TR7 Engine Rebuild Advice

[johnnyj]

Hi folks

My '77 FHC has gone off to be painted, so while it is away I figured I may as well do some work on the engine.

Many years ago I bought a job lot of spares from a gentleman who was too ill to continue his restoration. He was a lovely guy who dropped off the spares, which included an engine on a pallet. He said he had rebuilt it, timed it up and left the head-to-block fixings loose. I put it in the garage and turned it over by hand every now and then during the years, with a drop of oil in the bores. It didn't surface again until 15 years later, today.

I am pleased to say that despite being very dirty from all of those years, it turns over very freely. The head bolts and studs also are free, ready to be torqued down.

So, my question is around what I need to do to recommission it. What would you do as a minimum to check it over, given that (a) I can't vouch for the quality of previous work and (b) it has been in storage for so long? I am inclined to trust the old gentleman but I imagine I do need to do a bit of work to confirm all is well.

All advice greatly appreciated!

Thanks

John

[Beans]

As you don't know the age of the rebuilt it might be wise to change (or at least inspect) all the seals. But that depends a lot how and where the engine was stored.
And after all those years the oil that should have been used for assembling and protection on first start up might have disappeared from the various bearing surfaces.

[Hasbeen]

I believe you need to get the oil pressure up to at least 30PSI, before starting it.

You can find some way of pressurising it, pumped into the galleries, or use my old system with my Brabham. I would tow it around, plugs out & in second gear until I had pressure. This saved the Cosworth engine on one occasion, when someone had left a plastic stopper in the return line from the oil tank when reconnecting it.

The TR engine has trouble with the oil pump priming on occasions when drained, so I would definitely not start it without knowing it has primed.

Good luck with it.

Hasbeen

[FI Spyder]

Now is not the time to be lazy. Trust no one. Assume nothing. I've heard, know of, too many tales of missed this or that, even from respected engine rebuilders to knowledgeable amateur ones. Tear it down, rebuild it (retorque it), coat bearings etc. with assembly lube, even make your own if you want. Not doing it is a crap shoot.

[johnnyj]

Thanks everyone for the advice. I took the head off today to have a look but to be honest I don't really know what I am looking for. Sure, everything was quite dirty (and oily!) but after a clean the tops of the pistons and the bores look ok. The lobes on the cam look good too.

I think I could do with a step-by-step guide of what to take apart, measure for tolerance, replace etc.

Cheers

John

[Stag76]

If you pull it down, you will have to replace the bearings. Once they are "crushed" into place, they will never seat
correctly again, and will have a very short life.

As Phil said, get the oil pressure up first. If you remove the distributor, the oil pump drive can be accessed.
It's a Hexagonal shaft (approx 6mm) , and I brazed a socket onto a length or 6mm rod so I could spin it with a drill.
It only took a few seconds to raise the oil pressure, then you can turn the engine by hand to distribute the oil through
the engine. The oil-pump spins ANTI-CLOCKWISE.

Next, run a compression test, and, if that comes up OK, start it and drive away.

[johnnyj]

Hi guys

The engine is currently out of the car and today I started to strip it. It is a bit of a dilemma really, as the guy I bought it from said he had rebuilt it. All I have to go on is his word, and clues - for example he said that he hadn't torqued up the head bolts/studs - he hadn't. I should also say that the "rebuilt" engine has never been put back in a car.

However, I measured the tappet clearances today as per the Haynes manual and the results were mixed. While all of the outlet/exhaust measurements were spot on, all of the inlet ones were out. I checked and double checked, but came to the same conclusion. That is worrying. What else might not be right?

It seems to me that stripping it in order to inspect it is pretty much the same job as rebuilding it from scratch. Is there a halfway house? I am thinking:

- Replace all seals and o-rings
- Check the crank bearings/tolerances
- Re-shim the camshaft
- Change the timing chain & adjuster

Any help in formulating a checklist would be greatly appreciated!

All the best

John

[FI Spyder]

Do you have a build list that would list the make of crankshaft bearings? If they were Vandervell, I wouldn't touch them and hope all is well. If they are something like County bearing then not that much is lost as they will only last about 10,000 miles. Make sure crankshaft end clearance is correct as I had a friend whose Sprint engine was destroyed in no time by excessive end clearance that went unnoticed (because you assume everything is done correctly).

[johnnyj]

Thank you Spyder, that is great advice. Unfortunately I don't have the build list so don't know the make of the crankshaft bearings. Is there any way of telling, without dismantling the crank? For that matter I don't know if they were changed at all! I am starting to talk myself into a full re-build, just to be sure.

As an aside, I am astonished that a maker of bearings would produce a product that would last for just 10,000 miles (although I don't for a moment doubt you, given the amount of crap parts out there). How is that not anything but scandalous?

End float - well, that gives me something to check. I could take the view that if it is not correct, then the engine has been badly rebuilt (or not at all) and therefore the bearings etc should be treated with suspicion!

Cheers

John

[johnnyj]

Hi everyone and thanks for the advice. I am going to rebuild this engine, despite what the P.O. said, as it would kill me to put it in the restored car only to find it is u/s. I'm bound to have loads of questions along the way which I hope you'll be able to help me with, so here goes:

1. What engine reassembly lubricant would you recommend?
2. Are my original head-to-block studs/bolts re-usable?
3. What colour should the block be, when re-painted? A paint code would be great.

Thanks folks

John

[FI Spyder]

My brother who used to rebuild VW beetle engines as a hobby and soup them up for people used his own concoction of molybdenum and motor oil. You can buy assembly lube (which is probably the same thing essentially). The engine block is black. The valve cover is either silver/aluminum or blue but the silver goes with any paint job and looks better. Some people paint their engine/valve cover body colour but this is so obviously a modification and unnecessary change regardless how original or fancy the paint job of the body. Something about it just says "wrong" in most (but not necessarily all) situations.

[johnnyj]

I agree! The rocker cover in body colour? That's not for me. Thanks for the other info!

John

[Beans]

Never cared to much about originality, so a black cam cover for me

[johnnyj]

Looks great in black, Beans. And after all, it is the owner's car so up to them what they do with it. My current project is all about originality but who knows, maybe I'll do another one some day and throw away the rule book!

Just as an aside, and going back to my thought above:
- are the head bolts/studs re-usable?
- Is the block colour matt, satin or gloss black?

Also, I need to mount my block to my new engine stand, much like the thread here viewtopic.php?t=17978 . However I am struggling to find a source for the 5/16 x 3.5 x 24 TP bolts. Can anyone suggest a UK supplier?

Thanks

John

[Beans]

... are the head bolts/studs re-usable? ...

Yes, as long as they are not damaged by corrosion

... Is the block colour matt, satin or gloss black? ...

Not 100% sure there, but the engines I have dismantled over the years all looked fairly glossy (after the grime etc. was polished of),
as this picture of the inside of a low mileage engine in its original guise shows ...