D25 Engine Rebuild thread

[bamfordsgarage]

So we finally pulled the engine out yesterday. Clearly I'm going to have to pick up the pace to be running in the rebuild in early February. Thanks to all those who suggested I remove the transmission first and leave the fenders on. Right on both counts. This garage has a 9' ceiling, and we were able to get the lump just high enough to clear the horns and come over the front even with the front wheels still on dollies (6 extra inches).

Interesting to think that engine was in the hole for 64 straight years until yesterday. And today I start scraping off 64 years of oil, grease, mud and dirt.

Another question for those wiser and more experienced... it would suit me to bolt my engine stand to the back of the bellhousing for initial cleaning and disassembly. However, any photos of engines-on-stands I've found on forum show the stand bolted to the back of the block, with bellhousing and clutch etc. removed. I'm nervous about the strain on the stand bolts from the bigger cantilever and reduced vertical span of a bellhousing mount, but will do it if others have found it to be safe. My stand is similar to the third picture below showing boxer inv's engine and stand earlier this year.

Opinions, experience?

[Plymouthy Adams]

Interesting to think that engine was in the hole for 64 straight years until yesterday. And today I start scraping off 64 years of oil, grease, mud and dirt.

in the future kindly refer to this by it's proper name "Undercoatney"

[greg g]

Depends on your stand and its weight rating. I use a 1000 pounder from Harbor freight and bolted it to the block. I was very carefull during the times where I needed to move and or rotate the engine. It wasn't over stressed but I think the 1000 pound rating may be a bit exagerated with the Chinese steel....

Your picture #1 represents the point where my engine was when the cinch bolt on the boom extension gave up it meager frictional influence on the boom, allowing it to telescope back into the lower arm. This is where the taking the car off the dollies and lettnig the air out of the tires process began...

[Niel Hoback]

Opinion only.

There is no benefit to leaving the bell housing on the block during disassembly. But there are drawbacks as you mentioned the extended length will make it less stable. More important, removing the bell housing, clutch and flywheel give you better access to the rear main bearing and those parts are easier to clean when they are off the block.

My biggest concern would be tipping it over. I would not consider using a three wheeled stand, thats just asking for trouble.

I wore steel capped shoes with metatarsal guards for 40 years, this is the reason. Heavy hunks of metal on your foot can really hurt.

[Plymouthy Adams]

the joint at the bellhousing/block is very strong and you should not have any reason to be overconcerned if it will support the weight or not...this joint is how it is supported in the car...rear mounts are on the bell..so block weight is suspended across the joint and with an added twist of torque on acceleration...take the housing and flywheel off and go from there..if you are going this deep you will want to resurface the flywheel as it is..basic economics on pay me now or pay me later book keeping..

[greg g]

Depending on the condition of the flywheel ring gear, you may want to have your machine shop flip to deal with any worn teeth. Your machinist is goint to want the bell and flywheel off any way so you might as well pull it.

[Don Coatney]

Before you remove the flywheel mark it as pictured. It will only line up with the bolt holes one way. Also if you re-surface the flywheel it should be ground and not turned on a lathe. The flywheel developes hard spots over time and these hard spots will make a lathe tool chatter and not give a true cut. A grinder will remove the hard spots.

[Niel Hoback]

Don, I see your three little punch marks lined up. Wish I'd thought of that last summer. I'm using an eight hole wheel on a four hole crank and that would have saved me a bunch of pain. Thanks for the education.

Edited December 16, 2011 by Niel Hoback
typo

[Merle Coggins]

When I redid my clutch a couple of winters ago I remembered to mark the flange and FD unit for realignment on reassembly. I used a paint pen marker. All was good until I cleaned up the surfaces with Brake Clean and a rag before assembly and wiped off the mark.

Punch marks would have been better.

Merle

[JerseyHarold]

I've got the 4-wheeled HF 1000# engine stand, and the engine sagged on it. I propped-up the front of the engine with wood for extra security.

[Roger the Dodger]

I've got the 4-wheeled HF 1000# engine stand, and the engine sagged on it. I propped-up the front of the engine with wood for extra security.

Same for me, only instead of wood I used a spare hydraulic bottle jack, with a flat piece of wood on the sump

Roger.

[bamfordsgarage]

It appears, Neil, Tim, Shel and Greg, I gave the impression I hoped to complete this project without removing the bellhousing and flywheel et al — not so! I just like to do an initial cleaning before disassembly, then further clean the individual items after they come off. It seemed risky to bolt the bellhousing directly to my stand so I left the engine dangling from my hoist while I scraped off the first few pounds of underCoatney. As I don't plan to paint and detail the engine before re-installation, I mostly used plastic scrapers to avoid scratching what's left of the factory paint — going for the look of reasonably-clean-but-otherwise-untouched when I'm done. Don, thanks for the flywheel disassembly tip.

And a tip for forum members who occasionally need large sturdy pieces of cardboard — auto-glass shops often have lots of spare cardboard sleeves free for the asking. I used one opened as a Vee under the engine to catch most of the scrapings.

Photos: Engine dangling with my 1250 Chinese Lb stand at the ready; Oiley goo droozeling out of the water jacket; paint coming off by the square inch, auto glass sleeve.

[greg g]

Your stand looks stout enough to handle the task. Besides the engine should be at leat 10 pounds lighter already.... What is the yellow matter custard dripping from your petcock???? God, I'm sorry that just didn't sound right did it???

[Joe Flanagan]

For what it's worth, I used the same Harbor Freight stand as Greg. My engine was on it for about seven years and I did not use grade 8 bolts.

The only thing I can add to what others have said is make sure you insert the flywheel bolts through the crank flange before you put the rear main bearing cap on. Otherwise, you won't be able to get them in. I don't know if this was in your plans but I'd yank all the welch plugs and give the water jackets a thorough blasting with the hose. I tipped my block on end, flipped it every which way and shot water through it in all different directions to force the crud out. Looks like you may have a good amount of it in that block.

[Aussie D25]

DUDE!,

Please post every thing that you do! down to measuments, tools used, a billion photos from every conceivable angle...you get the idea.

I have never rebuilt an engine and picked up a "parts" engine that I hope to learn on without wrecking the one that actually goes... cause I is smarts.

I figure if I can get that one right I can put it in my hudson and then go about doing an even better job on my D25... 37 Terraplane parts are like unicorn poop here in Australia so I'm just going to yank out the original motor and sell it off to funds the rest of the build.

POST EVERYTHING!

[greg g]

Don't over complicate things Aussie25, it's like 6 briggs and stratons in a row. In fact it may be worth a few bucks to buy a junk one and tear it down and then put it back together...

Of course there are some differeces, water pumps and fuel and oil pumps but nothing to get over excited about.

[bamfordsgarage]

Some progress — and an exercise in patience — today as the manifolds came off and the Welch plugs came out.

I was at least three hours on the manifolds... reading past posts made me aware of the "hidden" studs and with the engine out it was easy to find them. All the nuts came off easily and a few brought their studs along for the ride. That was the easy part — from there on the manifolds fought me every step of the way. The rust build-up between the studs and the manifold ear holes was such that several hours of tapping, wedging, and jiggling was required to finally pry them loose. It could have gone faster but I was afraid of busting off an ear or otherwise damaging the castings. The main culprit was the long stud between #2I and #2E (photo). This is not a job I would want to do with the engine still in the car.

The Welch plugs were a piece of cake by comparison. Only the top front hole gave any real resistance, where a long-defunct immersion block heater was very firmly planted in the hole. Joe, your suggestion to remove the plugs and flush out the block was right on — the lower holes were almost half-ways filled with crud.

Photos: Two hours to move the manifolds 1/4"; Resistance right to the bitter end — a chisel hammered between two horizontal punches finished the removal; The long stud at cylinder #2 was the worst offender, the centre/lower stud was also a toughie; Left-hand side showing four Welch plugs and the immersion water heater in the upper front hole; Lower front hole (and the lower rear) were half-filled with 64 years of crud.

Edited December 18, 2011 by bamfordsgarage

[Frank Elder]

Chris, it's looking like progress:)don't forget to extract the block drain/petcock as there will be more crud hiding in that passage also.

Do you have some brass bristle bore brushes [try saying that real fast a couple X lol] they really will come in handy as you attempt to remove the muck.

[greg g]

There are two or three welsh plugs behind the flywheel. One of which I believe is directly behind the cam. Don't forget those.

[Don Coatney]

Welsh plug removal trick. Self tapping screw and a pry bar.

[P-12 Tommy]

I was looking at your engine and noticed the draft tube was pointing straight down. It's supposed to be pointing towards the rear to make it ventilate better. Right guys?

Tom

[RobertKB]

I was looking at your engine and noticed the draft tube was pointing straight down. It's supposed to be pointing towards the rear to make it ventilate better. Right guys?

Tom

No, the draft tube points straight down. It is the pressure inside the crackcase that causes any ventilation out of the tube.

[Don Coatney]

No, the draft tube points straight down. It is the pressure inside the crackcase that causes any ventilation out of the tube.

Yes and no. A healthy engine should not have any pressure inside the crankcase. The bottom of the tube is cut at about a 45 degree angle. When the vehicle is in forward motion this angle cut creates an eddy current or a slight reduction in atmospheric pressure so it actually pulls the fumes from the crankcase when the vehicle is in motion.

[greg g]

The balogna cut at the bottom of the tube, creates and area of low pressure at the bottom of the tube as the airflow from vehicle speed moves around it. This low pressure rather than pressure build up in the crank case is what draws out the vapor. See Bernoulli's principle.

As such the pipe should be vertical so as to expose the greatest area of the cut portion to the air stream.

[greg g]

Opps stereo replies. Great minds think alike?? More likely; Fools seldom disagree!!