Thanks!
The car tractor thing is interesting. There are many ingenious ways people use to get the low range gear needed, from hydraulic motors to machining new gears, using hub reduction gears to dual gearboxes. Just recently the low(ish) prices on early Porsche Cayennes mean there are a couple of 15 year olds running around in 20 mph Porsche SUV's :-)
Can't blame them though :-)
Gustaf
therealpinto said:Just recently the low(ish) prices on early Porsche Cayennes mean there are a couple of 15 year olds running around in 20 mph Porsche SUV's :-)
Can't blame them though :-)
Gustaf
I mean, it’s in their DNA, right?
via BAT
Note: Pictures of said Cayenne tractors are now requisite.
Yeah, the DNA thing is right.
They are quite stealth, since no body modifications are needed. Just the tractor triangle reflector, and the "box" that seals off the interior to make it a 2-seater.
If you compare it to what some kids run...well...
Gustaf
Gustaf
Yeah, the issue about time...
Summer has been hectic, who was I trying to fool we'd have lots of time to work on the car?
We have managed to prep and pain the new tow bar, done some more bodywork and I have also ordered some parts - speed limiter, something for the suspension and some conversion parts for the transfer gearbox.
Getting the transfer box connected to the rear axle was given some thought. I wanted the transfer box as far rearward as possible, so no real room for a propshaft between them. A rubber guibo seemed like a good option, and since many Volvo A-tractors use similar stuff to connect dual gearboxes there were off the shelt adaptors for Volvo propshaft to 90 mm pcd guibo. The Land Rover transfer box does indeed have a Volvo prop pcd on the output shaft, and the Sierra diff flange actually has 75% of a Volvo prop shaft pcd alongside the Ford pcd.
What I did not check, was what size Volvo prop the adaptors were. Volvo of course has three sizes - small, medium, and large. The adaptor turned out to be the small, I had the medium size of everything.
I could draw a new adaptor and have my water cutting friend make me some... Maybe I should have, but I need his services later. So we decided to redrill the flanges for the small pcd.
Almost 100% centered but at 20 mph I doubt it will be a big issue.
Guibo fitted to diff. And yeah, space for tightening the of the bolts is tight...but it works.
With that done, I could start mocking up the entire kit with a spare rear axle beam (needs to be swapped anyway since the 4.27 diff is the larger 7,5").
Lenghtwise it works out pretty good I think. But we're gonna need to raise the floor quite a bit, the transfer box is fat.
Last night me and Kajsa set to work on building the mounts. The idea is to have mounts that tie the transfer box to the rear axle beam, making it possible to lift it all up as a kit. The transfer box will probably need a front mount to the body but if we can get it to attach securely enough to be raised and lowered as a unit I think it will be nice.
She is also working away with getting the license. The process is a bit...peculiar perhaps. The license itself is for a scooter (limited to 28 mph), so all education and training is done on a scooter . It starts with two half days of theoretical training, and then it's a practical session in a closed off area. When that is done, there is a city driving test. If you pass that, you can go ahead and take the formal theoretical test.
But you are not allowed any private driving training, there is no learners permit or something like that. We were lucky that a friend was moving house, and they had a scooter that needs a home for a while. So we have it on loan, and have made some very informal practising on a closed off lot. She passed the first driving lesson but the city driving is next week... Let's see how it goes.
However, the car is not ready by September 8th anyway...
Gustaf
Progress is not all that fast, but we have been working some hours.
Status as of yesterday night is that the transfer box is attached to the rear beam, and I have tested supporting the beam on its mounts only. The transfer box still hangs on! I call that a success.
I dug out an old 4.09 diff, since I need the stub shafts from that one to match the drive shafts in the car (the 4.27 one has the larger 108 mm CV joints, since it came from the rear axle that donated the outer stub shafts to the Capri). The shafts I need are now out but I have yet to install them into the 4.27 diff.
During the weekend I also tested the limiter (speed and rpm). At least 50% tested it.
The working theory behind it is this;
- In "normal" use, it senses road speed (from an inductive sensor usually), and when a set speed is reached, it limits rpm (by cutting power to the ignition coil, or fuel supply on a diesel, or something else)
- As a backup, it also has a rpm limiter active when there is no speed sensor input - it is set at the rpm that gives you 30 km/h + 10% in the highest gear ratio. This is to make sure kids just don't bypass the limiter by removing the speed sensor
The rpm signal should come from something that still gives a signal if power to the ignition coil is cut. Many people use a W-connection on the alternator, basically an rpm signal. If the alternator doesn't have one, you can add it. I didn't feel like opening up the alternator, so instead I looked at tapping into the signal wire from the ECU to the ignition module. It's right next to the coil, convenient. It worked great.
As for the speed sensor I am undecided. I have a bespoke inductive sensor, and the standard solution is to aim it at a diff flange or something like that. The output shaft for the front wheels on the transfer box would be an easy solution, and I have a nice 36 tooth trigger wheel to use. The limiter can take 2500 Hz and my calculations are that I would max out at around 760 Hz with this solution. More trigger points (people usually have something like 4) should in theory (?) give a more progressive limit.
However. Using the driven wheels, means it will also act as a traction control device. Not sure if that is good, or really, really bad? :-D
There are solutions for using a front ABS sensor instead, at about 80 USD. Going straight from the ABS sensor may work. But I'm not sure. I just realised that maybe I should investigate if the ABS ECU itself outputs a signal somewhere? That would be cool.
Anyway, current plan of attack is to try to get the Godzilla like transmission thing mounted, so we can build a propshaft and test drive with no limiter first. Just to make sure the mechanics work.
Gustaf
OK, so September was mostly the month when all things happened, apart from making real progress on my part. Too much travel with work and of course finishing off the racecar season.
At least Kajsa got her license and that should be a motivator...unfortunately it does not give me the 30 hour days I would need!
I swapped the stub shafts over only to discover I have mixed up the diffs (something that can happen when you have 4 of them around). What I thought was the 4.27 diff was actually a 3.64, so I had to swap the stub shafts back and drill a new flange for the adapter. Hours, hours...
But we linger on. The old rear axle was dropped to the floor after a furious session when Kajsa did great work on wrenching while I lay under the car beating different parts.
In parallell, we have also been on the lookout for winter tyres. We need (want) to keep the same rolling radius as the big 225/45-17 summer wheels, so stock Sierra wheels were out of the question. Kajsa was also very set on using something with a motorsport appearance and after a few missed chances I picked up a set of Peugeot 16" wheels.
Not the best I have seen but at 20 mph they should be fine. A lick of white paint and I think you all can see some rally wheels if you squint a bit!
Yesterday we fired up the metal saw to make space for the transfer box.
We will need to cut into the beam under the rear seat, so that needs to be strenghtened afterwards. Yes, the hole is bigger than necessary...as Kajsa pointed out. But when I put the rear suspension into the Capri, I would cut small pieces at a time and I just ended up with a mess. A large hole is no harder to weld shut than a small hole :-)
Some more hours and I hope we can look at making a propshaft work.
Gustaf
The last weeks have been a bit frantic (again). But there is result.
The floor and beam is cut even more, of course we also had to open up the tunnel and floor to the left since the transfer box input shaft if very much offset, as you can see in the pictures in the last post.
I then had to cobble together a propshaft. The transfer box input flange is a Volvo bolt pattern, and by chance I had a rather long piece of Volvo propshaft laying around. God knows where it comes from - I have never owned a Volvo, and for sure never changed a propshaft on one. But the offset meant that I needed to move the support bearing forward, and shorten the first part of the prop.
Last summer I got a gearbox from a friend, to possibly use in a Capri. The gearbox is from a Scorpio 2.3, so it's a version of the MT-75 that is in the Sierra. Lo and behold, it had a short front prop section! A little bit on the short side but there is a form of a slide joint there with quite some reach. It worked beautifully. As an added bonus, the end of the Volvo prop had just the right diameter to be pressed into a piece of Ford propshaft tubing. Success!
Then a spring snapped on the daily driver Kuga (wife not too impressed). Garage full, snow outside. So I needed to make the Sierra "moveable" again - and it sort of coincided with the point where it would be nice to actually test the drive train a bit.
Some quick wrenching and the Sierra could move out of the garage, under its own power, driving the rear wheels through the transfer box and new diff. With wooden blocks instead of rear springs, only front brakes and ice on the road, there was no test drive other than reversing out onto the drive - and going back into the garage. But it works!
A decent milestone before I leave for SEMA tomorrow morning...
Gustaf
Read through this thread this morning, and I have to say I love it! What a great project with your daughter, and such a neat loophole to let them drive younger. I have to say it was nice to live in a (US) state where the driving age was low, I started driving at age 15. Took my driving test the weekend after my birthday, and haven't looked back.
My current project is the US version of the Ford Sierra (Merkur XR4Ti, same body as the V6 XR4i) so it's neat see the similarities! I hope it all comes together for you all.
Re: Snow tires, nice set of what looks to be studded Nokian Hakkapeliitta's!
Thanks for reading :-)
We (me and my daughter) were speaking about XR4i's the other day, since it came up in a Swedish Facebook group. She googled them and fell for the early XR4i quirky body. She's turning into a real 80's fan and I would not be surprised if she tries to get an XR4i as her first enthusiast car. I would love to bring an XR4Ti into Sweden though.
Winter wheels actually turned out to have 3 different models of studded tires. Not ideal but at tractor speed it will be OK.
The wheels are being painted white and will have a nice WRC feel I think.
Setback from yesterday; I can't find the extra, rebuilt, rear calipers I was sure I had on the shelf. I might have sold them and forgotten about it...or they are "somewhere"... Too bad since Kajsa planned to paint them while I am in the US.
Gustaf
Im late to the party here, but could the 60% rear weight bias be accomplished by simply welding steel plates into the trunk? Or partially filling the spare tire well with concrete?
Seems that if meeting the weight distribution target eliminates the need for the pickup bed, that would make the project significantly simpler? If I'm understanding this loophole correctly, you'd just need to create some sort of "box" to render the rear seats useless. Or is the roof re-design a part of the learning experience at this point?
Yes, some people work with concrete filled spare wheel wells and similar. But you also need to be a bit careful about not exceeding the maximum permissible axle load for the rear axle. That's why working with the weight already in the car (battery...) is sometimes useful.
Regarding the roof re-design, you are 100% correct - the idea is to eliminate that need with just getting enough rear weight bias. Then we just need to block off the rear seat and the boot (no cargo space).
While it would have been a nice training experience in bodywork to cut and move the roof, it's something I'd rather avoid at this point. That would easily add a couple of months and also means a full paint job is needed right away. Now I'm sort of hoping to be able to get it on the road with just filling in some missing paint.
Gustaf
Back from the SEMA adventure (well, I have been back for a week now) and we should get things moving here. Key word "should" :-)
While I was away, Kajsa painted some brake calipers, because red brake calipers are important. She was allowed to take a set of calipers I had removed from my Capri earlier on. The ones on the car really looks like something on a free, 27 year old car...
While she was working on that, and giving the winter wheels some more white paint:
...I had started to fill the holes I had created in the floor.
First part "done". For the big section above the transfer box I will re-shape the part I cut off, and use that with some filler panels on the sides. Will work fine!
But before I did that I wanted a solution for the sensor for the speed limiter. I think I mentioned earlier that I was undecided if it should be on the driven wheels, or the non-driven front wheels. Kajsa was very determined that the sensor should be on the front wheels to allow for snow drifting. We rigged the sensor to read the backside of the wheel studs in the front hub, and it worked way better that I hoped for.
Until...I woke up in the middle of the night with that feeling - you know, the feeling that you have forgotten something. The brake calipers she painted...weren't they from my 280 mm brake kit for the Capri? And if they were...how would they fit the smaller Sierra discs? All calipers look similar but the brackets and radial distances differ.
Trial fit, and sure, that would not work. Paint and rebuild the small calipers?
Nah, of course she needs a big brake kit :-D
But the 280 mm discs presented another issue. Due to the shape of the disc, the sensor would no longer sense the wheel studs. Instead we decided on fitting M6 screws to the discs, further out. Not ideal, having "wear items" modified but I have a feeling 280 mm discs will last very long at 20 mph.
Sensor fitted to front hub, and I can plate the rear floor closed.
Gustaf
Rear floor plating is coming along, I reshaped the cut out piece of floor and with some extra pieces it went back in. Not "factory fit" but well...it will work.
I really want to be able to get out on a test drive to check that my gear ratio calculations seem correct, and spot any issues with the drive train. Right now there are some things that stop me from doing that.
- No rear springs
- No caliper fitted to the right front wheel (with the 280 mm disc)
- Exhaust ends by the gearbox (not necessarily a big issue)
- No rear brakes (that's OK, front brakes are sufficient)
- Weather, the snow is turning to slush...
The last point is beyond my control but the others I can work with.
Rear springs is interesting, I have had the airride kit on the shelf since spring (ahaha...) but now is the time to see how it will work. It's officially for a MkI Ford Focus, but people have used Focus MkI coilover kits on Sierras so I figure air will work too.
The rear springs on the Sierra originally sit over a large cone shaped thing, that also holds the bump stop. This needs to go away in order to fit the air spring. The cone is just spot welded to the chassis rail so it was rather easy to remove it.
Then, as luck (?) would have it, I feel the Focus air spring is pretty much the right length.
Looks good, so that can be used for a test drive. The exhaust middle muffler will have to go, it fouls the transfer box. But replacing it with a piece of straight(ish) tube should work fine. So just fix that and fit a front caliper and we can test drive.
Now...the slush...hmm...
Gustaf
Well...the quest for the test drive is meeting some obstacles.
The front brakes would not bleed at all. Left front would give no air or fluid at all, right front some gulps but no brake pressure at all.
Teves MkII ABS is supposed to be bled as a normal system up front, and the rears with just the electric pump in the ABS system. I did get the rear circuit to pressurise but with no rear calipers mounted, braking power is sub optimal.
If you've read from the start, you know the car had braking and ABS issues from the start. Swapping out the pump motor was a step in the right direction but we still had warning lights and the brakes never felt right.
Decision time here. Do we continue to put hours into the ABS system, a quest substantially complicated due to the lack of replacement parts? Or do we take the other way out, ABS delete and a normal, vacuum booster?
We agreed that the easy way out would be to fit the non-ABS parts I have laying around. So we ripped out the complex ABS master cylinder and hydraulic booster. Luckily, the vacuum booster is a straight replacement. Rebuild kits for the master cylinder are cheap if they are needed. So we just have to whip out some new brake lines, fit the proportioning valve, and THEN we might bleed the brakes and get to the test drive.
Then we need to remove the ABS warning light a but that seems like a walk in the park.
At least Kajsa got rid of the muffler that was in the way, and welded in a straight pipe in the exhaust instead. Some welds look really good at this point, actually. Progress there!
Gustaf
In reply to therealpinto :
in US, ABS warning light is only ON when the ABS module commands it to be ON. unless ECE 13 requires some other behavior, i believe that if you remove the ABS module from the car, the ABS warning light will never come ON.
Yes, that is probably right, will test that.
On the Sierra, there is also the standard brake warning light (parking brake, low fluid level but also, somehow, connected to the ABS). We'll see if that one stays on. Might just be a case of bridging the right connector at the brake reservoir cap. The ABS system has two separate connections to the fluid leven sensor, where non ABS cars only have one.
Gustaf
Re ABS,
I know you're planning on deleting it but if you want to persevere (or have other Sierra's with ABS still active) I scanned the Ford Diagnostic Manual some time ago and as far as I can tell the download link from MediaFire is still active:
http://www.mediafire.com/?yjhcjd6qwzy Sierra ABS manual
http://www.mediafire.com/?sharekey=bce44deff37f4a0ed2db6fb9a8902bda Sierra Trans Manual
http://www.mediafire.com/?sharekey=bce44deff37f4a0ed2db6fb9a8902bda Sierra 29R Engine Management 2,0 DOHC with CAT
http://www.mediafire.com/file/jlvryjznjbz Sierra 29H 2,9 EECIV.pdf
http://www.mediafire.com/view/?sdri4quqjb6zd63 System Test Manual 33C Auxiliary Warning System
I have included links to all the stuff I have uploaded on the off chance some of it may be useful to you or others
Best Regards
Richard
Thanks!
I'm still interested to learn more about the ABS system so that manual will come in handy. I didn't all the Mediafire links to work but the things I got (the 2.9 manual for example) will be useful.
I had trouble sleeping a couple of nights ago, and while counting cars or something to fall asleep, I got a nagging feeling that my weight distribution calculation might be off. As I re-checked the Excel sheet I spot a probable mistake...
So, I need to get the car down on the scales again to check. We might need a kind of load bed in the rear after all. Since I still hesitate on cutting the roof like the first sketches show, I will investage the possibility of removing the rear window and make a kind of inset box.
Something along these lines.
Gustaf
So, last night I slapped on the winter wheels, and put the car on the scales again.
I added stuff to the rear to simulate the air suspension stuff, tow bar and a rear battery. 51 % rear bias. Continued to add random junk to act as a body double for bass box and got to 52%.
The fuel gauge reads empty, so I may have another 40 kg or so in fuel to add, and there is driver weight (75 kg) too. But even if I add all that to the rear my improved (corrected) excel sheet says I am 130 kg short of reaching 60%.
While adding that would be possible I have to keep the axle weights in mind. That would put me at 940 kg rear, that's 40 kg over the standard max for this body. The estate was allowed 1060 kg and if I can use that, it would be OK...ish.
Lightening the front end would help but apart from a plastic bonnet there's not much to do. I can get a bonnet shell from Czech republic for around € 100 or a more complete one from a village more nearby for € 350 - that's kind of a lot. But if I could save 20 kg in the front that would reduce the rear axle weight necessary by 40 kg... hmm...
But at least I got to try the rear suspension, with air!
Up...
...and down!
The photos doesn't do it justice, it is kind of low when it is low...and at the 8 bar my compressor will deliver, it's quite normal in height.
The winter wheels could do with some spacers though. Or, we'll just call it the WRC style.
Gustaf
We sort of had a target set, test drive before Christmas holidays 2019. Always a milestone...
I got the brakes bled and also decided to put the rear brakes back - but modified all brake line fittings so the rear axle can be removed without opening the brake system again. The exhaust was temporarily re-fitted, and then I wired up the speed limiter, also temporarily, so we could check that it would read pulses at speed and also set the speed limit.
When permanently fitted, the speed limiter itself and the parts it control (ignition module and coil in our case) needs to be sealed in a tamper proof box - otherwise the kids of course can just reset the speed limit... But for testing and dialling in, it needs to be accessible from inside the car.
At first startup it ran kind of rough, until I realized that I removed the MAP-sensor hose when fitting the brake booster. With that sorted, it settled into the same blue-smoking but nice running it used to have.
So last night was the night set out for the test. Nice dry-ish weather (ice and snow but no slush on the roads). The local hockey team playing a home game (=minuscule risk of police trolling the streets - not that I am too worried about that). We drove away from our block and immediately it was clear that the front flange of the transfer box (the unused output for front wheels) was grinding on the transmission tunnel. I knew it was close...
On our designated test road we first checked what gear would be suitable for the 30 km/h limit. As my calculations suggested, 3rd gear was fine and we set the limiter at 31 km/h or so. Then we checked that low gear and 1st would meet the criteria ox maximum 10 km/h at 2/3rds of max rpm, 4033. We had something like 4300 rpm at 10 km/h so that worked out as well.
Next up, checking what gears needs to be blocked off. Both 4th and 5th as expected based on the calculations. Leaving 4th intact would mean a stationary rev limit at just 1300 rpm and that's too low.
The one thing I forgot to check, I realize now, is how the revs would be in 5th and low gear at 30 km/h. Blocking off high gear would be easier that blocking 4th and 5th but I think that would mean cruising at 3000 rpm and that's a bit high I think.
Anyway, we celebrated by doing some proper rwd donuts in the snow :-) Win!
So we deem this a success. There are some vibrations over 30 km/h but that's no problem. The grinding will be fixed by either removing the flange (would need a spacer to keep the bearing preload I guess but that's easy) or more work on the tunnel.
We leave Sweden for another couple of weeks in California over Christmas and new years, but then it's back to the garage again. We might start by tearing out the engine first, to determine how much work it needs. As I have stated, it smokes like crazy, and was down on oil pressure. I hope it is a case of valve seals and bearings only but only a partial teardown will give proper answers. Maybe a compression and leak down test before but I think we should open it up anyway.
Merry Christmas!
Gustaf
A nice, rather long holiday passed and now we are back to work and school, respectively.
Engine out was the plan and last weekend we set to work. I decided to drop the engine and gearbox down as a unit, since I still have horrid memories of replacing just the gearbox of my then daily-driver Sierra DOHC/MT-75 way back in 2002. It is really tight and dismantling the gear lever to get the gearbox down is tough. BTW, that was the first job I did in this garage, just after we bought the house...
My measurements said the lift height of the Quickjacks should be sufficient but of course I missed by an inch or so. Some careful re-jigging with extra lift blocks made it work but I really should fork out for the SUV extensions or build something similar.
But in the end there was success and the greasy messes ended up on the floor, and on the engine stand.
The engine is incredibly gross, I can't remember the last one I worked on that was so covered in oil. While it seems to be coming from the valve cover (since it is wet from the head down) the gasket looks pretty OK. But as you can see from the exhaust ports it's also quite clear that oil is getting in there too.
Dissection so far has removed the camshafts and revealed a slightly broken guide chain for the cam chain. Otherwise it looks OK, it's suprisingly fresh with no cam or bucket wear. Maybe the oil leaks have worked as a form of automated oil change...
The plan was to make a leak down test with engine in car but the spark plugs are hidden between the intake runners and injectors and I just gave up. We tried a quick test with the engine on the stand, cams removed to shut all valves. But we only had cylinder 1 at a true TDC - and it showed a 5% leak, almost too good to be true. The next cylinders were around 35-40% but they also had evidence of air leaking past the exhaust valves.
We need to remove the cam chain entirely to be able to test all cylinders at TDC. The oil pan needs to come off anyway (someone dropped a nut...) and that means we are really close to just popping the pistons out anyway. As Kajsa said yesterday - better to do it now with the engine out, than find out when it's back in the car...
This exercise has reminded me of why I don't like working on these engines. Everything is just cumbersome and backwards compared to a Pinto. I rebuilt one of those in my sleep :-)
Gustaf
are you planning to make this a "normal" car after she gets a regular license or will it be replaced?
We're trying to build so it can be converted back. But the second hand prices of these converted cars are pretty high, it's actually one of the few builds you actually, in some cases, can make money on. With a bit of luck, and some timing, selling it may give a nice starting point for a car. So that is the probable route.
The most popular ones (like Volvo 740/940's, Mercedes) are often in the $5000-7500 range - 10 times the value of the basic car it was built from. The market for a Sierra is smaller so the value of this one is more of a gamble. But the car was free :-)
Gustaf
So, a month (!) later the engine and gearbox is back in the car.
The leak-down showed some pretty big leaks in the other cylinders. With the head off, it was clear that all exhaust valve guides were really worn and all of them had also slid down into the exhaust ports (meaning of course that the valve stem seals also slide off).
The bearings were fine though so we decided that it would be a case of new valve guides, new piston rings and then just re-assemble.
But I also discovered the true reason for the low oil pressure situation we had when we got the car:
That's the screw for the pressure releif valve, halfway out... Nice that the engine block stopped it from falling out completely!
Getting the valve guides out, and new ones in, was a bit scary but I think we did OK. Kajsa got to learn how to lap the valves, get the cotters and retainers in place and also check the piston ring gaps. A good learning step.
In parallell, as she was doing those things, I attacked the gearbox. To make the speed limit thing not to easily reversible (or "trickeable") it is adviseable to lock out some high gears. In our case 5th for sure and 4th just to be safe. With the "Getrag style" MT-75 gearbox, a case that splits in two, it's not very easy to lock out gears by adding sleeves to the shafts.
I decided to work on the shifter gate, it's inside the rear casing so you only need to pull that off.
One issue is that the slot for 4th is the one that is at "6 o'clock" and also where the shifter slides in during assembly. So it can't really be blocked...
5th got welded up, and I made a pin that blocks 4th from the outside. It took a couple (or several couple) of tries to get it all working but in the end, it does work. The pin is welded to the screws holding the shifter gate on the outside, so it can't easily be removed.
I also tightened up the shift linkage itself, by eliminating some rubber bushes that always are really worn. Now this is the best shifting MT-75 I have ever had :-)
The head went on...
...and then I rememberd the sheared off exhaust stud. Better get to that before it's all back in the car...
Success, the weld-nut welding trick worked on the second attempt. The stud was at least 5 mm below the block surface but I got to it. Nice.
Now the whole shebang is back in the car, we just have to find all the wire loom connections and stuff. We're getting closer!
Gustaf
In reply to therealpinto :
Very cool and unusual (to us in the USA) project. Thanks for sharing!
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