Engine Rebuild - DIY or Specialist

[TR4'er]

Hi to all,

Advice and direction required.

Looks like my TR4 needs an engine rebuild. What options are available and what pitfalls are lurking which ever way I go. Can anyone suggest the best route.

 

1 - buy a newly rebuilt engine - where can I get one from ??

Any suggestions of suppliers, and what would be the approx. price for a unit.

I am looking for a standard unit, or uprated (not for racing, but regular road use around London and counties.) which ever is most practicable and reliable.

 

2 - DIY rebuild - have reasonable aptitude after 20yrs fiddling with TR's.

But aware that specialist advice/intervention required at certain points - balancing, selection of parts combinations etc.

Are there any suggestions for parties who may specialise in the details of building a TR engine.

 

I know its brief and such a big project, but any comments or suggestions would be most welcome.

My overriding intent is to obtain reliable, sturdy unit for my lovely TR4.

 

Thanks in advance for your comments.

 

Rob.

Edited September 17, 2016 by TR4'er

[ed_h]

This entire question rests mainly on two things:

 

Would you enjoy the DIY approach?

Do you have the skills or aptitude for it?

 

You seem to have answered the second question in the affirmative.

 

There is plenty of help online on this and other TR forums.

 

Ed

[John Morrison]

Best advice would be get along to your local Group, and talk to folk.

 

there will be some there who have rebuilt four pots motors I'm sure, plus they will know the local establishments to

frequent, and not as the case may be.

 

In engine terms the TR is very simple, and very straitforward, it sounds to me from re-reading your post, it is just a little confidence that you need.

The local group is where you should be!

Having said that, any questions you will have will be answered here.

 

John.

[Richardtr3a]

I had mine rebuilt by a well known engine building company in Brighton. I copied the page from the manual with information on liner heights. and gave it to them.

 

Back on the road the car overheated and it took over a year to discover that the liner heights were wrong. I took it to Racetorations , who discovered the fault, and they rebuilt the engine with a rear crank seal modification.

 

25 year later I have had to replace the timing chain and tensioner . I also used a new seal and a speedi sleeve. Darryl confirmed that it was out of warranty.

 

My advice is use a specialist who is well known in the Register. It is more fun driving the car than taking the engine out many times.

 

Good luck Richard & H.

[MichaelH]

If you are considering DIY then you will find it much easier to get the Blue Triumph workshop manual which will guide you correctly how to do it

The cost is the same you either pay in money or in time, effort and money

Good Luck

Michael

[RogerH]

Hi Rob,

Have you got the skill and facilities to do the various jobs.?

Have you looked at the economics.?

 

Only you know the answer to the first question.

 

The cost of parts and services will be in excess of £1000 (probably more) and you will spend many many hours doing the work.

 

£3000 should get you a decent full rebuild (not racing quality nor concours prices). Less time will be taken. C&M Engine Services in Bracknell do all their own work.

 

No connection just a happy customer.

 

Roger

 

PS -the TRShop often have fully rebuilt engines for sale. http://www.trshop.co.uk/special.html

Edited September 17, 2016 by RogerH

[Graham]

Rob my 2 peneth for what its worth, I rebuilt BUO's (tr6) engine under the watchful eye of the guys at Enginuity many years ago and I have to say I found it a really enjoyable experience. I was doing something I'd always wanted to do at the same time had the re assurance that what I was doing was correct. BUt I did actually do it on their premises so I was supervised VERY closely ! however I must have done it right as after an absence of 18 years I re acquired her and am now in the process of a complete rebuild,( the engine lasted 90,000 and was still going ok but as I was determined to pul the car apart I decided on an engine rebuild) What I have noticed however is that in the 20 or so years since I rebuilt the engine some sort of metallurgical alchemy must have taken place because the engine weighs so much more that it did when I last rebuilt it to the point that I now struggled to lift the crank of the bench, or possibly this might be the result of driving a desk for the last 20 years lifting nothing heavier than a Biro………. so this time I decided on a cheque book rebuild !

 

My point, and appreciate you have a 4 pot but don't under estimate how much the components weigh and not having ever rebuilt a wet liner engine I have to say that they do seem a bit more involved than a dry liner one.

 

But I'm in Bucks and have an engine stand if you need to borrow one ………as I don't think I'll be using it any time soon !!

 

ATB Graham

Edited September 17, 2016 by Graham

[Dave Larnder]

Rob

 

Answer these questions.

 

How old are you? I was 68 when I started the rebuild, so don´t think you are too old to learn and DIY.

Do you have the right tools?, Torque wrench, ring squeezer and if you are to do the head as well you need a valve spring compressor. If the head is not yet converted to sin plomb then let a machine shop do the head for you. I assume you have a full set of UNF spanners and sockets including deep sockets which are six sided not twelve, necessary to pull the 100 lb pulls without rounding the nuts off.

Do you have Williams´s book? a must! along with the workshop manual and spares book although a Moss catalogue will be O.K. for the second book.

An engine crane is a necessity to get engine and GB. out together.

A DTI ( dial test indicator) is best for liner insertion, height and TDC for pistons and valves.

As for specialist help you need a good machine shop to grind the crank and balance it with the flywheel. Make sure they take the plugs out of the crank before cleaning it, and replace them too.

Also have the clutch balanced and the prop shaft.

Get new liners and pistons, and have them balanced as well say to within half a gram. Careful with the figure of eight joint.

There is nothing more satisfying than rebuilding the engine yourself along with the pleasure of driving the car afterwards.

Best of luck which ever way you go.

 

Dave

 

[ChrisR-4A]

Rob, on an old engine there are a few things you probably won't be able to do yourself

1. Machine liners to correct height

2. Regrind crank and machine for rear seal

3. Helicoil block for poor stud threads

4. Fit valve seats for unleaded head

5. Ballance all rotating parts

 

Even for a standard 87mm bore road engine all the above are either necessary or desirable.

By the time you cost all the above plus running around you may find you would not pay that much more for someone to build it complete.

Chris

[tthomson]

Hi Rob,

 

The question I would ask in your situation is "What happens if the engine fails after the rebuild?"

 

If you do the initial rebuild you have no means for recovering the costs of a second rebuild, whereas having a reputable company rebuild it they will almost certainly guarantee their work.

 

As others have said, the cost to rebuild it is likely to be similar to having a specialist rebuild it for you.

In the end, it depends what you like doing.

 

Whichever you choose, good luck!

 

TT

[john.r.davies]

Too much specific knowledge aboiaboive for me to add anything, except to agree - hearing the engine you have rebuilt yourself burst into life is almost as good as hearing your first child's first cries!

 

John

[mike3739]

Too much specific knowledge aboiaboive for me to add anything, except to agree - hearing the engine you have rebuilt yourself burst into life is almost as good as hearing your first child's first cries!

 

John

I have to agree with you there John it is a wonderful sound & feeling, I have only done it on a 1340 A Series in my teens but It is a moment you never forget.

 

Cheers

 

Mike

[Kiwifrog]

Rob, on an old engine there are a few things you probably won't be able to do yourself

1. Machine liners to correct height

2. Regrind crank and machine for rear seal

3. Helicoil block for poor stud threads

4. Fit valve seats for unleaded head

5. Ballance all rotating parts

 

Even for a standard 87mm bore road engine all the above are either necessary or desirable.

By the time you cost all the above plus running around you may find you would not pay that much more for someone to build it complete.

Chris

 

Chris

 

To avoid modifying the crank for the rear seal fit one of mad marx's rear seal kit a very nice solution which avoids the removal of the scroll .

 

Rob

 

I rebuilt my 4 pot with ( a lot of) help from the forum. I found it a great way to get my mind off of other things (recovering from the effects of radiotherapy) at the time. It is a wondrful feeling to hear a motor you have had in a million bits actually start and run on its own after the rebuild .

 

cheers

 

Alan

[stillp]

Where's the fun in paying someone else to do it? It isn't brain surgery, just needs care and cleanliness.

 

Pete

[Ian Vincent]

Where's the fun in paying someone else to do it? It isn't brain surgery, just needs care and cleanliness.

 

Pete

+1

 

Apart from the need to get the liner height right, the rest is pretty straightforward.

 

Rgds Ian

[Motorsport Mickey]

+2 quite right too. Good engineering practice and a relentless attitude to measuring and machining the tolerances so as to obtain those specified does it every time.

Kind of makes you think about those specialist firms and the calibre of mechanics doing the work that they apparently find difficulty in achieving these non difficult, non brain surgery like tolerances.

 

Mick Richards

[Andy Moltu]

A clean and meticulous approach will result in a sound engine. If you pay someone else to do it you will always wonder if it has been done properly.

The TR engines are basic and easily in the capacity of a competent home mechanic.

The key thing to remember for the 4 cylinder engine is to set the liner heights correctly with no lows between highs.

Apart from a dial gauge and a torque wrench no special tools are needed.

Dial gauge for setting the end float and timing a non standard cam.

 

You can squander a fortune at the specialists and end up with and engine that is no better than you could do yourself.

For a road car you don't need a race spec engine, spending big money on an all steel bottom end for one that won't be revved to 7k is a lot of wasted money.

[Peter Cobbold]

DIY for me - there's a terrific, and lasting, sense of achievement when it works. And if it fails you'll know what to do yourself, rather than shelling out again a large sum to farm it out. Guarantees are not much use when a car does 1-3 k miles per annum.

On the other hand I'm no fan of wet liners...

Peter

Edited September 19, 2016 by Peter Cobbold

[Andy Moltu]

Machining the liner heights isn't usually required its achieved by using different figure of 8 gaskets.

Crank grinding and balancing you farm out.

Rebooting isn't often needed as you can change the liners and Pistons to suit if more than a honing is required

[Motorsport Mickey]

Machining the liner heights isn't usually required its achieved by using different figure of 8 gaskets.

Crank grinding and balancing you farm out.

Rebooting isn't often needed as you can change the liners and Pistons to suit if more than a honing is required

 

 

Couple of puzzling things there, I often find a blasted liner in the centre 2 liners will be a thou or more down on the outside liners, future possible failure point. You can't use single FO8 copper gaskets per liner (well I never have, I worry that separating the liner FO8 gasket will cause a leak area) they come siamesed and hence the adjoining liner heights are fixed in pairs, whether they be equal or down on one another. The liner variation is mostly caused by 50+ years of hot cold cycles which stress relieves the block allowing the liner seats to tilt in all directions, a minciscule tilt at the bottom being exaggerated by the liner length and causing a thou or more drop at the liner to cylinder head face. Don't think that a composite gasket will take up the 1 thou difference in height...because it will ! But more importantly on a mechanical front it WON'T give the same clamping force, it can't the gasket cannot be compressed to the same degree, being held high by the liners either side of the centre two.

Hence the liners are fitted on the siamesed FO8 gaskets and all measured and then machined to give an even liner height between the 3 and 5 thou liner to deck heights.

Also Rebooting ? Is this a spell check reborn (see that's what mine gives) No rebore, is I'm almost sure what you mean. Just remember you can extend these piston/liner uses up to about 5 thou clearance (pistons are made oval) which is the area competition piston/liner clearances live, which will give max power with new piston rings but not necessarily a further 100k of road miles.

 

Mick Richards

Edited September 20, 2016 by Motorsport Mickey

[Andy Moltu]

Yes, apologies for the spell check on her indoors ©Apple tablet.

 

As for machining - most garages won't do the machining themselves but farm out work like boring, grinding, balancing and machining to engineering workshops. Some may have the facilities but not many.

 

I concur that machining is sometimes required to get the liners correct, but a bit of fiddling around often avoids this.

Remember to bolt down the head first with an old gasket before you measure the height of the liners.