Cylinder head question

Hi all, my series 2a has a 12j n/a engine, and the garage informs me the head is cracked and very likely beyond skimming.
They’ve suggested I look for a replacement.

My question is; is the cylinder head for a 12j and 19j the same? The descriptions on what’s available online seem to be suggesting the two are interchangeable?

I’m just looking for a good price, and don’t want to overlook something advertised as 19j which might be what I’m after.

I’m still learning, so take it easy if it’s a dumb question.

Thanks.

asgothas said:

Hi all, my series 2a has a 12j n/a engine, and the garage informs me the head is cracked and very likely beyond skimming.
They’ve suggested I look for a replacement.

My question is; is the cylinder head for a 12j and 19j the same? The descriptions on what’s available online seem to be suggesting the two are interchangeable?

I’m just looking for a good price, and don’t want to overlook something advertised as 19j which might be what I’m after.

I’m still learning, so take it easy if it’s a dumb question.

Thanks.

Click to expand...

They are the same. Make sure the one you buy isn't cracked as well.

Thanks Turboman.
Appreciate your quick reply.
Yeah, I’m looking for a recon that’s been fracture tested. I’m wary of anything too cheap. No use throwing good money after bad.

asgothas said:

Thanks Turboman.
Appreciate your quick reply.
Yeah, I’m looking for a recon that’s been fracture tested. I’m wary of anything too cheap. No use throwing good money after bad.

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Good plan. 19j in particular are very prone to cracked heads. Usually between the valves, or round the swirl chambers.

asgothas said:

Thanks Turboman.
Appreciate your quick reply.
Yeah, I’m looking for a recon that’s been fracture tested. I’m wary of anything too cheap. No use throwing good money after bad.

Click to expand...

Giving it some further consideration. There will be a reason your old head has cracked. Possibly the engine ran low on coolant at some time, or else there is localised overheating, possibly caused by a faulty injector.
It would be a good idea to try and rectify any such issues, so that the new head doesn't get damaged later.

Turboman said:

Giving it some further consideration. There will be a reason your old head has cracked. Possibly the engine ran low on coolant at some time, or else there is localised overheating, possibly caused by a faulty injector.
It would be a good idea to try and rectify any such issues, so that the new head doesn't get damaged later.

Click to expand...

Hi, Turboman
Thanks for this.
Prior to the masses of white smoke out of the exhaust, I had been aware of the radiator appearing low, and was topping it up. I replaced the brass radiator plug/tap underneath (it’s a series radiator) And the bottom hose clip, as it looked suspect. So an ongoing coolant leak was on my radar, but I couldn’t see anything obvious other than what I changed.
On the day of the apparently blown head gasket, the radiator was practically empty, and the engine was very very hot after 6-8 miles.
I will make sure I raise the question of cause with the garage. I have asked them to replace the thermostat, as I don’t know how old the existing one is. I know know it’s not too challenging a job, but while they have it pulled apart....,
Also you point about injectors... When the engine was converted from petrol to diesel, I remember that the injectors were tested, they have not done more than 300 miles since then, but again I will bring it up with the garage.

If the fractured head has cracks that can be seen, might the placement of them be another indicator of what’s happening?

asgothas said:

Hi, Turboman
Thanks for this.
Prior to the masses of white smoke out of the exhaust, I had been aware of the radiator appearing low, and was topping it up. I replaced the brass radiator plug/tap underneath (it’s a series radiator) And the bottom hose clip, as it looked suspect. So an ongoing coolant leak was on my radar, but I couldn’t see anything obvious other than what I changed.
On the day of the apparently blown head gasket, the radiator was practically empty, and the engine was very very hot after 6-8 miles.
I will make sure I raise the question of cause with the garage. I have asked them to replace the thermostat, as I don’t know how old the existing one is. I know know it’s not too challenging a job, but while they have it pulled apart....,
Also you point about injectors... When the engine was converted from petrol to diesel, I remember that the injectors were tested, they have not done more than 300 miles since then, but again I will bring it up with the garage.

If the fractured head has cracks that can be seen, might the placement of them be another indicator of what’s happening?

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You need to make sure that the radiator, and all coolant hoses, are in good shape and holding coolant. These engines are not tolerant of low coolant level, it will cause damage.

Injectors should be fine, test/service interval on those is 40k miles.

Try and post up some clear pics of the bottom surface of the head. I can give you a breakdown on what has happened. And if James returns, he will be even more accurate at doing this.

Hi
Took some photos of the head earlier this evening. These two show the worst areas clearly.
They show the visible crack, and some heavy pitting. On inspection the crack also appears to veer off into the pitted area, possibly. The photo doesn’t show that up well.
On inspection the crack was visible disappearing into the lip of the circular recess. (Can’t recall what it’s called! ) The crack appears to be around 3mm deep - Again not clear on the photo.
Other areas described were blurred areas where compression rings seal was ? poor.

Hope you are able to assist in a translation?
Thanks,
H

asgothas said:

View attachment 138760 View attachment 138765 Hi
Took some photos of the head earlier this evening. These two show the worst areas clearly.
They show the visible crack, and some heavy pitting. On inspection the crack also appears to veer off into the pitted area, possibly. The photo doesn’t show that up well.
On inspection the crack was visible disappearing into the lip of the circular recess. (Can’t recall what it’s called! ) The crack appears to be around 3mm deep - Again not clear on the photo.
Other areas described were blurred areas where compression rings seal was ? poor.

Hope you are able to assist in a translation?
Thanks,
H

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Cracked and warped head. Scrap. Probably caused by major overheat due to low coolant, as you described in your earlier post.

Yes. Looks like I am in the market for a new one.
This has largely been the direction of conversation with the garage tonight ..
I will take on board what you said re hoses and radiator.
Thanks for taking the time, and responding quickly.

asgothas said:

Yes. Looks like I am in the market for a new one.
This has largely been the direction of conversation with the garage tonight ..
I will take on board what you said re hoses and radiator.
Thanks for taking the time, and responding quickly.

Click to expand...

If you want a proper job, try Turner, or try and get in touch with jamesmartin, search for him on the forum. He is a reconditioner, his work is good, I have seen it.

https://www.turnerengineering.co.uk/