Lancia Motor Club

Model Technical and Interest => Appia => Topic started by: lancianut666 on 15 May, 2016, 12:16:26 PM

Title: Appia engine timing
Post by: lancianut666 on 15 May, 2016, 12:16:26 PM
Hi all
I have had a request for help outside my knowledge range so if any of you experts can help much obliged, Dave is a consortium member but not a forum user his email is
here is the story so far
Vehicle :- Lancia Appia, 1960, 1090cc, Series 3, Engine Number 808.07*17786*
The car was bought about a year ago with the engine in a disassembled state. I have no idea when the engine last ran or if it indeed did.
I have had a reasonable degree of success starting to rebuild the engine but I am having a great deal of trouble trying to sort the valve timing out.
I have had a considerable amount of help from Don Cross but we have been unable to ascertain why the period of valve opening differs on my engine when compared with the figures given on the Data Sheet AST, Sketch 510J,5/2/59,sheet 2/3 in the manual.
The period that both of the valves are open on my engine are approximately 310 degrees. The specification gives valves opening period of around 247 degrees.
The tappets are set as on the aforementioned data sheet and the point at which the valves commence to open can be set as per the same sheet. However as stated the period of opening differs greatly.
When looking at the engine type on the sheet it seems that the data for the 808.07 is the same as that for the C10 from No 12501, C10S from No 12001 and the 814.00 up to No 3700. Further down the same sheet there is additional data for the 814.00 from No 3701 but nothing for the 808.07.
I assume that this means that there is only one set of data for the 808.07 engine.
I would welcome any comments from fellow Appia owners who have successfully timed their engines.

Title: Re: Appia engine timing
Post by: Parisien on 15 May, 2016, 02:27:36 PM
Clarkey, might be worth a phone call to James Parry via minera tyres


Title: Re: Appia engine timing
Post by: ben on 16 May, 2016, 04:52:52 PM
That sounds like an interesting problem.
Presumably you either have a special high lift camshaft or the clearance setting used for the timing measurements is too small.
There does seem to be scope for confusion on the setting because according to "La Lancia" the settings for S1,S2,andS3 engines are all different---viz 0,15/0,20 in/ex for S1, 0,80 for S2 and 0,40 for S3

If it is a special high lift cam with extended up and down ramps giving the increase in opening angle I would say your best bet is to assume the extra opening is equally added at the opening and closing ends. (I am assuming you do not have data for what the standard max lift is to compare with your shaft? Perhaps a fellow owner of a car with the S3 808.07 engine can take a measurement for you.)
The difference between your measured opening and the standard S3 opening is   310-247=63 degrees.
The standard opening for the inlet is 15 degrees before TDC so set the timing to 15+31=46degrees and for the exhaust valve where the standard opening is 52 degrees before BDC set it at 52+32=84 degrees.  These figures sound rather extreme but I don't see what else you can do.
The problem arises of course because on the Appia engine the inlet and exhaust valves are operated by individual camshafts.In most engines the in and ex valves are operated by the same camshaft so the relative timing between them is fixed and if the opening and closing angles are symmetrical the timing is set by having the changeover point from ex closing to in opening at TDC.

As a matter of interest are the camshafts driven by gears or a chain and how is the adjustment provided. Is there some sort of vernier system?

Title: Re: Appia engine timing
Post by: simonandjuliet on 17 May, 2016, 06:35:49 AM
A difficulty that I had timing my S3 engine was the camshafts slipping once I had apparently timed the camshafts correctly.

IE I set it up as per the workshop manual - setting a pre-set tappet gap and then rotating the camshaft to close the gap before fitting and dowel-ing the wheels

Tightened everything up, checked the timing and found wild overlaps - I got round it by making sure that the camshafts were blocked as soon as I had them in the correct position, bit fiddly, but once done won't need doing again

Title: Re: Appia engine timing
Post by: simonandjuliet on 17 May, 2016, 07:29:57 AM

found the reference from when i timed mine