Should I attempt lower end rebuild myself?

[2wrench]

Sounds like: Look at me. Do I look like I have high
blood pressure?

So I have replaced, over the years, nearly every kind of
engine bolt-on items. Appreciate the concept of fuel
and spark at proper times in proper amounts. Do have a
host of tools accumulated and garage space. Do have
an engine stand. Do have compressor. Do have a son
with mechanic shop experience enough to be dangerous,
but can also be a good help.

My '74 TR6 had top end of engine rebuilt and has low
thousands of miles on it. Bottom end is sucking and
burning oil. (Not my own observation, but rather suggested
by other mechanic types.) So needs rings, whatever else.

Though I've never pulled an engine from a frame, I am
tempted to try to do so with the help of the forum.
Never having removed nor dismantled an engine personally,
is it just crazy to consider? Do you folks think you
could walk me through this?

I could envision the scope of the thing expanding as
in: Might as well do "this" while in there. Was successful
in putting in the new dash pad and tearing the dash
apart, refinishing the wood dash, etc.

Thoughts/suggestions regarding possible scope of work
and cost range would be nice to hear.

Should I just pay somebody cause it just ain't worth
it?

Whatdaya say?

 

[TR6oldtimer]

An engine rebuild is not as big a technical challenge as say a transmission would be. The tools needed are readily available and not very expensive. I think you can do this if you have patience and the ability to pay attention to detail.

I would go for it.

 

[jdubois]

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I pulled an MGB motor and rebuilt the whole thing (except for the machining work) without any previous experience. No big deal. Lots of fun. Just take your time, and make sure you keep everything spotlessly clean.

 

[Brosky]

Just as long as you're prepared for the inevitable "hidden extras" that add $$ to the project. Once you take it out, there is only one way to do it and that is the right way.

You don't have to modify it for racing, but crank refinishing, cam bearings, etc., will all need to be considered, depending on the wear that exists.

Don't neglect the clutch and flywheel while it's apart.

 

[TR3driver]

I'll add my ditto : Go for it !

There are all sorts of expensive special tools you could buy, but you can do a quite good job with just feeler gauges and Plastigage and a little creativity. Instead of a $500 bore gauge, use a piston ring & feeler gauges, etc.

The workshop manuals actually cover the process very well, likely you won't even need our help.

 

[RonMacPherson]

Not that complex an operation, considering you stated you have done a lot of mechanicals. Do you have a Bentley manual? That will get you over a lot of "what should I do now" questions. Plus forum responders should answer most of your questions.

And there are a lot of web site listings on people who HAVE rebuilt their TR6 engines and they should be able to help you on the "what to watch out for's".

Brosky did hit on two of the basics, that I would consider for any 6 engine. Install cam bearings. For that you will need a machine shop that can line bore an inline 6 block. Most shops that do truck engine work should be able to undertake that for you. Possibly a rebore to the next size larger pistons, crank regrind if necessary, but the shop should be able to measure cyl wall bore and runout and crank thickness and runout. Pin the thrust bearings, a good flush, replace the studs with heavy duty, go over the front seal installation several times(or upgrade if possible) and you should be able to do it with basic hand tools, piston ring compressor, and a torque wrench, lint free rags, compressor or some source of air to blow things clean.

 

[Mickey Richaud]

There's nothing like the satisfaction of hearing a freshly rebuilt engine fire up, and saying, "I DID THAT!"

Find a reliable machine shop to check everything out: size the rings and bearings, flush the block, etc., and spend a few extra dollars to have them balance the crank and rods.

Mickey

 

[70herald]

I rebuilt my herald engine last year. Very similar, just a two cylinders less. There is really nothing complicated in these engines. It just comes down to cleanliness, double and triple checking every thing you do and patience. The only "special" tools you need are: torque wrench / feeler gauge / piston ring clamp and ideally a dial indicator.

Choose a good machine shop, and listen to their advice.
Ideally, you will be able to find a shop with LBC experience, but if they are good it shouldn't really matter. If they tell you that the crank / camshaft / ... needs /doesn't need grinding listen to them.

You should have the machine shop make measurements (such as cyl, crank diameter/roundness cam shaft bearings in any case. Any of those measurements are very much influenced by the skill of whoever is measuring. let a pro do them.

Disassemble everything, take photos and MARK the location / direction of main bearing caps and connecting rod caps. I reused the original bolts in the engine since they all were in very good condition. When I went to reinstall the head reusing the original studs caused me significant grief, and eventually, I ordered a set from ARP, which is what I probably should have done in the first place.

Also it will take twice as long as you planned, and will not really be cheaper than ordering one, but there is that satisfaction when you get it all together.

 

[TexasKnucklehead]

Actually... if you can find a shop willing to do the work, and get in the waiting line, and they do it, I think you'll find you could do it faster and better yourself (and maybe cheaper).

Take pictures before you take things apart. Label everything. Both sides. Make notes on why some things are installed a certain way. At least pull the motor out and tear it down. Most machine shops will offer to re-assemble the motor for you (small fee included), in case you don't trust yourself. But you need to remember, it's not rocket science, it's an engine. With the right attitude, it can be a lot of fun. Go for it.

 

[2wrench]

The Bently Manual is on back order but is in the
pipeline. I have no idea what that means, in terms of
time.

I was thinking that maybe the rebuilt wouldn't be so
expensive as the top end was recently done. I do
anticipate wanting to change out stuff just to be
sure it's good, so could just consider doing the whole
thing all over again, but if stuff looks really great,
why toss it? I don't know, never done this before.

Also, of course, we have the added issue of attacking
the engine bay -- wiring and other stuff in there jumps
out crying to look new.

Ever stood at the very edge of that rock over the water and looked down and the distance sort of sent a chill down your
spine before you jumped? Not exactly the same, but I
do hesitate cause I know I'll miss my driving while I'm
working on her.

With a little more time and a little more research and
prompting, I'll probably do this. Seems the first thing
is to get the Bently manual and read.

Thanks for your responses. I am archiving for reference.

 

[Guest]

Couple of questions, 2Wrench. How many miles does the short block have on it and has it ever, to your knowledge, ever been overhauled? The reason I ask is you may well need more than just a ring job. If you have any slap in your pistons (out-of-round cylinders), you will need more than a ring job. This can and should be measured with the proper tools. Is your crank in good shape? How much crud do you have in the water jacket of your block? These question point to any block that is really in need of a complete overhaul, all of which will be out of your reach without the services of a good machine shop. If you have a really tired engine, and plan on pulling it to do a complete overhaul, this is really a job for someone that can do things such as boiling out your block to clean the water jackets and change all freeze (casting) plugs, perhaps bore your cylinders and turn your crank. If it is just a matter of honing your cylinders and replacing the rings and all bearings then you may well be equipped to do so. Just have someone check all tolerances and don't cut any corners.
My engine was quite tired and needed a major overhaul when I rebuilt everything. I too am pretty good at bolting things on but needed the services of a good machinist to bore and sleeve (yes, sleeve) my engine and turn my crank. I was fortunate 5 years ago to have availability of Vandervall bearings and such; just make sure that whatever brand of bearing you use is the best available (check with Moss and/or TRF tech dept.). And remember...clean is everything when you are going back in with new guts.
So, I will veer from the other opinions and say get a good shop to help. May be cheaper in the long run.

 

[70herald]

Bill, I don't think ANYONE was suggesting that he bore the cylinders by himself!

 

[70herald]

I was thinking that maybe the rebuilt wouldn't be so
expensive as the top end was recently done. I do
anticipate wanting to change out stuff just to be
sure it's good, so could just consider doing the whole
thing all over again, but if stuff looks really great,
why toss it? I don't know, never done this before.

On my engine I wound up replacing:
pistons, bearings, all gaskets, oil seals, cam followers, timing chain, and tensioner. Other than the pistons which the machine shop will decide if you need, this is about a minimum list of parts needed.

At the same time, several other parts such as the timing chain wheels were in very good condition. The machine shop said my crank and camshaft were fine as is. I used parts from two different used oil pumps, get a one that was tightly in spec. Basically, as you take stuff apart, you have to inspect each bit for signs of wear, but keep in min

 

[jdubois]

The Bently Manual is on back order but is in the
pipeline. I have no idea what that means, in terms of
time.

If you don't want to wait for Bentley, you can get the WSM on CDROM

 

[Guest]

Here's a safe idea.
You live in CA, the no rust capital of the USA auto world.
Why not rebuild one from a junk yard while you are still capable of using your own. There must be hundreds of donor TR6 engines in CA. Then, rebuild the one that comes out of your car and you will have two!

 

[tomshobby]

I have rebuilt a lot of engines both as a hobbiest and as a professional. When it came time for my TR6 engine I found the best professional rebuilder I could find. I removed the bolt on parts and delivered it. He finished the disassembly, did the machining, and assembled the moving parts.

Not only does it run great but I also have a guarantee.

 

[YankeeTR]

Pull one piston...check the cylinder taper.

Pull the rod caps and mic and inspect the crank. Pull the mains (one at a time!) and inspect the crank and use plastigage to measure bearing clearances.

If everything looks good your engine is a good candidate for an in-frame overhaul. No need to do a full rebuild when a freshening up will do.

I know most guys here would do a full overhaul but an in-frame is a cost effective way of returning your 6 to good operating condition for a lot less $$$. This was standard procedure for years before the car mags and internet experts started touting complete rebuilds.

May the beatings begin...

 

[tomshobby]

That is how I did my TR4 when I changed to larger pistons and liners, 40+ years ago.

 

[TR3driver]

Me too, except the last time was more like 10 years ago.

I even cut some corners that probably shouldn't have been cut, but I was anxious to get the car back on the road ASAP; and it's a lot of extra work to pull the engine on a TR3A (the front apron has to come off). Worked out fine, my "poor man's rebuild" (with used liners & pistons no less) ran great for a long time. That short block is still in the car and ran fine when it was wrecked.

I see it as an attitude thing ... if it has to be "as good as new" (or better) then pull the engine and do everything that can be done. But, if it just has to be "good enough" ...

 

[Popeye]

...bore your cylinders...

Perhaps a silly question, but then I sometimes resemble silly:

On a TR engine, does one ever bore the cylinders? I thought the liners get replaced?
item #4:
https://www.victoriabritish.com/icatalog/t6/0058.asp

Or is boring the existing liners more cost effective?

I have never rebuilt an engine, and will do some form of this in the coming year(s).

Thanks,
Mike 66 TR4A