Alfa 1750 alfetta

[cameronfurnival]

Information about the 1750 engine can be found here.

[dbazdavies]

Re: Alfa 1750 alfetta

Think its the Fuel injection manual only Cameron ??

[cameronfurnival]

Re: Alfa 1750 alfetta

here's the duetto engine link. hth

[Blue Marlin]

Re: Alfa 1750 alfetta

Very helpful document, do you have one for the 1750 (this is for the1600) as some of the torque values / clearances will be different. I am the process of repairing this very engine and I do have a manual but it's always hand to double / treble check values.

Thanks

Derek

[cameronfurnival]

Re: Alfa 1750 alfetta

Hi Derek, I found this...

alfa_torque_chart.pdf

and some more detials here... http://www.international-auto.com/al...ifications.cfm

[Blue Marlin]

Re: Alfa 1750 alfetta

Thanks for these. Saved to favourites. The head scratching and plodding progress will continue,picked a few bones out of the 1600 doc that were not mentioned in my manual. All new ground for me :O)

[ggrum]

Re: Alfa 1750 alfetta

One little tip that may apply to the 1750 engine is to seal the rear crankshaft oil seal to the housing to prevent oil leaking past. I only found out about this after I had re-built my 2 litre Alfetta GTV engine. The only good thing about the resultant oil leak is that the entire underside of the Roadster aft of the engine is covered in oil so corrosion should not be a problem.

[Blue Marlin]

Re: Alfa 1750 alfetta

Good call, there is a fair bit of old sludgy oil in the bellhousing. Will seal seal!

Did you rebuild the engine out of choice or necessity? I am the latter which is making a large dent in my meager refurb budget.

I have lost compession compression in cylinders 1+2, removed head / skimmed,new gasket, same result . Engine now on stand in garage partially stripped but still no obvious cause :O(

[ggrum]

Re: Alfa 1750 alfetta

I re-built mine because it was a complete unknown quantity when I picked it up about 20 years ago now. Regarding loss of compression worth checking valves are seating ok before removing pistons and checking for ring or bore damage. I seem to remember having to replace one cylinder liner, piston and rings on mine.

[Blue Marlin]

Re: Alfa 1750 alfetta

Valves are good as they were checked, re-ground then vacuum tested by the engineering shop that skimmed the head.

Pistons are out and all looks ok.

What did you use to remove the liner as after 40 years they look to be jammed solid? I have seen pictures of the official removal tool but this seems to be like hens teeth to find.

Kinda new to this engine stripdown / rebuild business but someone said to me earlier here " It's only nuts and bolts"

Thanks

Derek

[ggrum]

Re: Alfa 1750 alfetta

I think I was lucky as my liners came out fairly easily enabling me to replace the seals at the bottom. I have heard they can be tricky to get out but you should be able to check for excessive wear or damage without removing them. In my case a ring had broken, damaging the piston and scoring the bore. I'll have another think about the compression problem.

[Blue Marlin]

Re: Alfa 1750 alfetta

All pistons now out and no sign of scoring or broken rings. I feel the problem is head to block sealing somewhere as when I drained the oil nice clear water came out the sump first, there was water in the bottom of the oil filter housing and even water lying underneath the oil in the head.
There had been no sign of this prior to losing compression intially.
The engine did start (with difficulty) and run rough on 3 cylinders, No4 having a fuelling issue.
After the gasket was replaced it was nightmare to get going.
I think i will have to attempt to remove the liners and check the block deck is flat and not cracked.
Break out the credit card I think.

[ggrum]

Re: Alfa 1750 alfetta

On my engine the vacuum pipe for the brake servo is connected to the no.4 cylinder inlet manifold. If this connection is not made or the hole not blanked off then no.4 will run very lean due, presumably, to excessive air being drawn into the cylinder. Not sure if the 1750 is the same.

[Blue Marlin]

Re: Alfa 1750 alfetta

On my engine the vacuum pipe for the brake servo is connected to the no.4 cylinder inlet manifold. If this connection is not made or the hole not blanked off then no.4 will run very lean due, presumably, to excessive air being drawn into the cylinder. Not sure if the 1750 is the same.

This is the same on the 1750. The connection to the servo is there however if I ever get the engine back together I will certainly look at this as I could get No4 to pick up if I choked the carb barrel with my hand to draw fuel.

[philcoyle]

Re: Alfa 1750 alfetta

If your servo is a bit iffy or getting on in years it could be leaking air through the seal between the master cylinder and the servo unit, or fit a non return valve in the hose from manifold to servo.