The Triumph Dolomite Club - Discussion Forum

Hi

After refitting my new unleaded cylinder head, I adjusted the valve clearances to 0.25mm as per the book from cold.

I though it sounded too noisy so I took them down to 0.20mm but just the same, could there be wear on the rockets causing the noise?

Regards

Barry

I have found with my 1500s that it takes some time for the rocker oil feed system to get the oil supply flowing around the rockers so they may get quieter after good run.

You can get wear in the faces of the rockers where they contact the valves. But if present you should have been able to see it easily when the shaft was off if it was of any consequence. I'd first run it with the rocker cover off and make sure all the rockers are getting oiled. there's only about 6psi gets through to the rocker shaft so it's not messy. (unless you have one of those external rocker feed pipes)

Steve

My 1300 engine in the Herald has wear on the shaft the arms rock on, so one of them won't set quiet by measurement. But if I push that rocker sideways on the shaft against the spring, just a smidgen, the noise goes away while I'm pushing.

I can get it to go quiet by setting it by ear when the engine is warmed up and running. But I'm not convinced enough that's safe, because the noise sometimes goes away for a bit when running set by measurement. So I would worry it might sometimes go over tight and expose the seat if I set it by ear. So I don't.

Also, there are them as say "A tappy tappet is happy tappet." And in my case at least, the noise don't seem to be getting worse very quickly.

Graham

It's when they get quieter as you're driving you need to worry! Nothing says valve seat recession better!

Steve

Edit, yeah what Graham says is true and possible. The rockers CAN wear the shaft away and you can't always see it. But truthfully this is a result of poor lubrication and a rocker shaft this badly worn is scrap, the case hardening has gone, i've seen it quite a few times, more often on the longer 6 cylinder variant, but it happens to the 4 bangers too. Again, check the LOOK of it with the engine running and the cover off, if more oil is coming out the sides of the rockers than the holes in the top, you have a little problem!

PPS, Anyone remember the Talbot Alpine of the early 80s? They were notorious for noisy tappets (the old 1300/1442cc Simca inline 4) I found a way to shut them up without burning valves!

Carledo wrote: ↑Thu May 20, 2021 10:25 pm
PPS, Anyone remember the Talbot Alpine of the early 80s? They were notorious for noisy tappets (the old 1300/1442cc Simca inline 4)

Who could forget those?

Carledo wrote: ↑Thu May 20, 2021 10:25 pm I found a way to shut them up without burning valves!

You burnt the car instead?

When I had my workshop we had a bloke bring one of those in that he'd just bought. he was so impressed that it only had 46,600 miles on the clock, sadly when we looked at it we noticed all the odometer numbers all out of line and realised that someone had given it a "haircut", and they weren't very good at it, because it was a milion mile clock and what they'd actually done was set it to 466,000.......

harvey wrote: ↑Fri May 21, 2021 2:00 pm

Carledo wrote: ↑Thu May 20, 2021 10:25 pm
PPS, Anyone remember the Talbot Alpine of the early 80s? They were notorious for noisy tappets (the old 1300/1442cc Simca inline 4)

Who could forget those?

Carledo wrote: ↑Thu May 20, 2021 10:25 pm I found a way to shut them up without burning valves!

You burnt the car instead?

When I had my workshop we had a bloke bring one of those in that he'd just bought. he was so impressed that it only had 46,600 miles on the clock, sadly when we looked at it we noticed all the odometer numbers all out of line and realised that someone had given it a "haircut", and they weren't very good at it, because it was a milion mile clock and what they'd actually done was set it to 466,000.......

There's always one isn't there!

Naw I didn't burn the car, though the temptation was there! I was working for a small trader at the time you know the kind, like Mike Brewer but with less charisma. He bought the things by the dozen from the auctions and did well off them, they were cheap and cheerful but good basic transport. The other major failing was lack of synchro on the 4 speed manual box, I got so good at that, I could pull the box, strip it, replace all 4 baulk rings reassemble and replace it in less than an hour. I used to buy baulk rings 20 at a time, I used so many.

Steve

Carledo wrote: ↑Thu May 20, 2021 3:51 pm You can get wear in the faces of the rockers where they contact the valves. But if present you should have been able to see it easily when the shaft was off if it was of any consequence. I'd first run it with the rocker cover off and make sure all the rockers are getting oiled. there's only about 6psi gets through to the rocker shaft so it's not messy. (unless you have one of those external rocker feed pipes)

Steve

Well after a longer 25mile run I think it does sound better. I ran it with the cover off and did seem to bubble away out oil holes.

I did think about the external rocker feeds when I was building the head back up, but reviews I found suggested it was just robbing peter to pay Paul and wasn't worth it?

Regards

Barry

I did fit an external oil feed on one of my 1500 Dolomites but I did take it off in the end when I read the comments about it robbing Peter to pay Paul.

I did replace one rocker shaft because it had worn away but I think it must have been a shaft that had not been hardened correctly as when I checked my other dolomites the rocker shaft were fine.

Here's a pic of what Steve does mean with worn faces. It's a common thing and not just Triumph.

You adjust to 0.25 but the actual play is twice.

Jeroen

Get one of these - : - this ones a bit pricey but there are plenty on fleabay.

https://www.frost.co.uk/gunson-clikadju ... TKEALw_wcB

I've used a version of it for years made by SPQR, simple and easy to use and automatically takes account of any wear on the rocker faces.

Roger

bazyerma wrote: ↑Mon May 24, 2021 10:50 am
Well after a longer 25mile run I think it does sound better. I ran it with the cover off and did seem to bubble away out oil holes.

I did think about the external rocker feeds when I was building the head back up, but reviews I found suggested it was just robbing peter to pay Paul and wasn't worth it?

Regards

Barry

I don't know of anyone who knows this engine and it's idiosyncrasies and who also has a good word to say for the external oil feed.

If the engine is working properly, oil feed to the rockers is sufficient in standard form. If it's not, you've got bigger problems than a tappet rattle!

Adding the external feed is just masking the symptoms of a bigger and more expensive problem. With this engine's propensity for underlubricating crank bearings, taking some of that neccessary pressure to OVERLUBRICATE the valve train is sheer folly!

Steve

Ps, You'll need to retorque the head in a few hundred miles, so the rocker shaft will have to come off again. Time to get it right after that!

If I remember correctly, the tappet screw is 5/16th UNF which has a 0.041 thou pitch, so you could nip up the screw till there is a slight resistance on the valve stem and back it off a 1/4 turn giving you a 0.0104 (ten thou and 4 tenths) gap.

Malcolm

Magenta Auto Sprint wrote: ↑Wed May 26, 2021 8:25 am If I remember correctly, the tappet screw is 5/16th UNF which has a 0.041 thou pitch, so you could nip up the screw till there is a slight resistance on the valve stem and back it off a 1/4 turn giving you a 0.0104 (ten thou and 4 tenths) gap.

Malcolm

Yep that is what this tool does, the "screwdriver" handle clicks as you rotate it once every 1/16th of a turn so "four clicks" and you are done - or something like that. If you know the thread / pitch of the tappet screw you can of course work it out for any engine of this type. The SPQR tool just makes it essentially idiot proof.

Roger