More tinkering than driving.

[Harry]

I never seem to get much time for anything other than short drives of 10 - 30 mile, but plenty of time to tinker with the old Marlin, anyhow I had noticed a very loud tappet but could not drum up the enthusiasm to do the job until this evening, in fact I think I liked the rhythmic clicking, but it had to be sorted and boy did it need doing I think it was 16th of an inch instead of 13 thou, the rest were done in due course and the engine now sounds far better, I'm not sure why the gaps had increased so much in such a small mileage since last adjusted ? I also checked and adjusted the timing as I was not convinced it was as accurate as it should be so I adjusted it at 1800 rpm this time. I had noticed that it became increasingly over advanced as the speed built up and I have an inkling that it is an issue with these replacement electronic ignitions ( No Vernier adjustment knob ) As far as I'm aware its a better option to send the original lucas distributor to a specialist to be rebuilt and converted to an electronic system.
The engine now sounds far better and revs up smoother, but not run out to test it as it started to rain.

Harry.

[stevejgreen]

Re: More tinkering than driving.

Rocker shafts wear on their underside, where the load is greatest, tappets wear similarly on the underside of their bore. If your B Series engine gets too noisy, replace the rocker shaft with a tufrided one, and slip on some re-manufactured tappets. It is possible to do your own tappets, but ideally the bushes need final reaming as they are a push fit.

Distributor Doctor has always been my preferred source for Lucas distributors.

[Harry]

Re: More tinkering than driving.

Thanks for the reply Steve, I did give them a wriggle but could not detect movement, I'm tending to think that it may be the volume of much in this engine coating everything, when I bought the engine and checked it I found it to be in fairly good condition apart from lacking oil changes, I planned to fit it and change the oil regular until it 'self cleaned' itself, it seems to be working too. No time to strip it all down and mint it. I will see how it goes.
Have you had any dealing with Cross flow heads suitable for the B series engine, 120 - 140 hp so I've read on the net ?

[stevejgreen]

Re: More tinkering than driving.

Are you getting enough oil up to the rocker shaft? The oil gets to the rockets through the rear rocker pillar. Some have an offset foot. It's only about a 1/8" passage.

Sorry no personal experience of B series Xflow. For the head alone, not forgetting you will need new inlet manifold and carbs, and a new exhaust manifold, along with loads of ancillary items, comes to more than a Zetec engine conversion.

[dbazdavies]

Re: More tinkering than driving.

what are you setting the tappets too Harry ?? should be set cold - try setting the ignition timing at 3000 revs too,

[greyV8pete]

Re: More tinkering than driving.

........... I also checked and adjusted the timing as I was not convinced it was as accurate as it should be so I adjusted it at 1800 rpm this time. I had noticed that it became increasingly over advanced as the speed built up ...............................

Harry.

Check that you have the correct mechanical advance springs and that one is not broken or slipped off the locating post. As Steve says Distributor Doctor is your man. He has a test rig and could tell you immediately what your advance curve is. Also worth checking that you have the correct Vac unit (if fitted).

[Harry]

Re: More tinkering than driving.

Thanks for the replies, the cross flow head idea would cost £700 for the head alone and as Steve said a lot of other gear would need to be sorted, as for the other suggestions, the Distributor is a new unit, the original Lucas unit is in my cupboard, the engine is now running smoother and I'm waiting for this rain to stop before taking the Marlin for a run, I've just replaced the bottom steering bush this morning, it's an old compressed Felt type bush and a nice easy job.
The clearances were set to 13 thou cold and are far better till next time eh, three of the adjusters had been over tightened in years past and are difficult to turn and set but that's old motors eh.

[dbazdavies]

Re: More tinkering than driving.

the best head to fit in my MGB tuning days was one off an Austin 1800 S FWD - had big inlet valves !!!

[stevejgreen]

Re: More tinkering than driving.

the best head to fit in my MGB tuning days was one off an Austin 1800 S FWD - had big inlet valves !!!

Quite true, but even that can be improved upon by following Peter Burgess recommendations in tuning an MGB 4-Cylinder Engine, when converting a stock MGB, Marina or Landcrab cylinder head to unleaded.

[Harry]

Re: More tinkering than driving.

I do look out for one of the Austin 1800 heads, I should think they are very rare these days.