Phill's Nova Project finally begins

[BlueNova]

.... I would appreciate any thoughts as to what the issue is that's causing the rough running and knocking noise?

That's great news Phill

... and you're taking the right approach by commiting to a full rebuild at a leisurely pace since your Nova's already on the road.

As for the noise, it sounds more like a top end rattle (especially when the engine is reved a bit) rather than the heavier knocking sound of the bottom end. However, if it was the top end I'd expect the engine to be running rougher.

It's difficult to make out from the video if it's smoke or condensation coming from the exhaust. Anyway, given that you're planning a full rebuild you should be able to find out what's wrong and put it right.

Really looking forward to following your rebuild

Alistair

[steve]

Can't help with the knocking noise but good to hear about the Type 4 lump

[Mikemrb]

Hi Phil is that a hydrolic tappet version of that engine, it's difficult to diagnose from the video but could be a hydrolic tappet, doubt it'll be a thrust issue as the noise doesn't go when the revs increase
Mike

[Alzax3]

Doesn't sound too healthy! I remember my type4 sounding much smoother than the type1, and it was great until the early Bosch computer (it was the injection engine) decided it didn't like living in the nasty plastic Nova! Noise wise it sounds quite 'endy', though not quite deep enough for the big ends - I can see a dramatic investagative strip-down on the cards before too long! (My cam was quite worn when I got in there many years ago) - how easy are spares for type4s?

[Phill]

Not sure if this version of the engine has hydraulic tappets - it's a 72/73 engine? My own thoughts are that the sound is the same as you might hear if a spark plug was missing, so perhaps something as simple as a missing plug (though you would expect the seller to spot that) or a damaged valve. A simple compression test should give a good indication of where to look.


I don't think it's likely to be bottom end as these engines have a reputation for durability in that area. So a top end re-build is hopefully all that would be required. Spares are available though more expensive and less ubiquitous than type 1 spares