cobra95blk

Hey! Everybody! I am a diesel truck mechanic with 40 years + experience. My first 25 years was spent working on Mack Trucks---specializing on Mack engines---6 cyl. and especially Mack V8's--- 864's , 865's , 866's and early 1005 series (998 cu.in. ), known later as E9's. I left as a heavy line mechanic for dealership's ( Bruckner's in Amarillo , TX--1985-- and factory branch ( San jose , CA in 1983) since then most of my work shifted to PM and repair work for fleets. I began my diesel mechanic's apprenticeship at Dallas Mack Trucks in March of 1968. Moved back to Amarillo , TX in Nov. 1968 and finished my apprenticeship at Bruckner's Mack Trucks there. I moved to San Jose , CA and started work for Motor Truck Distributors ( A Mack factory branch ) in Aug. 1974. It seemed I had an above average apptitude for working on engines--- I started working on naturally aspirated 864's in early 1970---nobody else liked to work on the V8's---but, I did. Then , Mack came out with the Maxidyne 865 V8 at 325 hp and a little later the Thermodyne 866 V8 at 375 hp. The two engines are virtually identical inside and out. There were some production problems on the early 865's and 866's that required extensive modification in the field and these were mostly carried out when these engines came in for a rebuild. Well! WHEWW! that was a quick synopsis for now. One more thing ---I really liked these engines and when properly set up ( advance timing 6 degrees--- a couple of turns on the fuel rack in the injection pump---raise injector pop pressure 10%----set exh. valves loose--- .028 not .024; set int. valve tight----.012 not .016 , shim the puff limiter valve with 2 .100 shims--- bring the RPM's up to 2400 RPM. These engines would come alive like you wouldn't believe. I set an 866 up for a produce hauler that was putting 425 hp to the wheels!!!!! And as long as he kept the RPM's on the engine under 1800 on the flat stretches of highway ( approx. 63 MPH ) with Mack 3.17 rearends, he was getting almost 8 MPG!!! And there were other similar V8's I set up this way for Owner/operators. Of course these modifications were highly illegal by the CA. and FED EPA, but I didn't care at the time--------I just knew these engines could run if you set them up right. See Ya! Have any qestions --just ask. mackV8mechanic