Restoration of 74 TCS - 044615R

[BDA]

The cylinders look pretty rough. A great reason to rebuild it so that you'll be comfortable with it for a long time to come.

[racurley]

Thanks BDA.  I have some questions regarding what to do and how to do some things.  I'll just toss a few out here.

Regarding the cylinders, what is the best way to handle this?  I was thinking I would get the pistons out, clean them up and replace the rings.  Do you think I can clean out the cylinders and then hone them or is this something that needs to go to a machine shop?

Looking at the manual, I'm not sure I can rebuild the engine - tools and know-how.  I would like to do it even if it takes a while.  Is this something we can reasonably do or is this best outsourced? 

Suggestions on removing the gasket from the top end, cover, and oil pan?  Recommendations on best way to replace?  It looks like they require a jointing compound.

I'll post some questions regarding the valves once I post those pictures.

[BDA]

I've built and helped build a few engines over the years but never a TC. If this is your first engine build, unless you have an experienced friend who can hold your hand or at least help you if you get stuck, I would advise you to farm it out to a machine shop. If you are a member of a local classic/sports car club, somebody there would probably be willing to help you out. I would advise you to join a club like that anyway (I'm a member of the local MG club, for example). Overhead cam engines are a bit more complicated than push rod motors so it bears making sure you're doing it right.

If you decide to take up the challenge, I would take it all apart and take the block, rods, wrist pins, pistons, head, etc. to a machine shop and have them clean up and check it over everything. Have them rebuild the head (valve job, etc.). Most of the special tools listed in the manual are things a machine shop would have but things like a torque wrench, dial indicator, calipers, engine stand are things you'd need to have. Someone who has more experience could advise you about some of the other tools that are listed.

My favorite gasket scraper is a putty knife. They are usually flexible enough not to gouge aluminum and stiff and thin enough to get under a gasket and scrape it off. I clean it with a wire brush on a bench grinder which makes it sharper. Everybody has their favorite tools to do things. Usually for a cork cam cover gasket, I like to glue the gasket on the cam cover with silicone seal and then spread lithium grease on the side that seals against the head. I would use silicone seal on both sides of the pan gasket. I used to use a Permatex spray product for a head gasket. You want to make sure you don't use too much silicone sealer because you don't want a chunk of it to fall in the oil pan and you might need to be more careful in fuel systems because gasoline can soften the silicone and clog things up.

I'm getting in the weeds a bit. Those are a few of my thoughts. There are likely issues that are specific to the TC engine that somebody else can help you with.

Good luck and ask whatever questions you have.

[EuropaTC]

Hi there,

Firstly a word of encouragement.     There's nothing difficult on the TC engine, it might look scary but these are low tech by modern standards so if you can use a torque wrench and follow instructions, you'll be fine.  When I think back my Elan engine was the first time I'd actually had to take an engine of any sort down to it's component parts, so if I can do it then anyone can.

The workshop manual is normally the place to start but in this case I'd recommend you get hold of Miles Wilkin's book on the TC engine which is a very comprehensive guide to  stripping, examining for wear and finally re-building the TC engine. Quite seriously, it is better than the Lotus manual if only because the latest reprint has been revised in light of modern sealants, etc, whereas the Lotus manual is firmly set in the 70s.

https://www.amazon.co.uk/Lotus-Twin-Cam-Engine-Wilkins-November/dp/B00CB5V2E0/ref=sr_1_7?ie=UTF8&qid=1528316314&sr=8-7&keywords=miles+wilkins

It's always hard to judge on photographs but if there's any significant rust in the bores I'd be tempted to do a re-bore and fit new pistons. Although expensive and needing a machine shop for the bore it immediately gets away from any question about the piston/bore wear. It would really annoy me if I rebuilt it all and then found it was burning oil or lousy performance.  For the crank I'd look at the current shells, measure and decide after seeing the results; you could strike lucky and find it's fared better over the years and be ok with just new shells ?

Cylinder head; if it's a high mileage engine then I'd fit new guides/seats/valves which is a machine shop job but you can strip & assemble afterwards. Like the crank I would take a decision based on the condition of the valve seats and if there is any noticeable movement in the guides. There are no valve stem seals so if there's significant movement then the engine will burn oil which doesn't really harm performance much but does end up with smoke as you leave the traffic lights.  That was the reason I did mine, it was just so uncomfortable to see the smoke in the mirror as I pulled away.

The water pump should be replaced, all parts are available but you need a press to get the impeller on the shaft. I used a 6" bench vice (three times now !)  but it's something you could walk into a machine shop with and leave 5 minutes later all done. Relatively cheap to do while it's in bits but if you put the old one back and it failed a year later then it's head & sump off to replace it....   major hassle when it's all back in the car.

Even if you decide not to rebuild it yourself I'd still get Miles' book, it will give you some great insights into how it goes together, etc.

Brian

[jbcollier]

The above referenced manual is very good.  TC engine’s are not difficult to assemble but they are difficult to seal properly.  Most leak, some quite a lot.  Careful preperation and assembly will result in a dry engine.

Reading your posts leads me to believe you do not have much experience overhauling engines, left alone with twin cam Fords.  Carefully strip the engine and mark all the bits and pieces with their location and orientation.  It is very important, for instance, that the cam followers are kept in their proper order.  Bring the crankshaft, block, main bearing caps (you marked their location and orientation, right), connecting rod/piston assemblies (rod cap position and piston locations and orientations marked), camshafts (position marked), followers and shims (ditto), etc.  To the machine shop for inspection, evaluation and refurbishment.  An assembled head will be much easier for the machine to work with rather than a million plastic bags with tags that have fallen off.

[Sherman Kaplan]

I'm in the same situation as you are.   I did rebuild an MG T series engine about 25 years ago, but I did have a lot of help from a master mechanic.  Now that I'm retired I'm going to attempt the rebuild of my Twin Cam engine. However, I did send the entire head to John McCoy at Omnitech to be rebuilt.  My thinking was the aluminum head needed someone with experience.  I stripped the block and it, along with the crankshaft, rods, etc. are at the machine shop. The machine shop also has the clutch cover plate and flywheel so everything can be balanced.  If you have a good machine shop they will tell you what you need to bring them.    The block still had the standard original pistons, but because it sat for 30+ years had to be bored 0.030 oversize.  I purchased new pistons from QED in the UK,  However, both John McCoy and my machinist suggested purchasing better piston rings.  My machinist was able to supply all of the needed bearings.   I bought the Miles Wilkins book and I also found a dvd on ebay.  I looked on google and it seems to be available here:

www.classiccarengines.co.uk/product/018

Also, one discovery I made.  My number 4 piston was stuck solid and no amount of soaking (I tried marvel mystery oil, ATF/Acetone, Kroil, Diesel Fuel and basically every penetrate in the auto parts store) would free it.  I let it soak for a few weeks and it still would not budge.  I then discovered a great trick for freeing frozen parts. Buy a can of canned air duster.  If you turn it upside down and spray, it will temporarily freeze the part shrinking it.  I did that on the piston and was able to use the handle of a small wood hammer and get the piston to move.   

I am hoping that between the Miles Wilkins book, the shop manual, the dvd and this list I will be OK. 

Good luck,
Sherman

[GavinT]

G’day, racurley,

I would echo the remarks of others.

If this is your first engine rebuild, I’d make sure you have someone tame to discuss stuff. Some things are a matter of judgement and others involve well known TwinCam considerations.
Choosing a machine shop that’s helpful can make all the difference.

The Miles Wilkin's book is well regarded and this forum is very helpful but I reckon it’s worthwhile having someone local to provide guidance.
I don’t know much about TwinCams but I'm led to understand that some L blocks can be a bit thin in places and care needs to be taken if you’re going to bore it out to any large increment. Just one example.

If you’re going to have a go yourself, the first thing to do is dismantle it completely - mark everything as you go.

Have your machine shop drop the parts in their (alloy friendly) degrease/wash tank.
At that point, measure all critical components in order to assess where you stand.

[cwtech]

To me, one of the more tedious tasks on the TC engine is setting the valve clearances on re-assembly, especially after the valves/valve seats are ground or replaced..  ....Shims need to be of the correct thickness, and usually each valve may require a different thickness shim.

Another task is to insure proper timing of the camshafts.  ....Not difficult to do, but rotate the engine through a few revolutions by hand to verify that the cam timing is correct before buttoning everything up.  .....Be mindful of timing chain tension while doing this process.

The TC water pump! ---Now that the engine is out of the car, THIS is the time to renew or replace the pump components.  ....Clean all surfaces thoroughly, but carefully!

Cleanliness and attention to detail during engine re-assembly are a must.  ....Clean all threaded holes with a tap before final cleaning.  ....Clean all threaded fasteners to remove any crud or prior sealing compounds.

There are "Scotch-Brite" type discs (available at many auto parts stores) which you can use with an electric drill to clean gasket surfaces.  ....These discs are more gentle than a wire wheel or wire brush.  ....The discs are available in various coarseness, but pick something mid-range.  ....Too coarse can remove aluminum, too fine wastes time and discs.

Take lots of pics on disassembly, as it is easy to forget things a month or two later. 

Marking bearing caps or connecting rod caps for proper orientation should be done by light punch marks made with a center-punch or number punch.  ....Marks made with a felt marker are too easily wiped off.

[racurley]

Thanks everyone for the sage advice.

I ordered the book as was suggested and it arrived yesterday.  Need to spend some time with it now.

I'm located in Virginia Beach, VA.  I found a machine shop close by that looks like a possibility.  http://theheadshopinc.com/services.html.  Looks like quite a few options around as well.  I need to weed through the list of car clubs in the area still.  My son and I attend a few classic car meets and will find the British car guys next time.

I have two neighbors who have experience restoring cars but I'm not sure about engine rebuilds.  Will check with them.

My maintenance records show the water pump was replaced within just a few hundred miles.  But, like most things, may still be worth replacing again while I have it apart.

[andy harwood]

Danville Va is a ways away from you, but this company has Lotus experience.
http://www.motionmachineinc.com/

[BDA]

And if you look at their "Pictures" section, there's apparently a lady there who is very easy on the eyes! 

[andy harwood]

Ha! I missed that. The building was a car dealer at one time, I think. The machine shop is one side of the building, the other side/shop side is a race car builder. The showroom seems to always have some vintage racers in the window, older Lotus included.

[racurley]

So, not getting a lot of time on this lately. We pulled the engine and tyranny this afternoon. Any advice on separating the two? I have them on a hoist now but resting on blocks of wood.

[racurley]

That was actually easy. I got a bottle jack up under the transmission and it relieved the pressure on the studs. Came right apart. Will remove the clutch and put it on the engine mount now.

[racurley]

OK. Another session of staring at it. Clutch plate off. Not sure how to pull the flywheel. Maybe the bolts behind it that attach to the block?