188d engine rebuild

Any tips for me on procedures for reassembling overhaul kit upper end ( for timing of engine that was a runner and injection pump was not removed)and new head since it was cracked?
Have post on main site but someone said I should post it here instead to get more help? thanks Matt
 
I don't know exactly what vintage your engine is, but old 188D's spec .014" valve lash intake and exhaust cold. The manual states .012" & .014", I don't know what's up with that.

Also depending on vintage, rocker shaft oil supply holes must match between block & head. Head has a thru hole for oil but I don't know what to look for in the block.

Some folks advocate eliminating drilled bolt behind water pump. Otherwise you're supposed to loosen it for the retorque.

If you're not removing timing cover, will be a bear to seal that up well.
 
People on here are probably sick of me harping on about this, but be sure to check your sleeve protrusion. When Case machined the early 188's there was some variance in the bore depth, resulting in some sleeves sitting a little deeper on some blocks. Case dealt with this by having head gaskets with separate fire rings; different thicknesses of fire rings were available for different sleeve protrusions. On the later 188's they had this nailed down more precisely and went with a once-piece head gasket with the integral fire rings - all one thickness. This is the head gasket that would have come with your rebuild kit. If you have one of the older engines and put on one of the new style gaskets there's a good chance it will leak antifreeze into the combustion chambers and down into the crankcase.

The old style gasket and separate fire rings of different thicknesses are still available, but it takes some skill to find. They're not listed on the Case parts books for any of the 30 series tractors. You have to go to the 188 industrial stand-alone engine catalog to find the numbers.

As WilBury noted, there's been discussion about whether the bolt behind the water pump is necessary. I've always put it in because I've heard of problems with the gasket it pinches getting loose and leaking coolant into the crankcase if it's left out or (more typically) forgotten, but I've never left it out myself so can't comment personally on whether this is true.
 
Having my 188D rebuilt & I instructed them to omit the drilled bolt. The timing cover goes on after the head and they can put a bolt in temp just till the sealant cures. Hopefully should be golden.
 
It's a 1972 188d and yes the rebuild kit head gasket is one piece ( looks like metal fire rings are already molded into head gasket)
When measurements are taken for sleeve protrusion are you checking measurements from block surface to first step up on sleeve or from block surface to top of sleeves?
Thanks Matt
 
The real truth of the matter is that the early blocks upper counterbore was not wide enough to support the sleeve properly and the sleeve would recede into the block, later blocks the counterbore was widened and that for the most part stopped sleeve recession, the early narrow flange sleeves required the fire ring gasket and the later engines can use the composite with the crimped in fire ring. We reset the sleeves on many of the narrow flange blocks by planing the top of the block and machining the narrow flange block for the later wide flange sleeves.

Have a competent machinist measure the counterbores with a depth mike and for cracks in the counterbore. Installing wide flange sleeves is the right fix as planing the block and recutting the counterbore assures flatness in the new counterbore. be very careful as the engines are very tight on top at overlap and if to much is taken off the top of the block there can be valve to piston interference. I have personally taken engines apart with many thousands of hours on them with valve prints in the valve reliefs. It would be best to check the valve to piston clearance with the piston at TDC and light springs and a dial indicator and then again with the valves on their overlap position to assure running clearance. will be watching this post as I have been down this road many times.

Before ordering sleeves make sure that you know the outside diameter of the top of the sleeve because a competent parts person is going to ask.

As far as rocker oiling, early engines oiled at the center rocker support and later at the rear support, if the block is drilled at the rear where there is a hole in the gasket, that is wher it should oil from, the early engines overoiled on top and the later metered oil through the rear cam journal as it rotated.

You did not say but if it is a pencil injector engine there is a good chance it may be wide flange and rear rocker oiling but at least now you know what to look for!

Get with John Saeli to help you out on parts.



This post was edited by mEl on 10/03/2022 at 04:51 pm.
 
Wilbury,

When I assemble those engines with the timing cover on, I just put the head down and torque it and then take a large screwdriver and drive it in at the front of the head between the timing cover and the head and spring the timing cover enough that the gasket slides in easily from the side, never used sealer and the 3 housing bolts are more than sufficient. I have never had one leak without the internal bolt in the many years I worked on them.
 
My manual shows putting a bolt in washer to hold sleeves in but I believe that's only if your doing the engine overhaul out of the frame which I'm not (I'm doing an in frame so I won't need to flip the engine upside down like on an engine stand, which I believe is the only reason they say to put bolts and washers to hold the sleeves in?)
But then I got to thinking my manual doesn't really call out how to take the sleeve protrusion measurement as in whether it's before or after putting those bolts in temporarily to hold the sleeves in? I just pressed mine in with the block and o-rings lubricated and I made sure the top recess in the block was super clean with nothing in it... The protrusion on the sleeves is where it should be but I don't have the temporary bolts holding the sleeves down with any kind of pressure, so I'm wondering what is standard when measuring sleeve protrusion (held down with temporary bolts, or just pressed in until they stop at the block recess and sound tight? Thanks Matt
 
What is the importance of using a ball to check sleeve protrusion? These tools are no longer available so I'm tempted to just use a thick steel plate on top and put a socket in between instead of a ball like in the pictures?
cvphoto137368.jpg
 
The purpose of bolts with washers to hold the sleeves is to prevent the sleeves from moving if the engine is turned over (this means rotating the crank, not flipping it upside down) as the friction of the piston rings can move the sleeves.

Using a ball between the bar and plate is intended to provide even pressure all the way around. A socket or such could put more pressure in one area than another if the bar is tightened down unevenly.

This post was edited by Jim.ME on 10/05/2022 at 03:31 am.
 
Yep, the drilled bolt behind the water pump is the one we're talking about eliminating. They want you to loosen it when you retorque the head so the head can move freely. Quite the PITA. Ideally, I want my rebuilder to replace it with a socket-head setscrew(for potential removal) with 1/2" straight threads drilled appropriately & set flush with the head, loctited & maybe staked too. I don't really know squat, I thought one used sealant on those gaskets normally but the manual doesn't mention sealant. I was going to ask them to seal it with a regular bolt overnight to cure, then put the setscrew in. I have the oldstyle timing cover. Comments mEl? No sealant on all the timing cover gaskets except at the bottom?

mEl was a Case dealership mechanic when these engines were new & bled on scads of them so you can pretty much take his word as gospel.

I went whole-hog on mine, shaved the block (.005" ?), recut the counterbores, & upgraded to the wide-flange kit. Head redone, valves flush.

I also asked them to check valve-to-piston clearance thru the overlap stroke saying I wanted at least .025" clearance before it leaves the shop. Unreasonable?

My head had the drilled rockershaft oiling bolt installed in the wrong position. The only lubrication the top end was getting was from the blowby! I went for a new valve train from a reground cam including new rocker arms (ouch) & aftermarket shafts so hopefully that'll control the over-oiling for a while, or do you think I should restrict it?

Hunt4ihhayrakeid, if I'm interfering in your thread, say so, & I'll start a different one.

This post was edited by WilBury on 10/05/2022 at 06:49 am.
 
Wilbury,
I think the purpose of the drilled bolt is to provide a recirculator for bleeding air out of the top of the head. I have never seen a hint that any engines were damages or short lived without that bolt, if you want to provide the restriction of the small, drilled bolt I seen both no problem with you doing it or leaving it out, the choice is yours.

A very minor amount of Silicone at the gasket mating surfaces where the pan gasket meets the front timing cover and the rear seal retainer unless the oil pan gasket is cork in which case use no sealer. Silicone ruins cork gaskets, it makes them slippery and they squash out.

You maybe could restrict the top oil supply but I would try it first, with the new sleeves and pistons your blowby should be minimum and the new rocker parts may slow the volume of oil down

Rocker setting, .014 served me well for years and you would never know the difference in .002 difference and most people who do this stuff only occasionally probably could not hold thar t tight a tolerance across the whole engine.

I probably missed a couple questions you asked but here are a couple things you asked about
 
Only the valve-to-piston clearance mEl. I know it's still an open question on this forum. Some say a miss is as good as a mile but I want at least some clearance. I'll post my measurements when the engine is done with new parts & flush valves. I do know the mechanic found .045" recession on some valves so the initial clearance I measured will be drastically reduced!
 
I would say .025 is a reasonable figure, I would not mind it being tighter than that but we want no collisions there. As deep as the valve reliefs are u should be good It is hard to visualize but even running at 2000 everything is close to a complete stop at tdc as the piston stops and reverses direction. Tightening things up up there will make a really nice starting engine cold if the injection system is up to the job. I was thinking about it and while you have the engine apart I definitely would replace the camshaft drive key with a hardened key, I have had to change a few of them, enough that I would not take a chance while you are close to it.
 
I specifically ordered the listed woodruff key but I'm running into a different problem now. The new crank gear is an interference fit with the new cam gear (insert rant here) but they get the same .011" backlash with old crank gear to new cam as I measured with old gear set. So will likely end up going with old crank gear (superior hardness anyway) & it almost seems silly to put the new cam gear on it if it doesn't tighten up the timing anyway. Hardness would be suspect there too. The mechanic is sleeping on it, waiting to hear from him.
 
I'm not sure I'm following you on the interference fit with .011 backlash, that backlash does not seem excessive to me. To me, interference would indicate touching with no backlash, maybe you could elaborate on that a bit, are you working with aftermarket gears, asking as you said there is a difference in hardness?
 
Specced backlash crank to cam is .0006" to .006".
My total, crank to fuel pump is .045", spec is max .030".

Yes, the aftermarket crank gear is an interference fit with the aftermarket cam gear & probably would be with the old cam gear too the mechanic said, meaning it left a mark :shock: .

As I said, he tried it with the old crank gear to new cam gear & got the same .011" I measured with both old gears.

This post was edited by WilBury on 10/06/2022 at 06:52 am.
 
I guess I would be a bit worried about quality control on the aftermarket gears, they cannot have both .011 thou clearance and interference at the same time unless it is tight at part of the rotation and loose at another point in its rotation which would mean that the gears were not concentric or had some damage. To reduce the gear backlash to spec would require gears that are cut right for the application since specs were written over Case's parts. If you found OEM gears and they were not in spec the only way to tighten them to spec would be to mill the main caps and line bore the block to bring the crank up a few thou, at what point do you say it's good enough? These accumulated clearances are why you are instructed to turn the engine in the direction of rotation when aligning the pump timing lines, to take the slack up in the gears.
 
I do have a talent for creating confusion, don't I?

The aftermarket crank gear had no backlash all around when installed. It even got marked by the new cam gear so we called it interference. I don't believe the main bearing caps got touched, only checked. The mechanic & management would have had a bird if they thought they caused the problem.

Then the old crank gear was re-installed for comparison, & it turned out to have the same .011" backlash with the new cam gear as I had with the old cam gear. Interesting...Ergo, the new crank gear is out of whack & the new cam gear might not be much of an improvement but at least it seems to be of better quality.

The verdict was to go with the old crank gear & the new cam gear and damn the torpedoes. He rechecked it & the backlash was actually improved a bit with the new cam gear after all. It's too bad I couldn't tighten up the timing a little more but yeah, it's time to call it good.

LOL, I almost posted a question about advancing the timing to compensate for worn timing gears the other day until I thought for a minute & gave myself a slap. Timing the beast will be my delight, fuel pump & injectors courtesy of Dieseltech.
 
Thank you for using Diesel Tech, He tirelessly gives advice here and sometimes I can feel his frustration at the way some posts go.

You will have no trouble timing your injection pump at all, the backlash will not be evident in the process, just do your setup in the direction of rotation to set the timing pointer and normal drag will keep the slack out of the gears, you absolutely made the right decision to go forward with assembly, you will have a fine running engine that will outlast a lot of us on here. You are paying a lot of attention to detail, truthfully, more than I would, LOL
 
Not sure if it's a blessing or a curse but if I don't have the experience on something I try to think thru every little detail. Can't see the forest thru the trees. I was lucky to have an old-timer doing the work, too. Yours & other folks advice from this forum was absolutely invaluable. Engine & crawler will definitely outlive me. Thanks!

How are you making out Matt?
 
If noone else has anything to add Matt, I'll give you my $.02 summary.

-new head? They differed in which rocker arm support carried the oil so you really must verify it matches the block supply or you'll end up with a destroyed valve train like mine did. Serial and casting numbers may help you there too.

-sleeve protrusion? Do the best you can to get a decent measurement & make your call. If you get .002" or less & you're not machining the block, I'd at least consider the fire ring option.

-drilled bolt behind water pump? Manual wants you to loosen all those bolts at the front face of the head a bit for the re-torque. Kinda makes sense. As mEl said, if you eliminate the one behind the water pump to save you from pulling the pump, there are still 3 more there to make the seal.

-valve-to-piston clearance? Those El-Cheapo valve spring compressors that work with the head on worked OK for me. Toilet paper hanger springs make excellent cheap test springs. Hopefully, you already have a dial gauge. I only did it on one pair of valves. My valve train was pretty beat up so was impossible to get accuracy, but I found closest approach during the overlap stroke was in the neighborhood of 5-6 degrees BTDC for exhaust & in the neighborhood of 4-5 degrees ATDC for the intake. Also recommended somewhere is that one should back off the adjustment on the the rocker arms at first install just in case things are in interference. Then you can bring the valve lash to spec when you know it's safe before you run it.

That's all I can think of at the moment. Any more questions & I'm sure people are happy to help.
 
I guess I do not understand where you are looking for the oil passage, on later blocks there is a drilled hole at the rear above the camshaft,, even in the earlier blocks there was a drilled hole in the center of the block dedicated to the earlier center fed oiling setup, never did the oil come up the 1/2 inch head studs, the later gaskets will have a opening in the rear to match the head drilled at the rear to go up into the rear 3/8 rocker hold down stud the stud that is drilled to oil the tappets has a different marking on the top than the 3 others, it has a symbol resembling an A as well as hardness markings. Again, none of the 1/2 head stud holes have anything to do with rocker lube drillings. If your nSN is as you stated, look at the rear hole for the rocker stand , it should be drilled clear through and match the hole in the block.
 
The thru hole I was referring to is in the head. One of the 3/8" threaded holes for the rocker arm stands goes right thru to the block, the rest are blind holes. At least that's the way it is on my old 188 & of course, mine is in the center position.
It is possible to obtain the wrong head for the block in which case this hole won't match & you'd have to get creative. That's why I'm stressing the point.
 
(reply to post at 21:00:40 10/11/22) I am trying to remember but I think at least for a time that some later blocks would oil either way, both oil passages were drilled in the block. Of course the early head will not oil in the rear rocker stud hole on a late block. I am thinking that any head would work on the old block as long as injectors and lines were used that match the head. Personally, I would not put that engine under any load till it goes through a couple of warm up to operating temperature cycles and cool downs. Others will disagree, but I would also do a retorque using the method Case recommends then a final valve lash adjustment.
 
After looking at it more my block has both
passageways drilled through them to supply
oil to the rocker arm assemblies (I was
very careful when disassembling everything
in my drilled bolt was in the rear
position and I checked my new head and it
does have a through-hole in the same rear
position so I think I'm good) thanks for
all the great info guys!
 
Yes there is a break in procedure I will
do. When retorqing the head bolts and
doing a final adjustment does that mean I
have to do this after the motor is broken
in (if that's the case I'm not going to
put the hood back on and is it possible to
do the break-in procedure without the
valve cover on? I've seen videos of guys
running diesel engines without the valve
covers on them although I'm no engine
mechanic so I don't know if that's bad for
them other than the mess of oil flying
everywhere? Thanks Matt
 
That engine will not be broken in for several hundred hours, that is a wearing in process that takes time. As I said previously several warm up and cool down cycles should put you in shape to do a retorque and do the rocker adjustments. Good luck, sounds like you are getting down to the end of the process. Running W/O the cover, just messy if there is no dirt flying around, that way you can watch for proper oiling.

This post was edited by mEl on 10/13/2022 at 05:27 am.
 
Wilbur:
I dont know what / how to use toilet paper
springs how to check valve to piston
clearance (or if I even need to do this, I
did not have the block machined down and I
bought the head remanufactured with valves
already lapped and installed by a machine
shop so is what you're talking about still
necessary?)
 
Depends who you ask. My engine rebuilder balked saying why bother? Mechanic found .045" recession on one or another valve when the spec is flush +/- .005". He brought them flush, so there goes .045". plus new valve train plus block shaved a bit. mEl scares me with his stories of marked pistons, tho could be other causes. Normal clearance is tight to begin with apparently.

Light test/checking springs in place of regular valve springs allow you to depress the valve with just finger pressure with your dial gauge on the valve spring retainer while you move the crank thru the overlap stroke. Reasonably accurate & a lot easier than claying the pistons. I already had my front hydraulic pump off so was easy to turn the crank. Also had sight of the timing marks on flywheel.

For me, I just have to know. It's my nature. I can give more details later if you want, but right now it's naptime. Comments from experienced mechanics would be better.

Hoping to talk to my rebuilder today, he just might have numbers for me.

This post was edited by WilBury on 10/13/2022 at 08:02 am.
 
The drilled hole through the head that
provides oil to the rocker arm assembly
does not travel horizontally through the
head only passes straight up through the
block through the head and into the rocker
arm cap correct? Some mud daubers decided
to plug this without me knowing until now
and I want to make sure that there's not a
blind hole that has mud in it horizontally
milled from the vertical hole? It doesn't
look like it but it's not a perfect hole
either so there's some doubt there in my
mind that I want to be sure of...
 
Good catch! Straight up as far as I know. Nothing else there to lubricate. The oil does its horizontal travel thru the rocker arm shafts.

Picking up my engine today! As far as valve to piston clearance goes they said "Piston to valve clearance, .051" intake, .049" @ zero lash." I assume the second number is exhaust, I'll check the spec sheet when I get it. I'm pretty happy with that.
 
Wil,

One thing I have noticed on ones I have done the sleeve mod is how much better the cold weather starting is improved, there is definitely enough of a Compression Ratio change to make the fuel fire easier. If you have the pump gone over and have good injectors you will notice it. You can imagine that if a bit of valve recession because of a poor valve job can affect starting as it does, how much gain there must be bringing the piston up .010.
 
(quoted from post at 08:57:48 10/14/22) Double

This post was edited by mEl on 10/14/2022 at 08:59 am.
Can anyone tell me for certain if rod bearings that are undersized .010 are the same length and od as standard size bearings?
Odd thing while reassembling rods/ pistons/ bearings( old rod I bought to replace one of mine that I didn't like looks of had .010 bearing still installed in rod end, so I removed them and when I put standard bearings in it they protruded slightly past rod ends?)
I can't image anyone would alter a rod end as to make it smaller but now that I installed it I'm having second thoughts on leaving it?
 

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