Addressing post 237 :

The material might not outright fail but the bolted interface could give issues long term. To test your model, start removing bolts , leave them loose and reduce bolt diameter then see where the failure point it. If you don't get a simulated failure, you model is incorrect. I also doubt Inventor can simulate torque spikes / torque reversal.

The heater core resides in the truck and the interior box stays the same for AN / Non AC. If you open the glove box, squeeze the sides to get it to drop down, there is a rectangular access cover that you can slide the heater core out of the box rather than taking the entire dash apart.

For more under hood clearance you need a heater fan box from a 84 - 90 non AC truck. Have a look at the guys that put the Thunderbird / Merkur XR4Ti turbo 2.3 in these trucks as they trim the non AC box.

Here are some links to live vibration simulations. The displacement is exaggerated, if it was actual it wold be difficult to see.

crank ( look at the crank to flywheel interface, at some RPM's you will see a green line where the two meet. )

https://www.youtube.com/watch?v=Mcp_Y0h_oXQ



engine block and trans case

https://www.youtube.com/watch?v=-DO-oAOn_h0



flywheel in rotation, no crank. This is testing centrifugal force only and not vibration that would turn the FW into a pie crust edge.

https://www.youtube.com/watch?v=jtwMocuJgmM

I posed the question below to the best mechanical engineer we have. ( He is far too good for the company actually and is treated far too poorly. )

Q
Subject: Inventor FEA question , side project

A 10 second "Is this possible in FEA" question when you get time.

Someone on a car message board I frequent is trying to stress a flywheel bolted to a crankshaft using Inventor Pro and I don't think inventor will give useful results. The goal is to apply cyclic torsion and torsion reversal to the crank / FW interface in order to test for bolt failure and fretting on the crank / FW face.

From what I'm seeing, Inventor can only test for slowly applied static loads and not failure after a high number of cycles. Does this sound about right?

I told them in order to partially validate the model for sanity, reduce the number of bolts / bolt size until you get a failure then compare to existing systems.

A
I have not heard of an FEA analysis that predicts wear directly. That type of prediction may be possible if the analysis results were calibrated to real-world results. The stress results of a particular FEA loading could be matched to fatigue test results. If this is done at several different load situations, a correlation between FEA part stress and fatigue life could be revealed.

Traditional fatigue analysis (repeated loading) is possible with Autodesk Simulation Mechanical (part of the simulation group of products and separate from InventorPro). This is an automated way to perform fatigue analysis based on well-known philosophies (Soderberg. Goodman). These types of calculations will not predict tribology stuff like fretting.

The flywheel adapter will be steel. I didn't have the inserts in my CAD model and so the bolt spacing looked fine but after my friend enlarged the bolt holes and counter bores I can see that there is actually to little material to safely use inserts. Oh well it was free and will help line everything up. It will be most likely be made of A36. The main adapter should be good but I'm having my friend pull some measurements off the starter and flywheels with his shop's CMM to be sure.

The engine doesn't crush the truck down toich and the oil pan clears until the wheels are turned all the way. Shouldn't have to take out very much to make it work.
3 more weeks and I'll be done with finals and should have some time to work on this again!

The main adapter is basically done. I still need to check the starter position but I need the flywheel adapter to do it. The starter does hit the engine but I think if I nip off the casting tabs on the bottom of the block it should fit.

I forgot to bring the bolts that hold transmission plate onto the engine with me to the hardware store, anyone know what size they are? M10.0x1.5? I'm also getting new bolts to put the manifolds on because the studs aren't in great shape, flywheel bolts, and a new bolt for the turbo because I had taken it off and dropped it somewhere. I was thinking grade 10.9 for the manifolds and flywheel and 8.8 for the missing turbo bolt, thoughts? I can't use Mercedes flywheel bolts because they're too long with the adapter but I figure that if I torque them to 50 ft lbf they should be good because that's what Ford did and used half the number of bolts.

Anyone know what size the fittings are on the power steering lines and oil cooler? Pressure hose on the ranger power steering gear box is 16mm I believe and 3/8 for the low pressure.

Something to remember on the oil pan / tie rod clearance. When the RF wheel goes over a bump, the tie rod link will move upwards. You will probably end up cutting a notch or welding in a pipe cut length wise then welding it into the oil pan. ( easy )

On the flywheel bolts:
1. There are two lengths, one for sticks the other for automatic transmissions. If they are long enough I'd want to use the mb bolts even if it took a washer.
2. I'd go with the torque value mb uses from the factory too. What Ford did is irrelevant. Its a structural system designed by some of the world's best engineers. Don't expect to change one part of it with no consequences.

The flywheel is a buzz saw waiting to come loose and cut your feet off.

Yup looks like a section of 2" angle iron to replace the back of the oil pan will work good.
The original MB bolts will not work. Tighten to yield bolts are a good idea, but the same end result can be achieved by tightening the bolts more and adding thread locker. MB calls for the flywheel bolts to be torqued to 30 ft lbf max and so if I increase that to 50 ft lbf it should be fine. All 12 bolts aren't going to back out and if one did I'd hear it.

30# ...is that correct? Seems light, but I cannot find my diesel handbook at the moment. ...and arbitrarily overtightening by more than half again seems dangerous too.

Sheet metal is a much better choice, it will be very difficult to weld thin to thick as the thin will burn away before the thick even has a chance to warm up.

Be sure to bolt the pan to an old engine or rigid flat surface with all the bolts to prevent warping. Pans can warp just by cutting a section out because they are stamped / drawn formed.



Can you shorten the MB flywheel bolts or look at auto trans bolts? I'd also be looking at other makers for similar sized bolts. Have a look at the ARP bolt web site for possibilities, ( You won't need ARP stuff unless it is priced well and easier to get over stock bolts. )

I'd go with the torque rating for the bolt since the material you are bolting into will be the same as stock.

Another consideration. Do not use the engine / trans to slow the truck down though it is OK to let off the throttle in a gear. ( RE down shifting to slow rather than applying brakes isn't good ) Hard torque reversals can loosen bolts and cause all sorts of bad things.

Trust me, the 617 oil pan is NOT "thin". I was amazed at how stout that sucker is! I think the idea was to quiet the engine with a heavy gage pan though I am, of course, guessing. It IS sheet steel but probably in the neighborhood of 1/16 thick (more or less 16 gage).

Still, you do have to be careful when welding but I MIGged mine w/o issue then brazed it to try to assure total seal. Wish I was a better welder! I just started on the angle iron (that was the Volvo pan, actually) then pulled the bead over to the pan metal and it worked well. So anyhow, I'd do whatever works for you.

Dan

Yeah I was surprised too but that's why I haven't been to worried about it seeing as the crank flange can easily withstand tightening the bolts a bit more. If you find a different spec please let me know.

Thanks for the tip about the oil pan, I might work on that this weekend.

The flywheel was designed to be held on with TTY bolts which maintain the same clamping pressure regardless (mostly) of temperature and so they are much less likely to back out. The problem with them is that the stock bolts only have a 1/2" of thread before they neck down and so if I cut them they will fail. Also, TTY are specifically designed for the application and so are hard to purchase. I decided to go with grade 10.9 bolts for both the crankshaft and the flywheel and will tighten them extra to try and reduce the likely hood of them coming out. The crankshaft is hardened steel tapped for M10x1.0 bolts and so are unlikely to strip. Alot of adapter's don't even use all 12 bolts so I should be fine A-MB204 Adapter Kit

If you contact ARP with the bolt size you need they can hook you up with better than aircraft grade. Their stuff is TOUGH!!!

I'm no fan of "torque to fail" bolts. The concept is great but the reality is that in service many application using them have had the bolts loosen over time. One example is the 3.8L Ford V6. Replace the factory-style bolts with ARPs and the heads stay tight from then on. Same with SBFs. My guess is that the TTY bolts only have X number of cycles in them until they start to grow slightly in length and subsequently loosen (I repeat, that's a guess). So I think you're better off with what you're planning to do.

I reused the factory TTY bolts and simply torqued them to the standard torque for bolts of that size and screw pitch (I don't remember that torque value but there are online tables with that info for both metric and English bolts), adding red Loctite. No issues yet and this is an engine that routinely sees 5300 RPM. My justification is that there are so many bolts on that flywheel that none of them are doing much work (12, IIRC).

Dan

Trust me, 1/16" is thin when you are trying to weld it to 1/4" angle iron.



I MIG oil pans let it cool then spray the seam with brake clean / carb clean to check for leaks. For oil / fuel tanks, pressurizing with 5 PSI + bubbles does a good job. Any leaks I get are where the weld has stopped, started. When using equal thickness material, first time leaks are minimal. When using wildly differing thicknesses, leaks will be assured. If you are going to braze, tack with MIG ( or pop rivet ) and just go ahead the braze the entire seam.

In order to achieve a leak free weld, the base material must be melted not just hot metal pulled over top. This can be made to "work" with brazing but it is extra time / work.

TTY bolts were invented to take thread friction out of the installed clamping force to torque calculation giving us more constant results.

These bolts are preloaded to a minimal torque ( where thread friction plays a minimal role ) then tightened a certain rotation to achieve full clamping force. TTY install procedures stretch the bolt to plastic deformation, leaving you with a bolt that is as tight as it is ever going to get.

In order for the bolts to become loose in your examples I'd tend to think the head gasket is crushing out.

I never recorded TTY final install torque so I can't say if this is over / under tightening. Many manufacturers had said that one reuse is OK but you can't be sure if this had already been done so some say just to change them every time. When reusing TTY bolts I preload to spec torque, go through the first rotation, then torque until I feel the torque level off and call it done. From installing new TTY bolts this is only slightly less rotation than the final spec. ( and remember, once the bolt yields this is as tight as it is ever going to get so further rotation does nothing. )

I don't think I described my weld technique very well. And of course I don't use 1/4" angle iron! Just the thinner stuff, no more than 1/8. But what I was trying to get across is that you start the bead on the thicker stuff and flip your bead up and into the thinner stuff which is a standard technique for welding different thickness metals together. There are online tutorials on this though I got the technique at a seminar put on at a local welding shop in MI. You're right, of course, that done improperly you just sort of splash weld metal up on the thinner material which is NOT the way to do this.

The only way to know if the TTY bolts are doing what I think they're doing would be to have a before and after exact bolt length. There is, of course, a much better way to assess bolt tightness (assuming that they're thru bolts like rod bolts) by measuring actual installed bolt length. There are measurement systems made to read this with great precision. But as a practical matter, really tough bolts installed with the correct torque and given a Loctite insurance policy have kept race engines together for decades and I've never experienced a failure - and I stress them significantly. One of the engineers I worked with (and he was a PE, BTW) said that a difference isn't a difference unless it makes a difference.

Dan