Herald 1200 rocker cover and breather cap

[Jack Hartshorn]

Hi everyone. I'm on the look out for a herald 1200 rocker cover in good condition and a new breather cap. I have tried looking on some of the parts websites and I can only find them on rimmers and Canley classics but they're out of stock on Canley. If anyone could give me a pointer on where else to look for a rocker cover and breather cap or if anyone has them for sale it would be greatly appreciated if you could let me know. Thank you 🙂

Edited April 5, 2023 by Jack Hartshorn

[PeteStupps]

Hello Jack, the steel rocker covers are no longer available but often come up on ebay for pennies. I think aluminium ones are available from lots of places but not looked recently.

Is your current one missing in action or bent out of shape from over-tightening? They can be straightened if not too badly distorted. I stood mine upside down on two blocks of wood, put a broom handle in one fixing hole and whacked with a hammer. Then same on other hole. Whack until sealing face is approximately flat.

Pete

[Jack Hartshorn]

2 hours ago, PeteStupps said:

Hello Jack, the steel rocker covers are no longer available but often come up on ebay for pennies. I think aluminium ones are available from lots of places but not looked recently.

Is your current one missing in action or bent out of shape from over-tightening? They can be straightened if not too badly distorted. I stood mine upside down on two blocks of wood, put a broom handle in one fixing hole and whacked with a hammer. Then same on other hole. Whack until sealing face is approximately flat.

Pete

Hi Pete, my rocker cover is there but it's got like a layer missing from it, I'm not sure if it's paint but it's the same colour, I think it's leaking from somewhere I took it off and checked the gasket and it seemed fine since I just replaced it a few months ago. it did however when I bought the herald have 2 metal plates where the nuts were to secure it on which struck me as slightly odd. I'm not sure if it is leaking through the breather cap or not but would like to see if I can replace them both soon just to eliminate the problem. I'll have a surf around eBay to see if i can find any. thanks Pete

Jack

[standardthread]

10 hours ago, Jack Hartshorn said:

 when I bought the herald have 2 metal plates where the nuts were to secure it on which struck me as slightly odd. I'm not sure if it is leaking through the breather cap or not but would like to see if I can replace them both soon just to eliminate the problem. I'll have a surf around eBay to see if i can find any. thanks Pete

Jack

Jack,

It's a long time since I looked inside one, but from memory those two metal plates should be tacked to the inside of the cover to strengthen the cover as you tighten the nuts down to prevent distortion. If they have come adrift you could try cleaning the cover and the plates and epoxy them back if you aren't competent at welding.

In terms of leakage from the breather cap your 1200 was designed to let the engine breath from that cap, it shouldn't be a closed system like the 13/60's etc.

[Jack Hartshorn]

6 hours ago, standardthread said:

Jack,

It's a long time since I looked inside one, but from memory those two metal plates should be tacked to the inside of the cover to strengthen the cover as you tighten the nuts down to prevent distortion. If they have come adrift you could try cleaning the cover and the plates and epoxy them back if you aren't competent at welding.

In terms of leakage from the breather cap your 1200 was designed to let the engine breath from that cap, it shouldn't be a closed system like the 13/60's etc.

The plates were on the outside of the rocker cover they don’t look original to the rocker cover it just looks like 2 steel rectangles that were under the nuts but on the outside of the rocker cover there wasn’t anything inside it. As for the breather cap, I didn’t know if they got older they can start letting out too much oil

[standardthread]

Jack,

They were probably an attempt to spread the load from the nuts. The only items outside/on top of the cover, coming up from the cover on each stud are, a fibre washer to keep the oil in, then a plain washer (about the size of a new penny if you can find some), then the nyloc nut.

When I take the cover off I count the turns on the nut, then put it back with the same number of turns, the torque setting on these nuts is about 2lbs.. I don't change the gasket every time because I stick it inside the groove in the cover with dabs of liquid gasket.

If you think you have a leak from it what I do to make sure I have every scrap of old gasket off the head I a pull a wallpaper scraper held vertically along where the gasket seats (make sure the tappet holes etc. are covered with rags). The scraper acts like an engineers' scraper, but isn't as vicious.

The breather cap can't let oil out, oil vapour yes because that's what is was designed to do. If you have the correct cap on it SHOULD be cup shaped (about the size of your cupped palm) and around the hole where it fits on the rocker cover should be a ring of holes, these breath the engine. What might have happened it that over time your cap might have got bunged up with dust and oil because inside the cap is a kind of steel wool to stop muck getting in but letting vapour out. Try taking the cap off and washing it in paraffin or white spirit. You will be surprised how black the liquid is.

Edited April 6, 2023 by standardthread

[Jack Hartshorn]

5 minutes ago, standardthread said:

Jack,

They were probably an attempt to spread the load from the nuts. The only items outside/on top of the cover, coming up from the cover on each stud are, a fibre washer to keep the oil in, then a plain washer (about the size of a new penny if you can find some), then the nyloc nut.

When I take the cover off I count the turns on the nut, then put it back with the same number of turns. I don't change the gasket every time because I stick it inside the groove in the cover with dabs of liquid gasket.

If you think you have a leak from it what I do to make sure I have every scrap of old gasket off the head a pull a wallpaper scraper held vertically along where the gasket seats (make sure the tappet holes etc. are covered with rags). The scraper acts like an engineers' scraper, but isn't as vicious.

The breather cap can't let oil out, oil vapour yes because that's what is was designed to do. If you have the correct cap on it SHOULD be cup shaped (about the size of your palm) and around the hole where it fits on the rocker cover should be a ring of holes, these breath the engine. What might have happened it that over time your cap might have got bunged up with dust and oil because inside the cap is a kind of steel wool to stop muck getting in but letting vapour out. Try taking the cap off and washing it in paraffin or white spirit. You will be surprised how black the liquid is.

I think the first thing might be the problem, there’s no fibre washer and it’s a normal nut not a nyloc nut. I’ll get these done as soon as I can. I think I’ll bug a new one just to be safe I’ve seen a couple on eBay and it would be good to keep a spare anyway. If that doesn’t work I’ll try the second option

[standardthread]

The fibre washers are the first thing to get lost, rubber can also be used, and are ten a penny, the same goes for nyloc nuts. Get yourself some to keep in stock, they are 1/2" A/F and are used all over the car.

Rocker covers aren't spares I have used, or needed in well over 40 years, they don't wear out.

Edited April 6, 2023 by standardthread

[JohnD]

Six cylinder cover don't have stiffening plates, so I wonder what those on Jack's are really for.

To stop any leaks around he studs and nuts that hold mine down, I use a washer, with a slightly-too-large-for-the-stud hole, and an O-ring around the stud below the washer.   The ring needs regular replacement, but they cost less than pennies.

John

[Jack Hartshorn]

8 hours ago, standardthread said:

The fibre washers are the first thing to get lost, rubber can also be used, and are ten a penny, the same goes for nyloc nuts. Get yourself some to keep in stock, they are 1/2" A/F and are used all over the car.

Rocker covers aren't spares I have used, or needed in well over 40 years, they don't wear out.

okay that's good to know I'll get a small stock of them and i'll clean out that breather cap with white spirit as well. Thank you

[Wendy Dawes]

Hello Jack,  if you remember when you first bought the car and Darren and I came over,  I did say to clean the breather cap gauze about every 2 months to make sure it’s doing it’s job properly.  
they do clog up with oil vapour and need to be kept clear.

I did Mabel’s last week, filled it with white spirit and let it stand for an hour,  the liquid, as Steve said, was black.  It will certainly help -   the engine needs to breathe 😊

 

 

Edited April 7, 2023 by Wendy Dawes

[standardthread]

8 hours ago, JohnD said:

Six cylinder cover don't have stiffening plates, so I wonder what those on Jack's are really for.

 

Probably some ham fisted previous owner who over tightened the nuts and distorted the cover. As Pete suggests, it's a simple job to correct and make it flat again.

[Jack Hartshorn]

On 07/04/2023 at 06:42, Wendy Dawes said:

Hello Jack,  if you remember when you first bought the car and Darren and I came over,  I did say to clean the breather cap gauze about every 2 months to make sure it’s doing it’s job properly.  
they do clog up with oil vapour and need to be kept clear.

I did Mabel’s last week, filled it with white spirit and let it stand for an hour,  the liquid, as Steve said, was black.  It will certainly help -   the engine needs to breathe 😊

 

 

Yes I do remember it’s currently soaking in white spirit it’s been in for about 30 minutes so I’ll take it out in another 30. I’ve bought a spare cap off eBay just in case for a spare as well for £6 which wasn’t bad