361 piston

[IA1456]

Just a quick question is it at all
possible to change a piston in a
361 from the bottom with just
taking the crank out and not
taking the head off

 

[rustred]

what is your reasoning? why would you want to do that? pistons come out the top and back in the same way. you will be doing more than a piston change.

 

[caterpillar guy]

Fighting the rings in will be more work than removing the head. It will require a split to pull the crank. Not needed to pull the head.

 

[Janicholson]

And in addition to what has been said, there could be a ring ridge that would immediately cause the top ring land to break that new piston! Jim

 

[IA1456]

The reason being have a fresh overhaul with about an hour and just started to load the engine and spun a rod bearing so have to pull the crank and rod just thinking it'd be nice not to have to pull the head

 

[Janicholson]

That makes sense, good luck, many engines have interference with main bearing bosses. JIM

 

[DeltaSteve]

Remove the engine,turn it upside down,remove pan,front and rear covers.Unbolt crank and lift it out.

 

[the tractor vet]

PULL THE HEAD . Bet you did not get the rods reconditioned . nor the engine line bored or did the .010 over bore off the crank center line or hand fit each piston to the bore it was going in or checked each hole after the sleeves were installed for any sleeve wrinkling or checked the crank for out of round . These engines are not a take the parts out of the box and stuff it together and all will be well. You are NOT the first guy to loose and engine in the first fifty hours and probably not the last . I had one guy that lost FIVE D 361's because he could do it cheaper , the sixth one he brought it to me . I have night mares over doing the D361-407 and any two stroke Detroit . At and early age i saw several old Detroits come unglued on the test stands that were rebuilt by guys that worked on the everyday .

 

[IA1456]

For what it matters I did have the rods checked and wrist pin bushings replaced. Also I am well aware that the sleeves have to be honed to fit the piston. Having worked as a machinist for over 20 years and running a cmm I am aware of wrinkling and egg shaping of the block bore.I am guilty of doing a inframe overhaul .so if you are as good at diagnostic as criticism tell me what went wrong I'm all ears

 

[the tractor vet]

Ok so you put the mic to the ends of the rod and all seamed good . With the 361 and 407 they will core shift . When i do one it is and out of frame total rebuild . After they come out of the tank the first stop is a LINE BORE , not a line hone ,then you do a .010 over bore off the center line of the Crank , then a light dusting of the deck and a recut of the counter bores , next on the list is checking rods for straightness and a dusting of the cap then a resizing . Reason for spinning a bearing is something got tight real fast due to something out of alignment or lack of lube . I have seen them lock up and shove a rod out the side of the block just after first start . I have been playen this game for many moons and built many engines since i was 15 and now heading for 75 . so yes i am grouchy , can be hard to get along with BUT i am good . Yep i make mistakes . And like i said only two engines make me nervous a Detroit and and the D -DT 361-407 . That core shift i was talking about COULD have that one hole running catty whampous to the crank . Look closely at the bearing and crank and see if you can see extra heavy riding . My one friend had the machines to get everything right with the world . His line bore was state of the art and the stationary boring bar would set up off the crank center line and would hold within .00002 . When we would do the over bore we would bore to within .0015 and hand do the rest AFTER we Miced each sleeve and finished to fit with , my mind just went dead on the press fit pressure required . Anyway this is what the gauge SHOULD read on the dual ram puller /installer on the 17 1/2 ton OTC set , God i can't believe i forgot that . anyway you had something binding up be it a piston to wall due to it not running true or to tight OR you had a lack of lube pressure on that throw . On one D T 361 we had to over bore and use a heavy wall repair sleeve on three holes to correct the shift to get the over bore inline with the crank. I will do and inchassis with the 300 and 400 engines but NONe of the rest they come out .