Hi all

Had an hour or two in the garage today and managed to resolve the electrical problem I had t may have found another... When running the engine I can see water coming up from two of the cylinder head studs.. Upon more inspection I think I have water in the oil... Checking the dip stick I see what looks like an emulsion rather than nice clean engine oil..

Would I be right in thinking a head gasket problem would cause both? Or could it be something more sinister like a cracked block?

Cheers
Robbie

Location: Horsham

Yes unfortunately it is the head gasket
M

Location: Chichester

I wouldn't say unfortunately if it is only the gasket

Location: Oakley ,Hants

Thanks Martin

Wondering, why do you think the head gasket would "go"? I've only had the engine running about 6 or 7 times since rebuilding it and not out on the road.. when fitting the gasket I did not use any sealant.... Just smeared surfaces with as smidge of oil and bolted the head down.. Should I use a sealant? What other reasons for blowing the gasket? Is it common to see water coming up the studs? I know a couple of them screw into the water jacket..

Any thoughts/advice on how best to flush out the engine before putting in nice clean new oil?

Location: Horsham

Hi Robbie,

Sorry but I'll guess the block is porous.

The water coming up from the stud could just be water working its way around the thread. This usually happens if the studs are new. The rust over time stops the leak. Or put the studs in with locatite.

There could be a leak in the gasket, just hope it is. Because it would be the cheapest problem to solve.

More and more blocks are starting to show the little black spots half way down the bores. This is were they are starting to rot through from the water jacket.

Hope for the best, but expect the worst.

Tony.

Location: Leics

Thanks Tony,

The studs are indeed new and I certainly didn't seal them when installing. Was probably thinking too much about future removal than sealing them in place 😜

The block looked OK when I fitted it and I'm keeping fingers crossed that it's not rotten..

Any advice on what to use to flush the engine prior to fitting new gasket?

Location: Horsham

Before you pull it to pieces,run it up a bit,take the plugs out,get someone to crank the engine over and see if it blows water out of the plug holes,at least you will know which bore it possibly is.
The centre head stud hole is prone to cracking,it can crack into the centre bores if bad.

Thanks, will do that tomorrow..

Location: Horsham

Had black spots in the bore of the Rosengart (was stood with water in the engine for the best part of 60 years). new linnings circa £100, fit and rebore circa £250 and new pistons circa £180. Prices vary from our cherished suppliers so do your home work.

Location: Oakley ,Hants

Have you checked and re-tightened the head bolts since the rebuild?

Location: Pembrokeshire.

Hi Phil

Yep, all were nice and tight.... Will remove the head tomorrow after checking for water in the bores (as above) and feedback what I find..

Location: Horsham

Location: huncote on the pig

I'd be tempted to use Loctite 243 Lock and Seal.

Location: Near M1 Jtn 28

I have had repeat water in oil problems with other cars. After about 30 miles it seems to all boil off with no apparent effect. However Seven rolling bearings do not like water. It may be worth running the engine for a few minutes, no water, with just enough fresh or good used oil to serve the pump and flush things out.

Bob Culver

Location: Auckland, NZ

Location: As far east in Kent as you can get

Location: Horsham

I think Tony's suggestion of porous bores is the only way to get engine water into the oil, but there are other sources of water.
If there is just a little bit it could be condensation, or if there is more have you been splashing about in water?
If you drop the oil out of the sump the water will come out first, so you will get an idea how much is in there. Normally I'd ask if the oil level was increasing, but that might not be relevant if you use a fair bit, equally is your water level dropping?

Andy

Location: Oxfordshire

As Andrew says condensation can form,usually in the filler tube,moisture in the cold metal tube mixing with the oil creating mayonnase around the filler neck and cap.
Duckhams 20/50 used to be really bad for that in 60's-70's OHV rocker covers.

Robbile Before you start to strip down it may be advisable to re check your head nut tightness. Then run the engine a little until it is hot and re tighten them as cast iron heads should always be re tighten when hot. I believe it is something to do with the head studs expanding in length as the engine warms up thus making them loose some of there tightness.
Another thing you could try if it's water leaking up the threads is to put some radiator sealant in your water and seal then from inside so to speak.
Whatever you do you must change your oil to get rid of the contamination of water even if my fix works.

John Mason

Location: Nottinghamshire

Refreshing the oil is obviously not a cure but it may help preserve the bearings whilst one is found.
One virtue of the Seven is the limited potential passages between water and sump. But can water find its way via the studs into the manifold?

Bob Culver

Location: Auckland, NZ

Thanks all for the advice

I had checked the tightness of the head bolts when the engine was warm last weekend so I know they were ok...

So, decided to whip the head off and have a look.. Head gasket didn't look to bad but there was definitely water in the bores (at least 2)

took the following photos of the bores. Can anyone advise if they look knackered as suggested by Tony?









I'm thinking the 3rd and 4th photo show significant black spots as described by Tony... Think I must have been blind when looking at the bores during the rebuild...

thoughts?

Location: Horsham

IMHO whether it is leaking or not I would not hesitate and get the block rebored or relined, thats knackered. Revert to my previous post.

Location: Oakley ,Hants

Hi Robbie,

Those bores look well warn out to me.

If the bores are warn, there is little point in fitting new Pistons and rings.

If it was me I would rebore it,

Have the block blasted clean first, as I've seen them crack in many places, inside the valve chest in the water jacket is a fun one.

Once it's clean you can check all surfaces.

After it has been bored, leave it in the shed for a week.

With a fresh bore the surface is dry without oil, with the damp in the air. If the bores are porous, it will show little black dots two thirds of the way down the bores.

As suggested the problem will need sorting out, ignoring it or trying cheap fixes will cost you more in the long run.

Tony

Location: Leics

Just spoken to father and he has some spare sleeves.. Looks like a trip up north is in order 😄😄..

Thanks for the comments and advice as ever
R

Location: Horsham

Thought I would provide closure to this thread with the results of re-sleeving the block. Hopefully the photos will show below.
When we started to bore out the block ready for the new sleeves it became more and more apparent that the block was indeed porous and we even found a hole in one cylinder when bored out to the full extent ready for the new sleeve. Photos below are of each cylinder bored ready for the sleeves.









Boring tool in action:



Photo below should show the finished article. The block certainly took some heating up to get it to expand enough to take the new sleeves but it was very pleasing to hear them clunk into place when "dropped" into the bores. A rather loud sigh of relief too when they all went in

Location: Horsham

You haven't mentioned the size of the bore in the block but as well as the cylinder wall thickness in the water jacket area there is the cylinder wall thickness below the water jacket to consider.

From recent experience it is possible to have this reduced to thousandth of an inch by heavy over boring and sleeving will do nothing to recover strength in this area.

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

The sleeves were standard so I presume are within tolerances for wall thickness etc. Cant remember the exact measurements now but think we bored the block to 59.7mm which is within a few thou of the OD of the sleeve.

Will see how long things last now the new sleeves are in...

Location: Horsham

Robbie-

With a standard Austin 7 2.2" bore or 55.88 mm, 59.7 mm on my calculations is 150 thou oversize- you may need to check the lower wall thickness!

From discussions the castings vary but given 80 thou oversize seems to be a suggested maximum overbore it could be close.

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

Hi Robbie, The last photo has it been bored to size and just ready for Honing.
Cheers

Location: Tinopai NZ

Looking at the sectioned block and considering the casting thickness - with around 60 mm cylinder bore the offside flange of the block, held by five of the eight studs to the crankcase, is connected to the block by a 1 mm (40thou) wall in cast iron.

The sleeve may keep the water in the block but will be of no help in tension where the bottom flange is concerned.

It is possible that with a low compression engine 40thou of cast iron is enough to hold it all together for a while !

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

Thanks all for the comments. I must admit to being a little confused as I have heard of many blocks being re-sleeved but not of many failing due to insufficient "meat" left to hold them together.. We used standard sleeves (New old stock) and bored as per the guidance on the paperwork that came with them..

Anyway, will have to see what happens. I'll feedback with any news as and when I get the engine running again..

Location: Horsham

Having recently seen a couple of blocks lose the bottom flange maybe I am being unnecessarily pessimistic.

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

Hi Robbie, you haven't answered my last post, you will need to hone the bores with a cross hatch pattern before the pistons are fitted,
this can only be achieved using a hone with parallel stones.
this is very important for the bedding in of the rings.
and for the final sizing of the bore

Location: Tinopai NZ

Sorry Colin, last photo was at the "ready for honing" stage

Location: Horsham