1.8 B engine tappet clearance

[beergutdave]

Hi Fellow Marliners, could anyone help re a correct tappet clearance. My engine originated in a Marina 1.8 TC, but when setting the clearance as specified in my Haynes manual the tappets are quite noisy. So looked at the setting for an MGB 1.8, the gap setting is smaller so I reset the tappets. Yes they were very quiet but the engine ran lumpy, obviously the tappets were too close so I backed them off. Does anyone know of a gap setting that will suffice to give a quieter engine without burning the valves or seats. Reards Dave

[stevejgreen]

Re: 1.8 B engine tappet clearance

In simple answer to your question, No.
Most 1.8TC's and MGB's that use the same engine, set things at 0.013" Cold but...... It was once said that the only way to get a B series to stop rattling was to turn it off. Reducing this clearance will result in burned valves and seats as you say.

Sorry its not a quick fix but lets see what others might say.

Not knowing the state of your engine, no offence, but its rather critical if you want a quiet lump.

The first thing to remember is that you rarely look at your rocker shaft. Assuming it has a good oil feed, it is under shock loadings as the cam rises and falls, the wear on the underside of the shaft is sometimes easily visible (once you have dismantled it) and the same amount of wear is likely to be inside each rocker that will move around on the shaft.
So if you are struggling to quiet an engine down it is possibly this wear that is the cause and is easily rectified.
The answer is a new tufrided rocker shaft from MOSS and a new set of bushed rockers to go along with it. Its not eonomic to rebush the rockers yourself IMHO.

There are also several schools of thought for setting clearances in sequence. Haynes use the rule of 9 i.e adjust Valve 5 when Valve 4 is fully open (5+4=9 etc) others swear by the use of propriety rocker setters, others still do it all by ear (like me with a feeler as a starting point)but unless you have good starting point you will be wasting your time.

What I have not mentioned is the cam shaft. I once spent a long time setting clearances only to notice that one valve was lifting less than the others. That was serious cam wear and no amount of tweaking would solve it.

If you have bent a push rod or other cause a follower to stop rotating (and wearing evenly) it will be another source of noise.

Sorry but most of the problems are likely to be hidden wear of important working parts of your engine.

[pearwood]

Re: 1.8 B engine tappet clearance

hi dave. my engine is a mgb which is very simular to a tc i had my rockers re ground made a big difference .i fitted a ally rocker cover which also made it a lot less noisey. as they say the only time you get no noise out of a b series engine is when its switched off.

[beergutdave]

Re: 1.8 B engine tappet clearance

Cheers Steve and Mr T for your responce. Re my engine, I bought off ebay and the chap assured me that the person he had bought if from had spent a small fortune on it prior to upgrading for his hill climb roadster. Incidently it has a ally rocker cover complete mithe a Marlin name disc. The engine runs and pulls great with no smoke, knocks or rattle, just the noisey tappets. I completely forgot about possible wear on the tappets, I'll check them out over the coming weeks. Regards Dave