Nord engine - rebuild or replace?

[Campbeli]

My mechanic is suggesting a top end rebuild of my 1600 engine ( there is an overheating problem which could be head gasket, burning a bit of oil too) Then the suggestion is to do the bottom end too. This then opens up the question of replacing with  a 2 litre instead.
It's a 1970 1300 junior so the engine is not original anyway. I do intend to keep the car for a while.
Anyone else recently gone through the pro's and con's ?

[aggie57]

In simple terms if you plan to keep the car a rebuild is typically better.  In my humble opinion....

[AikenDrum105]

Hee hee - can of worms - Opened !

I love talking about engine conversions with people - if you're not terribly concerned with originality and want a great street car that doesn't kill you on a work commute - I would think about a 2L TwinSpark conversion.   It's really easy these days, and not terribly expensive, to fit one of these and run it happily on carbs and a dizzy  - rather than shoe-horn in all the motronic injection gear (just to keep it simple).   

I converted my 1600 super to a 2L nord (carbs / dizzy)  and ran that way for 12 months,  and then converted to a 2L TS running the same carbs, and also running single spark (other plugs disconnected)  on a standard dizzy (with timing retarded a bit of course)   I continued to run the VVT mechanism on the TS with a simple RPM switch - not ideal,  but certainly worked well enough in that form to make me very happy I'd moved to the TS.   

I found a significant difference in torque made the car much easier to commute in (heavy traffic / stop-go etc)  and definitely more poke up the top end.  Considering that was with the same jetted / choked carbs,  and same single spark ignition  - running on a stock rebuilt nord  with 10548 cams   vs a stock rebuilt TS (flat top pistons, steeper valve angle, VVT trickery)    Both were running the same exhaust header design too (Vin's)    it's a reasonable comparison.   

Then moving to the MS3 trickery made another big leap - but that's another story ..... 

One recurring point of difference between the 1600/1750  and the 2L is the 'revviness' of the engine.    I often wonder if it's the significant extra weight of a stock 2L 105 flywheel that causes a lot of this engine 'feel', rather than just the additional stroke of the engine....   I have a stock 2L flywheel in my car, which Vin Sharp cut a significant amount of weight out of, which I think is still heavier than a 1750 unit....   Everyone's entitled to my opinion on that one

Pretty much the same rebuild cost for a TS or Nord  (but some more opportunities to up the performance on a TS cheaply - using the 1mm longer Nord rods for example)  but extra cost to pick up a TS engine to start with - I think it's well worth the extra mile of going to a TS if you can stretch, particularly if you're going to keep it for a while.   


Not sure if this post helps, or just adds to the noise.  Hope it helped a little 

Cheers,

[Campbeli]

Thanks Scott, good info. TS conversation was also suggested....but I'm not sure how I'd feel lifting the bonnet and not seeing a nord engine .

[AikenDrum105]

Oh I don't know,  here's a nice one a good friend did ....



from http://www.alfabb.com/bb/forums/sedan-1962-1977/186158-super-modified-super-3.html#post1089906

Maybe the frequency differential of lifting the bonnet and frowning a little versus applying the loud pedal and smiling a lot ...  heh heh.

Whichever way you go - a newly minted engine is a lovely thing  

[giulia_veloce]

Hi Campbeli

I sent you a PM

Robert

[Alfapride]

wow the twin spark motor looks superb - fantastic conversion there! I've seen other posts where many people have used the twin spark engine as a replacement in alfetta gtv's also and have heard nothing but praise about this upgrade -  however if you prefer originality - look at a nord engine rebuild with maybe some mild improvements to give you the extra performance.

[Campbeli]

Thanks for all the replies - that twin spark does look tasty !

[LukeC]

I have have done the TS conversion on both 105 and 116. Great in both!

My opinion as far as the lack of reviness of the 2 litre is that is was under-cammed (and slightly under-carbed). Alfa did not increase the lift and duration of the cams to match the engine changes from the 1750.

I went from a Nord with 116 RW kW to a TS with 106 RW kW in my GTa-R back in 1998. The TS was a much nicer animal for everyday use, even on Canberra's uncongested roads. They both ran the same (45 mm) carbs and 4-1 headers.

Unless you can do the conversion yourself, and get a good TS engine at the right price, I think a 2 Litre nord with a few well chosen improvements is the way to go. Yesterday, the guy I sold my old Nord engine to rang me asking about putting a TS into his Super (the Nord is still going strong 15 years later, but he has got the TS bug). I have got a fresh TS engine with super-duper head and 11:1 comp sitting in my shed, but I have to be honest and tell him that unless he has some serious $$$ (did some quick number crunching) and really wants a TS, that he should stay with the 2 litre Nord and give it a freshen up.

Glad I did it though...

[Alfapride]

Hi LukeC, what 'quick win' recommendations would you give to improve the nord engine?

[LukeC]

Now this is a bigger can of worms....

This is my opinion only:

If the question is: I have a really healthy 2 litre Nord, and I want to get more power without opening up the engine (lifting the head) and not change the power characteristics. You are limited to cams (maybe just the inlet ~ 11 mm lift and a smidgen more duration than stock), headers and 34 mm chokes in the carbs. This would give a nice boost to power (I reckon 15-ish) without making the engine cammy down low.

If you are rebuilding, then start with the above and add porting, seats (45* inlets), 10:1 pistons....