Motor Assembly Issues

[Phish]

Ok, so. I got some parts together and am starting to assmeble a motor. The motor itself is a 4.6l. Long story short, after cleaning everything up, new piston rings, and hoaning the block. I install the bearings, crank, and pistons. Now, before torqueing everything down i can spin the rotating assembly. Its somewhat hard to rotate, but it spins freely and smoothly. I jsut chalk it up to being new rings in a newly honed block. Now as i torque down the mains, it progressively becomes harder to rotate. when all said and done, i can no longer rotate it.

I have taken off all the main caps and checked to make sure there is no debris or dirt anywhere to be found. Reinstalled and same thing.

My question is this. (besides the obvious what the hell is going on) Woudl waiting to torqe down the main studs till after the piston rods were installed have an effect on the crank when torquing it down? The reason for not doing the main caps before the studs was i did not have an adapter for the torque wrence to use a 3/8 socket.

Anyway any suggestions would be good. THanks.

[86svo9L]

Did you plastigage all the bearing clearances?

[drfast4ward]

Ok, so. I got some parts together and am starting to assmeble a motor. The motor itself is a 4.6l. Long story short, after cleaning everything up, new piston rings, and hoaning the block. I install the bearings, crank, and pistons. Now, before torqueing everything down i can spin the rotating assembly. Its somewhat hard to rotate, but it spins freely and smoothly. I jsut chalk it up to being new rings in a newly honed block. Now as i torque down the mains, it progressively becomes harder to rotate. when all said and done, i can no longer rotate it.

I have taken off all the main caps and checked to make sure there is no debris or dirt anywhere to be found. Reinstalled and same thing.

My question is this. (besides the obvious what the hell is going on) Woudl waiting to torqe down the main studs till after the piston rods were installed have an effect on the crank when torquing it down? The reason for not doing the main caps before the studs was i did not have an adapter for the torque wrence to use a 3/8 socket.

Anyway any suggestions would be good. THanks.

sounds like you need to plastic gauge the bearings to see what was done wrong ether machine shop gave you wrong information or you ordered wrong bearings.

[Newgen]

sounds like you need to plastic gauge the bearings to see what was done wrong ether machine shop gave you wrong information or you ordered wrong bearings.

Not to jump in but the whole rotating assembly: Pistons, Rods, Crank, Bearings, Hardware all came out of a running block and it spun freely before it was taken apart. All we did was disassemble and reassemble.

We did not plastigage though.

[JustinS]

Not to jump in but the whole rotating assembly: Pistons, Rods, Crank, Bearings, Hardware all came out of a running block and it spun freely before it was taken apart. All we did was disassemble and reassemble.


all internals put in a different block?

[Newgen]

That is correct, Could it be possible the other block could of been line honed and had bigger main bearings?

[Phish]

I can even take the main caps out and jsut have the pistons mounted on the crank (i did this check the bearings and what not for a second and third time) and it still takes alot of force to move the pistons insideteh cylinders. Also, When its all together and spins (before torquing to spec) its like it sticks. It will be extremely hard to get mocing, but once the initial movement occurs, then its easier to spin

[slow ride]

All that stuff should be measured with a dial bore gauge. Use plastigauge if thats all you have though. Crank should spin nice and smooth when free from the rods.

[h22apwrd94]

What kind of P2W are you running and what are your clearances on the bearings? Used bearings? Not something I would do to be honest. Rings new or used?

[Clinical]

+1 to what he said.
First step IMO would be to run new bearings.. I'd never re-use bearings. But yes I'd get all measurements to be sure you know what you're dealing with.

[garyLT1]

I can even take the main caps out and jsut have the pistons mounted on the crank (i did this check the bearings and what not for a second and third time) and it still takes alot of force to move the pistons insideteh cylinders. Also, When its all together and spins (before torquing to spec) its like it sticks. It will be extremely hard to get mocing, but once the initial movement occurs, then its easier to spin

Agreed..I just finished assembling my block with all new bearings and rings everything. with everything plastic gauged and torqued it was very difficult to rotate by hand once everything seats it should be fine long as all your clearences are correct with your blueprint you made

[sparkles]

You need to get the crank torqued down AND THEN put the rods on. If it rotates fine then, your crank, bearings, and clearances are fine. As far as the re use of bearings goes, you know my opinion. Don't know much about the 4.6s, but you're aware that I had no issue with mine. If they are in good shape and have the few miles you say they do, do it. If they are showing wear AT ALL, you need to take it back apart and figure out why.

After you get the crank in good order, then you can throw the pistons on. New rings on those WILL make it tough to turn by hand until the motor gets broke in and the rings seat. You know this though. Why don't you give me a call and I can stop out and take a peek. Doesn't hurt to get another set of eyes on it.

[SLVR7]

When I went to the Ford factory class when the 4.6 came out, they said the block wasn't square until the heads were torqued.

[Phish]

I may take it all back apart and start over again and plasti gauge everything. It really is not much work considerign the work i will have to do later. The Piston rings are new rings. The bearings are extrememly low mile. I will start all over again and see how things go and check all my clearances

[Deimos]

if I remember correctly the 4.6 main bearings are kind of junk in the first place

[h22apwrd94]

Phish, what are your plans with this engine? What are you running for ring end gaps?

[CROWN]

Phish, what are your plans with this engine? What are you running for ring end gaps?

Was just going to ask if you checked the ring end gap. I have some plastigage if you need any. If you need help just let me know. Have rebuilt plenty of engines if you need help. Can get all the machine specs for you to if need to check everything. Let me know.

[BGjohnson]

Get new bearings, bad place to cheap out.

And I couldn't really get it from your post, did you say you have main bearing studs now? Or did you mean side load bolts?

[sparkles]

The side load bolts weren't in.

[Phish]

The Mains and rods are studded now instead of the factory bolts. I dont have the side load bolts in and its already to tight to turn. I have been way busy catching up on things around the house. I will most likely get this thing towrn down and plasti gauged tomorrow (wednesday). If things check out and it was just an assembly error then i may be moving forward. Either or i may jsut go ahead and get new bearings. Especially since everyone is on my ass about it.. I understand that its a bad place to cheap out, but you figure when you open the motor up and there is still assembly lube on the bearings they could be reused...

[slow ride]

Adding studs to to shortblocks can cause bearing surfaces that were once true with the stock hardware to become uneven. Most times you should hone the rod and line home the mains after the studs. Same thing for adding studs to the heads as they will alter the bore more than the stock bolts would have. You can get away with just adding studs from time to time, but I'd rather just run stock stuff if you are not machining after the addition of studs.

[h22apwrd94]

Adding studs to to shortblocks can cause bearing surfaces that were once true with the stock hardware to become uneven. Most times you should hone the rod and line home the mains after the studs. Same thing for adding studs to the heads as they will alter the bore more than the stock bolts would have. You can get away with just adding studs from time to time, but I'd rather just run stock stuff if you are not machining after the addition of studs.

One big reason I bypassed doing main studs on my new build. Nobody around here I trust to do it properly. New OEM main bolts and it is all good.

[sparkles]

Somebody's gotta explain to me how replacing a bolt with a stud screws up the alignment.

[Drifte]

Somebody's gotta explain to me how replacing a bolt with a stud screws up the alignment.

Thats what google is for. Studs require you to check tolerances.

[h22apwrd94]

More often than not, a stud has a higher load capacity and requires a higher torque load be used with it. The higher torque load makes the block flex as compared to the factory torque load that it was originally designed around.

[slow ride]

Somebody's gotta explain to me how replacing a bolt with a stud screws up the alignment.

Adding more clamp force or changing the way it's applied will distort metal. It might not be much, but when you measure to the .0001" it makes a difference. It's not a rule that it will need to be done, but good practice to check afterwards and machine if/when needed. I'd use factory fastners if they are up to the task of the build.

[sparkles]

Thats what google is for. Studs require you to check tolerances.
Thanks genius. I think that's already been said, hence the nature of my question.

More often than not, a stud has a higher load capacity and requires a higher torque load be used with it. The higher torque load makes the block flex as compared to the factory torque load that it was originally designed around.
Wow, a real actual answer from a person to a specific question that makes sense. AND ON THE INTERWEB NO LESS! That's kinda what I was thinking, but I'm guessing in this particular case, he's using factory spec torque values which, correct me if I'm wrong (I'm retarded), shouldn't cause it to distort the block. Granted, the studs aren't getting "stretched" like they should be, but the damn crank should turn.

Like I said when I was out there Sunday. You need to take it apart, torque the mains onto the block, and mic out the crank and the bore and see if they're factory specs or have been turned. This is what happens when you try to make a motor out of 4. Nothing wrong with it. It'll just take a little more time to get right. For shit's sake though, pull the pistons out and put them on the bench until you get the crank in and torqued down for good.

[sparkles]

Adding more clamp force or changing the way it's applied will distort metal. It might not be much, but when you measure to the .0001" it makes a difference. It's not a rule that it will need to be done, but good practice to check afterwards and machine if/when needed. I'd use factory fastners if they are up to the task of the build.

That's good advice. Especially for a motor that's advertised to hold 1000 hp out of the box with a factory bottom end.

[h22apwrd94]

I agree with Slow Ride on the factory fastener thing as well. Especially if you are using a stud that is made to be torqued to a higher load than you are using (torquing to factory spec , not the desired spec of the stud manufacturer). If the stud is not loaded properly, it could react differently when there is heavy loads on it. Use the factory hardware if it is capable, otherwise do the work that is needed to use the other hardware properly.

[Phish]

Well, All that being said, I pulled everythign back out of the block last night. Checked everything and its all the stock sizes. No machiene work to the block. The main and rodl bearings even haec the STD stamp on them saying they are the standard size. I believe i do have a set of the main bolts i could swap back in instead of the studs. Not sure if that would be my issue though. I also ordered all new main and rod bearings. THey should get here fridayor monday. Then i start all over again. I will plastigauge the bearigns this time and make srue the tolerances are correct. So.... does everyone think i should remoce the studs and go back to the factory main bolts then?

[8204Cobra]

Is this an iron or aluminum block 4.6? And sounds like it needs to come apart and have all clearances check with ALL bolts installed and put together meticulously. Yes studs can change your bearing clearences, even something as simple as installing arp bolts in your rods can change bearing clearences.

The crank needs to come out whatever bearings your going to run installed, torqued down (with all bolts) then check your bearing clearences with set of mics and bore guages.

I also have 4.6 torque plate that needs to be used when setting ring gaps and/or honing

Sounds like a lot of good resources and people willing to help, on here.... including me

Ben

[Phish]

Its an Iron block. I have no problem with people who want to dive in and help out. I have delt with older 302s that seem to be not nearly as picky as this 4.6 is. However i am outside of Des Moines so i am not sure how much of a trip it would be for you guys to come out and have a look see at whats all going on.

[sparkles]

You can bring it here. I've got an awful nice stand I got from a place one time that it can sit on :)

[CROWN]

Did you have any crankshaft end play when you had it assembled and it wouldn't spin?

[Scott]

Well, All that being said, I pulled everythign back out of the block last night. Checked everything and its all the stock sizes. No machiene work to the block. The main and rodl bearings even haec the STD stamp on them saying they are the standard size. I believe i do have a set of the main bolts i could swap back in instead of the studs. Not sure if that would be my issue though. I also ordered all new main and rod bearings. THey should get here fridayor monday. Then i start all over again. I will plastigauge the bearigns this time and make srue the tolerances are correct. So.... does everyone think i should remoce the studs and go back to the factory main bolts then?

I would be very surprised if going to studs would vary your clearances that much "not saying its impossible" not sure about the 4.6 but I know the windsor motors and alot of engines have a good size chamfer on the crank rod journals where they meet with the counter weights and you have to make sure you install the rods and rod bearings the correct direction "should also have a chamfer on 1 side of the big end" or this will lock the engine up. I've always installed the crank first and make sure it turns freely as you torque down every main cap. then rotate it after each piston is installed and rods torqued "or stretched" very minimum plastigauge but I always use a mic and dial bore gauge "or inside mic" to check every journal, bearing, cylinder, piston, for clearance, out of round and taper. Check your endplay after each main is torqued, and check rod side clearance. Engine building is 99% measuring and 1% building

Make sure you do a reality check on the stupid stuff like a flywheel hitting the engine stand and stuff like that.... laugh now but you might be surprised

[Phish]

Ok. I have some more information for you guys. I measured up a few things and got some numbers. however, they make NO sence. Here we go

Main Bearing Bore Diameter:

Mine: 72.2 mm
Stock Spec: 72.402-72.422 mm

Main bearing journal diameter:

Mine: 67.47
Stock Spec: 67.493 mm

Obviously there are some descrepencies with the Blocks bore diameter for the crank. I dont understand how it could read SMALLER then stock size.

Also, just for the hell of it i plastigauged the mains. The smallest the plasti gague went was .025 mm The reading that it gave me would have been smaller then that.

Any ideas or suggestions on what the next step would be besides droping it off at a machiene shop and saying take care of this?

[Phish]

Well i believe i have decided that for some unknown reason the iron block is measuring out smaller then stock specs (i dont even think this is possible but thats what i am getting and others have seen me mic this also). So, I plan on using an Aluminum Teskid block that i have instead. It Mics out to the correct size for the crank and all should go well from that aspect. However the cylinders need boored to fit the pistons that i am using. Thus, the aluminum block goes in to get hot tanked, bored, and decked this week. Hopefully that and returning my main bearings and purchashing the ones for the aluminum block will get me back underway and moving right along.

[Sleepy]

So is the rx8 going to be an rx4.6 or did you snag the fox body you were looking for?

[Phish]

Honestly i measured up the engine bay in the Rx8 to see if a 4.6 would fit. Withought some extensive cutting, it would not. So the RX8 is sold and gone. I have damn near everything to get this motor put together, but now am still looking for something to slide it into. A fox will be the weapon of choice. Trying to get the motor together and ready that way i know what i can spend on the fox and everything needed to get the motor swapped in.

[85XR7Project]

How exactly were you measuring these bores? I have a hard time believing it's .017 undersized.

[86svo9L]

What kind of condition are you looking for on the fox? I have a 79 notch that was a project of mine 7 or 8 years ago and got left behind at my great uncles farm when I joined the military. It is literally a shell ready to be filled with goodies, not sure how much is useable on it. But it could be yours with a clean up to date title for $200, but needs a ride out of there. I have not checked its condition in several years so we would have to go see what is up with it.

[AutoMods]

bear with me because i don't know fords but if your doing a budget rebuild (non-forged) isn't it cheaper and quicker to just buy a junkyard long block that is already running?

there was an ls motor vs mod motor discussion a while back on here and the ford guys were saying how affordable the mod motor was. if it were a 5.3 liter ls chevy truck/suv motor, nobody would rebuild it or pay for machine work because you can pluck them from any junkyard for $500, longblock running, and they will support 550whp reliably.

Also that ls motor would've fit in the rx8 ;)

[Phish]

Measured the bore with a digital caliper. I measured the iron one from the 03 cobra and it measured small as stated before. However, when i measured the Aluminum block it came out correct within spec. I measured both multiple times and kept getting the same reading. My crank works in the aluminum block, but not the iron block.


I already have Two Aluminum Teksid blocks. They are rated at 1000+ hp. Going inside of them is all forged internals from an 03 cobra. Using stock B heads (98 Cobra Cams). It will eventually be a turbo car, and those heads flow quite a bit up top but somewhat suck from NA and low end. The motor should be 1000hp strong. Not saying i will put that down, but it should be able to handle it.

As far as the shell goes. I was looking or a clean roller as far as the outside and paint goes. Interior, i was wanting a full clean interior. However, if the price is right and the body is clean i can figure out somthing a little different with the inteior.

[86svo9L]

$200 if the shell turns out to be good. I need to go out there and check it out and make sure its not rotted away to the ages. If it looks decent and has not picked up any rust I will send you a PM if its something you want.

[JustinS]

Lots of foxbodys on craigslist right now, shells to. Also a couple of caged roller sn95's.

[Phish]

Dont want an SN car.

If its rust free and has full suspension under it i would be interested. So go give it a look and let me know what you find out.

I have kinda been holding off on a car untill i got the motor together due to not knowing the amount i woudl need for hte motor. I looked at a few that caught my eye but they never worked out. I will get a little more serious now that the motor is going together.

[Sleepy]

That is actually a pretty good idea of building the motor then finding the car. Well glad you were able to get rid of the rx8 and hope you have good luck finishing the engine and finding a shell.

[85XR7Project]

Ahh caliper, that's probably where you are "gaining" material. Calipers are not the most accurate measurement tool for bores. Figure +.010 to +.020, its better to gauge using a dial bore gauge as that doesn't have to deal with how tight you are spreading it anand you can gauge from front to back not just the average with a caliper. Another way would be telescoping bore gauges and a caliper but you have to know how to use them correctly. Either way its just food for thought.

[Phish]

Either way, the bearings that came out of the Aluminum block and the bearings that came out of the iron block measure the same. They are also both stamped standard on the back of them.

When i put my crank in the iron block with bearings, and torque down the mains to 22lbs. (dont even give them the extra 90 degrees they are supposed to get) then it will not turn. Not even with a 1/2" breaker bar on the crank.

When i put it in the aluminum block and fully torque it down to spec, i can spin that bitch with my hand.

This has to be a block issue in my opinion. Dont know what else it could be.

[85XR7Project]

Maybe the block is fucked. Either way with the aluminum block at least you will get somewhere. Are you planning SOHC or DOHC?

[Phish]

DOHC motor. Will be running a stand alone and turbo. I am shooting for 182WHP. Thats 1 more HP then the Rx8 put down NA :-)

[85XR7Project]

That would be a realistic goal if you were building a Mopar engine but this is a mighty Ford. Lol

[slow ride]

Are the caps on the iron block the origionals? Do the caps look like they have been cut on the bottom (like you would with a line bore or hone)? I'm sure you could have just had the mains line honed with studs to make the bottome end even stronger.

[Phish]

Correct. It basically came down to what block i wanted because they both woudl need machiene work. I Believe i have decided to go with the aluminum block because of hte lighter weight and they still withstand more then enough horse... 1000+...

[slow ride]

I'm just curious how this iron block is undersized on the mains? If it ran before something doesn't jive. Either way good luck with it.

[Phish]

Acreed... i honestly can not figure that one out either. Maybe someone did modify the caps like your suggesting. I would have no other clue.

[slow ride]

You could tell by looking at the bottom of the caps if it looks like old factory machining or newer markings I'd think. If you have time just check the caps between the different blocks and see if the machining looks different.

[Phish]

For arguments sake lets say they are differnet (have not looked yet). Why would someone do that? You can always get a thicker bearing if the crank gets machiened.

[slow ride]

It's done before line honing to tighten the area on all the caps. Then the hone opens up everything to the exact same clearance. It's the same process as re-sizing rods, etc. Only reason I can see them doing it would be to get the block ready to hone the mains, but they never went through with the hone is my guess. It's what you would want to do when installing the main studs in the block and having then torqued to the stud manufactures specs before machining.