80 replies to this topic

[Rorf]

Coolant will find the smallest channel to leak through. Put the water in and take the car for a long trip to get engine up to optimum heat and give it the gears. If the oil goes milky then its leaking into the oil. You need to just drive it now and if it still seeps after a few weeks then its head off again and composite gasket time

 

Also there are coolants and coolants - use a good quality name brand like Castrol. It must be copper friendly - many of the newer engines only have aluminium components.

 

Just make sure the engine does not over heat.

[Spider]

Your breathers look right (and the Carbs have the CCV Port). All you'll need there is a vented filler cap.

 

In regards to the gaskets, here's ACL's tech sheets. The bit on coolant / water re: head gaskets, is at Q14 on bottom of page 3, I've included them all for completeness;-

 

 

 

 

[Rorf]

Mokespider to the rescue, definitely some good Aussie engineering info there, apart from the reference to Holdens

[Rorf]

Some more info from an old school expert Mr Calver - https://www.calverst...asket-problems/

[Spider]

Some more info from an old school expert Mr Calver - https://www.calverst...asket-problems/

 

"All you have to do is torque the standard head studs down to 42-45lb ft (a generous lee-way there I feel), DRY. That’s no lubrication on nuts, washers, or studs. ALL torque settings in the manuals are quoted with the relevant threads DRY. And that's the way they're done at the factory."

 

I know Mr Calver has always said the Torque figures are Dry, however, that's inccorect (not sure where he gets that from?).

 

From the Rover Factory Manual;-

 

 

All Torque Figures in the factory Manuals relation to engine components are oiled.

[carbon]

John,

 

Surprised to see it is still weeping, a couple of quick questions:

- did you check the cylinder head for skimming depth when is was off? Standard head depth is 2.75 inches between faces

- is the coolant leak from the same place as before or different?

 

And (unrelated to water leak) could you check on the standard plastic oil filler cap you have fitted if the hole on inside of the cap is about 4.5mm diameter, and also is the oil filler cap otherwise making an airtight seal with the rocker cover?

[Rorf]

But Moke Spider the Rover Manual you are referring to is an Aussie one - you know opposite to the northern hemisphere

[Spider]

But Moke Spider the Rover Manual you are referring to is an Aussie one - you know opposite to the northern hemisphere

 

Bhahahaha,,,,,,,, actually,,,,that one is a UK one

[mini_pooper]

John,
 
Surprised to see it is still weeping, a couple of quick questions:
- did you check the cylinder head for skimming depth when is was off? Standard head depth is 2.75 inches between faces
- is the coolant leak from the same place as before or different?
 
And (unrelated to water leak) could you check on the standard plastic oil filler cap you have fitted if the hole on inside of the cap is about 4.5mm diameter, and also is the oil filler cap otherwise making an airtight seal with the rocker cover?

Some good info here, thanks everyone!

Carbon - I forgot to check the depth of the head while it was off unfortunately... my mistake!

The leak however is in a different place, it’s now on the end of the cylinder head on the clutch side, as opposed to between spark plugs 2 and 3.

Regarding the filler cap, I will measure it, but having looked at it while doing the head, it’s certainly not far off 4mm. The cap was new when I fitted the engine last year and is tight to get on and off so the seal should be spot on (if I remember correctly there’s a rubber ring on the cap, between it and the filler neck).

Moke Spider - the cap fitted now is a vented one, so that should be fine, but since the carbs are now drawing air through the engine and putting it in after the needle, in addition to the normal route through the carb (now with less air coming that way), is my thought process correct that I will have to richen the carb so that the now lower amount of air coming over the jet draws with it enough fuel?

In example numbers (not accurate ratios!): Without the breather attached, 100% of the air came through the air filters, over the needle, which brought with it 100% of the fuel needed. Now, with the breather attached, 70% of the air comes through the filters and over the needle, and 30% comes through the breather which bypasses the needle. This means the engine is still getting the same amount of air (100%), but less fuel as only 70% of the air will be “fuel enriched”. Should the needle be adjusted so that the 70% of air that still goes over the needle brings with it, say, 30% more fuel to cover all the air going through the carb AND the breather?

If this is the case, one fix would be to plumb the breather into the filters before the carb so 100% of air passes over the needle, but if richening the carb will have the same effect and avoids modifying the air filters to accept a breather connection, then that’s much easier. Just want to check my though process is correct :)

John

[Spider]

Glad that the posts that people are contributing are of help here, after all, that's what the forum's here for

 

You'll need to check your fuel mixture and no doubt make adjustments.

[carbon]

John,

 

Just to check, are there any other engine or rocker cover breathers? The 4.5mm hole is a restrictor which prevents too much air getting pulled through the crankcase and into the carbs.

 

If you take the rocker oil filler cap off when the engine is idling you should see a big change in tickover and it will probably stall.

[KTS]

 

In example numbers (not accurate ratios!): Without the breather attached, 100% of the air came through the air filters, over the needle, which brought with it 100% of the fuel needed. Now, with the breather attached, 70% of the air comes through the filters and over the needle, and 30% comes through the breather which bypasses the needle. This means the engine is still getting the same amount of air (100%), but less fuel as only 70% of the air will be “fuel enriched”. Should the needle be adjusted so that the 70% of air that still goes over the needle brings with it, say, 30% more fuel to cover all the air going through the carb AND the breather?

 

 

 

i think you may be overestimating just how much air will be drawn in to the carb through the breathers, and so how much adjustment may be required

 

under open throttle conditions the vast majority of air being drawn in will be through the mouth of the carb. because that's the path of least resistance as it's much bigger (..if my maths is correct, and if you're using 1.25" SU's, with a 4.5mm restrictor on the breather bore its nearly 50 times bigger..) than the breather bore, and has nothing to restrict it other than an air filter.  

 

the breather, as well as being much smaller bore leads to the interior of the engine which apart from the vent in the oil filler cap should be pretty much a sealed unit (..assuming all the piston rings, oil seals etc are in good shape) so should present a pretty restricted path for airflow

 

the only time the volume of air being drawn through the breathers should come anywhere close to that through the carb. mouth would be when the throttle is closed at idle or on the overrun

[Cooperman]

I am wondering if, once again, there are some bad quality head gaskets around. Some will recall that several years ago production of our favourite gaskets was moved to S. Africa and quality was very poor.

 

I have exactly the same problem as the OP with a newly-built 998 weeping water very slightly from the head/block interface. This engine has a newly skimmed block & head, the stud holes have been lightly chamfered and new studs fitted. Gasket is a copper-faced one as I have used for a long time with no problems.

 

Next week I am going to re-torque it again, this time to c.53 lb.ft and if that doesn't cure it the head will have to come off and another gasket fitted.

 

That makes 3 problems with new parts so far this year - bad tolerancing on a set of duplex timing gears, a 998 oil pump which wouldn't prime and now a 998 head gasket. 

[mini_pooper]

John,
 
Just to check, are there any other engine or rocker cover breathers? The 4.5mm hole is a restrictor which prevents too much air getting pulled through the crankcase and into the carbs.
 
If you take the rocker oil filler cap off when the engine is idling you should see a big change in tickover and it will probably stall.

No other breathers on the car, no. Haven’t tried taking the cap off yet as it was stalling on its own without doing so (until I disconnected the breather and plugged the carb connections, then it was back to it’s good bubbly self aside from the coolant drip which is another matter).

KTS - I’m aware the figures were overestimated, just used them as an example to describe my thinking and exaggerating made it a littlw clearer :)

[KTS]

no problem - just thought it may help to provide a bit more detail should anyone who's less familiar with the setup stumble across this thread

 

on the breather issue, sounds like there's vent to the crankcase somewhere that's letting air in.  is the dip-stick correctly seated ?  half moon seal over front crank bearing in place ?  tappet cover gaskets seated properly ? 

 

if you can figure out a way of connecting a hoover to the breather canister and use a length of flexible pipe as a stethoscope you may be able to track down where the air is being drawn in