TR4a Engine Noise Post RBRR Found

[Boxofbits]

Hi Triumphers

After a few months in err ‘dry’ storage finally found cause of engine noise and down on power which suddenly appeared on the Friday night of the RBRR and put us in some doubt of continuing. However, we decided to get very wet and press on!

Today, hooked the timing cover off and found a piece of chain tensioner floating around inside which explains the rattle.  I’m guessing this would’ve left the valve timing to go all over the place too hence down on power. Could’ve been a lot worse but crack on now and get it repaired and ready - it’s a promising start to Feb!

Picking up the cylinder head next week hopefully from Peter Burgess for valving and porting work so should be back in action soon. 

Anyone else fitted a 22% overdrive to these and is it worth it?

Thanks 

Kevin 

 

Edited February 1 by Boxofbits

[Tim Bancroft]

Blimey Kevin, very poor quality.

Not sure on the percentage additions for A type overdrives, higher the better for road cars though?

[glang]

Yes heat treatment/material obviously wrong so too brittle. This is a worry with many after market components now as theres no way with out a full laboratory to know if an item matches the correct design spec☹️

Overdrive a personal thing really as depends what speed you tend to cruise at. If you pootle on smaller roads and avoid long motorways runs then the cost/work/added unreliability of overdrive makes it not worthwhile especially if most noise comes from wind rather than engine. There will be slightly less engine wear but thats not a major factor for most people these days and neither is fuel saving which is also pretty much negligible....

[TRTOM2498]

2 hours ago, Boxofbits said:

Hi Triumphers

After a few months in err ‘dry’ storage finally found cause of engine noise and down on power which suddenly appeared on the Friday night of the RBRR and put us in some doubt of continuing. However, we decided to get very wet and press on!

Today, hooked the timing cover off and found a piece of chain tensioner floating around inside which explains the rattle.  I’m guessing this would’ve left the valve timing to go all over the place too hence down on power. Could’ve been a lot worse but crack on now and get it repaired and ready - it’s a promising start to Feb!

Picking up the cylinder head next week hopefully from Peter Burgess for valving and porting work so should be back in action soon. 

Anyone else fitted a 22% overdrive to these and is it worth it?

Thanks 

Kevin 

 

Hi Kevin,

If you already have an A-type o/d gearbox, which would be correct for your car, (optional when new) it should be a 22% as standard.  If you currently have a non o/d car, and like using it, which I can see you do with the RBRR, then an A-type o/d (22% o/d) is worth every penny, and will transform the drive beyond all belief.

If you already have a 22% o/d, and want to reduce the revs further, you can get a 25% or even 28% o/d, by having it converted. ORS in Sheffield would be my suggestion of who to talk to in this regard.

 

If you have a standard engine, I would just stick with the 22%, should be more than sufficient.

Cheers.

Edited February 1 by TRTOM2498

[Boxofbits]

2 hours ago, Tim Bancroft said:

Blimey Kevin, very poor quality.

Would agree with that Tim..definitely not your finest Sheffield sprung steel is it.
 

More likely made in the GonnWong car parts factory somewhere in the Far East !

Kevin

[Boxofbits]

36 minutes ago, TRTOM2498 said:

Hi Kevin,

If you already have an A-type o/d gearbox, which would be correct for your car, (optional when new) it should be a 22% as standard.  If you currently have a non o/d car, and like using it, which I can see you do with the RBRR, then an A-type o/d (22% o/d) is worth every penny, and will transform the drive beyond all belief.

If you already have a 22% o/d, and want to reduce the revs further, you can get a 25% or even 28% o/d, by having it converted. ORS in Sheffield would be my suggestion of who to talk to in this regard.

 

If you have a standard engine, I would just stick with the 22%, should be more than sufficient.

Cheers.

My apologies I meant to say I do have the 22% standard overdrive which as you say is standard equip.
 

I suppose when it was mostly ‘A’ and ‘B’ roads back in the day, the gearing was about right, so that’s why I was considering an overdrive with a higher ratio for the straighter faster roads we encounter these days, both here and on the Continent. The only issue I know of is that it will virtually be on a par with some of the standard gearbox ratios at 28%. However, I wanted it to have longer legs on the top gear cruising speed if anything. I’ll have a chat with ORS as you say.

Thanks

Kevin

[Boxofbits]

1 hour ago, glang said:

Yes heat treatment/material obviously wrong so too brittle. This is a worry with many after market components now as theres no way with out a full laboratory to know if an item matches the correct design spec☹️

Overdrive a personal thing really as depends what speed you tend to cruise at. If you pootle on smaller roads and avoid long motorways runs then the cost/work/added unreliability of overdrive makes it not worthwhile especially if most noise comes from wind rather than engine. There will be slightly less engine wear but thats not a major factor for most people these days and neither is fuel saving which is also pretty much negligible....

As you say the tensioner far too brittle and just snapped, so it can’t be good quality sprung steel. I don’t remember them ever snapping like that. 

Funny you should mention wind noise. On the RBRR the wind noise through the soft top gets a bit of a pain after a while, and as it happened shipped a fair bit of water in the ‘lush’ conditions!

Luckily I do have the original aluminium hard top stashed away somewhere, so I’m thinking of fitting that for events like the RBRR in future.

Regards

Kevin

[glang]

Trouble is how do you find better quality components like tensioners as few manufacturers so all suppliers often stock the same thing....

Are there any other lower ratio diffs available as thats another way to drop engine revs albeit at a possible cost in acceleration?

[thescrapman]

28% overdrives featured on Big Healeys, Aston Martins and The old “Auntie” Rovers, I think.

Not overly common.

I was luckily given a Rover box that the owner had been trying to sell for a year or so without any luck.

 

[Dale]

Looking at the tensioner, the broken bit would certainly explain the noise but not a lack of power. There's plenty of tension left in the remaining half to hold the chain pretty well tensioned and, if anything, a slightly slack chain will make the engine go a bit better by allowing the valve timing to change slightly - Vitesse's I've had in the past always seemed to pick up better before a new timing chain was fitted although they were smoother afterwards.

[Boxofbits]

2 hours ago, glang said:

Trouble is how do you find better quality components like tensioners as few manufacturers so all suppliers often stock the same thing....

 

I know The TR Register have an initiative called the ‘Spares Development Fund’, and many owners or companies manufacturer spare parts of a high standard. Some very useful previously unobtainable parts there back in production. This is the link..

https://www.trsdf.uk/projects

But I’ve not come across this one with the tensioner before though it could always be a one-off. I’ll have a chat with Moss and TR shop tomorrow about it. It would not be difficult to manufacture it from high quality sprung steel I wouldn’t have thought?

1 hour ago, thescrapman said:

28% overdrives featured on Big Healeys, Aston Martins and The old “Auntie” Rovers, I think.

 

Am I right in thinking the Standard Vanguard also was 28%?
 

Not surprising the engines only did 60k before rebuild back in the day as the gear ratios were so much lower! 

Thanks all

Kevin

Edited February 1 by Boxofbits

[glang]

19 minutes ago, Boxofbits said:

I know The TR Register have an initiative called the ‘Spares Development Fund’, and many owners or companies manufacturer spare parts of a high standard. Some very useful previously unobtainable parts there back in production. This is the link..

https://www.trsdf.uk/projects

But I’ve not come across this one with the tensioner before though it could always be a one-off. I’ll have a chat with Moss and TR shop tomorrow about it. It would not be difficult to manufacture it from high quality sprung steel I wouldn’t have thought?

Quite often I think the problem is only quality control so you get components like that tensioner which are fine and then a batch which are too hard or too soft! Unfortunately to get them made by a company who will do things better usually means quite an increase in price (especially if not made in a cheaper labour area) and finally the buyers have to be convinced of the improvement... 

[Boxofbits]

1 hour ago, Dale said:

Looking at the tensioner, the broken bit would certainly explain the noise but not a lack of power. There's plenty of tension left in the remaining half to hold the chain pretty well tensioned and, if anything, a slightly slack chain will make the engine go a bit better by allowing the valve timing to change slightly - Vitesse's I've had in the past always seemed to pick up better before a new timing chain was fitted although they were smoother afterwards.

Maybe it didn’t matter too much though it definitely seemed down on power. With the reworked head and a good engine tune that may well come back. I know the carbs ‘swallowed’ quite a lot of water that weekend so possibly the filters were saturated? We’ll see what it’s like when all back together fingers crossed.

Kevin

[GT64fun]

15 hours ago, Boxofbits said:

More likely made in the GonnWong car parts factory

Probably made from Chinesium!

[JohnD]

I've read before  of modern  copy chain tensioners breaking.  I've always reused the old ones.

John

[Boxofbits]

6 hours ago, GT64fun said:

Probably made from Chinesium!

😆😆definitely!

[glang]

how long ago did you buy it and how many miles has it done?

[Tim Bancroft]

Volvos and Ford Transits had 28% o'drives.

[thescrapman]

On 03/02/2024 at 08:40, Tim Bancroft said:

Volvos and Ford Transits had 28% o'drives.

Weren’t they all J-types?

[Andy Flexney]

On 01/02/2024 at 18:30, Boxofbits said:

My apologies I meant to say I do have the 22% standard overdrive which as you say is standard equip.
 

I suppose when it was mostly ‘A’ and ‘B’ roads back in the day, the gearing was about right, so that’s why I was considering an overdrive with a higher ratio for the straighter faster roads we encounter these days, both here and on the Continent. The only issue I know of is that it will virtually be on a par with some of the standard gearbox ratios at 28%. However, I wanted it to have longer legs on the top gear cruising speed if anything. I’ll have a chat with ORS as you say.

Thanks

Kevin

I changed the overdrive on my TR3a to a 28% but did not like it. 2nd overdive was basically 3rd and 3rd overdrive was higher than 4th so you could not "change up through the gears". It basically changed a 7 speed box into a 5 speed box. It did make motorway cruising much more relaxed or, when in Europe faster i.e. cruising at 90 to 95 MPH. This was with a 3.7 diff not the usual 4.1 which was standard for the overdrive cars..

AndyF

[Tim Bancroft]

On 04/02/2024 at 21:04, thescrapman said:

Weren’t they all J-types?

Yes, correct.

I hired a Transit van in the mid 80s that had overdrive, made it a relaxed vehicle to drive.