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MG MGB Technical - Not an MG but a brain twister

Sorry this is not a MGB, I just respect the board's engine skills and experience so here goes:

I'm setting up an 1971 Alfa Romeo 1750 Fuel Injected (SPICA) with double overhead cams.

In reading through the invoices the shop his brother (previous owner) took it to for a complete engine rebuild read like a text book way to do an engine.

However, something is way, way off. My friend claims the car hits a wall at 4K (should go to 6K without issue) and is really hard to start. Once running, in his mind it runs fine except for the above. He mentioned this is passing not knowing how the car should work as its the only Alfa he's driven. I got alarmed looking at the all aluminum engine DOHC thinking that's not right.

Having only really worked on British cars my whole life, I offered a hand, but read everything I could. The SPICA is the mystery to me which is mechanical fuel injection.

However, it was supposedly completely rebuilt as with everything else. So I suspected the cams were timed incorrectly. Being DOHC its a breeze to verify. Found the intake cam was 1º retarded. The SPICA was not timed properly at all or even close. 6 of the 8 valve clearances were off. A bit loose ( few thou) which naturally is better than tight. Still none of those things really would account for the 4K issue.

I found the waterpump was failing and didn't want to fire the engine to check distributor timing. Its an electronic Alfa distributor from the early 80s cars which I'm told is a normal mod. Spark plug wires looked suspect and I told him to get new ones. When I went to measure their resistance I found them slathered in Vasciline at the dizzy connectors. IE the contacts inside the push on connectors on the dizzy cap.

The SPICA stop was also way off although the manual states it should be .019" hot . Cold its 3/8 of an inch or more. Interesting to see if it closes up when hot. There is also a cold start solenoid, an AF mixture solenoid and a barometric device. I'm confident once the SPICA is set up right and he still has start problems I can adjust some things. Plugs looked perfect so no need to screw with the A/F solenoid.

So what's my question? Brick wall at 4K instead of high revs to 6K. I'll check the dizzy timing naturally when the car is fired. I'm now wondering what could cause this if the cams are timed correctly?

I hope you guys don't mind me asking. Its really a tribute to your knowledge that I'm asking here.
Max71

It seems to me all you can do is correct everything you can see that is wrong then try again. If you still have problems then there may be errors that you can't see, unfortunately.

I'm hoping to get my V8 back and installed in a couple of weeks time after eight months of aggro - nervous already!
paulh4

Max, I'm not sure if you have seen this website, but it looks very good as a fault finding guide.

http://www.wesingram.com/SPICA_Roadside_Diagnosis_Nov2004.pdf

I've seen the Lucas mechanical injection system on my mates TR6, but never seen anything like this. Think I'll stick to SU's......

Andy
Andy Robinson

Wes seems to be the man and I told my friend last week to order his book. I do have that PDF I believe but just in case I'll copy it again.

I hear you!

Apart from the SPICA, I've been diving into the iginition and now believe the PO putting in a electronic ignition from a later Alfa, while popular at the time, is certainly not curved for his engine. I'm asking him to ask Wes if there's anyone in Portland or if Wes can do it. Wes is only a few hundred miles away.

There's an intersting article in R/T about the SPICA. Fascinating. As you said, I'll stick with Lucas. My brain is wired that way.


http://www.roadandtrack.com/car-culture/a26665/mechanical-fuel-injection/

Max71

Spica is a known problem with these engines and needs a lot of knowledge to set up correctly - if it is working correctly in the first place. Best to change to a couple of Delortos or Webber's...
David k Brenchley

I tend to stay away from Alfas out of habit but---all I can offer is--basics first--
Has it got a nice clean fuel filter--???
A clogged filter will stop it revving out and possibly make it hard to start as well
willy
William Revit

Yup, first thing I had him do. Two fuel filters and a SPICA filter.

Right now I'm really focusing on that dizzy curve. I know once I had mine done the MG rev'd easier. Now there's a confusion where there are Euro cams but early or late have different timing and differnt clearances.
Max71

Interesting, I know it's no help but my son briefly had a 1988 Alfa Spyder. Everything was worn out, knackered, shagged, ripped or rusty, except the engine. The engine was fantastic!

The points in the distributor did close up at some stage all by themselves. Is there any chance of fitting a known good distributor?
Mike Standring

This thread was discussed between 24/05/2017 and 08/06/2017

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