Newbie '73T 2.4 MFI Engine Rebuild

[Inkblot]

@Jonny, @Ed:

Originally Posted by ed mayo

There is a slight difference in the case hole diameter to account for the o ring on the shoulder of the thru bolt versus the o ring on the nut end is on a narrower diameter of the bolt.

On my mag case, I can't see this at all. I did a quick measurement sample and got the same 11mm inner hole diameter on both sides of the case. Also, it doesn't really make sense to me- either way, isn't it the thick washer coming into contact with the case? Meaning, aren't the washers spacing the bolt-heads on one side and the nuts on the other side out from the case the same distance?

So, there may still be a good reason to orient the bolts as the factory did (and that's what I'll do...), but @Jonny, at least from my sample set of 1, I can't see any reason why flipping them would cause a problem! Hopefully the experts will weigh in.

@Mark: I think the pic is misleading. There's absolutely no sealant on that bearing... I think the grey assembly grease is creating a contrast that makes the inner track look white like the the sealant, but it's really just the bare silver surface of the bearing. Here's another pic of the bearing itself, just after removal:




Hoping to get everything back together today...

-Jake

[Inkblot]

Ok, got everything back together today. I was feeling pretty good about it; went much lighter on the sealants, had minimal squeeze out. Here are some quick pics:






Looked pretty much like that all the way around the seam. All of the pics are oriented with the (EDIT: Left!) half of the case up; that's the half to which I applied the sealant, so when some of the squeeze out looks like it's above the seam, that's actually just the excess from when I fingered-applied it on the surface prior to putting the case halves together (and thus not indicative of the sealant actually getting squeezed out...). Anyway, the actual squeeze out is minimal, almost to the point of making me wonder if I had put too little on.

I didn't notice any issues while putting the case together or torquing down all of the through bolts and perimeter nuts.

Then....


Defeated!


F* me, the crank is frozen.


Not sure what happened. Looks like I get to tear it apart again.


I threw a couple of flywheel bolts in to try to turn the crank with a cheater bar, just to see how frozen everything was. I could rotate the crank, but it took a LOT of force- not good. I turned it only a few degrees, hoping to minimize whatever damage I might be doing.




I went back and reviewed all of the pics I took today during the assembly, hoping to find something obvious like forgetting assembly lube, or an errant glob of sealant on a bearing or something like that... no luck. I'm afraid either a bearing slipped out of place and got wedged somehow, or maybe my excess sealant the first time around (things spun fine then) somehow masked a bearing tolerance issue... I dunno- reaching here.

I'm fairly sure it's not the oil pump or IMS bearings. If the IMS was frozen, I'd still get a little "click" of movement out of the crank.

So, I'll tear it apart again, and see if I can find the offending part and whatever new grooves or scratches I've created. Until then, any thoughts out there?

Good times. Keeping it positive, I'm glad it's my own motor, on my time. Whatever mistake(s) I made would be hard to live down if this were a customer car!

- Jake

[Jonny042]

Originally Posted by Inkblot

Ok, got everything back together today. I was feeling pretty good about it; went much lighter on the sealants, had minimal squeeze out. Here are some quick pics:






Looked pretty much like that all the way around the seam. All of the pics are oriented with the right half of the case up; that's the half to which I applied the sealant, so when some of the squeeze out looks like it's above the seam, that's actually just the excess from when I fingered-applied it on the surface prior to putting the case halves together (and thus not indicative of the sealant actually getting squeezed out...). Anyway, the actual squeeze out is minimal, almost to the point of making me wonder if I had put too little on.

I didn't notice any issues while putting the case together or torquing down all of the through bolts and perimeter nuts.

Then....


Defeated!


F* me, the crank is frozen.


Not sure what happened. Looks like I get to tear it apart again.


I threw a couple of flywheel bolts in to try to turn the crank with a cheater bar, just to see how frozen everything was. I could rotate the crank, but it took a LOT of force- not good. I turned it only a few degrees, hoping to minimize whatever damage I might be doing.




I went back and reviewed all of the pics I took today during the assembly, hoping to find something obvious like forgetting assembly lube, or an errant glob of sealant on a bearing or something like that... no luck. I'm afraid either a bearing slipped out of place and got wedged somehow, or maybe my excess sealant the first time around (things spun fine then) somehow masked a bearing tolerance issue... I dunno- reaching here.

I'm fairly sure it's not the oil pump or IMS bearings. If the IMS was frozen, I'd still get a little "click" of movement out of the crank.

So, I'll tear it apart again, and see if I can find the offending part and whatever new grooves or scratches I've created. Until then, any thoughts out there?

Good times. Keeping it positive, I'm glad it's my own motor, on my time. Whatever mistake(s) I made would be hard to live down if this were a customer car!

- Jake

Aw crap!!! Well I guess there's a bright side........ you get to reverse engineer your sealing methods again!! (HANG IN THERE!!)

[Jonny042]

Originally Posted by Inkblot

@Jonny, @Ed:

On my mag case, I can't see this at all. I did a quick measurement sample and got the same 11mm inner hole diameter on both sides of the case. Also, it doesn't really make sense to me- either way, isn't it the thick washer coming into contact with the case? Meaning, aren't the washers spacing the bolt-heads on one side and the nuts on the other side out from the case the same distance?

So, there may still be a good reason to orient the bolts as the factory did (and that's what I'll do...), but @Jonny, at least from my sample set of 1, I can't see any reason why flipping them would cause a problem! Hopefully the experts will weigh in.

-Jake

I had to talk myself of a ledge yesterday with this LOL. I think the holes are the same diameter, but on my SC there are (or WERE) chamfers on one side of the through bolt holes only.

I was either stupid enough or arrogant enough to think that I was going to outsmart the factory and add chamfers to the case where they were "missing". I did this for two reasons - first, I did a test of the o-rings and the one on the non-chamfered end was pretty much destroyed. Second, adding the chamfer was recommended by a few different knowledgeable and experienced forum members.

I based my faulty o-ring squish test on putting the bolt through the WRONG WAY!!!! as shown in "The Book". Which I am now referring to as "That Damn Book". I suspect the test would have had different results had I double checked the orientation of the bolts.

Thankfully, the suggestion to add the chamfers, although it may be based on the same incorrect bolt orientation, comes from people who have built a few motors - and were it resulting in chronic leaks from the o-rings they wouldn't have done it more than once, and probably wouldn't be suggesting others do the same.

Thinking back to a bunch of the threads I read while researching the whole through-bolt thing, people were having trouble with o-ring "squish-out". I am willing to bet this was a result of (incorrectly) putting the bolt head at the non-chamfered side of the case.

So - fingers crossed.

[356RS]

Jake, I must say your doing a fantastic job on this and keeping a positive attitude working through some of the problems that have come up. You will be able to rebuild these engines blindfolded now.
Keep us posted on what caused the bearing/gears to bind up.

[Neil Harvey]

Jake,

Before you disassemble the case again, check (if you haven't already) that the rods at the Oil pump end of the crank are not wedged up against the oil pump. Unless you keep them somewhat in their operating stroke, they can tip over and wedge against the pump body.

Good luck.

Neil

[Inkblot]

@Jonny Looks like you've got it worked out! And, if we weren't all a little stupid and arrogant, we'd probably never attempt any of this stuff in the first place

@Mark Thank you for your nice feedback. I really hope you're still following this thread by the time I get to the MFI tuning!

@Neil Thanks- yeah, I checked that, as well as confirming that neither of the chains were somehow binding. I'm tearing it down now- will post some pics soon.

-Jake

[Neil Harvey]

Jake,

Don't worry, we have all been there!!!

Just some of us are too proud to admit it.

Back in the ""olden days"" when I worked at Andial in the race engine dept., my primary role was performing all of the dyno testing with Herr Springer. I know, someone had too!!! But occasionally, I would build an engine or two. Once, the old trick of placing an important O ring or nut was placed on my bench next to my newly completed engine. It doesn't matter how many times that trick is played, it still gets your heart rate up!!

[Inkblot]

Well, I'm a bit flummoxed.

Got the case apart again this morning, and was expecting to see some horrific gouges or scratches or something indicating that I'd made a terrible mistake. But, everything kinda looked ok- leaving me to wonder what the heck was binding the crank.

First test I did was after loosening the perimeter nuts and through-bolts, but before splitting the case. In that state, the crank turned by hand just fine (as it did in the same state before I torqued the bolts last night). To me this indicates that there's not some mechanical obstruction of some sort, but that the full torque is causing something (probably a bearing, cuz what else is there?) to deform and bind.




Let's take a closer look:









First off, the sealant looks much better! No globs, minimal squeeze-out but full coverage. Looks like I could still go lighter on the 1211 around the #8 bearing; or, at least pull it even further away from the inside of the case.




Here's a good pair of pics, where you can see areas of bare metal on one side, but the mirror image on the other; I think this shows that there was full coverage, as opposed to some kind of dramatic variation in the surface itself.






Here are a few pics of the bearings, crank, etc. I really can't see anything wrong; there's no obvious area on any of the bearing surfaces which would indicate excessive wear or binding.






At this point, my only working theory is that either my bearing journals, or bearings themselves, are slightly out of spec, and once the case is fully torqued down, the offending bearing(s) deform just enough to bind the crank. However, I can't yet find any visual evidence to support this- I just can't think of any other possible reasons.

All suggestions appreciated!

- Jake

[Inkblot]

Here are a few more bearing pics:








In this pic you can see some dark cloudy areas under the assembly lube. I wonder if those are a sign of anything.




The only real trend I can see is that there seems to be less assembly lube at the bottoms of a few bearing-halves. Maybe that indicates uneven squeeze on the bearings? I'm reaching here... I guess maybe I'd expect to see that on right side bearings, as that's where the crank was sitting before torquing down the other case half.

Gotta think on it. For now, my only rough plan is to go back and carefully measure the bearings and bearing journals to see if something's outta whack.

-Jake

[Jonny042]

If you haven't already done so, it would be a good idea to clean the assembly lube off carefully, the surface of the bearings should tell the story. The babbit (the soft surface of the bearing that is easily marked) will have polished up in the places the crank was binding.

The backside of the bearing shells and the case bores themselves should be spotlessly clean and dry when you put the shells in the case halves, I wonder if that detail was missed on your second go-around?

[Inkblot]

@Neil: Sounds like good times!

@Jonny: Thanks- yeah, I was pretty good about cleaning everything, even the second time around... maybe even better, as I knew I had introduced a bunch of new detritus while I scraped off all of the old sealant. Never knew the bearing coating was called "babbit"- cool.


Ok, I've cleaned up the bearings. Only a few spots stand out.

Left side, #1-7:



#7-1



In the first pic, #5 shows a little horizontal line towards the top. You can also see some of the darker cloudy areas, but I can't tell what that is; might just be some kind of surface imperfection. There's no linear (radial?) component to it, which I'd expect from when I forced the crank to turn a few degrees.

Right side, #1-7:



#7-1:



#3 shows a some wear marks at the top. #1 has a few shiny areas, including a horizontal mark similar to #3.

Bearing journals look clean; can't tell any difference from what they looked like prior to install.






The #1 bearing also has some noticeable wear on the flange. The direction of the grooves suggests to me that this happened while I lowered the crankshaft down into place, as I had to jiggle it around to get the #8 bearing pin to align before the whole crank dropped into place.




The thin lines in the babbit that run along the center of each surface were there from the factory. You can see a little more of the cloudy patches:




So, knowing nuthin' from nuthin', I suppose I'd start by investigating the journals at #1, #3 and #5. Perhaps there's an alignment issue with my case. My machinist said that my case didn't need align boring, but maybe something changed.

Let me know what you think!


Jake

[Neil Harvey]

Jake,

First thing to do is to understand you are now building the engine for the very first time. Forget about the other 2 times. So start all over again.

Remeasure measure the main housing bore. Is it to spec and are the bearing housings aligned?

Now fit the main bearings after checking they are the correct ones, ( not an oversize on the inside) and measure the bearing ID's. Why re do this, cause you may have made a mistake before and this could be the problem. As I said, forget about the other assemblies. think this is the first build.

Now measure the crank shaft journals. Do the math and see that you have clearance. Now before you install the crankshaft, check the end play of the crank in the 4/6 side of the case. Then take out the # 1 Tbearing and swap it for the one in the 1/2 side. Recheck the end play. You should see at least 0.002" and probably as much as 0.004" - 0.006". Now you can at least know that each T bearing shell is ok for end play.

I know it time consuming, but did you have the crank checked for straightness. These cranks are always bent as most used cranks are. An easy way to check, although not to accurate, but it will show up a bent crank is to place a dial indictor on the nose of the crank and rotate it. You can do this in the case half. The front of any crank is the part that does the most moving, in any engine. This is why dampers are fitted to the nose.

Check the Oil pump for something that doesn't belong in there too.

Go slow and be deliberate.

[Jonny042]

I wonder if it might be worthwhile removing the rods and trying out the crank in the case, with nothing else. See my post:

Project Heavy Metal - an all steel classic, remastered

[mike sampsel]

Thanks for pointing me to this thread. I’m doing a redo of my case closure. It made me aware of Ed Mayo’s comment on the acorn nuts going on the side without chamfer in the bolt holes.

I noted my o-rings (some) were a bit smashed from my bolt per the orientation in Wayne’s book. I’ll be switching my through bolts so acorns are on the side with no chamfer.

Thanks for sharing this was helpful.
Only the acorn nuts on the oil cooler side are the ones in the cooler cavity. I got it

[Jonny042]

Originally Posted by mike sampsel

Thanks for pointing me to this thread. I’m doing a redo of my case closure. It made me aware of Ed Mayo’s comment on the acorn nuts going on the side without chamfer in the bolt holes.

I noted my o-rings (some) were a bit smashed from my bolt per the orientation in Wayne’s book. I’ll be switching my through bolts so acorns are on the side with no chamfer.

Thanks for sharing this was helpful.
Only the acorn nuts on the oil cooler side are the ones in the cooler cavity. I got it

You got it! Enjoy.... at least everything gets easier the more times you do it!

[cmcfaul]

My 73 E did not have the screen I see next to your oil pump. There were also tabs on the oil pump screws to keep them from backing out. Guess possible difference in models / years?

Chris

73 E

[47silver]

my 72 had the splash screen and 2 cases I bought also had them...

[cmcfaul]

My 73 2.4 E had the 7 R case. Maybe thats the difference.

Chris

[Inkblot]

Originally Posted by cmcfaul

My 73 E did not have the screen I see next to your oil pump. There were also tabs on the oil pump screws to keep them from backing out. Guess possible difference in models / years?

Chris

73 E

Hi Chris, yeah- pretty sure the screen is normal/stock for my motor. I did have the little tabs for the oil pump screws, but I removed them in favor of Loctite (and as suggested by Neil Harvey).

Jake