11BL with ID block

citroenthusiast

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Fellow Frogger
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Took the engine/transaxle out of my recently-acquired 1954 11BL. When I split the transmission from the block, I saw this.

190317 11B flyweel.jpg

The clutch and pressure plate appear to be ID/DS, but the flywheel is nothing like anything I have seen. Any speculation why the flywheel was so extensively modified? The back of the flywheel has about 25mm of clearance with the face of the block.

Will an ID/DS flywheel fit inside the 11BL clutch housing without modification or is that the reason for the conical taper at the end facing the transmission?
 
Probably a lathe spun flywheel to reduce inertia and improve accelerator response. I would stick with that arrangement as long as you do not get snatch in the drive line. Pre Perfo engine flywheels were about 25 lb and were quite thin. A noted Aussie/New Zealander campaigner of a heavily modified Traction racing car also lightened the flywheel of that car.
 
Thanks for that information. I was thinking I would replace the flywheel because I wanted to make the clutch as forgiving as possible. I have a couple of spare 1911cc DS/ID flywheels. I have no idea if I would get any driveline or other problems because the car was inop when I got it. Also there is a hole about 5mm diameter through the friction surface of this flywheel. Not sure if it is a casting flaw that was revealed when the flywheel was lightened or what. The hole almost looks intentional..

190317 flywheel.jpg
 
Yes I am inclined to agree. The hole is a puzzle. Maybe to clear dust from the wearing of the friction plate?
Maybe the modifier went too far. All that is necessary to convert the ID flywheel is to either fit a different spigot bearing or make a circular shim to use a TA original spigot bearing. Either way the ID spigot bearing has too small an inner diameter to fit a TA mainshaft spigot.
The ID flywheel needs to be turned to the profile of the RA pressure plate rim at the front as has been done on the flywheel you have at the moment.
I ran a 25lb flywheel with the earlier much lighter pressure plate on a perfo engine many years ago and encountered the drive line snatch I mentioned before. Changing to the later, heavier pressure plate improved the situation dramatically. On the same engine I am now running an original unmodified flywheel and pressure plate. Sometimes I think that it is best not to modify the cars from original however fitting on ID or DS block at least gives you more modern bearing shells on mains and big ends, stronger connecting rods and a more effective main oil seal arrangement.
If using an ID block the give away is the plate that needs to be fitted to close over the low pressure pump mounting position in front of the fuel pump. A DS block can be made to look almost identical especially if you fit a TA aluminium engine number plate in the original TA position and remove the one from the left side of the DS block. That would depend on how fussy you want to be about originality!
 
Thanks again for the insight. I actually have a spare DS block, but I will probably stick with the ID block that came out of the car. Apparently, the DS block can only accept a DS camshaft, whereas the ID block will accept either, so as I sort through my cores for regrind I have more camshaft options. Plus, it was actually nice to know what block was in the car. Had the prior owner done too good a job at disguising it, I would have potentially inventoried some incorrect parts.

Your observation about the spigot bearing is also spot on. The spigot bearing that is currently in the flywheel is a 6203 with a circular shim to hold it in place.
 
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Well, what do you know. I found a special motorcycle bearing type 6203a which is 17 x 42 x 12mm, so it will fit the bore of the ID flywheel and has a bore that will accept the T/A input shaft...
 
Well, what do you know. I found a special motorcycle bearing type 6203a which is 17 x 42 x 12mm, so it will fit the bore of the ID flywheel and has a bore that will accept the T/A input shaft...
Well done! Good luck with the rest of the job!
BTW I had a good friend ( sadly passed on now) who fitted a DS crank and flywheel to a Perfo block just to get a stronger bottom end, modern bearing shells and a better oil seal. A lot of work machining the block for the end thrusts and slipper type shells! I drove that car and was very impressed with its smoothness. He was a gifted engineer you might remember some of his posts to this forum as 'lhs2.1'
 
I was preparing to put the engine/transaxle assembly back into the frame, then I noticed this....

IMG_6139.jpg



The engine was upside-down on the engine stand when I assembled it, otherwise I would have noticed it months ago. Bummer. I will have to take the timing cover off again to see if it the crack penetrates all the way so as to cause a potential oil leak or if it is only on the outside so could possibly be repaired with JB Weld....
 
Wow, what has caused that?
I see the obvious marks from some sort of impact, but the crack?
It looks almost that the bolt was tightened when there was something stuck in the joint, at one side.
But then it would tend to close up, when that foreign object was removed allowing it to sit flat again?
Very strange!
Was the impact first, then the crack?
Was the crack first, then the impact?
Maybe we'll never know.
 
Only the very early tractions had an aluminium timing case. The later ones were of cast iron. I wonder what would have caused it to crack like that?
It looks as though the camshaft pulley and fixing nut were fouling the inside of the timing case as it was tightened!
 
I am thinking the cork gasket was too soft so when I tightened the screws to what seemed a reasonable torque, I cracked the casting. Not sure why there would be an early timing cover on a 1954 11BL... The divot was there before I painted it, so that was an old injury. The crack does go through to the inside... I think my local source has a cast iron cover, so that is probably the way I will go.
 
The gasket did catch my eye,

Maybe the crack was also there but in a closed state?
Maybe the soft gasket and the tightening sequence opened it again?
If you used a thinner or harder gasket, and tightened that bolt last, maybe it would stay closed, then you could wick in some loctite 290 sealer.
If there was enough inside space, I might be inclined to not fit a gasket, and just seal it with loctite 515 sealant, in both the crack and the mounting face.

515 is my preferred engine assembly sealant.
The list of reasons for its use is extensive, and I'm yet to be disappointed by it..... after at least 30 years of using it.
 
I wonder if the reason Citroen changed from aluminium to cast iron is the early aluminium cases had a tendency to crack. I'm pretty sure I torqued the DS19 aluminium cases to about the same torque (it's in one of the manuals) but never had a problem with cracking. I imagine the metallurgy must have improved... In any event, the replacement cover will go on with a paper gasket..
 
The argument about metallurgy is probably correct. Citroen went from alloy accumulator bodies back to steel in about 69 because of internal stress cracks. Remember the DS housing is just that, a cover. In the Traction it is a stressed member with the engine mount attached.
 
The original gasket is quite thin! Approximately 1.5mm!
I actually have two of those aluminium timing cases covers from earlier tractions. Neither of them are cracked!
 
I was fortunate to be able to source a cast iron timing cover in fairly good shape. I had no problems applying the torque of 16N-m (which is the torque recommended in the ID19 manual) using a paper gasket. The takeaway from this is don't torque to 16N-m on an aluminium cover with a cork gasket.....

IMG_6158.JPG
 
John, what is the pipe leading from the main oil gallery at the rear of the block? Have you been able to install a full flow oil filter?
 
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