DIY 2.0 TC engine step-by-step rebuild with GC

Road-race engines and ancillaries - general discussion
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

No, but someone stripping his engine here will soon be able to tell you,

G
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

I see you have the flywheel off already. That's slightly out of sequence. No matter.

When removing the fw it is good practice to mark the relative position of the fw to crank before removing. it can go in one of two positions. If you don't mark them (eg: with white paint) you've lost the original balanced position. In saying this I assume that the crank-fw pair are balanced together at the factory. That would be good practice but whether mfrs bother I cannot say, except that the crank and fw will certainly have been separately balanced. Of course we will be contemplating fw regrind and maybe lighten and post-balancing will be essential. Nothing about an engine is more dangerous than an out-of-balance crank assembly. If you were not carrying out any mods then marking pre-removal must be considered essential and that is true of all engines (and propshafts too FWIW). I am always nervous about crank-fw balance and always recommend it on rebuilds.

Ordinarily I would take the head off with camboxes on it, two reasons:

1. You can see the position of the valves relative to each other so no risk of valve clash undoing the camboxes. Your method is Ok assuming the belt is in the right place ie: cam timing is right before you start
2. There is a lot of oil in the camboxes and it spills everywhere (buckets tend to fall out too..)

So I would have cut the cambelt (because we always discard it) and undo the head bolts in the same sequence as tightening them up, see att. Then I would set the head (complete) aside - upside down so the valves don't get bent - on a tray to catch all the oil.

So - from where you are:

Remove the head. It's heavy and may require a bit of persuasion at the corners with a pry bar. Take off the old head gasket and take out the two gasket locating dowels and put them in a bag with say, the coolant drain plug.

Unbolt the oil pump and put in on a tray to drain. Take off the distributor on the block - or in this case the blank plug and remove the 'driven gear' (as it is correctly called) with a magnet or a piece of wood tapped into the spline. You may need to rock the aux d/s pulley to free it. Put it with the pump.

Now we are looking at a bare crankcase assembly. Re-attach the flywheel (just spanner-tight) with two bolts. Turn the crankcase over so the big ends are visible. use some Scotchbrite to clean the carbon off the tops of the bores. This will make getting the pistons out much easier. Wipe clean

Turn the crank to tdc 1&4 and using a 15mm 3/8 drive socket and long T bar slacken and remove the big end nuts on rods 2&3 (nearest to you). There is no problem mixing up rod nuts but it is important to examine them and the face of the rod (on which they sit) after removal. On the side of the rods adjacent the crankpin (big end journal) the rods are stamped with numbers 1-4 (by cylinder obviously). Big ends are paired to respective rods and must not be mixed up. The numbers are on the ex side on the original engine. Remove the big end caps. Some bearings will fall out of position, but either way mark them eg: 2 U (upper) and L (lower). Take a look at the bearings and see how much damage there is. When stripping down observation is awfully important. Use a piece of copper pipe slipped over rod bolts to ease each piston assembly out of the bore. Don't use any steel object against the upper rod half - it can easily score it irreparably.

Turn the crank 180 deg and do the other two. The pistons tend to fall out of the bores after the rings have come free - make sure you catch them. Naturally you should turn the cankcase to what I'd call an 'advantegous' position to do this - upside down is asking for trouble. Always position a job in an advantageous position. Put all the rods and pistons together in a box. On no account separate the rods and pistons. That comes later.

With pistons out it's time to remove front pulley, housings and auxiliary driveshaft (aux d/s as I call it..) Often I find it unnecessary to lock the fw when I'm using battery or air-powered nut guns but in case you need to, screw a bellhousing bolt or any available fine thread M12 (fully home, ie: right in) into the end of the block and use a decent sized adjustable spanner as a restraining strap - one end of it bolted right through the fw with an M8 bolt and the other bearing against the bellshousing bolt. The engine rotates clockwise viewed from cank front pulley end so make sure the locking device (so to speak) is fitted the right way round.

The front pulley will have either a bolt or a nut holding it in place and a nut gun as described earlier is by far the best way to remove either. If it's a bolt it has an anticlockwise (reverse) thread and to undo it you have to turn it clockwise. The nut is turned the conventional way to release ie: anticlockwise. If the nut gun won't free it off there is good chance Loctite has been (incorrectly) used on the thread and a long T bar with 1/2" drive will be needed. Before really bearing on the T bar makde sure your holding device is secure - you don't want to rip any threads out. I actually use a main bearing cap bolt with an old gudgeon pin fitted on it to bolt to the end of the block. That way the bolt has some preload in it (stretch) and that makes it a stronger holding device. And watch you don't end up with the engine on the floor - get someone to restrain it if need be. Sure, I could make a special fw holding tool, but I'm British, if I don't have to stop and do that - I never will. All engine builders have different little tricks for holding fw..

The front pulley is keyed onto the crank and should come off easily enough. If it needs a bit of persuasion tap it with your dead-blow mallet. Behind it is the cambelt drive pulley and they can often be tight. You need to lever it gently with a small pry-bar like the one shown below if it's tight, first on one side then the other. Of course I have pullers too, but I have never had to use one for this.

Take off the fw now because we need to get to the crank rear seal housing. Photos below (I trust) adequately cover removal of aux d/s pulley and crank front and rear housings. Go as far as removing the aux d/s as shown.

Leave the crank in and the tensioner in place for now. Ideally - provided I am not too slow for you - I want you to strip according to my instructions.


I have no idea of your budget on this, my job is to tell you how to strip and we'll keep most of the unit until the decision about rebuild is made. But - you won't be able to save many gaskets and all the seals should be junked as a matter of routine. I junk the lot - but then I have huge stocks of them all - and suggest you do the same.


Tip!

Don't waste too much time now trying to 'inspect' - or measure - things that are covered in oil/carbon. Cleaning comes after everything is stripped and inspection follows that. Learn what you can as you strip - look for signs of unusual damage or things out of place - but otherwise just got on with the strip.



I want to see photos of one of your pistons & rods and all the big-end bearings. The latter esp so that I can comment on wear patterns.


GC

Note: Photos displayed: I have not taken them specially and the order in which they appear may be out of sequence or show ops that are out of place according to the article. But I hope they will paint an adequate picture nonetheless.
Attachments
Gasket & Bolts.doc
This GC 'How To' has details of bolt removal sequence.
(29 KiB) Downloaded 459 times
Always take the breather clips off with care and try and save the hose. Not easy to replace.
Always take the breather clips off with care and try and save the hose. Not easy to replace.
breather being eased off with dead-blow mallet.jpg (108.26 KiB) Viewed 12465 times
Using a nut gun on head bolts. No reason why not...jpg
Using a nut gun on head bolts. No reason why not...jpg (115.58 KiB) Viewed 12467 times
Block with head removed showing gasket dowels.jpg
Block with head removed showing gasket dowels.jpg (75.03 KiB) Viewed 12469 times
The 130TC has a gasket under the pump, some models eg: this Volumex - have an O ring. It is so important to observe and record what you see when you strip - there may not be a manual to help you on reassembly..
The 130TC has a gasket under the pump, some models eg: this Volumex - have an O ring. It is so important to observe and record what you see when you strip - there may not be a manual to help you on reassembly..
Undoing the M8 bolts that hold the oil pump.jpg (116 KiB) Viewed 12463 times
I just use a regular piece of plumbing pipe with a cloth over the end to stop it cutting into my hand. A tap here or there with the mallet soon gets stubborn pistons moveing but watch you don't 'shoot' them across your workshop because you'll break a ring for sure. That will not matter if you are junking them of course..
I just use a regular piece of plumbing pipe with a cloth over the end to stop it cutting into my hand. A tap here or there with the mallet soon gets stubborn pistons moveing but watch you don't 'shoot' them across your workshop because you'll break a ring for sure. That will not matter if you are junking them of course..
Copper tube to remove pistons.jpg (109.87 KiB) Viewed 12462 times
For really stubborn fixings I use a very powerful air tool by Puma. It has a lower striking frequency than the Snap-On battery tool and delivers a heftier thump..
For really stubborn fixings I use a very powerful air tool by Puma. It has a lower striking frequency than the Snap-On battery tool and delivers a heftier thump..
reverse thread crank front pulley bolt and vital thick washer.jpg (111.98 KiB) Viewed 12463 times
Just showing the pry bar - I don't have photos of every single op, for obvious reasons..
Just showing the pry bar - I don't have photos of every single op, for obvious reasons..
using a small pry bar to get water pump pulley off.jpg (109.32 KiB) Viewed 12458 times
cambelt drive pulley.jpg
cambelt drive pulley.jpg (120.43 KiB) Viewed 12456 times
This drives the oil pump off the aux d/s
This drives the oil pump off the aux d/s
Driven gear.jpg (112.57 KiB) Viewed 12453 times
We'll talk about your bearings when we see them. The type of wear and damage from use is 'many and varied'.
We'll talk about your bearings when we see them. The type of wear and damage from use is 'many and varied'.
Big-end caps and bearings.jpg (115.06 KiB) Viewed 12455 times
Long T bar to loosen big end bolts. I would not use a nut gun unless junking the rods. I'm superstitious about nut guns...jpg
Long T bar to loosen big end bolts. I would not use a nut gun unless junking the rods. I'm superstitious about nut guns...jpg (117.61 KiB) Viewed 12453 times
These plugs have a gasket underneath.
These plugs have a gasket underneath.
Blank plug nut coming off. A bit of leverage with a screwdriver and a tap with the mallet will free the plug..jpg (90.81 KiB) Viewed 12450 times
This photo taken with the belt still on. However, with a nut gun you can virtually hold the pulley with a gloved hand to get the M12 bolt out. If you have to lock it because you can't hold it, brace against the teeth with a piece of wood. i stressed earlier that you need a nut gun - if you haven't got on you will find this job a real struggle. I have special locking tools from Fiat - but you won't.
This photo taken with the belt still on. However, with a nut gun you can virtually hold the pulley with a gloved hand to get the M12 bolt out. If you have to lock it because you can't hold it, brace against the teeth with a piece of wood. i stressed earlier that you need a nut gun - if you haven't got on you will find this job a real struggle. I have special locking tools from Fiat - but you won't.
Aux driveshaft pulley removal.jpg (113.57 KiB) Viewed 12444 times
Remove all the M6 bolts that hold front and rear crank seal housings and the aux d/s housing. No reason why you can't save the bolts and nice OE washers but don't waste time marking and bagging them - you can sort that out much quicker when they are all cleaned up.
Remove all the M6 bolts that hold front and rear crank seal housings and the aux d/s housing. No reason why you can't save the bolts and nice OE washers but don't waste time marking and bagging them - you can sort that out much quicker when they are all cleaned up.
Housings.jpg (112.89 KiB) Viewed 12449 times
Undo the two bolts and the aux d/s can be pulled out.
Undo the two bolts and the aux d/s can be pulled out.
aux ds collar.jpg (114.36 KiB) Viewed 12439 times
kremlingazette
Posts: 12
Joined: December 25th, 2008, 6:36 pm

Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by kremlingazette »

Excellent reading Guy....

My block is cleaned , however I am still unsure what to do with the wear ridge at the top of the cylinders. I am working to a tight budget and am trying to avoid going to rebore & larger pistons. I understand ridge dodger top rings are no longer available ?

My cylinder head is stripped and cleaned, and appears intact without any issues. It will get a skim in the next few days all being well.


I hope my posts here are within keeping with the theme of original thread, and go more or less hand in hand with with the work Alan is currently doing.

To keep the budget low is the name of the game for me personally, so any advice will be gratefully received.


Regards

Ivan
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

I will cover this in due course but it is no 5 minute job to do far less write up.


G
Alan
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Hi Guy.
As you use an impact tool to remove the head bolts, is it correct to assume that they do dot need to be released slowly (i.e. 1/4 turn at a time) going round each bolt in sequence?
My wondering is in relation to minimising the possibility of any head warpage (which may not be relevant but I have to ask).

My intention is to strip the engine specifically per your guidance, I will get some more done tomorrow night an post details thereafter.
Alan.
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

All my heads get refaced so it's immaterial whether they warp during strip or not. As a matter of course we will cover the key decisions of budget/ops so if you wish to err on the side of caution undo them with a T bar. I would not go as far as undoing them progressively, but stick to the 1-10 sequence.

G
Alan
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Hi Guy.
I continued the strip-down this evening, removing the head first.
It came off very easily (just lifted off).
DSCF2824.jpg
DSCF2824.jpg (47.55 KiB) Viewed 12288 times
One of the chambers is covered in a light corrosion, but it dosent look to be too difficult to remove:
DSCF2825.jpg
DSCF2825.jpg (56.41 KiB) Viewed 12287 times
I then got out the Scotch Brite and cleaned the carbon deposits of the top of the cylinders:
DSCF2804.jpg
DSCF2804.jpg (40.66 KiB) Viewed 12278 times
There is no obvious wear on the top of the cylinder, I am not sure where the scratches came from though or they effect the performance:
DSCF2808.jpg
DSCF2808.jpg (33.66 KiB) Viewed 12278 times
Moving underneath, I removed the oil pump:
DSCF2805.jpg
DSCF2805.jpg (47.09 KiB) Viewed 12275 times
Not sure what the purpose of this pipe is (is it a standard item?), possibly to guide the oil back to the sump.
DSCF2810.jpg
DSCF2810.jpg (34.08 KiB) Viewed 12277 times
What is the eccentric cam on the end of the oil pump drive shaft for?
DSCF2816.jpg
DSCF2816.jpg (40.84 KiB) Viewed 12273 times
Pistons 2 and 3 out followed by 1 and 4.
Good practice or not, I reassembled the caps and bearings after removing the piston to keep all together in an orderly fashion.
DSCF2817.jpg
DSCF2817.jpg (22.42 KiB) Viewed 12274 times
Each piston has been previously engraved with its number:
DSCF2820.jpg
DSCF2820.jpg (28.08 KiB) Viewed 12274 times
The crank journals all seem to be in excellent order, and the wear on the bearings looks minimal:
DSCF2813.jpg
DSCF2813.jpg (39.93 KiB) Viewed 12271 times
DSCF2819.jpg
DSCF2819.jpg (25.74 KiB) Viewed 12271 times
More fun tomorrow eve.
Alan.
Alan
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Guy, I proceeded with removing the aux drive pulley and shaft.
These both came of with ease.

Thankfully you mentioned about the bolt on the crank bolt being Left Hand thread, otherwise the outcome might not have been pretty.
I used the nut gun and it was really easy.
I didnt even have to hold the the crank pulley, the rapid torque/impact just spun it off.
Its small but still has 590 NM of torque. I cannot recommend one of these highly enough for working on old cars:
DSCF2829.jpg
DSCF2829.jpg (51.06 KiB) Viewed 12207 times
DSCF2827.jpg
DSCF2827.jpg (60.61 KiB) Viewed 12204 times
My pulley system is not standard:

DSCF2828.jpg
DSCF2828.jpg (46.14 KiB) Viewed 12204 times
Here is a montage of the rod bearings (cleaned using a decent solvent spray) hopefully the image is clear enough to make out the wear pattern.
The lower bearings are shown as the bottom ones under the picture.
Rod bearings.jpg
Rod bearings.jpg (145.48 KiB) Viewed 12206 times

I will hold off on the crank removal until you offer further instructions.
Regards,
Alan.
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

Next:

TOOLS:
1. A dial gauge - also known as dial-type-indicator DTI - with a magnetic base (mag base DTI on short) is an essential tool needed now - and I recommend Mitutoyo measuring equipment above all_other_makes. I recommend digital NOT analogue (clock face type) for engine building because it is more accurate and far quicker. Plus you can't ever make a mistake with the reading.
2. Long T bar or impact wrench & sockets 19mm and 16mm 1/2" drive
3. Small and large screwdrivers
4. Marker pen!

Before taking out the crank (assuming all the housings are off) use a dial gauge with magnetic base to check the end float. See photo. The crank is levered (quite firmly) one way and the other with a screwdriver or pry bar. The OE spec on end float - which is the free movement a crank MUST have to allow oil film between the vital thrust washers and the crank flange - is 0.002" - 0.012". The trouble with end float is that if you aren't careful you can end up in a situation where - on rebuild - it's too loose or too tight and you don't know why. So check it now.


If your float is within limits undo all the main bearing cap bolts - and again - nut gun fine for this but wrap a cloth around the socket (which will need to be a balck 'impact' socket because ordinary chrome vanadium sockets can shatter at these big sizes under high applied 'undoing' power, 1 x 16mm hex at the front near the oil pump and 9 x 19mm hex on the 2 liter unit).

The main bearing caps (see photos) should carry the same numerical code as the block and the front cap (which has two different bolt sizes) cannot be fitted in any other position, whilst the others can easily be mixed up especially the wide center main cap (where the bending load on the crank is highest) which looks as if it should be the one at the FW end of the block where the thrust washers are located. It carries a wider bearing than the other 4 caps too.

Keep every bearing with it's caps. Lift the crank off carefully and try not to dislodge the thrust washers. If they fall out make sure you note which one it is. Usually the rear thrust brg is more worn than the front because it carries all the thrust load when the clutch is depressed (a very good reason for taking your foot OFF the clutch when driving by the way..).
Remove all the main bearings and record positions and bearings with the marker pen. When the crank is out wipe the item dry and next we'll inspect and measure it but in the interim have a very careful look at the crank webs and see if you can find a machined flat region (known as a 'flat') with a number like +.03 stamped on it. We will confirm by measurement of the journal with accurately calibrated micrometers but check anyway because it will indicate the use of an 'odd' factory journal size on crankpin or main for which unique bearings were fitted by Fiat and which have never been available in the aftermarket.

You will probably find a bush pressed into the FW end of the crank although it may have come off with (and be in ) the FW.
FWD (front wheel drive) engines generally have this - rather than the bearing that RWD units generally have to support their longer gearbox input shaft. The item is there, in this FWD case, purely (and importantly) to center the FW on the crank.

GC time taken: 20 minutes

Incidentally - for the benefit of readers whose technical English is not great I am tending to mark important technical terms and phrases with 'inverted commas'. I try to be correct about language and all readers should try and adopt the terminology I use because it helps so much if we all have a common system

More later, your feedback when you're ready.

GC
Attachments
end float check - this on a rebuild with caps off. The thrust washers
end float check - this on a rebuild with caps off. The thrust washers
GCC 050.jpg (111.03 KiB) Viewed 12089 times
main bearing caps from a 2 liter TC Fiat showing the two types of bearings in the engines and numerical codes. Caps 2-5 have notches to indicate position and when fitted the numerical code should read the same way up as the code on the end of the crankcase skirt.
main bearing caps from a 2 liter TC Fiat showing the two types of bearings in the engines and numerical codes. Caps 2-5 have notches to indicate position and when fitted the numerical code should read the same way up as the code on the end of the crankcase skirt.
GCC 051.jpg (118.32 KiB) Viewed 12087 times
the main caps are held in proper position by a reasonable tight fit along the edge parallel to the crank. No dowels and none needed. When stripping bolts ALWAYS inspect the mating face where the bolt head (or nut) sits. Minor embedding or scoring can be dressed with a fine (oiled) carborundun stone or in the case of severe  marking - remachined by a milling op known as 'spotfacing'.
the main caps are held in proper position by a reasonable tight fit along the edge parallel to the crank. No dowels and none needed. When stripping bolts ALWAYS inspect the mating face where the bolt head (or nut) sits. Minor embedding or scoring can be dressed with a fine (oiled) carborundun stone or in the case of severe marking - remachined by a milling op known as 'spotfacing'.
GCC 055.jpg (55.64 KiB) Viewed 12088 times
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

Some notes re your progress to date.
Attachments
Looks like the outer flange to restrain the alternator belt is missing..
Looks like the outer flange to restrain the alternator belt is missing..
Belt.jpg (59.49 KiB) Viewed 12076 times
This steel pipe (held by two of the most important bolts in the region if they come loose you're in real trouble) is the scavenge return pipe that allows oil from the very effective cylcone breather on the outside of the block to return to the sump. It should discharge right next to the oil pump pickup at the same level the pickup sits and must never be omitted on a wet sump unit.
This steel pipe (held by two of the most important bolts in the region if they come loose you're in real trouble) is the scavenge return pipe that allows oil from the very effective cylcone breather on the outside of the block to return to the sump. It should discharge right next to the oil pump pickup at the same level the pickup sits and must never be omitted on a wet sump unit.
DSCF2810.jpg (39.19 KiB) Viewed 12074 times
The lobe is what drives a mechanical fuel pump and we will definitely (100% sure!) be cutting it off just outboard of the rear bearing journal and plugging the gallery. Otherwise there is a risk - if the aux d/s is not very accurately timed up 'in synch' with the crank - it will strike no2 con rod. This problem is common to all TC units (non reversed-port) with stroke of over 79.2mm
The lobe is what drives a mechanical fuel pump and we will definitely (100% sure!) be cutting it off just outboard of the rear bearing journal and plugging the gallery. Otherwise there is a risk - if the aux d/s is not very accurately timed up 'in synch' with the crank - it will strike no2 con rod. This problem is common to all TC units (non reversed-port) with stroke of over 79.2mm
DSCF2816.jpg (46.03 KiB) Viewed 12073 times
Naming of parts.
Naming of parts.
DSCF2817.jpg (44.53 KiB) Viewed 12071 times
Your non-standard pulley array with some pertinent notes! Your engine was dry-sumped oncejudging by the 3rd (redunant) pulley - or maybe had power steering, dunno. The missing flanges can lead to belts chafing (cam belt) or running right off the front (alternator belt)
Your non-standard pulley array with some pertinent notes! Your engine was dry-sumped oncejudging by the 3rd (redunant) pulley - or maybe had power steering, dunno. The missing flanges can lead to belts chafing (cam belt) or running right off the front (alternator belt)
DSCF2828.jpg (57.74 KiB) Viewed 12072 times
Your bearings with notes. Tri-metal were very good because the soft lead coating gave them a high degree if 'embedability' ie: debris would tend to embedd and not score but are quite simply NOT available anymore, and these ones actually do look 'low hours run' and fit for re-use. Wipe with a soft clean cloth and brake cleaner and then number them on the bearing face with fibre pen. Remove carefully by prising the lug with a slim screwdriver and when they're out wipe the backs and turn them over and see if there is a number like +0.010 on the back indicating an undersize crank. There will be a long part number - we are not concerned with that here in this case. The coating is very SOFT - you can scratch it with your fingernail - so line a box with a wipe and set them aside for now.
Your bearings with notes. Tri-metal were very good because the soft lead coating gave them a high degree if 'embedability' ie: debris would tend to embedd and not score but are quite simply NOT available anymore, and these ones actually do look 'low hours run' and fit for re-use. Wipe with a soft clean cloth and brake cleaner and then number them on the bearing face with fibre pen. Remove carefully by prising the lug with a slim screwdriver and when they're out wipe the backs and turn them over and see if there is a number like +0.010 on the back indicating an undersize crank. There will be a long part number - we are not concerned with that here in this case. The coating is very SOFT - you can scratch it with your fingernail - so line a box with a wipe and set them aside for now.
rod brgs.JPG (78.07 KiB) Viewed 12070 times
dflinkmann
Posts: 13
Joined: June 4th, 2008, 12:46 pm

Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by dflinkmann »

Hello Guy,

As you generally saying: Model Post!
It is a great help to have these pictures with detailed technical explanation as it help talking about the same things.

Thanks again,

Daniel
Alan
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Hi Guy.
Finally got back to this.
I removed the oil seal carriers on either end of the block:
DSCF2875.jpg
DSCF2875.jpg (52.96 KiB) Viewed 11018 times

And checked the end float using my favorite leaver. (I placed a ½ inch drive extension into one of the holes on the outer part of the block, and using a parallel to protect the crank, levered the crank fully one direction and set the dial gauge to zero (not digital but I am happy with using this one), then the other way and measured the result. Exactly 0.4mm or .0157”, so outside the tolerance you specified. (Picture taken before I removed the rest of the bearing caps).
DSCF2876.jpg
DSCF2876.jpg (39.78 KiB) Viewed 11019 times
I expected to see bearings fully round rather than just a half circle on either side:
DSCF2895.jpg
DSCF2895.jpg (80 KiB) Viewed 11021 times
Thrust bearings.jpg
Thrust bearings.jpg (203.67 KiB) Viewed 11022 times





Here is a montage of the cleaned crank main bearings:
Main Bearings.jpg
Main Bearings.jpg (208.9 KiB) Viewed 11020 times


There is some wear marks on the journals, but nothing I can feel so most likely very slight.
DSCF2886.jpg
DSCF2886.jpg (61.02 KiB) Viewed 11020 times
Now that all of the internals are out, the block needs a good clean to get the crud out from the innards, any suggestions? Is a caustic soda bath too strong?
As the thrust bearings are out of spec, will these have to be replaced with new (are they available?).
Alan.
Guy Croft
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Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Guy Croft »

No cleaning yet!

Used cranks always exhibit some marking especially with trimetal bearings. Soft bearings allow minute debris to embed and this cuts the crank. Naturally the extent of marking of the crank (tiny grooves around the journal is quite usual) depends on the quality of oil, change frequency, cleanliness of build etc etc.

The big end float may well be some wear. We can deal with this in due course, perhaps with oversize thrust washers but later on when we build up we'll try new std ones first and try to get inside the 4-12thou" limit. Thrust washers - yes, naturally I - for example - stock all these kinds of things. Check the condition of the crank thrust faces with your finger. No groove or evidence of wear - we hope. When they wear you get a distinct groove, and it's usually on the outer end face of the crank thrust region where the clutch load is applied.

Your response please to:

When the crank is out wipe the item dry and next we'll inspect and measure it but in the interim have a very careful look at the crank webs and see if you can find a machined flat region (known as a 'flat') with a number like +.03 stamped on it. We will confirm by measurement of the journal with accurately calibrated micrometers but check anyway because it will indicate the use of an 'odd' factory journal size on crankpin or main for which unique bearings were fitted by Fiat and which have never been available in the aftermarket.

You will probably find a bush pressed into the FW end of the crank although it may have come off with (and be in ) the FW.
FWD (front wheel drive) engines generally have this - rather than the bearing that RWD units generally have to support their longer gearbox input shaft. The item is there, in this FWD case, purely (and importantly) to center the FW on the crank.


Tip!

Make sure you print off everything I write and mark it off as you proceed.


Might as well do some prelim inspection of the crank right now.

No point prepping a 'dud' (unserviceable) crank. Now put the crank between centres on on Vee blocks on front and rear seal journals and rotate it with a dial gauge on the centre main. What you see in the photo - 0.04mm runout - is close to the limit of 'bow' (bent-ness) we want. Also check the FW mating flange for true as shown. We would always dress this face with a fine carborundun stone as part of the routing prep and it is quite normal to have a bit of bow there - but we want it pretty flat. The cast iron flywheel is very weak in bending and we don't want to generate a 'stress raiser' there, it can overstress the centre region of the FW and cause it to crack.

Tools required:
Vee blocks
Dial gauge 0-10thou"
Straight edge (piece of flat ground steel bar)
Feeler gauge with 0.0015" min thickness

GC Time:
40 minutes - 1 hour

Next - full crank measurement and head/oil pump strip.


GC
Attachments
checking crank for straightness on the centre main
checking crank for straightness on the centre main
PH 00.181 prep (15).jpg (110.13 KiB) Viewed 10978 times
checking the FW mating (driving) flange. Inspect the bolt holes too - though I should add I have never seen any wrecked threads on one.
checking the FW mating (driving) flange. Inspect the bolt holes too - though I should add I have never seen any wrecked threads on one.
PH 00.181 prep (20).jpg (110.55 KiB) Viewed 10976 times
Alan
Posts: 25
Joined: May 14th, 2007, 1:50 pm
Location: Galway, Ireland (A)
Contact:

Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Hi Guy.
I got to check the crank for run-out, and its reading 0.025mm, so within your 0.04mm tolerance.
The FW mating surface on the crank is pretty flat, a .05mm feeler gauge won’t fit under a parallel.
I gave the surface a quick rub with a honing stone first to ensure no burrs were sticking up. A little more time would probably clean the entire surface.

The thrust bearing faces on the crank are smooth and appear to be in good condition.

I have been unable to locate a machined flat with and numbers stamped on it.

With regard to the FW to crank mounting, there is no bushing to be seen.
DSCF2753.jpg
DSCF2753.jpg (279.71 KiB) Viewed 10735 times
Only the bolts were holding the FW in place. I don’t have the FWD gearbox for this and I will be running a RWD box at any rate. If needs be I can turn a bushing to fit.
Alan.
Alan
Posts: 25
Joined: May 14th, 2007, 1:50 pm
Location: Galway, Ireland (A)
Contact:

Re: DIY 2.0 TC engine step-by-step rebuild with GC

Post by Alan »

Guy,
These are the measurements from the crankshaft journals:
Front to rear
Main
No.1 52.984
No.2 52.979
No.3 52.979
No.4 52.979
No.5 52.985

Big End
No.1 50.795
No.2 50.796
No.3 50.795
No.4 50.795

Regards,
Alan.
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