3406b pyrometer temps

Was the truck being run flat on the floor or feathering the fuel petal when it was showing 700 degrees?

 

Sounds like you have a good motor set like it came from factory, if you turn the screws to it you may have more power but you will have to be care/full with hard pulls and be watching the heat going up into destruct levels,

 

If you have a temp gun you can stop somewhere safe to get a ballpark reading after a pull.

 

Temperatures drops fast when you stop.

 

i have a 88 b model 7fb engine, my probe and line from prob to gage is new, engine is advanced to 31 degrees all in , fuel and torque screws turned out 6 turnes each, getting about 34-35 psi full boost, my pyro with hit 800 if i lug it wich i don't usually on hard long pulls ill only run 700 mabe 750, i was told by gye who timed it and turned it up to get out of it at about 1050 to becsafe but it dont even come close to that temp

 

Tj 379...idk if your talking pre of post turbo on the 1050° but either way its too hot...you can run them at 850° post turbo all day and the pistons wont crack...900° and theyll be junk in 150-300miles and thats being concervative. The reason they crack worse when timing is advanced too much is the amount the crown expands during spool up...its a huge amount in the stock all aluminum pistons...thing about this every time you tromp on the throttle the piston expands, when you let off it retracts...seing how alumunum is so prone to fatigue eventually they will fail from heat fatigue to the crown of the piston...seing how the aluminum pistons have a steel piston ring land cast into the crown and skirt design them two things alone will cause the crown to seperate from steel ring land and early on they will show themselfes as small heat cracks and further down the road a chunk will break off and bend valves...some times a portion of the crown bends/lifts and will sound like a nock..thats usually the piston rocking in the severly totally liner is what makes it nock...and the motor usually miss because it will wack a valve in its piston crown issue. All these reasons are why i always convert to steel crowns...theyre available in compress ratios frm 13:1, 14:1, 14.6:1, 15.9:1, and 16.4:1...these will all worm work great as long as you have the large rod journal crank, and the correct fuel injector nozzles, piston cooling nozzles. And oil pump OR-1792 releif valve spring with 2 extra 1/2" shimms between plunger and their releif valve on the fiter housing....then just back your screw towards the one on back of pump under the the fuel shutoff solenoid man would the old thermostat ever push it some cold! lop.

 

post turbo about 6 inches, i never come close to even 900 , like i said mabe 750, if it does rise ill down shift to to raise boost to get some more air threw it, but downshifting is rare , it pulls like crazy