Turbo boost gauge

Does anyone have a boost gauge on their turbo engine? I thought it might be good diagnostic tool especially for twin engine installations comparing the two readings.

Any idea what the max boost pressure might be? I was thinking of getting a couple of gauges for my twin FLs as soon as I can locate a fitting in the intake and figure out what kind of weird British thread it is.

Bob

I did hook up the one from my car for a time. My Perkins ran 14psi at WOT same as my turbodiesel car.

Not sure what use it would be.

Boost guage is nice, know a few friends with them and it can tell if you are having any type of turbo issue/intake blockage, also could be misleading, such as a fuel issue not allowing the engine to spool up would give you low boost but its fuel related. In the end I passed on adding them, basically relying on good maintenance (clean air filters, turbo wash procedure by Yanmar).

I was thinking that by comparing the two under load it might give some early indication of problems developing.

Intrigued by "turbo wash procedure by Yanmar". Could you elaborate or provide a link?

After I posted the message I remembered there was a discussion of boost gauges some time back which answered my questions.

Thanks,

Bob

I have two spray bottles, one with 8 oz of distilled water with 2 teaspoons of Dawn dish washing detergent and another with just 8 oz distilled water.

While cruising (under-load), over the course of a few minutes I spray the water/soap solution. Then I wait a bit and spray just the distilled water over a few minutes as well.

Yanmar sells turbo wash, and boat yards will do this for you, but its expensive and very easy to do it yourself.

BobH said:

I was thinking of getting a couple of gauges for my twin FLs as soon as I can locate a fitting in the intake and figure out what kind of weird British thread it is.
Bob

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I can't help you with the boost on the FL's, but the thread on the fittings are BSP. I expect it is a tapered thread, which would make it BSPT (British Standard Pipe - Tapered)

In the US, fittings are normally NPT (National Pipe Thread)

BSP threads have a 55 degree angled thread cut, vs 60 degrees on NPT threads.

Also - a BSP thread is slightly finer (19 threads per inch vs 18 TPI for NPT) on 1/4" and 3/8" fittings.

To confuse the issue, on 1/2" and 3/4"fittings, both NPT and BSP have 14 threads per inch and appear to be a match but the sealing integrity will be compromised due to the difference in thread angle.

In other words, don't mix them or you'll end up with possible leaks and cross threaded fittings.

By the way guys - BSP aren't weird threads, -Its what the rest of the world has standardised on.

Heres a link for more info.

NPT vs. BSP Pipe | Pipe and Hose

I always have used Isspro boost gages on my trucks and on one Cummins 6BTA in a boat. They sell what they call the "Turbocator" which is a boost gage and pyrometer combination.
My Cummins 270 made 30 psi of boost. My old {erkins 160 made about 14 psi. Generally speaking you'll get close to 1 psi per 10 engine hp.

jleonard said:

Generally speaking you'll get close to 1 psi per 10 engine hp.

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Interesting rule of thumb...

I have both boost and EGT.

They are both great diagnostic tools, as are fuel flow meters.

My engines and others I've seen and worked on produce almost no boost until they get up to 1800 rpm or so.

At a cruise rpm of 1400-1500 rpm there is no boost.

For the boost pressure max this may be one area you will be better served by contacting:
http://www.americandieselcorp.com/

They may even know exactly what you need.

It was hit in other posters, the EGT is far more important then boost, together real good diag.