[remogw]

Hi All,
I am replacing my blown oil depleted 01 Trooper 3.5L engine with a rebuilt 3.2L Rodeo engine. So with that being said...I am in the process of rebuilding the engine now. I just got the block back from the machine shop, bored .020 over and new pistons. These pistons have the same oil hole configuration as the stock ones, 2 per each side of the piston. ITM Engine Components RY6791-020 Piston With Rings.

I have only ever heard about the 3.5L being oil burners. Are the 3.2L as well and should I add additional holes to each piston before I install them?
I only want to do this once, but if it is not needed I don't want to manually drill into pristine pistons unnecessarily.

Please let me know your thoughts and experience in this area.
Greg

 

[JLEMOND]

YES DRILL THE EXTRA OIL HOLES IN THE LOWER OIL RING GROOVES , OR YOU CNA BANK ON HAVING OIL BURNING PROB AGAIN AROUND 6O K MI . THEY ARE EASY TO DO AND WILL DUPLICATE THE FACTORY OIL ING CHANGE. AND WILL NOT HURT THE PISTON IN THE LEAST, IF YOU HOLE THE PISTON LOOKING STRAIGHT AT THE THRUST SIDE OF THE PISTON ONE HOLE WILL BE TO YOUR LEFT OF CENTER AND ONE WILL BE TO THE RIGHT ON EACH SIDE , MEASURE OVER THE LEFT OF THE LEFT OIL HOLE EXACTLY 18 MM AND TO THE RT OF THE RT SIDE 18 MM AND RILL A HOLE THE SAME SIZE AS THE OIL HOLE THAT IS IN THERE NOW , IF YOUR ARE USING A BATT POWERED DRILL YOU CAN ACTUALLY DRILL A HOLE JUST A TAD BIGGER THAN THE FACTORY HOLES , VERY EASY , USE A NEW SHARP DRILL BIT AND IT WILL DRILL RIGHT THRU, IT SHOULD COME OUT RIGHT AT THE EDGE OF THE PIN BOSS ON THE INSIDE , BE SURE AND CLEAN THE SHAVING ALL OUT AND THEN INSTALL YOUR NEW RINGS.

THE FACTORY PISTONS AND THE OIL HOLES DRILLED IN THE EXACT SAME SPOT I JUST DESCRIBED , AND THEN DRILLED ONE MORE OIL HOLE IN THE OPPOSITE PIN BOSS SIDE RIGHT UNDER WHERE THE WRIST PIN COMES THRU , I DONT RECCOMEND EVEN TRYING TO DRILL THERE , SINCE THEY DRILLED THE HOLE ON ABOUT A 45 DEGREE ANGLE UPWARD RIGHT THRU THE RING LAND IT WOULD BE TOUGH TO GET THAT PISTON HELD TO WHERE YOU COULD DRILL IT WITH OUT TEARING UP THE RING LAND . THE EXTRA 4 HOLES WILL BE FINE . AND THERE HAS BEEN A LOT OF THEM FINISHED LIKE THAT, I HAVE PROBABLY SOLD AT LEAST 3 DOZEN SETS OF THOSE PISTONS LIKE THAT AND DRILLED ALL OF THEM BY HAND . AND NEVER HAD A PROB , OR COMPLAINT ABOUT OIL USAGE

 

[remogw]

JLEMOND thanks for the advice. I completed drilling the pistons tonight. Used a 1/16th bit. 18mm from each original hole as suggested.
No issues, very easy as stated. Here is a link to a few photos of the job.
2001 Trooper Engine Rebuild

I already completed refurbing the heads. Lapped all of the valves and actually replaced four intake valves in the RH head. New valve oil seals and timing gear seals.
My goal tomorrow night is to install the crankshaft and plastigage the main bearings. The machine shop recommended that. They said it was not necessary to plastigage the rods since they were all just precision ground to match the crankshaft.

I will continue to update and post the photos as I go.

 

[remogw]

If anyone is interested...I have updated the pic link above showing the crankshaft install, plastigage, rings, and pistons install. I need to get some new head bolts, oil pump, and a water pump/timing belt kit still.

 

[Buster28]

Please post any pics you have, don't get to see a nice clean and shiny engine very often.

 

[remogw]

More progress this week. I have the engine mostly built. New oil pump, water pump, timing belt and bearings.
A few pics of the rod Plastigage checks. All within specs. Heads installed.
Installed starter and turned over for initial compression test.
Compression test was interesting. :?
RH Head
1=145, 3=150, 5=153
LH Head
2, 4 and 6 were all at 65 psi. Noticed air coming out of intake ports. Little inspection showed that I used the RE exhaust mark on the left cam instead of the LE mark. Doh! Corrected and results changed as expected, 2=150, 4=146, 6=150. Pics of the incorrect marks are shown if interested.
Not bad considering I just lapped all of the valves.
Pics are here...3.2L Rebuild Updates

More to follow if interested.

 

[Gilligan369]

More progress this week. I have the engine mostly built. New oil pump, water pump, timing belt and bearings.
A few pics of the rod Plastigage checks. All within specs. Heads installed.
Installed starter and turned over for initial compression test.
Compression test was interesting. :?
RH Head
1=145, 3=150, 5=153
LH Head
2, 4 and 6 were all at 65 psi. Noticed air coming out of intake ports. Little inspection showed that I used the RE exhaust mark on the left cam instead of the LE mark. Doh! Corrected and results changed as expected, 2=150, 4=146, 6=150. Pics of the incorrect marks are shown if interested.
Not bad considering I just lapped all of the valves.
Pics are here...3.2L Rebuild Updates

More to follow if interested.

Maaaan, that is pretty. Still running? What was performance compared to the 3.5