Engine Liners

If you have to rebuild your PRV V6 because of water in the engine oil the chances are apart from head gasket falling the liners will be the problem.
From what I have found I think the problem starts with the build up of debris around the back liners this starts the bace of the liners to rust which then compromise the liner seat and seal, which then stars the corrosion of the aluminium surface.
Also the liners can crack at the bace or becomes porous, out of 12 liners I had for one engine only 6 where any good.
Once the aluminium is pitted or badly corroded there are two options open send the block away to someone who is willing to machine out and place a new seat in which will not cheep or Clean and fill the pitted surface.
The second option I never considered until recently when I had another aluminium component that was no longer available for my Ds and i sent it away to be welded and re machined but this could not be done so they recommend a specialist epoxy type product that can then be machined once set, it came back and it’s amazing stuff and has
So one of the blocks I have someone had what looks like put an angel grinder to a part of the seat so I got some of this stuff and applied it and I now have a perfect rock hard seat.

Here are some pictures of some of the liner problems, you will need to tap on the pictures to view in detail.

I will go through the method I used to obtain a new seat surface tomorrow it’s a 2 to 3 day process.

Ok so there are probably loads of engine blocks that have been dumped because of this, I took my block to the people that that I use that have machines for carrying out anything to do with engine work or modifications, and the look on his face was yes I can do it but I am to busy to sort that out.

So I thought I would see if there’s a way to fix this that would last for hopefully another 10 to 15 years.
There are several products that are available they are Devcon plastic Steel putty or 3M Scotch Weld 125 Gray, or JB Weld, the price comes down in the order I have listed.

The method, first of all it goes against every thing which is to remove all the oxidation of the aluminium which is best achieved by shot blasting the area to give a clean and ruff surface so that the putty can get a good key.
The thought of putting any form of grit or bead near an engine is a no no to me as it is vary hard to remove all traces from an engine, however save a block or no block. I duck taped the liner holes and sealed up the internal engine void, then blasted the bad seat hovered up and cleaned up.
I then cut off the top of one of my bad liners just leaving the bace section this is so you can apply the putty and fit the liner bace.
You then smear a thin amount of grease over the liner and then put cling film on the liner area. Then mix up the putty and apply this to the blasted seat pushing it In making a good contact so it can bond in, then remove the excess and get the shape, then carefully put in the cut liner and push down hard, then get a full liner and put on top to keep the pressure on and leave until the next day.

You then can pull out the cut liner which will then just leave the cling film then peal off the film you will find you have an almost perfect seat surface, sand off the excess around the bace below the seat surfaces. Then coat the liner surface with engineering blue put some smooth valve grinding paste on the liner seat a small amount of light oil as well and seat the liner like doing a valve.
I found you then might have a few pits so to get it perfect I just repeated the process until perfect then just set the liner height with the paper rings. I didn’t even need an extra paper compared to the others.
The best repair will all ways be re machining the seat but if it is just bad pitting this I think is a viable option that you may want to consider.

Brilliant. I once used araldite to glue together a snapped valve guide that was letting oil in on shut down. Was like smoke screen when i started the car. Araldite on the stem and under the valve spring did the trick. Was a Datsun lasted another year. No problem

Ref your JB weld repair.. I am going to give it a shot on my rebuild..

Couple of questions.. the rust/clag in the block where the corroded liner sits, how do you clean this out.. it's very difficult to access on mine..
Maybe a very small drill on flexi drive?

Also how to stop this reoccurring?

I assume it's all about keeping the engine cool in that area if possible..

It would be useful to borrow your cut down liner if you have no more use for it.. I do have spare liner but no means of accurate cutting..

Happy to pay for shipping each way.. I could collect but guessing u are miles away from SN66JT

Thanks
Peter

Sorry l have been away and have only just seen this, I tapped up the block and grit blast the area, a dremel or something similar you have to get back to the aluminium and it needs to be ruff.
I don’t use anti freeze anymore, water less fluid so this will prevent any more corrosion happening.

No need to apologise... and thanks again for reply... I'll update when I have had a go at this..

Peter

Just read through the above and it worked well, don’t rush it first application gets the shape, second is fine filling the blemishes, the 3rd should get it spot on, application off fine valve paste on the liner bace with a spray of WD gets the high spots of and then it should be spot on, then just build the engine as normal.