Series 1 engine mods

[I-Wen Foo]

Hello all,
My 1962 3.8 litre engine has been dismantled, and apart from scoring on one of the pistons and liner (probably necessitating a new set of pistons), the rest of it appears in good shape.
I'm looking for advice on modifications which help long term reliability, and modifications to improve the performance of the engine.
Among those for reliability are tying down bucket guides with bars, changing to a rear oil seal (though how reliable this is I'm not sure), and changing the con rod fixing bolts to XJ nuts and bolts. I'd also like to fit hardened valve seats for unleaded petrol. Any advice regarding the list above would be most welcome, as well as any other suggestions.
As far as performance is concerned, I'm looking for relatively small improvements, (not going crazy)... I might consider a mild port & polish, hotter camshafts if anyone's got recommendations. Have I missed anything obvious? Generally looking to keep the looks original, apart from installing a stainless steel exhaust later.
Looking forward to any comments, with thanks in advance.
I-Wen

[christopher storey]

I doubt that you need to change the valve seats, as they have always been cast iron because this is an aluminium head . I would not change to a lip type oil seal either, as my experience of this has been discouraging , and there is no going back if the change is not to your liking because of the machining of the crankshaft . Nor can I recommend a change of camshafts ( although I know there are those who disagree) . What happens in my experience is that even "fast road" cams radically reduce the bottom end torque up to about 2,500 rpm, and only really give a payback beyond 4000 rpm. When you consider that perhaps 90% of your motoring will be below 3,000 rpm, with perhaps a further 5% up to 4,000 and only another 5% beyond that , the sacrifice in my experience is just not worthwhile . It is worthwhile remembering that for the entire life of the XK engine the valve timing for road cars was maintained at 57/15/15/57 except for the last 8L engines when the timing was retarded by about 4 degrees for emission purposes.Even then, the overlap was preserved at 30 degrees and thus there was little if any torque penalty

[Peter B.]

Hello,
please regfer to another part of this forum, there you will find a lot of suggestions when it come to improving your engine.
But I have to totally agree to the statement before, keep in mind how you use your car, lots of improvements, like Webers or racing cams, give you more horsepower and/or torque, but mostly in regions where you not really need it, unless you go for track days fun.
All that has to be kept in balance, means carbs, needles, air-filters, cams, ingnition timing, exhaust etc. must fit together, in order to give you a real improvement. Working on just one part may even let you end up with less power and torque and a less drivable engine.
So it?s up to you to decide how far you will go and what you want to acchieve.
Personally I still use the big "marmelade pot"-like air filter, the triple SU?s and the original headers, and she?s fun to drive from zero to 5k revs.
Have fun!
Peter

[Heuer]

I-Wen

As Christopher and Peter have said you need to be circumspect when doing 'upgrades' as you may lose the character of the original design. Brakes, cooling and ignition are the things to concentrate on to allow the car to mix with modern traffic and be reliable. A stainless steel exhaust system is worthwhile but take car with replacing the original cast manifolds with tubular ones. Not only will under bonnet temperatures be much higher you may see a drop in torque between 2,250 and 2,750 rpm unless you fit one designed to overcome the problem (e.g. Classic Fabs). Cast manifolds with a big bore stainless steel silencers and resonators are probably the best combination.

[I-Wen Foo]

Thanks for all the comments
I would be more interested in modifications for the sake of long term reliability and engine life.
As far as modifying the crankshaft rear (asbestos) oil seal, are there different types of rear oil seals? I've just read Chris Rooke's book where he mentions a replacement oil seal that has to be cut in half and then re-joined with super glue to fit over the crankshaft flywheel flange. He goes on to mention that failure could be a real possibility. Have I got this right, and is this typical of an 'upgraded' seal? Are there other alternatives? Or is it best to remain with the asbestos rope seal?
I was planning to be fairly conservative with respect to any performance enhancements to do with the engine, and I take the point about upsetting the balance or character of the engine. It looks like I'll leave it pretty stock, but keen to go for the ClassicFabs SS exhaust...
Regards, I-Wen

[Heuer]

The rear crank lip seal requires the crankshaft to be machined and the seal is indeed cut in half and super glued back in place. You will know immediately you start the engine for the first time if it has worked! The rope seal fitted correctly is fairly reliable - CMC for example only recommend this option. They did mine which was weeping after about 25,000 miles of spirited drivingand put the cause down to the amount of oil vapour being produced by the VSE02 engine at high revs which overcame the breather outlet and pressure built up in the crank case. Their simple, cheap and effective solution was to fit their own design twin breather outlet. So I would expect a properly fitted rope seal on a standard engine to last about 50,000 miles.

[Nick]

The design of lip seal by Rob Beere uses a complete lip seal, not split and reglued, but this means machining the flywheel boss down to the journal diameter. Otherwise to get the lip seal over the flywheel boss the seal has to be split and reglued. I know someone who used a split seal and he said it is leak free.

It's difficult to advise on oil leaks. A small amount of seepage isn't going to affect the reliability of the engine. It comes down to how much you mind drops of oil on the driveway !

Nick L.

[JEP41]

I have just installed a lip seal on the engine I am building at present. The seal was not in two halves it came cut through in just one place only. Once the seal is installed on the shaft by just manipulating the seal around the crank, the split was then superglued back together using a good quality Loctite super glue. I then rotated the join to what will be the top position when the engine is installed in the car. I cannot say if successful because the engine build is not completed yet. Time will tell.

[pmansson]

I don?t like the oil spills caused by the open crankcase vent on my 3.8. After every proper drive session, the nice, new garage floor gets a 4" pool of oil on it....

Someone mentioned CMC has their own simple solution.
Is that so? Easy to install oneself? If so, I will order one.
S2 had a different system, probably similar to what I have in my S-type, where it?s re-routed back into the intake manifold.

[Heuer]

CMC have a modification which allows two breather pipes for modified engines - twice as much oil on the floor! You can install a catcher tank similar to that used on the Lightweight E-Types. Basically route the breather pipe to an old can and empty it every few weeks. I am sure you can buy a proper Lightweight alloy tank from somewhere.

[chuffer]

I am sure you can buy a proper Lightweight alloy tank from somewhere.

Or a half-litre plastic milk bottle tie-wrapped to the frame, with the breather tube shoved into it. Works for me and it's free! :)

Ray

PS I'm pleased (and lucky) to say that I've done 1700 miles since the engine rebuild and not added any oil! Only water is collecting in the milk bottle - about four teaspoons of condensation in 12 months.