Working on Alfa 24V

[mudhut]

Has anybody completely stripped and rebuilt the Alfa 24V engine? If so were there any special tools that were found to be necessary or anything that had to be made?

In particular, I'd like to know about changing the cam belt, water pump, oil pump - the usual stuff its prudent to do before putting the new engine in.

We already know about a suitable socket/extension for the spark plugs...

As you might have guessed, I've recently bought a 164 24V donor but will run it for some months to get a feel for it. Seems a shame to break it up.

BTW if anybody has a set of five stud wheels (16" x 6.5"), I'd be interested to buy them. They don't have to be particularly pretty, just serviceable - the car I have has 7.5" fitted and these are just too big.

Regards

Peter

[chris.richard]

Water pump and timing belt fairly straightforward. Oil pump is in the depths and requires engine dismantling.
There are special tools needed, but you can make your own. See picture for my version of flywheel immobilising tool and cambelt tensioner. The cambelt tensioner is two sawn off bolts welded to a pice of angle section, then you hang an appropriate volume of water at an appropriate distance to achieve the desired torque.
i immobilised the cams by wrapping cam wheels in clingfilm, then putting epoxy putty between them so as to form a wedge that engaged the teeth of both wheels. Worked a treat and just slid out afterwards. With cams and flywheel fixed, it didn't need to be set at TDC or anything fancy. This approach makes the assumption that the cams are all appropriately timed to start with.

[mudhut]

Thanks Chris - most helpful. I'm not going to strip the entire engine but might freshen up the bottom end. Anxious not to bite off more than I can chew! I think there's more potential for misery here than on the old twin cam which was pretty easyto deal with.

Anybody set up 24V cams from scratch - i.e. when the original timing was lost?

Regards

Peter

[chris.richard]

There are marks on the cams under the cam covers at the pulley end. That means pulling off the intake plenum etc.etc.

There is some issue about removing the sump. I think there are a couple of bolts holding it on from above behind the flywheel IIRC. Makes it impossible with the engine in the car.

[alfagene]

The flywheel lock that is commonly available for the air cooled VW bug engine works fine on my Alfa 4 cyl and Montreal V8. It should work on a 164. Mine cost about $5.00 at a VW shop.

Gene Brown

[roger001]

I have timed the cams from scratch - this involves buying, hiring or borrowing cam locking blocks -these replace one cam bearing on each shaft and lock the cams in the correct position for TDC which is found with a dial guage and the adaptor supplied in the kit, then when cams and crank are all in the correct positions and the belt tensioned correctly you tighten the camshaft pulley bolts to check remove the blocks rotate the engine a few revolutions bring it back to TDC then check the blocks slip on correctly.

FWIW a set of cam timing blocks and the associated TDC adaptor might make a good club purchase.........

[mudhut]

The timing kit gets my vote too Roger. Is the tensioning device part of the kit? I'm referring to the thing with the sliding weight shown in the car disc manual. There seem to have been several TSBs revising the tensioning procedure.

As far as the locking device is concerned, this would be useful in doing the cam belt and some other operations. I'll look into a supplier over here. Very good picture of its design, thanks Gene.

I'll PM you about the Car Disc printing issue Chris - looking into it a bit more this evening.

Regards

Peter

[roger001]

The kit I borrowed was from a 156 so had the wrong tensioner device in it, but did have the 4 blocks and TDC adaptor, I have not looked into buying a kit as I was able to borrow one, I guess the best people to ask would be someone like E B Spares for kit contents/prices etc

[mudhut]

Justoffbase.com (http://www.justoffbase.co.uk/s.nl/sc.9/category.145/it.A/id.8297/.f) do the Sealey Power Products valve timing kit for the 156 at around £162.

About £36 will buy the Sealey probe for finding TDC (not including DTI), also from justoffbase.com (http://www.justoffbase.co.uk/s.nl/sc.9/category.127/it.A/id.5145/.f).

This would appear to indicate Roger that the valve timing is the same on the 156 2.5 litre as the 164 3 litre. Can anybody confirm this or definitely repudiate it?

Flywheel locking tool for VW as recommended by Gene is £5.99 from retrodubs (http://www.retrodubs.co.uk/Tools.html)

[chris.richard]

This would appear to indicate Roger that the valve timing is the same on the 156 2.5 litre as the 164 3 litre. Can anybody confirm this or definitely repudiate it?
These tools just immobilise the cams. The cam timing is determined by the marks on the cams and the heads.

[roger001]

The marks on the cams and heads are not accurate enough, the blocks replace a cam bearing cap and have a machined cut out that fits over one lobe on the cam to hold the cam in the exact TDC position. see http://www.ebspares.co.uk/new23.htm which shows the twin cam version.

[mudhut]

Been looking over this thread to try to resolve a few unanswered questions.

Roger, when you used the 156 cam locking kit, did you use it on an ex-164 3 litre or another variant? If so was the engine OK on that timing? I'm tempted to obtain this kit if so.

Chris, as you'll already know, the Cardisc does not state the torque to be applied to the tensioning device. The only data given is the distance that the weight must be along the arm but the weight itself is not known, nor is the exact distance from the centre of rotation. What weight did you use and how far along the arm (assuming effect of the arm is insignificant relative to the sliding weight)?

As far as I can tell, Alfa do not seem to publish tha cam timing data. Does anybody know the figures for the standard 24V cams?

[roger001]

I used the 156 kit on an ex- 164 3 litre, as a double check using this the cam timing marks on the ends of the cams were fine.

[chris.richard]

Chris, as you'll already know, the Cardisc does not state the torque to be applied to the tensioning device. The only data given is the distance that the weight must be along the arm but the weight itself is not known, nor is the exact distance from the centre of rotation. What weight did you use and how far along the arm (assuming effect of the arm is insignificant relative to the sliding weight)?

2.12 Kg, 224mm; My mark is from the level of the left hand pin, but I can't remember why it is there - it might be obvious when assembled in position for use. :cool:

Maybe the mark is 224mm from the centre of the pulley :confused:

[mudhut]

Thanks guys.

[rutthenut]

Has anybody completely stripped and rebuilt the Alfa 24V engine? If so were there any special tools that were found to be necessary or anything that had to be made?

Camshaft, dial gauges and tensioner tools available at this eBay shop
http://stores.ebay.co.uk/Totally-Alfa

[rutthenut]

Water pump and timing belt fairly straightforward.

I take it that if I want to pull the water pump off just to see if it is faulty, then I will have to remove the cambelt and redo the whole tensioning process (and put on a new belt, naturally)?

Or is it possible to get the pump off without disturbing the cam belt?

J.R.

[chris.richard]

yes, & no. (In that order)

[mudhut]

May be wrong but I'm not sure that the tool for sale, item 110009957745, is exactly right.

The open end part will be ok to turn the cams for positioning the locking blocks but looks too thin to hold the cam while "torquing up". In any case I think it is the pulley wheel that needs holding so that the torque is not applied along the camshaft to wherever the spanner holds it.

The cam belt tensioner for the later 24V engines is different to the early one used on the 164. Not sure that the two pins will fit the adjuster and even if they do, the tool looks like it may obstruct access to the nut that clamps the tensioner into position. The "correct" adaptor for the cam belt tensioning tool is shown below - the distance between the 6mm diamter pins is 15mm.

You can get the dial gauge adaptor from any stockist of Laser or Sealey tools.

I'm currently collecting the tools needed for the 164 engine - don't have them all yet.

Chris Richard has done this job - any comments Chris?

[mudhut]

On the matter of 24V engines, I think the 166 engine has a slightly different route for the cam belt insofar as the belt wraps more completely round the rear exhaust cam pulley. I think this might make it a better choice if you come across one cheaply enough. Some of the spare parts for it are much cheaper than for the 164 24V unit.

[strat6v]

A few more differences too. I think the oil pump is driven differently(chain)

[chris.richard]

Since my engine was low mileage and running fine, I made the assumption tha the cam timing was correct and didn't remove the cam covers, using my patented chewing gum method (documented elsewhere) to immobilise the top end.

[rutthenut]

Since my engine was low mileage and running fine, I made the assumption tha the cam timing was correct and didn't remove the cam covers, using my patented chewing gum method (documented elsewhere) to immobilise the top end.

I saw that. Think that is the approach I may have to take too.

Means I should be able to get the water pump off and see if it has failed internally or not (some Alfa pumps are known to do this).

Procedure will be to 'lock' the camwheels in place, as you had done, leave car in gear, handbrake on, to try and lock the crankshaft (engine in car, but wheel removed for access on rhs), remove cambelt, remove water pump and inspect it.

If pump appears faulty, replace it, fit new cam belt (and associated tensioner parts), tension belt according to [some] procedure and see how it goes.

If pump looks healthy, assume engine rebuild required - top end at least. Forget about cam belt and tensioner. Look at some big bills, or replace with a reliable engine from a running car - if I can trust it.

[roger001]

Another check is to put the engine at TDC and put paint marks on the cam wheel teeth that face each other at the nearest point between each pair of cams then if the cams move it will be easy to spot, and if they do move will give you a guide for realigning correctly. also usefull to put in pace anyway as a quick way to check for jumped teeth.

[rutthenut]

Another check is to put the engine at TDC and put paint marks on the cam wheel teeth.

Sounds like a perfectly sensible and useful tip.

Of course there are two 'TDC' points - need to get the right one for Cylinder 1 I guess? Or mark both points but with different colours, maybe.

I've just had the car taken somewhere to have the work done, as I really don't have the time [and inclination] to mess around with the engine at the moment.

Expect to find out next week if it is only a pump problem, or a more expensive rebuild required.

Target to have the car racing again at Combe. You weren't doing that one, were you Roger? Then a couple of weeks from then to Donington.

J.R.

[roger001]

Correct - I am on holiday for the Castle Combe round, but intend to be at Donnington. There is a CSCC event at Oulton on 12th August I have entered thr DDMC sports and saloons rece as a guest.