I can only speak for differences between Spider 115 and Alfetta 116 here is the US.
The differences are:
Oil pans and pumps - It is easy to swap from one to the other
Crankshaft - the rear of the 115 is bored for a bushing, the 116 is not.
Dipstick fitting - it is in the block in the 116 and in the oil pan in the 115
oil pressure switch - 115 has one, 116 does not.
Flywheel - just swap them.

I think that everything else is the same. The last motor in the my Spider had a 116 block, front cover and connecting rods.

 

Ok thank you for the advice I really appreciate it. If you're right I think I'm best off saving for a twin spark conversion or getting my current engine rebuilt.

Cheers

 

Actually the 116 2 litre engines often have the crankshaft drilled for the 105/115 pilot bush. 105/115 Spiders were still being made well after the Alfettas were current product. Worth checking the 2 litre engine if you are entertaining a swap still.

 

What Richard just said. :yes:

If one of the engines you're looking at is good and has the hole for the pilot bush, you're in business. If not, you're going to need to tear the new engine down, remove the crank, have it drilled and then do a rebuild. Unless you just want the extra grunt of a 2 liter, that's not very cost effective because you could just go ahead and rebuild your original engine and avoid a lot of to-ing and fro-ing parts swapping. That said, you can do a fast-nnd-dirty fix. Machine shops hate to do this but it is possible to drill a pilot bushing hole without tearing down the engine. This is done by up-ending the 2 liter, carefully marking the crank, and drilling in situ. It's been done before but you'd best be friends with your machine shop because not only is the job hard to setup, you're also having to drill a hole in a nitrided (hardned) crank.

 

Actually the 116 2 litre engines often have the crankshaft drilled for the 105/115 pilot bush. 105/115 Spiders were still being made well after the Alfettas were current.

I can only tell from my Euro point of knowledge. 116 engines never have the hole drilled; sometimes they have it pre-drilled, but not deep enough. Latter TS engines do have the holes drilled, thats right.

 

hunttheshunt, as a former Euro garage proprietor, and having done the swap more than once certainly the engines we got in NZ in our 2 litre Alfettas were more likely to have the right sized pilot hole than not have it. If you think about it why would they have suddenly reverted when the twinspark came into being which appeared first in the later 75 but did not appear in the still being made 105/115 spider.

 

Richard, I'm just reporting what I've discovered when taking apart a lot of 116 engines as donor engines for a 105 build. If not, why did I have to drill more than once the hole or to drill it deeper ?

 

Most of the 116 engines sold here in the US didn't have a hole of any kind drilled. Only vary occasionally would you find one with a pilot bushing hole. The difference between countries and continents is another one of those curious Alfa lore mysteries.

 

Thanks for the input everyone. There's still a bit of confusion so I guess the best thing to do would be to look at the Alfetta engine myself. This is the first Alfa I've worked on so I'm guessing that the pilot bushing hole is just a hole drilled into the rear of the engine case. If anyone has pictures that would be extremely helpful. Once again thanks for the advice.

 

I'm guessing that the pilot bushing hole is just a hole drilled into the rear of the engine case

No, it's drilled in the chankshaft. It is for the pilot bushing. The input shaft of the gearbox goes into the bushing.

I have an Alfetta/Spider hybrid short block on the floor in my garage. I can take pictures of details if they would be helpful.
Where are you located?

 

Oh ok thanks for clarifying. Some photos would be great! I'm in Australia.

 

Probably worth noting, IIRC, the 2L crank has different flywheel bolt attachment from the 1750, and your existing 1750 flywheel won't fit.
If your car has a hydraulic clutch, then you can use the appropriate stock 2L flywheel and clutch.
If your car has a mechanical clutch, then you have to get something custom to use a 2L motor.

 

Actually there are quite a few differences between a Euro 1750 and a 116 series engine, even a 1.8. One thing I didn't see mentioned in a quick scan of the thread is the oil filter - on a 1750 it's a canister mounted to the block but on a 116 its a spin on mounted to the engine front cover.

if you swap out the flywheel (as CDM correctly points out will be needed) then you'll also need to swap out the starter, or the starter drive at least. 105 series 2-litre flywheels can be hard to find.....

Really, unless you want the torque of a 2-litre, Alfa engines are so easy to rebuild as you say you're probably better off rebuilding the current one. Unless there is a reason why you can't, such as corroded liner seats.

 

Thanks everyone for their input. I've decided to avoid the hassle and will look at getting the current 1750 engine rebuilt once I finish the bodywork.

 

Hi,

Would it be possible to use the crankshaft from a 1750 105 engine in the 116 1.8 engine and then use the flywheel etc from the 105?

Would this cause any problems ? I have a complete, cracked 1750 engine and a chance of a good 116 so have all parts available.

Thanks

Derek

 

I believe it'll work fine - however the 1750 crank is not nitrided, while the 116 1800 crank is - just means the 116 unit is much less likely to be suffering wear.

 

It's not the question about the bell housing. If you have a crankshaft with 8 holes you need a flywheel w/8 holes. You've asked for fitting a 1750/105 CS which should have 8 holes. Did you check how many mounting holes your CS you want to fit really has?

 

Good evening and please forgive the newbee questions. The new engine has 6 pins. I found an oil pan and pump. What else do I need to consider to mount the nee engine in my S4?

 

If crank is coming from an 116, you need to check depth of pilot bearing bore in the crank/rear boss. Some 116 cranks need to be modified to take a 105/115 pilot bearing.