Exhaust port - cleaning

loxley007

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Hi all, I’m looking for advice on the best method of cleaning the inside of my exhaust port. They look pretty filthy/corroded.

I’ve attached two photos for info.

Any advice?

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Biebs

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Diesel fuel and transmission fluid mixed - soak it.

Engine running run some diesel in the gas it is a good cleaner and with the heat from the engine will help clean.

Diesel fuel should be abundant in your neck of the woods.
 

loxley007

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Cheers, I’m doing a full rebuild as it is seized. A quick question though, is it possible to take the head off even with seized pistons?
 

SenseAmidMadness

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Cheers, I’m doing a full rebuild as it is seized. A quick question though, is it possible to take the head off even with seized pistons?
Yes, that should be entirely possible, though depending on why the pistons are seized you may have damage that would make the head worthless. A massive amount of rust being one such problem. Hopefully the valvetrain is in better shape than the pistons.
If you're tearing the entire engine down for a rebuild, including splitting the cases, then you don't have to worry about saving the long cam chain.
 

loxley007

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Yes, that should be entirely possible, though depending on why the pistons are seized you may have damage that would make the head worthless. A massive amount of rust being one such problem. Hopefully the valvetrain is in better shape than the pistons.
If you're tearing the entire engine down for a rebuild, including splitting the cases, then you don't have to worry about saving the long cam chain.
Thanks, I’ve now removed the head. The pistons had thick (half inch) of grime on them and the valve train is badly corroded as well.

My plan is to try and knock the pistons out using the wood and hammer method and then maybe remove the cylinder sleeves to measure them properly.

The valve train is badly rusted and seems to have the valves stuck at various different heights in each bank.

Photos attached and I’d be interested in comments on my next steps/the damage.

Thanks all.
 

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SenseAmidMadness

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Holy guacamole, that's some nasty rust in cylinders 1 and 3. No way to know how much of it is loose but it looks to me like you may need a replacement cylinder section and new pistons/rings with how bad that is. This poor engine must have had water in it for years.

I don't even know if you can get individual replacement sleeves for these engines, but even if you could it probably wouldn't be as cost-effective as buying a used set of cylinders. I've seen plenty of them on Ebay here in the US.

That head doesn't look nearly as bad, but you've still got your work cut out for you if the valves are stuck in their guides due to rust.

How serious are you about saving as much of the original parts as possible?
 

dirtdigger

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Dont worry about measuring pistons and cylinders because they are definitely no good. Best off looking for a better cylinder that can be honed or bored next oversize. I am betting you will be needing new valves in the one cylinder for sure, probably guides in all and a full valve job.
 

loxley007

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Thanks all. I’m not that worried about keeping the original parts more about getting the engine running for as low a cost as possible.

I think next steps are to get the pistons out and see how much damage there is on the cylinders/pistons before then starting the hunt to get some new ones.

For the head, I’ll try and get the valves out and see how damaged the guides are. Any advice on how to remove them ?

Thanks for advice.
 

dirtdigger

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Start with some sort of rust penetrant, depending on how stuck they are. Make sure the stem is free from rust etc before trying to push them through the guide so you dont score them up. If they are really stuck you may just have to consider the valves sacrificial and tap them out or work them back and forth with a hammer of some sort in which case they will definitely be junk. If valves are rusted in they are pretty much junk anyway as well as the guides.
 

loxley007

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Start with some sort of rust penetrant, depending on how stuck they are. Make sure the stem is free from rust etc before trying to push them through the guide so you dont score them up. If they are really stuck you may just have to consider the valves sacrificial and tap them out or work them back and forth with a hammer of some sort in which case they will definitely be junk. If valves are rusted in they are pretty much junk anyway as well as the guides.
Cheers, that a job for the weekend!!
 

loxley007

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Some progress has been made with the valves - they are now all out. I ended up carefully tapping them out and using a bunch of lubricant.

The stems were really rust free beyond where they went into the valve seats so hopefully no scoring took place as I tapped them through.

I now need to clean up the head and see how clean everything is including the valve seats. I’m going to try and get some light in the valve seat to see if it is rusted up.

If they are rusted up would you guys recommend replacing the valve seals? Cost is a definite concern so trying to keep it economical.

Thanks for advice.
 

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dirtdigger

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The seals need to be replaced regardless. The rusty seats will for sure need to be cut as will all the seats on all four cylinders more than likely. If the valve faces are pitted they need to be replaced, you can not grind the valves as the surface hardening is not thick enough to grind. The valves and seats wear on these motors anyway and tighten up the clearances causing burned valves.
 
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