Dave is the owner of a 1974 Kenworth conventional that was re-powered in 1991 with a CPL 625 NTC 400 Cummins engine.  In 1993 Dave brought his KW to Diesel Injection in Pittsburgh, Pa. To have the engine built to 800 plus horsepower.  Around 490,000 miles into the engine Dave noticed a noise coming from the front of the engine.  Shortly after the noise was audible two thermostat housings broke, the alternator pulley on the front of the crankshaft broke and twice the flywheel bolts broke and that ruined the flywheel once.  The serpentine water pump pulley belt would not stay in the grooves and after every repair the noise still remained in the engine.

When we built his engine in 1993 a new vibration damper was installed on the front of the crankshaft.  Now keep in mind that the Cummins engineers recommend changing the viscous damper every 380,000 miles.  However, very few truck owners do so.

Dave Lanz finally grew tried of replacing parts that were breaking for no apparent reason, started reading our high performance booklet and answered his own question as to why all the breakage of parts.  His viscous damper had 110,000 miles over what was recommended by the engine company.  He called us, ordered a new damper and installed it.  The engine noise that he searched for over the past year is gone.  No further breakage of parts either.  After this experience Dave says that he will religiously change the crankshaft vibration damper every 380,000 miles.

Just think, Mr. Lanz, you could have broken the crankshaft or the camshaft.  You were lucky.  My hat is off to Dave Lanz.  He kept his cool and was very persistent in trying to find the noise problem.

  Dave is going to retire in six more years and at that time the 1974 Kenworth is going to be converted into a recreational vehicle hauler so he can cruise the highways of the USA at a more leisurely pace.

The next question is from Harry Brady in Panama City FL.  “My NTC BCII 350 won’t pull over 1600 RPM in the high side of the transmission.  I installed your high performance fuel pump and matching high flow injectors and it still only goes to 1600 RPM and then falls flat on its face.  What is wrong”?

After reviewing the specification to which we built Harry’s pump and injectors his 350 should produce 440 horsepower.  The top RPM is set for 2400 RPM and in the high side of the transmission this engine should just pull right up to 2400.

For the next 45 minutes Harry and I talked about how he set the overhead, what type of lubrication he used on the injector o rings and is the throttle shaft in the fuel pump going to wide open throttle.

Next we talked about fuel restriction and being his Kenworth is a 1980 when was the last time the fuel suction lines were replaced?  Harry stated that the filter head was on the passenger side of the truck and he has never changed the lines.  Why is your filter on the right side instead of the left side where it should be?  Harry stated that the KW was originally powered by a 430 8V92 Detroit diesel and that is where Kenworth mounted the filter.

As it turns out the fuel filter and filter head are remnants from the 8V92 Detroit and do not flow enough fuel for the NTC Cummins.  We shipped Harry our V-12 Cummins fuel filter and filter head and he replaced his suction lines with #12 Stratoflex.

After the new parts were installed I had the opportunity to speak with Mrs... Brady and she informed me that the NTC 350 Cummins will now nail you to the back of the seat in any gear.  Thank you for your help.