Technical Running bad, cylinder head

[koalar]

Right let's start with the driving symptoms

Knocking noise when accelerating cold engine, clear up when hot

poor power at lower revs, bogs down then picks up, clears up when hot

stalls at junctions

erratic idle, revs rising and falling, sometimes a bit shaky at idle

judder on pulling off

misfire can be heard from the exhaust

poor fuel economy

occasionally need the coolant top up and occasionally a gurgling noise after you switch the engine off

 

[koalar]

tests conducted

very little difference if you remove the HT lead from cylinder 1 or 2

stream of bubbles from the blead screw

compression on cylinder 1 and 2 nearly half that of 3 and 4

 

[jrkitching]

HG failure between the first two cylinders fits what you've posted so far, but you know that already.

Whatever, if the car is repairing (more likely at current used car prices), the next step is to lift the cylinder head and see what's going on.

 

[DaveMcT]

Throwing coolant down the exhaust can scrap the catalyst so take are you don't end up with a double repair bill.

 

[koalar]

Throwing coolant down the exhaust can scrap the catalyst so take are you don't end up with a double repair bill.

I very much doubt there will be an lose of catalytic converter performance, I have seen them full of coolant washed out with a hose and dried out and still fine.

technically it possible but highly unlikely

I will crack on with the faults I can see first

 

[koalar]

cam locking tools don't quite line up. worry about that later

here's the gasket

 

[Pugglt Auld Jock]

cam locking tools don't quite line up. worry about that later

here's the gasket

View attachment 404269View attachment 404270

Text book example! Fits the symptoms exactly. Why is it so often the cylinders at the front of the engine - 1 and/or 2 - which fall foul of gasket problems on these engines.

 

[koalar]

Text book example! Fits the symptoms exactly. Why is it so often the cylinders at the front of the engine - 1 and/or 2 - which fall foul of gasket problems on these engines.

no idea
cylinder head is flat
engine block isn't, it dips down but its between cylinder 3 and 4 and always has done so.

both the block and head are pitted, The block is worse, at nearly half a mm, cylinder head is deeper than the
permissible

depth doesn't really show up in photos

 

[koalar]

original JB Weld

slow setting but more sticky than the quick set stuff.

cleaned out, roughed up and applied, fingers crossed it will hold up


probably run the engine when its back together without any coolant and get the cylinder head gasket coating to melt. It will be a fine line getting it hot without damaging anything

 

[Pugglt Auld Jock]

There are many interesting videos on you tube about uses for JB Weld. I think your's may be one of the most extreme? Do let us know how long it lasts.

After many years of using Araldite, I was in Pilrig Motors on Leith Walk one day intending to buy some more when he recommended I try some JB Weld. I've never looked back! Don't know about you folk but I prefer the slow setting epoxy resin glues - I just don't find the rapid setting stuff forms such a strong bond?

 

[DaveMcT]

Old fashioned Araldite sets like hard glass when heated to accelerate the set time. But this job looks like a case for TIG weld and a light skim. If the block is damaged have to ask if the engine is worth the trouble.

 

[koalar]

Old fashioned Araldite sets like hard glass when heated to accelerate the set time. But this job looks like a case for TIG weld and a light skim. If the block is damaged have to ask if the engine is worth the trouble.

TIG cast iron without pre heating is asking for distortion and or cracking and is not really the way to repair this kind of damage

people have been repairing damage like this for over 40 years using spray welding

strip
chemical dip
bead blast
pre heat
spray weld
post heat
machine
good as new

it would be cheaper to find a new engine, Its not a rare classic car or ocean liner where replacement blocks are hard to come by and its cheaper to repair than replace

there is a Good vintage clip of spray welding on YouTube can't be bothered to dig it out at the moment. Need to crack on while the weather holds up

not a job for old fashion araldite either. Its a thermal insulator. You need something that will stop the heat from building up.

 

[DaveMcT]

I did say, "If the block is damaged have to ask if the engine is worth the trouble".

The cylinder head is ALUMINIUM so TIG and skim.

 

[jrkitching]

original JB Weld

This certainly isn't a procedure I've seen documented in any reputable technical manual. But if you're looking for a cheap way to try to eke a bit more time out of an end of life car, I'd say it's worth a shot. It's only going to cost you your time and the price of a HG. and it's less effort than doing an engine swap.

Getting a good bond between metal and epoxy isn't easy, and how this is going to hold up to thermal cycling is anyone's guess, but I hope for you that it at least works for a while.

Only thing I'd say is that I definitely wouldn't try running it without any coolant in an attempt to set the HG.

 

[koalar]

I did say, "If the block is damaged have to ask if the engine is worth the trouble".

The cylinder head is ALUMINIUM so TIG and skim.

post 8 above

block is worse than the head

 

[Pugglt Auld Jock]

Sorry chum, this is a bit of a lost cause I think? If the rest of the car is worth it I'd be looking for another engine. Have to say though that I'm most intrigued by the JB Weld repair and I hope you will keep us updated on the outcome please.

 

[timmycm850]

I think the reason it goes between 1 and 2 is the coolant travels through the engine block diagonally from the pump to the thermostat and cylinder 1 gets largely forgotten about in the water travel. This with heat coming from both cylinders and no cooling between them its a hotshot.

Tim

 

[timmycm850]

Hotspot even

 

[koalar]

mix two batches of JB Weld in separate upside down ally can and left a match in each

I can't pull the match out or chip the epoxy out. Which is encouraging especial as I didn't rough them up first

ground the block and head flat with some emery paper over a large piece of marble.

tighten the head bolts down

20 Nm
30 Nm
then a further 90 degrees
then another 90 degrees

I do have an angle gauge but didn't bother using it. Put a spot of tippex at the bottom of each bolt. Its all done when they all point to the top

timing belt is impossible to fit while the cam is locked in place. Had to back it up one tooth fit the belt. Turned the engine over a few times. Timing doesn't quite line up. About the same as when I took it apart.


loads of other things happened. Broken exhaust stud, Fail on fit tensioner and so on, My write up some of the bodges fixes, Maybe not.

Anyhow fired up, sounds good, Was going to run it for 5 minutes without coolant but bottled it after 3 rain and darkness came so enough for today.

 

[koalar]

Sorry chum, this is a bit of a lost cause I think? If the rest of the car is worth it I'd be looking for another engine. Have to say though that I'm most intrigued by the JB Weld repair and I hope you will keep us updated on the outcome please.

I will not right it off just yet.

I fired up and has good compression.

had a bit of luck. The pits run from cylinder 1 to 2 under the fire ring. But not quite to the edge about .5mm one side and 1mm the other.

its going to be a puddle of JB Weld capped by the gasket holding it all together

wish I had taken a better photo of the block. The surface finish was quite bad, also the back edge of the fly cutter has been dragging by a thou or two. Shows that they aren't too critical and the Viton coating fills some small imperfections