Alfasud Adjustable Tappets

Post Reply
User avatar
Spacenut
Posts: 1205
Joined: Thu Feb 20, 2014 9:43 pm
Location: Hampshire

Alfasud Adjustable Tappets

Post by Spacenut »

Hi guys - the manuals suggest a special Allen key tool is required to get to the tappets on a twin-lobe camshaft engine. Can anyone tell me how long the hex bar needs to be? I will cut down an Allen key to the right length and weld it to a bit of plate, like the original factory item (which I did find online, amazingly, but at a cost of £48 it seems a bit excessive :roll: )

I'm going to check the clearances at the next cambelt service, which is due about now(ish). One tappet is rattling far more than the others - maybe that is all I need to do to fix my poor compression in #2...?

Thanks guys,

Lauren

NEG
Posts: 306
Joined: Wed Oct 29, 2014 12:30 am

Re: Alfasud Adjustable Tappets

Post by NEG »

Hi Lauren, I’m away at the moment but can check on Friday. I cut down an allen key as you are suggesting works fine. To lock the tappets during adjustment I use an old solid centre punch wedged between them in the cutouts.

alfadave
Posts: 1411
Joined: Sun Jan 17, 2016 6:57 pm

Re: Alfasud Adjustable Tappets

Post by alfadave »

Mine measures 41mm (cut down leg)
33mm original leg

To get leverage, I pushed one end part way into a roll pin (8mm I think), and a length of 6mm stud in the other half of the roll pin, to act as a handle

alfadave
Posts: 1411
Joined: Sun Jan 17, 2016 6:57 pm

Re: Alfasud Adjustable Tappets

Post by alfadave »

..........photos on P34 of red Haynes manual

User avatar
Spacenut
Posts: 1205
Joined: Thu Feb 20, 2014 9:43 pm
Location: Hampshire

Re: Alfasud Adjustable Tappets

Post by Spacenut »

Thanks Dave - much appreciated!

I will see about making something up this weekend.

Lauren

User avatar
Spacenut
Posts: 1205
Joined: Thu Feb 20, 2014 9:43 pm
Location: Hampshire

Re: Alfasud Adjustable Tappets

Post by Spacenut »

A bit of an update on this thread.

So following the sage advice from this forum (many thanks guys) I made up an adjustment tool out of a spare Allan key and a strip of 2mm steel plate. To start with it looked just like the factory tool shown in the factory manuals.

Once the rear bulkhead panel and the window tunnel were removed, I undid the cam cover bolts (3 accessible from behind the seats and the last one through through the rear wheel arch) and withdrew the cam covers. I wanted to start on the LH cylinder bank first as this side has given me the most trouble.

I made a tappet bucket locking pin out of a short length of 7mm steel bar. This locked the inlet and exhaust tappets on cylinder #2 really nicely. Out with the feeler gauges and both the inlet and exhaust are reading 0.05mm below spec. I measured the inlet and exhaust clearance on cylinder #4 - same deal. So it was time to deploy my new adjustment tool!

I found that the adjustment is incredibly sensitive - about one hex flat to open up the clearance to the required specification. The only other issue was the rear cylinder in each bank, where the chassis rail restricts the movement of the lever. So I had to make some adjustments to the handle which made it difficult to get purchase on. After some choice words I finally managed to get the LH bank done. Now on to the RH cylinder bank, which due to the proximity of hoses, ignition coil and fuel pipes would be even less accessible than the other side. I took a deep breath and measured the valve clearances, which were all in-spec!

Greatly relieved and a little surprised, I changed the timing belts and refitted the cam covers. I think the reason the LH clearances were consistently incorrect is due to the head coming off on that side to change the leaking cam carrier gasket back in 2011. I fitted one of those new-fangled plastic gaskets instead of a paper one, and I guess it must be 0.05mm thinner than the paper type.

I also replaced the brand new, but rubbish quality distributor shaft O-ring seal, which has been leaking ever since I replaced it 6 months ago. I got it through a VW supplier as the bugs use the same Bosch distributor as Alfa. However, this time I bought seals from both Machine 7 (who supplied the last ones) and VW Heritage, who supposedly supply "good quality" Brazilian items. This time around it was Machine 7 who came good, supplying a pliable seal that was easy to fit and didn't have flash lines or other moulding imperfections. The "good quality" seals were made from the same hard plastic as the previous seals, with flash lines and other imperfections. They only cost a couple of quid so it was worth casting the net a bit wider. Still early days but after a few miles no leaks to report :D

The only thing I have noticed is that the carbs need re-tuning, which suggests my compressions may have come up on the (you guessed it) LH cylinder bank :D :D :D

So pretty much all set for Goodwood tomorrow, if the weather can make up its mind!

Lauren

alfadave
Posts: 1411
Joined: Sun Jan 17, 2016 6:57 pm

Re: Alfasud Adjustable Tappets

Post by alfadave »

Just looking back on your "Motor Mystery" thread........maybe redo the compression test once all is settled in?

User avatar
Spacenut
Posts: 1205
Joined: Thu Feb 20, 2014 9:43 pm
Location: Hampshire

Re: Alfasud Adjustable Tappets

Post by Spacenut »

alfadave wrote:
Fri Aug 20, 2021 3:45 pm
Just looking back on your "Motor Mystery" thread........maybe redo the compression test once all is settled in?
Yes, I will do that. The valve clearances will certainly have affected the cylinder compression. I can't believe that a 0.05mm adjustment to both inlet and exhaust would be enough to bring back full compression pressure on #2, but you never know!

Lauren

Post Reply