fitting a rev counter??

[crosser]

hi all...   im building a new instrument panel for my boat and wondered how hard it would be to add a rev counter and oil pressure gauge? 

i have a nanni 3.21 engine with just basic water temp gauge at the moment...   any advice would be great... 

[WotEver]

Take a look at your alternator.  Does it have an unused 'W' terminal on the back?

[crosser]

ah right, i will need to have a look...  does it mean i cant if there isnt?

 

[ditchcrawler]

3 minutes ago, crosser said:

ah right, i will need to have a look...  does it mean i cant if there isnt?

 

You could get one added

 

[Alan de Enfield]

5 minutes ago, crosser said:

ah right, i will need to have a look...  does it mean i cant if there isnt?

 

Its an easy job if you have it.

[crosser]

fingers crossed i have that...  cheers...   any idea on an oil pressure gauge?  i brought a set of 3 gauges and i know i can fit the water temp and volt gauge and just wondered if i could plumb in the oil one?

[PaulJ]

3 minutes ago, crosser said:

fingers crossed i have that...  cheers...   any idea on an oil pressure gauge?  i brought a set of 3 gauges and i know i can fit the water temp and volt gauge and just wondered if i could plumb in the oil one?

Should be easy enough-you will probably need a T piece /adapter though if you want to keep the oil light/buzzer though ?

[ditchcrawler]

Have you got a sender with your oil pressure gauge ?

[crosser]

i have the sender but no pipework...     

[ditchcrawler]

8 minutes ago, crosser said:

i have the sender but no pipework...     

Is it an electrical sender of capillary ?

[crosser]

its a capillary sender ....     

[Boater Sam]

From poor memory the capillary on mine is 1/8" nylon pipe or 3mm with copper olives.

You need a tee piece if you retain the warning system.  Nanni should tell you which thread you need.  Older engines are 1/8" BSP.

 

Tacho is + and - connections and "W" to alternator. That's for a non inductive tacho for diesel engines not an inductive for spark ignition, petrol, engines.

The "W" terminal is just a connection to one phase on the stator in the alternator before the diode, easy to put in if its not there already. Not particularly accurate. pulley sizes affect the output.

Edited January 9, 2019 by Boater Sam
added more

[frangar]

You could always fit a TinyTach. That way you don’t have to worry about pulley ratios or W connections. 

 

https://www.tinytach.com/diesel-tinytach

 

And this is the UK distributor

 

http://www.tinytachuk.com/diesel.php

 

[GUMPY]

If using the W terminal you will need some form of external tach to set/calibrate the tach running from the W terminal.

https://www.amazon.co.uk/dp/B077FY7J72/ref=asc_df_B077FY7J7257936539/?tag=googshopuk-21&creative=22146&creativeASIN=B077FY7J72&linkCode=df0&hvadid=231965104222&hvpos=1o7&hvnetw=g&hvrand=2024002992535124894&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=1006547&hvtargid=pla-431862248608

[Tony Brooks]

Make sure whatever tacho you buy it is NOT for use on petrol engined cars that often connected it to the coil LT terminal. That is what Sam calls an inductive tacho. You need one for a diesel engine that connects to the alternator phase tap (W terminal or flylead soldered to one of the diodes inside the alternator).

[jonathanA]

“  Nanni should tell you which thread you need.  Older engines are 1/8" BSP”

 

just be careful many engines use NPT threads which is very close but not compatible with BSP.

 

although I have seen the weak in t’head but strong in t’arm manage it (nearly)

 

I would be tempted to fit an electrical gauge and sender they are cheap enough on fleabay rather than have to run a capillary tube. 

Edited January 9, 2019 by jonathanA

[crosser]

thanks everyone for all your advice...   i didnt even realise you could get electronic oil pressure gauges, do they just connect to the sensor for the oil light...  will be so much easier than trying to fit pipe and sender etc....   

[WotEver]

14 minutes ago, crosser said:

thanks everyone for all your advice...   i didnt even realise you could get electronic oil pressure gauges, do they just connect to the sensor for the oil light...  will be so much easier than trying to fit pipe and sender etc....   

No, you still need a T-piece if you want to keep the oil light. The gauge is matched to a sender which screws into the block. 

[Jen-in-Wellies]

On 08/01/2019 at 23:10, crosser said:

its a capillary sender ....     

 

1 hour ago, crosser said:

thanks everyone for all your advice...   i didnt even realise you could get electronic oil pressure gauges, do they just connect to the sensor for the oil light...  will be so much easier than trying to fit pipe and sender etc....   

If you decide to go with an electronic sender, you will need a new oil pressure gauge, matched to that sender. The capillary gauge could go on ebay.

1 hour ago, WotEver said:

No, you still need a T-piece if you want to keep the oil light. The gauge is matched to a sender which screws into the block. 

There are some combined pressure gauge and oil pressure warning light senders around, which will screw in to the engine block and negate the need for a T piece and the extra complication and joints it needs. VDO do them, for example. If @crosser bought a VDO oil pressure gauge and a matched pressure sensor, with integral warning contact switch, then this would be the simplest way of getting the combination desired. As  @jonathanA says, be careful of the thread type. Many oil pressure ports in engines are NPT, not BSP and some are various fine pitch metric threads,  so get a suitably matched sender once you find out what thread Nanni use.

 

Jen

Edited January 10, 2019 by Jen-in-Wellies

[WotEver]

12 minutes ago, Jen-in-Wellies said:

There are some combined pressure gauge and oil pressure warning light senders around, which will screw in to the engine block and negate the need for a T piece and the extra complication and joints it needs.

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