ring gap is better then less especially if the motor is going to make lots of hp and heat. If the ring expand and bind it can score the cylinder, break or possibly damage the ring lands.

"Blue printing" the engine is a very involved process and goes way beyond what most people realize. A set of blue printed rods can cost over $1000 and usually is done using multiple sets of rods and QC'ing all of them to get a set that match the closest. The will weigh each end of the rod, measure for taper and alignment between the big and small end, roundness, twist and probably a host of thing I didn’t even think of and that is only the rods. You are also relying on the accuracy of the measuring tools and the guy working the micrometers and gauges. Measuring machined parts are just a much of an "art" as it is a discipline. Also the machine shop boring equipment may be worn or improperly positioning or clamping the parts can have bad effects. Just because they advertise that they build race engines does not guarantee they are doing it correctly or accurately. I have worked down to .0005” and things get real hairy in that realm. My experience is the factory usually does the best job because their machines are designed specifically to do only one job and it is very expensive if they machine a lot of parts incorrectly that will come back to haunt them with warranty repairs so they are real big on QC. The .001” PWC is a perfect example. Imagine what the results would be if they were off by .0005 which is 1/5th the thickness of a human hair and that all the way down the bore from all directions. One of my vendors runs their machines for half an hour to get it up to operating temperature to stabilize the machine before the cutter event touches the metal. There is a big difference precision machine shop and a guy with a boring bar.

The iron block will hold machining accuracy better then aluminum because it is stiffer, has 1/2 the expansion rate and will heat more evenly throughout the block. So there is less to worry about.

The factory shop manual is your best friend here but some of the parameters may change somewhat if your modding for more power. Do this one step at a time, post your questions and don't take any one persons word for it including mine. Cross check your answers before doing anything and you should be OK

 

[MalcolmV8]

Well I don't build engines for a living that's for sure. It's just a hobby and I love it. I've rebuilt many dirt bike engines, karts, lawn mowers, basic v8s and a few 4 cylinder car engines but never a high performance boosted motor like these Cobras. So yes I have lots of questions and want to make sure I do it right. That's why I'm going slow and trying to understand everything.

As for piston to wall clearance. The card that came with the diamond pistons says "install pistons with .0035 clearance measured 90 degrees to pin hole @ .850 down from oil ring". But it also comes with an application instruction sheet that has different uses. Applying to me it has " street - blower/nitrous/turbo add 0.001 min up to + .003 max". So really my machine shop only added 0.0005 where as diamond was calling for as much as 0.0065 piston to wall clearance max.

Power levels. Well I only have a ported blower and pulley now but hopefully next summer I'll have a kenne bell.

Gapping the rings is a work in progress. I'm still checking what the clearance is in each cylinder and different positions to see at what depth in the cylinder I'll get the most accurate readings.

Next step will be working out actual ring gap I want to file to. The card with the rings says bore x .0055" top ring. bore x 0.0035" second ring and oil ring it just says Min .015".

Machine shop told me my bore is 3.5725 so times .0055 is a top ring gap of .019. Would you all agree?

Thanks
Malcolm

 

[MalcolmV8]

How often do you guys check your torque wrenches? It got me thinking with ARP requiring I use their special molly lube on the threads and some even using stretch gauges. Not much good if my torque wrench is way off. It's a decent Craftsman but it's also 11 years old.
I called my local Sears and they ship it off to Dallas and I'll have it back in two weeks and it costs $50 + tax. Wow. I should almost just buy a new one at those prices. I need to see if I can find a local shop to do that.

 

[MalcolmV8]

OK I finally got a moment to tonight to get some work done on this block. First thing I did was put the crank in and check clearance and I got 0.002 which is what my machine shop said it would be.
The part that confuses me is crankshaft end play. The workshop manual shows to have all the main bearing caps torqued down and then check. Well when they're all installed the crank is pinched down to hard to move. How are you supposed to check end play?
So I removed the main bearing caps except for the #5 which is the one at the very rear of the motor with the thick lower main bearing that goes over the edge of the lower bearing cap setting end play. I also had the thrust washer in place which goes along side the upper #5 main bearing (rear of motor).

I got 0.008 inches which is 0.2032 millimeters. Workshop manual says it should be 0.130-0.301 mm so I'm right in range providing I'm measuring it correctly??

 

[dan04gt]

op:

 

[SlowSVT]

Does the crank freely spin with the caps torqued down? If not, loosen all but one and spin the crank. Repeat this until you checked all five to identify the tight journal. If it does spin freely with all the main torqued try tapping one end of the crank with a rubber mallet to push the crank up against the thrust bearing surface. Then take your measurement. Tap it to the other side and and back again an re-measure. Always measure several times to confirm the reading. If the rubber mattet doesn't have the "umpth" to push the crank put a block of wood between the crank and tap it with a metal hammer.

Let us know how you make out

 

[MalcolmV8]

No the crank did not move freely but I also didn't have any lube on it yet as I was checking with plastigauge and needed it dry. I wasn't about to tap it with a hammer or anything with no lube. I will put lube on it tonight and repeat and see if I can move it at all and then follow your steps.
As I recall when disassembling it the crank is pretty tough to move.

Thanks for the tips. I'll let you know what happens.

 

[SlowSVT]

Malcolm

If I remember correctly plastigauge is a bead of precision diameter wax and doesn't need to dry. I could be wrong and it might have changed since I last used it. Yes if the caps are torqued down with it in there the crack won't wanna move.

After you remove it, just put some motor oil on the journals and snug the bolts then torque the middle cap and spin the crack. There should me some "break-away resistance but after that it should spin almost like it's on roller bearings. if it does move to the next cap and repeat. If anywhere along the way it binds could mean one of two things: The bearings on that journal are too tight or the crank is bent/bearing saddles are warped.

After all the caps are torqued the crank should turn freely. Also the thrust bearing could be rubbing so keep an eye on that. Assembling a bottom end is careful and methodical attention to detail. Check things every step of the way. If you encounter a problem after completing a step you have just isolated a problem. Doing it right at this stage of the game will save you a ton of aggrivation down the road and is actually fun working with all that precision hardware. This is a learning process and when you done it won't be as intimidating should you do it again.

Keep at it man :thumbsup:

 

[MalcolmV8]

The reason I did plastigauge dry was because I saw that on TV They said to do it dry as the oil could fill up some of the space between the bearing and crank and give you inaccurate readings.

Anyways I cleaned off the plastiguage and repeated the procedure tonight with oil and as you said I could turn the crank quite easily. Even after torquing the mains down.
The big difference was the end play reading. I was able to move the crank back and forth to check end play by hand quite easily. No hammers or anything required.

End play with all the mains torqued is only 0.004" which is 0.1016 millimeters. Spec as mentioned above is 0.130-0.301 mm. So I need to increase my end play from 0.004" to around 0.006 to 0.008 or so.

The way I see this needs to be done is by removing the rear #5 lower bearing which wraps around the lower bearing cap and sand the sides of it till I get the end play I need?

Another side question on the main studs? When turning them into the block are you supposed to use lock tight? The reason I ask is each time I loosen the main nuts to pull a bearing cap it seems at least one stud turns loose from the block and I have get the allen wrenches out and tighten them back up. Is that normal?

Thanks
Malcolm

 

[SlowSVT]

Malcolm

Now I understand. Plastiguage should only be used with no oil on the bearing and don't spin the crank. It's a good sanity check but measuring the journals to make sure they are in spec. Bearing are made with extreme accuracy so if you don't have an inside bore guage the plastiguage is a quick and dirty method to confirm the clearance.

Don't use any oil when measuring clearances because the oil will give to too tight of readings due to oil film will prevent an accurate reading. That include the end play measurements. all checks should be done "dry"

If there is oil on the crank remove it and wipe off the excess off and take the measurement again. If there was oil cought on the thrust faces it's likely you will get that .002-.004" clearance you need.

Do not sand any of the bearings! Those things are layered with material like babbit, copper, aluminum, steel. you will screw them up sand them.

Yes, you can use "blue" locktite on the main stuts. Don't use "red" or you will never get them out


Gotta run for now.

 

[MalcolmV8]

Thanks for the info. I'll recheck the end play tomorrow wiping off all the excess oil I can.
I'll be sure and not sand the bearing. Thanks for that
Seems like some blue lock tight might be a good idea. Is that what most guys do or is it just a personal preference?

Thanks
Malcolm

 

[SlowSVT]

If you were using bolts to torque the main caps I would agree. Locktite would not be a good idea. But you are using studs which are stationary and is not what gets torqued, the nuts get torqued. Make sure you use a little oil on the threads of the nuts to get an accurate torque reading.

Blue Locktite is medium strength and can be removed. Using red locktite you mine as well epoxy then into the threads (that stuff will rip aluminum threads right out of the hole). Make sure the threads on the studs and the holes are dry and use very little blue locktite. 2 drops should do it. Brake cleaner does a good job removing oil and leaves no residue.

 

[MalcolmV8]

Thanks!

 

[MalcolmV8]

Did a little more work on setting crank end play this afternoon. I removed all oil as stated above by wiping down with some soft kleenex tissues (making sure not to leave any lint behind).
At best I gained maybe 0.001 end play. Just depends on the position of the crank as you rotate it. I was seeing between 0.004 and 0.005 end play.

The manual says to torque down all mains (they say with oil) and to tighten out jack screws in two stages to 44 in/lb and then 89 in/lb. I didn't have an 8mm allen key that would fit on a socket so I guesstimated the 89 in/lb and then put in the side bolts to the mains at 15 ft/lb as stated by the manual. This is when they say to check end play. I didn't think it would make any difference and it didn't.

I completely removed the thrust spacer by first removing main bearing cap and lower bearing #5. With the thrust washer removed I have a good 0.008 ~ 0.009 end play with the #5 main re-installed. That tells me the rear lower main that wraps around the bearing cap is not to big as I had suspected.

So I tried sanding... (way to slow and not working) and then I tried the side of the grinding wheel once the grinder was turned off and slowing down. I got off around 0.002 ~ 0.004 off the thrust washer. Re-installed and I now have 0.008 ~ 0.009 end play.

So I would assume this means I need to purchase a thinner thrust washer? or is it ok to use the one I've sanded/grinded down? It's smooth but I'm sure not absolutely accurate if you used a highly accurate straight edge across it.
My thrust washer was 0.097 so I would think buying one around 0.093 would be perfect. Or do people just sand theirs down if needed?

Just for reference factory end play should be 0.130-0.301 mm or roughly 0.005 0.011"

Thanks
Malcolm