Further adventures of the Renault 6 - update p7 - Honin' In The Honeyard

[djoptix]

3 hours ago, Slowsilver said:

Don't like to contradict you but judging by the amount of rust I saw on the old head I would have thought they were cast iron. Aluminium is a bit exotic and definitely not necessary for low-spec engines like these. Easy test: does a magnet stick to it? If so it's not aluminium. Happy to be proved wrong.
 

Definitely aluminimum - magnet doesn't stick and, if I'm not careful, I can shave bits off it with the Stanley blade ?

 

[Slowsilver]

Wow. I stand corrected. Can't believe they used an alloy head on a low-spec engine like this that was designed in the sixties.
 

[Mr Pastry]

2 minutes ago, Slowsilver said:

Wow. I stand corrected. Can't believe they used an alloy head on a low-spec engine like this that was designed in the sixties.
 

It goes back earlier than that, to the rear-engined 4CV of 1947.  A bit more advanced than the BMC A series.

[djoptix]

This was the head when it came off:

 

...and this is how it sits now. I've taken off the old gasket, done a moderate amount of scraping with a Stanley blade and gone round all the chambers and valves with the Dremel.

 

As you can see, the waterways are definitely gunged up, so I'm going to need to get busy with the pressure washer once I have some time for it. This makes me a little concerned that this was the state the engine was in before it stopped running, but hey ho - no point worrying about it now!  This was the waterpump inlet when the pump came off - so  clearly I'm going to have to clean the pump completely, or perhaps use Bob's original one if it's better.

 

I'm 50/50 on the idea of a head skim. The plan in my head for a while now has been just to get this thing back together ASAP at the minimum of expense. I feel like I need to answer the question of whether it's going to run at all. It clearly needs new rings so those are on the way, but I was hoping that with a good clean and a check for straightness I can just put it back together with a new HG. I've been checking it with a straight edge as I go and it seems to be nice and flat. For the same reason, I was hoping - at this stage - not to take the valves out, because if I do, I'll have to lap them in and do the clearances.

Mind you, there have been plenty of things so far that I have resolved not to do and then ended up doing, so maybe a top end strip and rebuild is just the next one of those  

 

Cleaning things is very satisfying. Look at this weird crusty deposit all over the smaller valve.

 

I don't know what was, but it was properly caked on. I had to chip it off with the end of a steel rule. A big chunk of it came off whole (bottom of this picture).

 

It came up well though, after the Dremel. Sorry for potato cam quality here.

 

 

[Mr Pastry]

It won't necessarily need skimming just " because it's alloy."  It may be perfectly OK, it is impossible to tell just from photo, though a continuous circle around each of the bores is a good sign.

I think you must take the valves out for an inspection, and you will have to set the clearances on reassembly anyway.  It's no big deal, and easier when the engine is out of the car.

I would suggest you take it to an engine reconditioner and get them to check it on a surface plate.  If necessary they can also reface the valves and recut the seats - not too expensive, and the valves will then seal properly with little or no grinding.   They should also be able to press the cam sprocket back on when the time comes. 

It's all  looking surprisingly good so far, considering what you started with.

[junkyarddog]

Get a new water pump,they don't like sitting idle,and it will most likely leak when it's all back together. 

[Slowsilver]

2 hours ago, djoptix said:

This was the waterpump inlet when the pump came off - so  clearly I'm going to have to clean the pump completely, or perhaps use Bob's original one if it's better.

IIRC the internals of Bob's original water pump were in much the same state as this inlet pipe, hence probably this:

49 minutes ago, junkyarddog said:

Get a new water pump,they don't like sitting idle,and it will most likely leak when it's all back together. 

And also this:

1 hour ago, Mr Pastry said:

It won't necessarily need skimming just " because it's alloy."  It may be perfectly OK, it is impossible to tell just from photo, though a continuous circle around each of the bores is a good sign.

I think you must take the valves out for an inspection, and you will have to set the clearances on reassembly anyway.  It's no big deal, and easier when the engine is out of the car.

If the head gasket shows no signs of having blown then the head will probably not need skimming. I think the cam sprocket will probably tap back on OK with judicious use of a hammer.
 

[SiC]

These guys were recommended by my local garage when I asked if they knew of any decent guys to rebuild my 1100 engine (which never happened in the end!)

Bristol Autocare

93 Summerhill Rd, Bristol, BS5 8JT

0117 955 4275 https://g.co/kgs/uJaiqk

They had a bunch of customer engines at the front waiting for collection. Varied from new stuff to a-series and the like. 

Might be worth a visit/chat on what services they can offer. 

[djoptix]

1 hour ago, SiC said:

These guys were recommended by my local garage when I asked if they knew of any decent guys to rebuild my 1100 engine (which never happened in the end!)

Bristol Autocare

93 Summerhill Rd, Bristol, BS5 8JT

0117 955 4275 https://g.co/kgs/uJaiqk

They had a bunch of customer engines at the front waiting for collection. Varied from new stuff to a-series and the like. 

Might be worth a visit/chat on what services they can offer. 

Nice. They're about 100 yards from my old house I think! 

[bunglebus]

On 9/14/2020 at 5:01 PM, Talbot said:

However, word of warning, there are a lot more places that claim to be able to skim a head these days.  In fact, what they've done is buy a cheapo knackered milling machine off the bay of snot and shoved a fly-cutter in it.  They've no idea how to level the head prior to skimming, and no clue how to dial out the slop that is guaranteed to be in the machine.  The result is a wonky skim with a valley down the centre of the head.  Seen it several times now.  The head will probably re-fit and work, but not for long, and will never be able to be skimmed again as they often take off shit-tonnes more than they need to.

Ask what machinery they use to do the skim.  If it's a dedicated skim machine, you've half a chance of getting a decent skim.  If it's a mill, the potential for a fuck-up is much higher.

You might not have liked the skim job I did on my MK1 Fiesta head, after hours at the toolmakers I worked at age 17. Took all the guards off the surface grinder and changed the belts to  make it rotate as slowly as possible.  It had an electromagnetic bed so was ideal for a steel head. Don't know how much I skimmed off but that and the larger inlet valve gained from using a 1.1 head on a 950, plus a DIY flow job saw me gain loads of power*

 

 

 

*actually it make fuck all difference as the bores were absolutely knackered

[Uncle Jimmy]

On 9/12/2020 at 1:02 PM, Mr Pastry said:

Personally I would use normal engine oil when honing - 10/40 or whatever you have handy -  which will probably give a better finish. WD40 isn't really a very good lubricant.    It's all starting to look good though.

WD40 isn't a lubricant at all, yep, a bit of regular engine oil best.

[busmansholiday]

Strip the valves and at worst lap them back in yourself, it's not like designing a moon rocket.

Head skimming is a different matter, whilst my dad was on first name terms with Rotherham Rebore (in the early 80's) when I had my Holbay Rapier (because he dropped the head off in a morning and collected it on his way home, Holbays were, at times, shite), these day, as said previously, you could end up in a shit cart. 

The long missed Dave numbers made a home made method of checking head flatness.

 

[Slowsilver]

@djoptix, sent you a PM on 16th Sept and have not had a reply. Notice that you were last on here on Monday but haven't posted on this thread since 15th Sept and not at all since 30th. Hope everything is OK.  How is Bob progressing?
 

[djoptix]

Hi all.

Still alive. Bit of a mental health crisis over the last couple of months.

No major engine progress. Bob still safe and dry. Hoping 2021 might perk up a bit.

[Kringle]

Best wishes to you dj, I was hovering over the reply to this thread and I was going to wait until the new year before being a nag about the latest news.

 

[Dick Cheeseburger]

Any updates on Bob, @djoptix?

[djoptix]

Much the same as when I last posted 😔

However, the MGF is now in its new home, Saab is going, Alfa will be going soon, and then I should have a bit of space to get the engine up and running.

[Dick Cheeseburger]

Whatever happened to Bob? 

[loserone]

On 06/08/2020 at 14:36, djoptix said:

Bob is an absolutely charming car. The interior is fantastic. The trim and switchgear has that elegant French feel in spades. The Renault 6 is a lovely shape, and I think better looking than an R4. 

Some years ago I had a nosy around Bob and have to agree.  Do give me a nudge if you are ever moving him on.  And in the meantime, updates!