Rebuild Alfa 90

[dehne]

Hi all
I'm looking into a complete resto of my 90, I am going to start with the engine, where can I get new items from, should I stay with the 2.5 or go to the 2.8 kit.

[Duk]

Are you restoring or modifying?
A 2.8 litre engine is a lot of expense and work just to stay using the 2.5 crank and original block.
If you really wanted a 2.8, it'd be a lot easier to put a 2.5 crank in a 3 litre engine.

[1969read]

I have new headlights when you are ready cheers Jason

[dehne]

I want to keep original engine was just inquiring, I think after 31 years a complete engine rebuild is deserved. As for head light I have been stock piling for years so I have about 5 complete sets.

[Duk]

You do realise that the block has to be bored to accept the 3 litre liners, don't you?
Not every machine shop has the capacity to bore engines like these. they are very tall with their head studs in the block and removing the head studs is not something I've ever seen done (in forum land).

And with such a big increase in bore size you will be using 3 litre head gaskets. So you have to make sure that the coolant passages in the 2.5 heads line up correctly with the cut outs in the head gaskets.
And make sure the head gasket firing rings don't protrude into a coolant passages or you will need to have the passages welded and reshaped to suit.
Or use 3 litre heads.

[dehne]

Thanks for the info, no I did not know that they had to be bored, I was interested in the 2.8 conversion because I read about it a few years ago on here, I was thinking about a 3 litre but I want to keep the original engine, but I am thinking I will stay with the 2.5 and just make everything else better. Inside it. Now to find the parts to do it .

[jazig.k]

I thought you just dropped the 3lt pistons and liner into the 2.5 and away you go, 2.8lt of still not 3lt engine. You can't port the 2.5 heads to match 3lt, so there's another con of the project.

I have a 99.9% complete 164 sitting out on a farm, about 10 minutes from Bendigo Dehne.
While I wanted to keep it to strip down and build a boosted engine, that just isn't likely to happen. It was bought registered and we drove it daily and on long distance holiday for 4mths faultlessly. Then rego ran out and it sat for the last 7~8 years? Rust around the sunroof was bad and the car lived its life on the Mornington Peninsula [within 100meters from the beach] so it wasn't worth my time when I looked under it. If I remember correctly I think the entire exhaust was severely rusted and almost everything had a coat of surface rust on it. Perfect donor/parts car.

[Duk]

1 of the best ways to make the engine better, get a decent quality programmable computer to run the fuel and ignition show.
With good tuning of course.
It will allow the tuner to get the best results that can be achieved from the engine with the fuel that you intend to run it on.

[The Count]

Duk...
Interested in your comments re programmable computer. Is it possible to replace existing unit in a 90 with a programmable unit? If so, how and where can these be obtained?
Nick

[Duk]

Nick,

A programmable computer for a 90 is no different to a programmable computer for most other cars.

There is a workshop/guy in America that offers a sort of plug in system using a Megasquirt. From what I've seen of it, it's designed to replace the old L-Jetronic, plugs into the existing wiring harness and so only controls fuel delivery and not ignition timing.
It would also only fire all of the injectors all at once..............
Some people think its fantastic, but it looks like a lot of money to only partly do the job.

To me the only worth while installations start from scratch with an all new wiring harness, a decent sort of cranshaft position sensing so the injectors can be fired in, at bare minimum pairs and also have the computer control the ignition timing. With said decent crankshaft position sensing, the ignition system can also be converted to almost any form of distributorless ignition system you like.