Cylinder liner protrusion

[Deantracy17 1]

Looking for help. I have a new block for my 1.6 engine and the cylinder liner protrusion is about 0.127mm. I used a straight edge and a feeler gauge to measure. The o-rings are not fitted. Looking at Haynes manual, pre 1987 blocks had a liner clearance of 0.08 - 0.15mm. The block is a B6D so what’s the chance it could be pre 1987?  Does anyone know any reason for the difference in protrusion pre 1987?  Post 1987 the protrusion should be 0.03 - 0.1mm so I think I might need to machine down the liners. Any help would be greatly appreciated. 

[DamirGTI 325]

Had just the same/similar "problem" last year :

 

 

 

... since i re-assembled the engine - no problems with the HG sealing , no coolant or oil leaks , everything seems fine .

 

So i'd suggest just bolt the head on and be done with it . (need to note i also fitted the thinnest HG available , 1.27mm if i remember , and i'm running a bit higher dynamic CR  .. if you're worried about the outcome , fit thicker 1.50mm "repair" HG)

Machining wet liners is tricky job anyway ..

 

D

 

Edited October 29, 2019 by DamirGTI

[Deantracy17 1]

Hi. Just read your link to the issue you had. I will try to lap the liners in a bit to make sure they are sat right. I don’t fancy machining liners, but do have access to a lathe in work. As you have had no problems though I might just leave it as is. Thanks once again. 

[petert 550]

You're at the upper limit, regardless of the year. I've see engines have trouble with 0.005" (sorry, I converted so I could understand) and coolant weeps out the back. I would definitely turn them down to 0.003-0.004" if you have the skills. They're hard to hold however. Do you have a mandrel to mount them on? You'll be annoyed if they aren't square.

Edited October 29, 2019 by petert

[DamirGTI 325]

More than likely it'll be just fine .. if mine is good @ 0.15mm protrusion and around 10:8 compression ratio , yours will be fine too @ 0.12mm .

 

As said , if you're worried about that , fit thicker head gasket .. i deliberately fitted the thinnest HG , just to see what will happened , and i'm keen on keeping the squish clearance low thus using the thinnest available gasket .

 

D

[Deantracy17 1]

No, but I can make one. I also have a spare set of liners so will take one in and give it a go.

Cheers.

[Deantracy17 1]

Cheers to both of you for your advice. 

[DamirGTI 325]

45 minutes ago, petert said:

You're at the upper limit, regardless of the year. I've see engines have trouble with 0.005"

 

Peter , in what state of tune where these engines which "sprung a leak" ? also , track or road use ?

 

Oddly mine is good without leaks or compression issues , and i deliberately did everything to make it fail if needs must ! if it's too much of the protrusion ..

Thinnest HG , higher dynamic CR than std. , 1.4Bar expansion tank cap and head bolt torque spec. done all per Nm measure without angular triple 100 deg. torque sequence (though i did loosen and re-tighten the bolts after a few miles of driving , but on the same spec with the 95Nm being final) .

 

D

[welshpug 1,622]

most likely to leak between head and block not head and liner wirh excessive liner protrusion, so your engine could be diesel and be fine in the combustion chamber and still leak

[petert 550]

The leaky engine was just a road car. A smear of 1211 would probably have prevented it. I fear that unless you're an accomplished machinist, you have more risk of wrecking the liners than you do getting a leak.

[Tom Fenton 1,525]

Are all 4 liners exactly the same protrusion? If not, it may be worth looking at shuffling them around which may allow you to get it within spec.

Also, have you actually clamped them into the block before measuring, not trying to teach you to suck eggs but we are talking about 0.02mm.

The only difference I can think of between pre/post 87 is the change from the hex head bolts (non stretch type?) to the torx type (stretch), but I don't know exactly the date they changed over. Blocks are the same as far as I'm aware for both types of head bolt.

 

[B1ack_Mi16 67]

I (sadly) didn't bother to check this on the roadgoing 205 I just built. And it seem to slightly weep/bubble some coolant between the head and the block (in the middle of the block).

 

I thought it could be due to a warped block so I have started to prepare another one, but maybe it's just the liners protruding too much... 

[petert 550]

Ditto about shuffling them around, also 180º. I never clamp them down to measure. I do grit blast around the seat area however, ensuring everything is super clean and zero contamination.

[Andy 105 1 Cars]

21 hours ago, Deantracy17 said:

Looking for help. I have a new block for my 1.6 engine and the cylinder liner protrusion is about 0.127mm. I used a straight edge and a feeler gauge to measure. The o-rings are not fitted. Looking at Haynes manual, pre 1987 blocks had a liner clearance of 0.08 - 0.15mm. The block is a B6D so what’s the chance it could be pre 1987?  Does anyone know any reason for the difference in protrusion pre 1987?  Post 1987 the protrusion should be 0.03 - 0.1mm so I think I might need to machine down the liners. Any help would be greatly appreciated. 

Evening,

Like Peter I go for between 3 and 4 thou, but no more. I am lucky that my machine shop can machine the liner seat in the block, then machine the deck face to give the required liner protrusion. This has several benefits, including an ‘ as new’ liner seat and equal protrusion across all four liners . If you can afford to wait, the company is called “Stanwoods “ and is based in Bawtry .They are excellent, therefore very busy , therefore turnaround is not quick .

 

[DamirGTI 325]

Myself , i struggle to understand why some specs (in Haynes) states 0.08-0.15mm protrusion , while others says 0.03-0.10mm ?!

 

Also , for the Grp A engines - 0.08-0.15mm protrusion .. being race prep Grp A engines , are they meant to be dismantled/rebuild after a few runs (thus having/accepting maxi 0.15mm protrusion) , or not ? 

 

16 hours ago, B1ack_Mi16 said:

it seem to slightly weep/bubble some coolant between the head and the block (in the middle of the block).

 

I thought it could be due to a warped block so I have started to prepare another one, but maybe it's just the liners protruding too much... 

 

This was the reason i had to resurface the block (in fact , i switched everything into one of my spare blocks .. but that one was also crap with around 0.03mm average liner protrusion and also needed resurfacing) , but the problem wasn't too much protrusion , protrusion was too small/low in the center of the block ! in the middle on the 2-nd and 3-rd liner which sunk down the block having barely 0.02mm protrusion liner-to-block deck .. and this engine blew the HG after 4 years of use twice , and each time blew in the middle on the HG fire ring .

 

Sadly my machinist is an old guy , and has pretty "agricultural"/old milling machinery thus he was unable to dial in the milling machine in "fine increments" to the specs i requested , and so the block ended with the 0.15mm liner protrusion after resurfacing ... must say i wasn't happy , but can't really blame him as he did it as best as he could with the tools he works with . 

 

Peter , is "three-bond 1211" safe to use on std. composite HG ? .. as they usually say that one must be cautious not use any additional sealant product on the HG and that it must be fitted dry as it is (risk of something about HG swelling if i remember if using additional sealant compound on the HG)

 

D 

Edited October 31, 2019 by DamirGTI

[B1ack_Mi16 67]

8 hours ago, DamirGTI said:

Myself , i struggle to understand why some specs (in Haynes) states 0.08-0.15mm protrusion , while others says 0.03-0.10mm ?!

 

Also , for the Grp A engines - 0.08-0.15mm protrusion .. being race prep Grp A engines , are they meant to be dismantled/rebuild after a few runs (thus having/accepting maxi 0.15mm protrusion) , or not ? 

 

 

This was the reason i had to resurface the block (in fact , i switched everything into one of my spare blocks .. but that one was also crap with around 0.03mm average liner protrusion and also needed resurfacing) , but the problem wasn't too much protrusion , protrusion was too small/low in the center of the block ! in the middle on the 2-nd and 3-rd liner which sunk down the block having barely 0.02mm protrusion liner-to-block deck .. and this engine blew the HG after 4 years of use twice , and each time blew in the middle on the HG fire ring .

  

Sadly my machinist is an old guy , and has pretty "agricultural"/old milling machinery thus he was unable to dial in the milling machine in "fine increments" to the specs i requested , and so the block ended with the 0.15mm liner protrusion after resurfacing ... must say i wasn't happy , but can't really blame him as he did it as best as he could with the tools he works with . 

 

Peter , is "three-bond 1211" safe to use on std. composite HG ? .. as they usually say that one must be cautious not use any additional sealant product on the HG and that it must be fitted dry as it is (risk of something about HG swelling if i remember if using additional sealant compound on the HG)

 

D 

Did yours leak any coolant from that area, or was the leak so small that it evaporated instantly?

 

Mine never seem to produce any droplets that will run down the block, just miscolouration and it looks slightly wet and some smoke as it evaporates, So I'm tempted to just use it like this for a while as I can't really be arsed to do more work to it at this point.

[petert 550]

9 hours ago, DamirGTI said:

Peter , is "three-bond 1211" safe to use on std. composite HG ? .. as they usually say that one must be cautious not use any additional sealant product on the HG and that it must be fitted dry as it is (risk of something about HG swelling if i remember if using additional sealant compound on the HG)

Not sure, but I use it almost everywhere, even on zits.

[DamirGTI 325]

1 hour ago, B1ack_Mi16 said:

Did yours leak any coolant from that area, or was the leak so small that it evaporated instantly?

 

Mine never seem to produce any droplets that will run down the block, just miscolouration and it looks slightly wet and some smoke as it evaporates, So I'm tempted to just use it like this for a while as I can't really be arsed to do more work to it at this point.

 

No mate , mine didn't leak any coolant externally thought the gasket between the head-block base , rather that that it leaked past the fire ring into the 2-nd and 3-rd liner and always in the top middle corner where No.1 head bolt goes in ... and the leak was pretty small , needed maybe 1dl of coolant topping up for full month of driving .

But the chemical block tester picked it up instantly , and sometimes the engine starter from cold with slight misfire for a second or two afterwards it cleared up and was fine and i was able to drive 200/300km run in one go without loosing much coolant .. no white smoke at the tailpipe neither coolant-oil mixing .

 

Think , from the years of torquing the head bolts in spiral and starting always from the middle up No. 1 bolt the block base deformed kinda oval in the center .. you can see from the pics of the old gaskets from that engine where the "crush" on the gasket/fire rings was most severe thus teared the material and started leaking inside the liners :

 

 

 

 

 

 

...... perhaps it could be better to switch the spiral torque opposite direction or using "X" pattern for head bolt tightening rather than spiral . 

 

If yours doesn't leak much , maybe try adding some coolant sealer and be done with it rather than tearing the engine apart ? ... there's a few proven good liquid sealers now which don't have tendency of clogging the coolant system like the old powder stuff and said to last years (till you flush the system) ... though i must say i used the powder sealers on this engine when i had cracked liner years ago and when i had this issue with the HG's and it sealed it perfectly ... but i added just a tiny bit of powder inside , surely half of the bottle or worse entire bottle of powder could've made an real mess inside .

 

D

[DamirGTI 325]

1 hour ago, petert said:

Not sure, but I use it almost everywhere, even on zits.

 

Guess then it shouldn't do any damage to the gasket ?! silicone RTV maybe but anaerobic/liquid sealer probably not ... will try it out once .

 

Anyways , aside from the PSA stuff i often do Japanese engines , and for some of them they state in the OE manuals the need of using liquid/anaerobic sealer around timing chain housing areas on the block base along with the MLS gasket ... like on this Nissan engine :

 

 

 

 

 

Also , i wonder what kind of sealing compound is this red one on the ordinary composite head gaskets ?! :

 

 

RTV or some kind of polyurethane based stuff ?

 

D

Edited October 31, 2019 by DamirGTI

[Philpooma 30]

As ever, this forum is a brilliant source of info with some knowledgeable contributors.

I’m just in the process of rebuilding an engine and I had measured the liner protrusions at 0.08mm across all liners and was a little “twitchy bum” that it was at the lower end of the tolerance.

I feel happier after reading this thread that I’m probably fine at that.

 

The only thing that I find a little confusing in the Haynes manual is the build order.

The engine is on a stand ie. not in the car.

 

Should I;
* install the liners and pistons at the top of their travel first.

* Clamp the liners in place 

* Then install the crank, checking the end-float

* finally attach the little ends to the crank

 

It may sound like a stupid question but the manual refers you back to earlier sections and the forward later in the build.

I would rather look stupid and get the correct sequence from this forum than get it the wrong way around.

[petert 550]

Definitely fit the liner/piston assemblies before anything else, then clamp.

 

I'd do end float first however, then remove and repair as required.

[Philpooma 30]

1 minute ago, petert said:

Definitely fit the liner/piston assemblies before anything else, then clamp.

 

I'd do end float first however, then remove and repair as required.

Thats great Peter, thanks, I’ll do that

[Thijs_Rallye 86 4 Cars]

On 12/31/2019 at 10:11 AM, Philpooma said:

I’m just in the process of rebuilding an engine and I had measured the liner protrusions at 0.08mm across all liners and was a little “twitchy bum” that it was at the lower end of the tolerance. 

 

Here a picture of the official rebuild manual. It is in Dutch, but I've translated the most important stuff in my post above.