Compression issue? Parts and guide to fix

Do you think I can get it back to a descent state, I've got a max of about 500 pounds to send on parts, I'm feeling a bit sad I was hoping it was just going to be the camshaft

 

How to do it on the cheap.
You don't have problems with the other head - don't even look at it - you wouldn't if your work was just to change the duff head.
Same for barrels and pistons. The last compression test you did looked good apart from the dodgy one and that was the head. Don't do a thing to them but don't mix them up or loose their positions.
Good oil pressure? There is nothing wrong with the bearings or the pump. You don't need to replace them. Leave the conrods on the crank.
That goes for the cam bearings too IMO. Probably. Do not disturb and bearings - leave them snugged in the case halves.
Get a matching pre-loved head from someone on here or ebay or somewhere.
Get a gasket set and new front and rear seals.
Get a cheap scat cam and followers.
You might have £200 change.

You actually could have left the other head barrels and pistons but it's as well you did remove them so you can torque it all up nice and sealed and you've had a look. If you had been able to leave them, you could have lifted the case half off and the crank and cam would reliably stay put in the other half. You can still do it though if you're careful - engine on it's side. If you do all this while ensuring you keep any dirt out, no need for a frenzy of cleaning out the case etc etc. Keeping it clean is paramount to doing this cheaply and quickly. That can't be over stressed. If a gust blows grit in it you are in for a world of pain. Anything that wore off the cam/lifters should be in the oil filter.

 

You're not trying to wind the engine's clock back to zero. You have to accept that it's wherever it is in it's life span. You're repairing it and it's tough that the broken bits are in the middle but don't be distracted by things beyond your budget. Stay focussed KEEP IT CLEAN.

 

So I bought this cam and was going to buy a new set of lifters from cool air.

Everything is covered in a thick layer of grim so that's why I took off so I can give everything a good clean,

Is there a trick to taking off the pistons haha

 

Slow down. Don't let outside grime inside.
Circlips out, warm piston until just too hot to hold (need a rag), slide out pin. There could be a burr caused by the circlip on the outer edge of it's slot. Gently remove it if it's stopping the pin sliding out. Don't mix them up. Did I say that?

 

Hmm. Not so much the lobes but the bearing surfaces don't look great, could be the picture but the centre one looks like it was cleaned up with 12o grit.

 

I hope that cam was cheap. It shows the typical Type 4 wear pattern and you can clearly see how the followers overlap the lobe. I wouldn’t use it but if it is better than the cam in the engine you might as well fit it and hope for the best.

I haven’t read all the comments but zedders has probably said to deglaze (hone) the cylinders and fit new rings - from the pics the bores and pistons look okay. I’d fit new bearings while the crankcase is split but if you’re trying to save every penny and the bearing aren’t worn you could reuse them. I’d definitely renew the cam bearings, they’re cheap, but that used cam will probably chew them up pretty quick unless the bearing journals are better than they look. New followers on a worn cam wont last long anyway so you’re not building an engine that will last 100k miles.

My shopping list would be:
- New head, or if you’re really lucky a decent used one but bear in mind all type 4 bus heads have a hard life and you’d probably have to fit new valves and replace the guides.
- New cam and followers. Web cams are the best but they’re expensive and would make a big hole in your budget. Scat, Engle and all the rest are more or less the same quality but get the cam and followers from the same manufacturer.
- New big end, main and cam bearings.
- New piston rings.
- Gasket set.
- Front and rear crankshaft seals.

 

I found this no idea if this is any good priced well or not

https://www.ebay.co.uk/itm/184297547947

 

I wouldn't write off the head just yet.. from the way the shadows keep appearing and disappearing I'm guessing the valve springs are off and the valves are moving. Wait till it's all cleaned up and youve had a better look at it.

Not too sure on the cam though but if money is tight.. I'm sure there are plenty of buses running with worse..might be able to russle you up a fitted but not run cam bearing set if you need .

As long as nothing is worn past re-use, £500 is do-able







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Looks like it sat outside for a while. It's rough. Are the exhaust ports like yours? Most are not like that.
I would try a wanted ad on here, you're more likely to get a good head here than ebay where people dig such things up from their gardens. But as I'm sure we all keep saying - don't buy anything yet, your budget is tiny, you don't know what you need yet!

 

Ok I have a big thing of degreecer coming tomorrow. So once everything is apart and cleaned hopefully we'll have a good idea what exactly I'll need

 

So I just had a good look at the head the one that zedders put an arrow on, it seems to me that it's been machined, even the spring is further out then the rest?
Why would someone do that, does it mean its dead

 

If the valve seat has sunk into the head the spring will get let out more..

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Check this out. If the head get's too hot the seats get loose and each time the valve claps shut they pound a little further into the head and get a bit looser in the process. Eventually they fall out and can jam the valve open.

 

Happened to me. I needed new head.

 

It's the thing that goes wrong for type-4's and a nudge to invest in a cylinder head temp gauge.

 

It’s difficult to tell from your angles / pictures IF the valve seats have recessed, however I can’t see any fretting etc so I suspect it hasn’t , I can see one blown head gasket ,

out of interest if your budget is £500 ish why are you removing the pistons ?

is the cam definitely damaged, don’t buy( waste your money ) on parts unless you need too as you will run out and just have a pile of parts and no way of finishing your build

put the heads face done , get a straight edge , lay it across the top of the valves to see if they are level

 

The second photo looks exactly like mine,

Right I am out for the day now, when I get home my cleaner should have arrive as I said I'll carry one stripping cleaning then, hopefully get a parts list together

Again I would just like to thank everyone for there advice, I am truly grateful. I wouldnt have dreamed on taking this on without you lot

 

Are you squinting at a phone mr oft? It hasn't fallen out yet, not that loose, but it's a mm or two into the head?

 

it does look that way, but it could be a perfect shadow , pictures are cheap enough to take more

but head flipped and ruler is just as easy tooooo