Hey all, been awhile since I have posted anything constructive but the truck has been down for a year now and I am just getting ready to put it all back together.
My question as the title suggests concerns piston protrusion. This is the 1st DMAX that I have built but have built probably 50-60 other gassers so the only thing new to me here is piston protrusion.
A little history...
I sold my engine running (298,000 miles) in favor for something a bit more fresh (98,000). It was a good deal because I ended up selling mine more than what I bought the new one for. The engine came from a fire salvage and other than some very minor pitting towards the top of #5 that honed out nicely the engine was in near flawless condition as far as the long block is concerned.
The problem...
I used a complete rebuild kit including new pistons as well as rod bushings and grade C gaskets. After assembly I have the following protrusions as well as height variations... The protrusion # is a highest point and the variation is the difference between the high side and low side. All measurments where taken on either end of the pin and I verified that this has not been because of the pin bushing being honed higher than center. All figures are with ARP rod bolts being torqued to 90% of total stretch and ARP main studs tightened to spec with STD bearings.
#1 .021 / .0035 high on the front
#3 .020 / .005 high on the rear
#5 .020 / .0048 high on the rear
#7 .023 / .0045 high on the rear
#2 .019 / .005 high on the front
#4 .026 / .004 high on the front
#6 .022 / .014 high on the rear (yes this one concerns me & im pulling the rod to check for straightness.
#8 .021 / .005 high on the front
Now to me other than #6 everything is pretty well in-line so I was wondering if the pistons need to be milled. They are stockers and came direct from MAHL with rings pre-installed so I can not see them needing machining however I have not checked the height of each piston (from bottom of skirt to top of piston). One other thing to mention, I shot myself in the foot because I knew I would be using new pistons and pins so I did not bother checking all of what I listed prior to disasembly.
I know its a long post but I had to get all the info I could to you guys so we dont go back and forth.
Thanks everyone.
My question as the title suggests concerns piston protrusion. This is the 1st DMAX that I have built but have built probably 50-60 other gassers so the only thing new to me here is piston protrusion.
A little history...
I sold my engine running (298,000 miles) in favor for something a bit more fresh (98,000). It was a good deal because I ended up selling mine more than what I bought the new one for. The engine came from a fire salvage and other than some very minor pitting towards the top of #5 that honed out nicely the engine was in near flawless condition as far as the long block is concerned.
The problem...
I used a complete rebuild kit including new pistons as well as rod bushings and grade C gaskets. After assembly I have the following protrusions as well as height variations... The protrusion # is a highest point and the variation is the difference between the high side and low side. All measurments where taken on either end of the pin and I verified that this has not been because of the pin bushing being honed higher than center. All figures are with ARP rod bolts being torqued to 90% of total stretch and ARP main studs tightened to spec with STD bearings.
#1 .021 / .0035 high on the front
#3 .020 / .005 high on the rear
#5 .020 / .0048 high on the rear
#7 .023 / .0045 high on the rear
#2 .019 / .005 high on the front
#4 .026 / .004 high on the front
#6 .022 / .014 high on the rear (yes this one concerns me & im pulling the rod to check for straightness.
#8 .021 / .005 high on the front
Now to me other than #6 everything is pretty well in-line so I was wondering if the pistons need to be milled. They are stockers and came direct from MAHL with rings pre-installed so I can not see them needing machining however I have not checked the height of each piston (from bottom of skirt to top of piston). One other thing to mention, I shot myself in the foot because I knew I would be using new pistons and pins so I did not bother checking all of what I listed prior to disasembly.
I know its a long post but I had to get all the info I could to you guys so we dont go back and forth.
Thanks everyone.
