Phill's Nova Project finally begins

[BlueNova]

Thanks Alistair

Just a thought - would it be worthwhile fitting the weber 32/36 that came with the engine onto my 1300cc twinport in the meantime? Any idea what sort of power increase it would provide?

I'm not an expert on carbs Phill, but it sounds like an interesting idea .... only thing that strikes me is would the inlet manifold for the 32/36 fit your 1300 heads, and would there be enough space for the 32/36 to clear the fan shroud and dynamo on the 1300?

[Dirk]

Thanks Alistair

Just a thought - would it be worthwhile fitting the weber 32/36 that came with the engine onto my 1300cc twinport in the meantime? Any idea what sort of power increase it would provide?

I am sure it would be a lot of messing without a huge gain, jets would probably have to be changed just to change them back again for the new engine

Dirk

[Mikemrb]

Thanks Alistair

Just a thought - would it be worthwhile fitting the weber 32/36 that came with the engine onto my 1300cc twinport in the meantime? Any idea what sort of power increase it would provide?

Hi Phil I doubt you would even notice any power difference changing the carb, if you really wanted to do it and it’s a weber DFEV here’s a starting point
26mm Primary venturi (fixed)
27mm Secondary venturi (fixed)
137 Primary main jet
140 Secondary main jet
F6 Primary emulsion tube
F6 Secondary emulsion tube
165 Primary air corrector jet
160 Secondary air corrector jet
45 Primary idle jet
50 Secondary idle jet
65 Pump jet
2.00 Needle valve.
Unfortunately there is a misconception of just sticking big carbs on an engine will make it a lot more powerful ,unless the engine can breathe ,i.e. moding the head ,valves,cam,exhaust etc. the gain is minimal
Mike

[Phill]

Thanks for all the advice. A suitable manifold is about £180 so given that this would only be temporary, and with minimal performance gains I think I'll put the idea on hold

[Peter]

[QUOTE=Phill;135976]Thanks for all the advice. A suitable manifold is about £180 so given that this would only be temporary, and with minimal performance gains I think I'll put the idea on hold[/QUOTE]

Good idea, as one thing leads to another it can soon become a major undertaking. bigger carb' leads to new manifold, which means porting to match and no real benefit until bigger valves (new heads) bigger pots and pistons, cam, exhaust, etc etc..
You end up with 110hp screamer and 2,500 quid out of pocket.

Z67YSX.jpg

[Phill]

Thanks to Dirk who very kindly sent me an old transaxle casing I was able to check the compressions on my type 4 engine, and was even able to start it and run it for a few minutes.

As expected, it's running rough with a nasty metallic thrumming noise though it's difficult to tell exactly where the noise is coming from but seems to be on the side containing cylinders 1 & 2

The compression figures are as follows:-

Cylinder 1 - 85
Cylinder 2 - 120
Cylinder 3 - 110
Cylinder 4 - 115

I rechecked No. 1 cylinder a few times and it's definitely down compared to the others

I managed to take some video of it running today, but apologies for the poor quality - but it does at least let you hear the noise that it's making.

I would appreciate any suggestions as to the issue?

Videos here:-

https://youtu.be/1lZHV9o2-6s
https://youtu.be/GXxCdU3iMU0
https://youtu.be/p622lI0mgek

[BlueNova]

Thanks to Dirk who very kindly sent me an old transaxle casing

.......

As expected, it's running rough with a nasty metallic thrumming noise though it's difficult to tell exactly where the noise is coming from but seems to be on the side containing cylinders 1 & 2

.......

I rechecked No. 1 cylinder a few times and it's definitely down compared to the others

......

I would appreciate any suggestions as to the issue?

Top man Dirk!!

Still difficult to diagnose, but given the sound appears to be coming from the 1&2 side and the compression is down on 1, I'd be tempted to start the strip down by removing the head and cylinders on that side