Title: Flaminia 2.5 spare engine Post by: Richard Fridd on 14 November, 2023, 05:26:45 PM I am now beginning a mechanical assessment of my spare engine.
Both cylinder heads removed today, one gummed stud demanding three hours careful coaxing to enable the liberation of one cylinder head. The opposite cylinder head was surprisingly easy to remove. Bores look very good, so sump removal next to draw out the pistons. Piston rings possible not so good. I would like to replace the head gaskets if anyone has a pair available for sale. Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 14 November, 2023, 09:15:18 PM Photos
Title: Re: Flaminia 2.5 spare engine Post by: DavidG on 15 November, 2023, 12:14:04 PM Well done!
Are you just using the weight of the engine to pull against the head or have you got the block tied down to something and pulling upwards with the straps? Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 15 November, 2023, 05:15:14 PM The straps and their adjustment were only to keep the first head square to the block, as it was pivoting very slightly on the gummed stud. If it wasn't for the one gummed stud the head would have lifted off.
The second head lifted as soon as the stud nuts were released by means of pressure from the valve train springs. Further disassembly today. Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 16 November, 2023, 09:14:08 PM Everything seems to be in very good condition. However the piston ring gaps are 2mm.
A set of 80mm rings required. Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 20 November, 2023, 06:05:18 PM As work continues, can anyone here explain how the vibration damper works?
Title: Re: Flaminia 2.5 spare engine Post by: willoroe on 21 November, 2023, 06:25:03 AM Yes, it is a torsional or harmonic damper (https://en.wikipedia.org/wiki/Harmonic_damper). There are two main parts, the first of which is the mass which is 18 in the parts drawing, it is like a small flywheel. The second is the energy dissipating element, which in this case is a small friction element 17. Now because it is Lancia and they thought they had unlimited resources they decided that the best thing to do this was to double everything, so there are two masses and two friction rings. The springs push apart the two masses so that they are held against the friction plates but not mechanically connected to them. So it is a bit like two little clutches. The crankshaft is connected to the mass only through the clutches and that damps out the harmonics.
I wondered if there was some way of checking if it was still working on my car, but I would be very reluctant to take it apart. I'm sure Mitka knows the saying about the kinds of people who take watches apart: watchmakers and fools. Now I'm glad I studied this in Engineering College 40 years ago! Willo Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 21 November, 2023, 06:58:04 AM Many thanks for your reply Willo.
If your engine is not vibrating would it be safe to say that your harmonic damper is working properly? The engine in this thread has always been very smooth during my ownership, but my other 2.5 not quite the same. Having wondered about other possible reasons for this, I could swap the harmonic dampers. Bearing in mind watchmakers and fools. Richard Title: Re: Flaminia 2.5 spare engine Post by: chriswgawne on 21 November, 2023, 09:45:09 AM "I'm sure Mitka knows the saying about the kinds of people who take watches apart: watchmakers and fools."
Never heard this expression before today......and last week I tried ( & failed) to reassemble an old clock platform escapement using parts from 2 similar clocks! Nothing like an old fool! Chris Title: Re: Flaminia 2.5 spare engine Post by: Mikenoangelo on 22 November, 2023, 08:07:29 AM Interestingly the vibration damper is very similar to that used from 1922 onwards on the 20hp Rolls Royce. Royce's version was adjustable, to be set to slip at a design level of torque level. I made a long lever to bolt to the damper with a spring balance on the end of lever to check the load at the slipping point - it was still at the right level after 90 years!
Mike Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 22 November, 2023, 07:06:06 PM The damper looks very good inside. Stripped and cleaned the sump and modified the sump plug and oilfilter housing to accomodate locking wire.
Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 28 November, 2023, 07:31:58 AM Rotating the crankshaft by hand, a tight spot was apparent. Camshaft? OK with the timing chain removed, and now both the crankshaft and camshaft move freely. A mystery. Progressing to the removal and checking of cam followers, the remains of a pop rivet revealed itself in the timing chest tube. The culprit of this mystery?
I now need to withdraw the camshaft, which although the three retaining screws are removed is not quite ready to come out. Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 29 November, 2023, 03:11:35 AM A question regarding piston rings. Having asked several experts, I have received conflicting comments about which way to fit the second/ scraper rings. These particular rings have a step on the outside circumference and are not marked with a dot or other identification.
Ideas welcome as usual Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 30 November, 2023, 08:23:51 PM 2nd scraper piston ring steps face downwards I understand. Once the tight cam follower was freed, this enabled the camshaft to be withdrawn. The solitary follower was impeded by sediment.
Camshaft and pistons now refitted. Richard Title: Re: Flaminia 2.5 spare engine Post by: lancianut666 on 01 December, 2023, 11:53:09 AM Loving this thread as I (hopefully ) will be doing all this lovely stuff over the winter.
Clarkey Title: Re: Flaminia 2.5 spare engine Post by: willoroe on 01 December, 2023, 01:36:53 PM Agreed, Thanks Richard, fascinating stuff.
Regarding the Crankshaft Vibration Damper the Workshop Manual only says 'check wear of friction disks and dowels'. No mention of how you might check that it is working. Willo Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 01 December, 2023, 06:13:20 PM Looking forward to Clarkey's report when the time comes. Seems to be a lot of Flaminia activity currently.
I should be able to reassemble the cylinder heads, sump and end covers next week, and have a complete spare engine. As I have spare triple DCNL carburettors, these could be used and at this stage a camshaft to match these carburettors could be fitted quite easily. Richard Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 04 December, 2023, 06:11:31 PM When refittng the oil sump it is worth leaving the pickup gauze until last, as the pipe needs to go through the baffle hole easily.
And the rubber grommet can be fitted without falling off. Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 10 December, 2023, 06:22:50 PM Engine reassembled to be returned to storage.
Surprises encountered, Cylinder Heads cooperative during removal Camshaft locating screws lining up first attempt The hitherto mystery of timing the valve train with feeler gauges not so mysterious. Title: Re: Flaminia 2.5 spare engine Post by: Kevinlincs on 10 December, 2023, 08:38:50 PM Looks great Richard, they're a lovely looking engine 8)
I'm soon to be building up my Flavia engine which has a similar cam timing system to the Flaminia, sounds complicated on paper but you found it OK once you get your head around it? Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 11 December, 2023, 06:39:45 AM The method which I interpreted was set the no.1 inlet valve clearance to 1mm+
The point at which this valve starts to open ie this clearance becomes zero, the TDC mark on the flywheel should be two teeth away from the 1/4 mark on the flywheel housing. With the engine rotating in it's normal direction and the cam chain taught, the cam sprocket dowel can be fitted in a hole which actually maintains the tension, rather than allowing slight chain slackness, which would erroneously equate to several degrees discrepancy. Richard Title: Re: Flaminia 2.5 spare engine Post by: DavidG on 11 December, 2023, 10:35:45 AM Engine reassembled to be returned to storage. Surprises encountered, Cylinder Heads cooperative during removal Camshaft locating screws lining up first attempt The hitherto mystery of timing the valve train with feeler gauges not so mysterious. That's great! Wish mine was so cooperative. Title: Re: Flaminia 2.5 spare engine Post by: lancialulu on 11 December, 2023, 11:40:44 AM Shouldnt cams be timed wrt Tdc not an advance on that?
Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 11 December, 2023, 01:10:52 PM From the manual.
Nothing lost in translation I hope. Most useful tools for this engine disassemble and reassembly turned out to be a low bench on castors, negating the need for an engine stand, a really well designed valve spring compressor and the modified oil pump drive shaft used to operate the oil pump. Title: Re: Flaminia 2.5 spare engine Post by: Kevinlincs on 11 December, 2023, 07:17:01 PM You also have the advantage over me with the Flavia engine in only having one cam to time up whereas I have one for each pair of cylinders.
Looks a very similar process to the Flavia engine too 8) Title: Re: Flaminia 2.5 spare engine Post by: Richard Fridd on 11 December, 2023, 07:48:26 PM Not that there is much to fix to, but probably a tool to hold the camshafts in position would be useful when the sprockets are 'free wheeling'.
I suppose much easier with all tappets backed off and the valve springs not influencing the positioning of camshafts. |