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Discussion Starter · #1 ·
After an over heating issue and need to replace head gasket I've managed to remove the head.
Gasket blew between cyl 3&4 allowing coolant into the cylinders which is turning rusty.
Is the block scrap or would a rebore and oversized pistons fix it?

Also, when I loosened the head bolts, some were tight, but some just gave way without much effort. Could this be from the bolts not being tightened properly a year ago when the gasket was replaced or could the overheating cause bolts to relax? Neil
 

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Alan St500
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I don’t know the answers to your questions bud but I would advise against reboring the already Parmesan based liners just get them replaced if it comes to that 👍
 

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The rust has only formed since the last time the engine was run so is a red herring in terms of the extent of any damage.

The photos aren't the best quality so it's hard to say but why do you think the block might be scrap?
 

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Discussion Starter · #4 ·
I thought it might be scrap due to rust, but yes, like you say it's just surface rust.
Thanks for reminding me about the thin liners, forgot all about them, so that rules out a rebore.
I'm now hoping a hone and new piston rings should be enough.
If the bores have worn to much I'll see if I can get them relined.
 

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I thought it might be scrap due to rust, but yes, like you say it's just surface rust.
Thanks for reminding me about the thin liners, forgot all about them, so that rules out a rebore.
I'm now hoping a hone and new piston rings should be enough.
If the bores have worn to much I'll see if I can get them relined.
From the symptoms you described I think the liners are fine. My best advice would be to get the liners checked anyway for cracks. Always worth getting the head pressure tested when it's off the car. If that's all ok and both the cylinder head and engine block surfaces are good then it should be a straightforward rebuild. There are several possible reasons why the head bolts had varying levels of torque but the most likely reason is that it was rebuilt by someone who had no idea what they were doing.
 

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Discussion Starter · #7 ·
Thanks for responses. I'm not sure if the bolts were reused but if so it might explain why some were loose if they were further stretched.
Researching loose head bolts, it could also be from the gasket being crushed/breaking up because of the exhaust heat which kind of makes sense.
Yes, definitely a pressure test on the head and strip down to check the valves.
Thanks for your advice :)
 

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Lubricate the pistons and turn the engine few times (maybe with power tools) and see if that surface rust will clean. It should be fine if its just surface rust. Redo the head, since you had issues with the gasket you might need to skim it a bit. Consider a thicker head gasket if you did last year as well.
 

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Discussion Starter · #9 ·
I rubbed the rust spots down with some emery paper but they''ve left very faint pits that can just be felt with a finger.
I really can't be ***** be ***** removing the block to rework or replace it, so what do you guys think? Salvageable or scrap?
 

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Alan St500
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I rubbed the rust spots down with some emery paper but they''ve left very faint pits that can just be felt with a finger.
I really can't be * be * removing the block to rework or replace it, so what do you guys think? Salvageable or scrap?
What scrap the whole car ? You’re most of the way to fixing it lol if the rest of the car is sound then get new liners in there
 

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Discussion Starter · #15 ·
I would have given the cylinders a good coating of oil and turned the engine over by hand a few times to sweep the bores with the pistons, then ensure a thin film of oil was left to stop them rusting up again anytime soon.
I bought the car spares or repair for a grand and by the time it was collected, trailered to the Midlands, diagnosed and head off, a month went by so the lubing piston boat has sailed.
At the end of the day, I am were I am and i need advice on what to do now, not what I should've done with insight a month back.
Imo the block needs relining, but would be nice to know if it can be honed?
 

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I bought the car spares or repair for a grand and by the time it was collected, trailered to the Midlands, diagnosed and head off, a month went by so the lubing piston boat has sailed.
At the end of the day, I am were I am and i need advice on what to do now, not what I should've done with insight a month back.
Imo the block needs relining, but would be nice to know if it can be honed?
I understand your frustration but all I did was answer your question!
 

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By the state of the engine it must have sat over an year or it had poor coolant in it.
As stated before, coat the engine with some oil or something like fogging oil/wd40 and turn the engine several times. Ideal would be to use some sort of a power tool to be efficient. With medium lubrification you should use the rings to scrape the liners.
Honing its going to take very little from the surface and will leave behind a finish pattern that will retain oil while reboring is taking a bit more material, probably 0.25mm in total diameter. I would say is to little to make a real difference in terms of liner resistance. But its going to be costly as it requires new pistons and rings.
Either of this choices are done after you (or a machine shop) will inspect the block really well. Just make sure you have a decent budget for rebuild and at least some sort of understanding about what is happening there.

Its hard to tell from the pictures how bad the rust is but try to spin the engine as told and see what you left with.
 

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Discussion Starter · #18 · (Edited)
I've rebuilt a few engines so aware of the cost which is why relining is preferred route as a I can keep pistons and just fit new rings.
Apologies Teflon if I sound frustrated, I'm not, I just don't understand how barring the engine over will get rid of those rust pits. If a gentle rub with some emery paper exposed them, then IMO scraping them with piston ring would also do the same.
Either way it would leave pits and comprise new rings.
I've now removed everything from the block and will try lowering it and sliding it under the wheel arch the next week. There's a machine shop nearby in Daventry that might be able to re-line. If worse comes to worse, there's a good used block on eBay for £230
 

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Alan St500
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I've rebuilt a few engines so aware of the cost which is why relining is preferred route as a I can keep pistons and just fit new rings.
Apologies Teflon if I sound frustrated, I'm not, I just don't understand how barring the engine over will get rid of those rust pits. If a gentle rub with some emery paper exposed them, then IMO scraping them with piston ring would also do the same.
Either way it would leave pits and comprise new rings.
I've now removed everything from the block and will try lowering it and sliding it under the wheel arch the next week. There's a machine shop nearby in Daventry that might be able to re-line. If worse comes to worse, there's a good used block on eBay for £230
Iirc if you get another block you have to get another part with it as they are machined to only work with that engine, sump 🤔head🤔 someone will tell you correctly though bud @Alb is the man to ask 👍
 

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Discussion Starter · #20 ·
Iirc if you get another block you have to get another part with it as they are machined to only work with that engine, sump 🤔head🤔 someone will tell you correctly though bud @Alb is the man to ask 👍
I know blocks are usually matched with the crank shaft ladder, or in this engine it's part of the lower housing as it's all bored as an assembly. If that's the case, it's fine as eBay block comes with it. But if it needs matching head or something else, then that's not good at all and will seriously screw things up.
 
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