Pete 359 8v92 Detroit power upgrades

HP is all fine and dandy, But i know from experience that the torque values wont change much at all, you wont find a seat of the pants feel coming out of the hole loaded at all even if you throw 500hp at it.

 

The only way I ever found to get any HP out of those 2 stoke Detroit’s, was to slam my hand in the door before I release the brakes!!!

Drive it pissed off and you’ll really think your getting things done!!!

 

Aside from bigger injectors I have heard that some guys change the timing to get more power.

To change the timing though you have to take the back cover off of the engine.

 

We have found that timing doesn't do anything to the 92 series. You can install larger injector's, a set of 110's will be ok, 9g90's are a stock injector. You can also lower the compression in the engine with different pistons, you can spin the blower faster also, it spins at a 1:1 ratio and with the proper gearing you will spin the blower at 2.62:1 ratio that will create more air flow, then you can get a larger turbo to balance out the blower air.

The hard part, finding the gears for the blower, I have a set, but they aren't for sale. And finding big injectors for those engines are getting harder also. Keep in mind the bottom end of the 92 series engine isn't the strongest, so the added fuel adds stress to the bottom end, lower the compression and increase the air and it should balance out. Also, a good tune on the engine will help also, if you don't have a good Detroit guy, there is a Detroit diesel enthusiasts page on Facebook loaded with old wrenches and tons of information.

 

I had a 8v92 silver. Factory 475. Took out the 90 injectors and installed 100s
On the Dyno made 450 rwhp. Ran good. Never hot .

Mpg was never there strong point thou.

 

Geez, one of my favourite engines, cool.

You can start by backing off the throttle delay, (if not already done), and cranking the rpm's up to 2500 or so, not so high that the valves float.
Cummins engines float the valves around 2600 rpm, a 2 stroke is a bit more.

There's also a trick with the rack you can do, can't remember exactly how it went.
Involved removing one of the rack hold down caps at the front of the rack on the passenger side, (shaft retainer, other?), and drilling the hole a bit bigger, made the engine a lot snappier, throttle responded quicker.

Back in the 80's, I spoke with the owner of the FL dealer in London ON while waiting for my truck to be repaired.
He had a brand new FL COE tow truck with a Silver 92 that he built, real fancy at the time.
He was friendly with folks at the GM engine plant and they helped him build it.

Had marine parts on the engine, two marine mufflers for sure, (one pipe in, two pipes out, four stacks), possibly valve springs and other valve train parts, (can't remember that far back), had twin turbos for sure and #130 injectors I believe.
The engine dyno'd at 760 hp @ 2600 rpm, top speed 140 mph @ 2600 rpm.

I drove a bunch of 92's hauling big weight, trains at 135,000 lbs, when properly tuned they were beasts.
Those trucks all had 15 spds in them, but in the hills the revs never got below 1800 rpm because the governors were all set around 2400 or 2500 rpm.
Wide open they ran close to 80 mph with 3:90 rears and direct drive transmissions.

One of the local legends had a small fleet of GM Astros with 8V71's in them, some were turned up to 3000 rpm.
The advantage was, they could run one gear lower than a bigger motor and keep up with them because of the gear reduction.

But....., I know you don't want to pay the fuel bill that comes from driving them that hard.
I've seen 3 mpg with a 8V92TA rated at 445 hp in a heavy wind, imperial gallons to boot, 160 ounces compared to the US gallon at 128 ounces.
Think I saw 5 mpg on a good day, 4.0 to 4.5 mpg was sort of normal.
Company didn't care about fuel costs, they wanted their product there yesterday and paid me well to do it.

 

You'll have to elaborate on these marine injectors..this is something I've never heard of. Make sure your getting correct information before you tear into this engine. You can have a 2 cycle run away real easy if your not careful.

 

I was never a fan of the "double breasted yamaha" but then again, an engine that can run backwards...................................