Rebuilding an engine, where do I start? (Page 1/2)
82-T/A [At Work] MAY 24, 02:11 PM
Hey guys, I posted something similar in my 2.5 thread in the tech section, but it was really much more specific and I had other unrelated questions.

I'm at the point where I'm going to be rebuilding the Iron Duke with my daughter, and it occurred to me that I've never actually rebuilt an engine. Most importantly, I don't actually have the right parts. The Iron Duke does not have really tight tolerances, even when built professionally, so I'm assuming it can handle a little bit of error or precision more than say, the V6/60 or a modern engine can. I'd like to do everything myself with my daughter, and not take anything to the machine shop.

Some questions I have:

1 - What tools do I need? I haven't the slightest clue... I know I need something to hone the cyl bores, but I know I also can't just order bearings and everything without measuring what I have now. How do I do that?

2 - Anyone know a decent engine rebuilding guide or video... or better still, one for rebuilding the Iron Duke? I just checked my service manual, and it doesn't really have anything about rebuilding.
Thanks!

3 - In short / simple terms... the engine runs fine right now... just down compression on a couple of cyls, so I assume it's probably in the cyl head. Why can't I say... just for example... disassemble it (tag everything), go insane with carb cleaner and degreaser, replace the crank / main / rod bearings, hone the cyl bores, install a new piston ring set, install new timing gears, and a new cam and lifters, and slap it back together? Is there anything specifically that ACTUALLY requires machining? Especially if the piston / rod assemblies are already balanced, and the pin and everything is already set, why do I need to take it all apart? Especially if the pistons appear to be in perfectly good shape?


Thanks!!!

[This message has been edited by 82-T/A [At Work] (edited 05-24-2023).]

Patrick MAY 24, 05:20 PM

As I posted Here, I think you might be jumping the gun doing a rebuild on this engine.
zkhennings MAY 24, 05:33 PM
I rebuilt a V6 in a similar manner with no machine work. A ball hone will resurface the cylinder but not change the shape. The three stone style hone will change the shape of the bore, for better or worse. I used the 3 stone style when I did mine but with no way to check the bore for roundness it is hard to know. A bore gauge can do this for you, but not cheap. I use a ball hone these days, especially if re-using the pistons.

You can use plastigage to check clearances when you install new bearings. This is cheap and easy, brake parts cleaner cleans it off very well.

I would lap the valves with a valve grinding compound and a lapping tool (piece of wood with a suction cup, cheap).

You need to use assembly lube on all bearing surfaces and anything that moves.

Keeping everything clean is of the utmost importance, I like microfibers for cleaning journals and things because they don't leave residue or scratch like shop towels.

A good torque wrench and service manual are a must. Many things are torqued to spec in certain patterns or stages.

A new set of lifters could save you a lot of headache down the road.

A nice tapered piston ring compressor is worth the $39 it costs.

Make sure your rings are not upside down, there is a dot on the side that needs to point up most of the time.

The pistons usually have a marking for which side needs to face the front of the motor.

I like 3 Bond for RTV if anything needs RTV.

Getting the bare block hot tanked and all the freeze plugs replaced may be worth it, I didn't do it though. But it is typically cheap and then you have a clean foundation.

Check the cylinder head flatness with a straight edge and feeler gauges, if it is out of spec it should be machined.

You will need a tool to compress the valve springs.

Put everything back where it came from.

Usually new headbolts are a must.

A new oil pump is smart too.

I wouldn't even remove the cam unless you have to for some reason.
shemdogg MAY 24, 07:27 PM
#1 pull the head and have it tested, while its off if the cylinders look scored- then plan on rebuilding. I would have the block tanked and checked, the crank magnafluxed, everything checked out and okayed at a machine shop then build it at home. Definitely put a new oil pump in!

shem
82-T/A [At Work] MAY 25, 05:23 PM
Just wanted to say thank you for the responses. I will do a much longer response, but didn't want you guys to think I didn't see it or didn't appreciate it, thank you very much! I'll respond later tonight...
Notorio MAY 26, 01:07 AM
Whatever you decide to do, back in High School a car friend showed me his Dad's trick for keeping bolts and small parts in order: he would take a piece of cardboard and draw the part on it (e.g. oil pan, valve cover, water pump), punch a hole in the drawing everywhere a bolt would go, then when the bolt was taken off it was stuck into the corresponding hole. Whenever I have followed his advice, it make putting the engine / brakes / whatever back together a snap. Today, with a cell phone camera, you can also make photos and videos to add more detail.
82-T/A [At Work] MAY 26, 04:07 PM

quote
Originally posted by Patrick:

As I posted Here, I think you might be jumping the gun doing a rebuild on this engine.




Thanks Patrick, yeah... I agree with you. In this case, my goal is to make my daughter's car as reliable as possible, while also teaching her how to rebuild an engine as I go through it myself. So the experience is probably more important than the extra effort. She's got all kinds of aspirations of what she wants to do when she grows up, so I try to expose her to as many things as I can in case anything particularly interests her. Hope it's cool if I brag for a minute, she's just went 5 years straight of 100% straight-As... not a single B in 5 years. I can't even imagine. When I was her age... literally, when I was her age, I was stealing my dad's liquor, knocking over Port-O-Potties at construction sites, and my friends weren't much better. I had one friend that **** on the driver's-ed car, and another that crapped in a grocery bag and hung it from a car's side mirror. My daughter on the other hand, has already written 3 novels with her friends... let alone the fact that she's managed to work WITH three people on a novel, but that the novel actually doesn't read like **** . It's perfect English, both grammatically correct, and with spectacular vernacular. Even pretty gripping. Like... she is basically the exact opposite of what I was growing up... hahaha. Anyway, I want to give her this experience, whether or not she decides to do anything with it, but she's excited.



quote
Originally posted by zkhennings:

I rebuilt a V6 in a similar manner with no machine work. A ball hone will resurface the cylinder but not change the shape. The three stone style hone will change the shape of the bore, for better or worse. I used the 3 stone style when I did mine but with no way to check the bore for roundness it is hard to know. A bore gauge can do this for you, but not cheap. I use a ball hone these days, especially if re-using the pistons.

... SNIP

I wouldn't even remove the cam unless you have to for some reason.



Man, this is fantastic... this is exactly what I was looking for, I really appreciate this. I disseminated this line by line, and here's what I wrote down...


TOOLS TO BUY:
- Cyl Bore Scope / Guage
- Cyl Ball Hone (not the 3-stone style)
- Valve Lapping Tool
- Torque Wrench
- *Service Manual
- Piston Ring Compressor (Tapered)
- *Straight-Edge
- Feeler Gauge
- Valve Spring Compressor (clamp-style)

MATERIALS:
- Plastigage
- Lots of Brake Parts Cleaner
- Valve Grinding Compound
- Assembly Lube
- Blue Shop Rags, Microfiber prior to re-assembly and lube
- 3-Bond RTV

PARTS:
- New set of roller lifters
- New Piston Ring Set (check side on install, dot up)
- New Head Bolts
- New Oil Pump (High Volume)


Couple of questions if you don't mind. What is a good torque wrench you guys recommend? I have one of the clicking-style ones, and when I tried to use it like 15 years ago, I was constantly breaking bolt heads off. It got so bad that I decided to just not use it anymore. It never clicked when it was supposed to, so I switched to the "needle-style" torque wrenches, for which I have like two of them. I really do want to get the click-style one, but I've broken two cyl head bolts on other engines when I've removed the heads, and then had to helicoil them. I mean, this was like 20 years ago, but **** ... what was I doing wrong? I have to assume the torque wrench was **** ... or I was setting it improperly. Thoughts?

I think I'm good on everything else... really appreciate this response.

Like you, I kind of want to re-assemble everything without having to machine it. I believe the bottom end is pretty solid, and will likely just need a cleaning, and new bearings would just be a plus. I assume the bearings that I take off will tell me if they are standard or oversized.

Thanks again!



quote
Originally posted by shemdogg:

#1 pull the head and have it tested, while its off if the cylinders look scored- then plan on rebuilding. I would have the block tanked and checked, the crank magnafluxed, everything checked out and okayed at a machine shop then build it at home. Definitely put a new oil pump in!

shem




Thanks Shem, definitely will get a new oil pump. The engine runs really well right now, I was planning on sending the cyl head in to have it magnafluxed, but I didn't want to go through the hassle with the block. It ran really well before I parked it in the garage 2 months ago, with no leaks or anything... so I'm hoping a simple cleaning and replacement of the bearings is all I need for the bottom end. I'll take the advice and leave the cam alone.



quote
Originally posted by Notorio:

Whatever you decide to do, back in High School a car friend showed me his Dad's trick for keeping bolts and small parts in order: he would take a piece of cardboard and draw the part on it (e.g. oil pan, valve cover, water pump), punch a hole in the drawing everywhere a bolt would go, then when the bolt was taken off it was stuck into the corresponding hole. Whenever I have followed his advice, it make putting the engine / brakes / whatever back together a snap. Today, with a cell phone camera, you can also make photos and videos to add more detail.



Yeah, I never did this in the past, and no idea how I managed to get everything back where it's supposed to go. In the past, like replacing a water pump, I'd just remove all the bolts, and then kind of put them back where I thought they fit, haha... but I've seen a lot of the car shows do this, so I will definitely do it too. Thanks!
82-T/A [At Work] MAY 26, 04:45 PM
Ok, just bought these tools.

I ended up not getting a tapered ring compressor because I don't know what size pistons I have, and I know the Duke's bore is 4", so I got one that was adjustable. I also ordered those little rubber boots that go on to protect the cyl bore when you're installing it.

Umm, only other question I had was what grit of ball hone and size... so I ordered one that was good for 3.75-4.125, and a 325 grit. I also had to look up plastigage, because I kept seeing the "gages" for sale, but didn't realize the string was inside, haha... so I found a YouTube video that explained it.


Big thing for me now is what kind of torque wrench I should get. I supposedly have a nice one, but again, twice, I've ripped the threads out of a cyl head bolt because I couldn't get the damned thing to click and just kept cranking away. I don't even want to chance it, I just want to get a new one. Any recommendations?


Thanks!!!
Spadesluck MAY 28, 11:29 AM
You should have two torque wrenches, Ft lbs and IN lbs. The ft lbs should be a beefier type for those head bolts etc. Beyond that no big deal. I have always used the "click" kind myself just because I already had them. I suppose if I were to be in the market for new ones I would get a digital kind. Not sure if one is better than the other though.

[This message has been edited by Spadesluck (edited 05-28-2023).]

armos MAY 31, 02:35 AM
You could set up an experiment to check if your click-style torque wrench is registering the same (or anywhere close) to where your other torque wrench(es?) do. That doesn't prove which one is wrong, though.
You could set up some controlled known torque on a breaker bar (maybe your daughter could stand on it) and see if the torque wrench agrees with what it should be.

As for buying a new one, I don't have any particular opinion of one to recommend.

[This message has been edited by armos (edited 05-31-2023).]