brettj3876 Posted November 6, 2018 Share Posted November 6, 2018 My dad rebuilt his 93 350 with 16.5 compression to the higher horse 15.3 kit. Went with stage 2 injectors and a bigger turbo, the. BW S475. 75/96mm 1.32ar. It has the same specs as the 171702 that the 60 series guys love. And the blixxton he's had since he bought the truck. Here's the issue. It smokes (unburnt fuel greish color) until it gets up to operating temp but then clears up mostly. We don't have an A-B light that mack says to use for adjusting the timing but my dad has it somewhere around 10.5-14 he's not 100% sure where. 93 was a change over year so we've been having difficulties finding out if we have the +10 econovance or the +20 econovance? It almost seems like the timing is too far retarded. Between gears its a trail of black longer than the 53 footer. Even on a steady pull it leaves a steady stream. From Binghamton NY to Boston mass there's some good pulls on I88 and 90 and the fan never came on once and coolant never got above 180. Pyro got up to about 925-950ish. Seems to me if it was advanced too much it would run hot but it doesn't. I'm thinking it could need to be advanced some more. Or could it be that it has a 350 file in it still and we need an ecm off a vmac1 427 or 454 to get it to run right. Mack doesnt support vmac1 anymore right? And if we updated to vmac2 the dealer would put a low NOX file in it which we dont want that bs installed. Maybe someone here has dealt with a similar problem? Seeing 40 psi and wont go over 950 on the pyro compared to 1100+ before the inframe with the blixxton Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/ Share on other sites More sharing options...
fjh Posted November 6, 2018 Share Posted November 6, 2018 Do you know if the econovance is even working? Does the sound change when the oil pressure starts!??? Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409018 Share on other sites More sharing options...
brettj3876 Posted November 6, 2018 Author Share Posted November 6, 2018 Yea econovance is working Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409025 Share on other sites More sharing options...
fjh Posted November 6, 2018 Share Posted November 6, 2018 We were handed wrong pistons once same symptoms Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409034 Share on other sites More sharing options...
theakerstwo Posted November 6, 2018 Share Posted November 6, 2018 retarded timing will cause a higher exhaust temp. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409043 Share on other sites More sharing options...
brettj3876 Posted November 6, 2018 Author Share Posted November 6, 2018 I think its either the timing is not advanced enough or the 350 file is messing up. Today my dad bumped it up to around 16 so will see how it runs. Gonna re-torque the heads and set the overhead Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409045 Share on other sites More sharing options...
fjh Posted November 7, 2018 Share Posted November 7, 2018 Let us know how it goes kind of an interesting issue if it don’t solve you problem maybe check the compression wrong pistons can lower your intended ratio! Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409053 Share on other sites More sharing options...
masterwelder Posted November 22, 2018 Share Posted November 22, 2018 How’s you’re dad like the section of I88 between Oneonta and Cobleskill? To say it’s rough would be kind! Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409779 Share on other sites More sharing options...
RobM626 Posted November 22, 2018 Share Posted November 22, 2018 12 hours ago, masterwelder said: How’s you’re dad like the section of I88 between Oneonta and Cobleskill? To say it’s rough would be kind! I was just up there last weekend actually... in my car tho. Completely different ha Quote Link to comment https://www.bigmacktrucks.com/topic/54758-timing-issue-maybe/#findComment-409812 Share on other sites More sharing options...
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