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vintaylor

help removing green/blue staining on cylinder block

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Hi Guys,

 

I've used degreaser, head gasket remover and thinner in the hope of removing the blue/green staining on the block head.. After about 20 mins of rubbing the surface in thinner I'm getting around 1.5 cm clean!  I've sprayed the surface of the block with gasket remover whilst using a plastic gasket scraper... Still not getting anywhere though

 

Does anyone have any advice on how I might be able to speed things up?

 

engine2.jpg

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This is a metallic salt so you'd probably have to remove it by means of a chemical reaction rather than a solvent. If it's an aluminium salt then most of those are not water soluble (which is why aluminium which is a very reactive metal doesn't corrode away, yes I do mean very reactive). You may find they are coper based salts (many blue/green salts are) in which case they are more likely water soluble.

 

Personally I don't bother, the salts will re-form and it's not as if you can see them, plus they are probably forming a protective layer form further reaction.

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Hi Andy,

 

The reason I am trying to clean this surface is to check the cylinder liner nip.. I have a feeling my engineer did not calculate this well, so I'm hoping to clean the block and paint it and have him re-check the liner nip before I hand it over to my mechanic to rebuild.

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In that case I suspect you'll have to remove it mechanically rather than chemically. If you're having new head studs it's easier as you can use a steel ruler to scrape it off, if not then going gently at it with a bearing scraper works but be careful so as to not damage the good part of the surface.

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Hi Andy,


I'm keeping the original studs as they are still in great shape.  Right now I've had my engineer change over the liners- I think he hasn't done this correct and I have agreed to drop off the block for him to re-calculate the liner nip.

I am planning on painting the block and have been cleaning the block during this time.

 

Do you recommend me leaving the head surface as it is until I finish painting the engine and then hand it over the engineer for him to skim it?

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If he has changed over the liners I hope he kept the right pistons as they are matched pairs and weighted, I think. You could run into problems if the liners have been moved away from their original pistons and of course the liners themselves need to be fitted in a particular orientation. There is a lot of useful information on CHANGES thread about 400 plus bhp from his four pot.

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If he's to skim the head then my question of keeping/ changing the studs goes, the studs will be coming out of the head. I'd have thought you can measure the liner nip with the metallic salts in place. You'll be putting a flat bar across the head which will be resting on the liner not on the head (the liners should be proud of the head's surface) and so you can measure the nip relative to the clean surface.

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If he has changed over the liners I hope he kept the right pistons as they are matched pairs and weighted, I think. You could run into problems if the liners have been moved away from their original pistons and of course the liners themselves need to be fitted in a particular orientation. There is a lot of useful information on CHANGES thread about 400 plus bhp from his four pot.

 

Hi Mike,

 

My engine came with grade B pistons.. I have informed Garry kemp about this and he has sent me a set of liners that should match.  Even if I could get a set of pistons, I doubt these are matched.  I have gone ahead and painted the engine block.. I'll be taking it to my engineer to get the liner nip measured again and if incorrect I'll get him to sort it out.  The original liners have had some wear over time and I have been advised by my engineer to change them, however the pistons are fine.

 

 

 

If he's to skim the head then my question of keeping/ changing the studs goes, the studs will be coming out of the head. I'd have thought you can measure the liner nip with the metallic salts in place. You'll be putting a flat bar across the head which will be resting on the liner not on the head (the liners should be proud of the head's surface) and so you can measure the nip relative to the clean surface.

 

I'm not 100% sure about skimming the head yet .. I'll take it back to the engineer and see what he says... If the liner nip is off, he'll have to pull the liners and re-install correctly.

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I agree about not having the head skimmed, if it can be avoided. Its not an easy job and there is some difficulty in setting up a straight edge. If the head gasket hasnt gone and there is no evidence of previous problems its best left alone particularly as the valves are very close to the surface and its easy to skim too much. You also presumably dont know whether it been skimmed in the past

 

Not sure what Grade B piston are but hopefully they overcome the necessity of having a weighted/matched configuration. 

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Sorry by skimming the head, I meant skimming the head of block rather then the cylinder head.  Lotus made both grade A and grade B pistons.  Piston grade will make the difference in what piston rings etc. are used.

 

Fingers crossed everything lines up and I won't have to get the engineer to pull the liners again .. I'll keep you guys updated

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Liner nip can be checked using a good steel rule and some accurate feeler gauges. The surface finish of the block isn't critical..as you say you've been trying joly hard to clean it and it won't come off, so it's unlikely to shift after assembly. Why do you think the liner nip is wrong???? Also, how did your engineer measure it? The nip ensures that the liner/head joint doesn't leak and at the same time the block/head joint doesn't leak either. The new Goetz gaskets are supposed to be more tolerant in this area anyway. If the head's flat it won't need skimming...again, a good straight edge and feelers will reveal any problems. In fact, a steel rule along the length of the head face allows you to squint towards a light and see if any is getting through between the head and the ruler. Flat ism of course, relative...(!) Somewhere I found a specification for how much deviation is allowable, but I'm nowhere near my workshop at the moment so I can't quote it.

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Just checked my old pistons and liners on the shelf behind me (they make really good bookends) and they do indeed have 'B' stamped on them. Knowing my car grade 'B' probably stood for substandard!

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I doubt the liner is correct since the engineer didn't even ask me for the old head gasket to be able to torque down the head to set the sealer off.

Also I had to clean off some old gasket material, so I doubt the nip has been measured properly



Either way, I'll have my mind a lot more at rest if I can confirm the nip is correct

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Using the old head gasket is good practice but if he has used the correct loctight sealant its anorobic which sets when air is removed so liners should seal themselves shortly after fitting into block.

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Not sure what your point is there Mike but the head needs to be torqued (for 4 hours) to seat the liners properly then the head is removed and nip is confirmed...

Edited by lotus4s

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Hi Vin if the alli is just stained you can check you've got rid of the old gasket material by running a thumbnail over the surface. It is perfectly acceptable to use 800 grit w&d with plenty of oil on a rubber sanding block. Keep light circular movements and don't concentrate on one area too long. You will of course have to remove the head studs and block up all the oil and water ways with kitchen roll to prevent ingress of swarf. It is also worth protecting the liner tops with masking tape.

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Hi Paul,

 

I'll head down to the local hardware store and stock up on 800 grit sand paper and a sanding block.  I've plugged to oil ways and covered the liners in advance.. Just need to get the dowels off the engine block. 

Is wd40 good enough to use instead of oil?

 

Here's a pic of the painted engine :

photo2-2_zps03e2ebc2.jpg

 

Still have to paint the crank cradle

photo3_zps568142ac.jpg

 

Sump and dipstick painted:

 

photo5_zps7998e2c1.jpg

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Hi Vin you can use WD40 no problem. Just remember to just clean and not try to remove metal.

The Goetz gaskets can be fussy too, so it's advisable to get some Wellseal for your engineer to lightly coat both sides of the gasket mating surfaces before fitting.

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Hold on there, I thought it was vital that headgaskets were fitted dry, I am sure I read on fitting mine that the only bit of Wellseal to be used on the Goetz gasket was around the small hole on the very edge of the block. 

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A bit of Wellseal around the edges wher the gasket seals to the block water jacket isn't going to cause any problem, the stuff is zero thickness to all intents and purposes. It will help to seal the joint and prevent coolant leaks or weeping. The engine is looking very clean and shiny....I've never managed to get mine all bulled up like that, getting the crud off has always sufficed!

I have always torqued the head down onto the old gasket when fitting new liners, it makes sure that the things are all the way in to the flange. When fitting them ensure the block is warm and the liners are out of the freezer, then coat the mating surfaces with the magic goo and slide them in!

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Honestly painting the engine makes a world of difference! .. I kept the aluminium coloured paint to keep it as original as possible ..  Will take note of all this and inform my mechanic to use well seal when installing the headgasket

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I agree that torquing down using old gasket ensures good crush pressure against new liners but it isnt specifically for ensuring the goo sets as Vin suggested. Also if you need to check nip height this should of course be done before any goo is applied

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So this is the current situation-

 

  • New liners have been installed into dirty engine 
  • Engine is now cleaned and painted
  • I am personally doubting whether the liner nip has been checked
  • I have agreed with the engineer to re-check the liner nip

This is how I am planning to go about it 

  • If nip is correct - hand over to my mechanic to start rebuild
  • If nip is incorrect - I will get the engineer to pull the liners and re-install liner until nip is correct (this time I will ensure he torques the head down with old head gasket.

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Vin

 

Basically yes. If nip is correct then tell engineer to be careful when rotating crankshaft when fitting new pistons as liner goo is not that strong and liner could easily be lifted from position. I think I used my made up liner clamps to hold each liner in place after fitting each piston.

If Nip is incorrect it may be necessary to move liners around if they are too proud rather than too low in the block. Hopefully they should be ok which will save a lot of effort and expense. 

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I agree that torquing down using old gasket ensures good crush pressure against new liners but it isnt specifically for ensuring the goo sets as Vin suggested. Also if you need to check nip height this should of course be done before any goo is applied

 

 

Mike,

 

FWIW, the earlier manuals may not reference it but the later Service Notes specifically call for dry fitting the liners to verify nip and then re-installing the liners with sealant and torquing the head down "within 4 hours to ensure that the liners are seated correctly before the adhesive cures".

 

Because there were different types of liner sealants spec'd over the years this step would be more critical with the use of an anaerobic sealant which hardens versus a Hylomar type product that never fully hardens.

 

Cheers,

Jim

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