$8 boost guage

I don't like spending money but I have a boat, so I have to get creative. OK, so it's a bit more than eight bucks bc i had the low pressure gauge already. I'm rebuilding my air charge cooler and tapped a 1/4 npt hole in one side. Then I ordered a SS plug plus a barbed fitting and some pvc hose from my favorite website, McMaster-Carr. I already had the 0-15 psi gauge, as those are cheap and used for testing home gas lines, available at home depot, or better, OSH.

Normally the plug will be in place, but when I want to check the boost I'll screw in the barbed fitting with 8' of hose and the gauge on the other end.

With an old T6.354 Perkins I have no idea what kind of boost I'll see. Any guesses?

No more than 13 psi, more likely 10.
BUT boost is a function of load so you'll have to see what you get and make that a baseline.

The Perkins manual says 11.0 to 13.5 psi, obviously at full power. They give only one pressure, even though that same engine has three different ratings, 250, 220 and 185 BHP.

I'm curious what you get, and what exhaust gas temperature you see at full power.

J.S.

Driftless said:

The Perkins manual says 11.0 to 13.5 psi, obviously at full power. They give only one pressure, even though that same engine has three different ratings, 250, 220 and 185 BHP.

J.S.

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JS I believe the engine in question is the old T6.534 which is rated at 160 BHP
It has a smaller Turbocharger than the higher HP range 4 series Perkins.

FYI
The "general rule of thumb" that the truck diesel guys use is approx 1 lb of boost per 10 hp . In my experience I have found that to be close if the engine is loaded.

Driftless said:

The Perkins manual says 11.0 to 13.5 psi, obviously at full power. They give only one pressure, even though that same engine has three different ratings, 250, 220 and 185 BHP.

I'm curious what you get, and what exhaust gas temperature you see at full power.

J.S.

Click to expand...

EGT at full throttle for 30 minutes is about 920F. I'm waiting for paint to dry before putting this all back together. I'll post the findings on boost. My boat though is a bit under-propped and can reach over 2500 RPMs. I don't exceed 2400, but that's not actually WOT. If I increased the prop so it was better matched to the hull, so WOT yielded 2450, then I'd expect a higher boost pressure. (Maybe I'll toss over a drogue)

You don't want egt much higher than that. And your wot rpm is fine I wouldn't change anything