1970 s2 0453R Reassembly

[GavinT]

However the m12 x1.5 extended shaft tap does not fit in any block. All head bolts are m11 x 1.5
So I ordered another tap, and will let you know the outcome. So what I think happened is the PO installed a 7/16 20 instead of a 14.

Dave,
There's something weird here.
Can you do a process of elimination?

Try a 821 head bolt in your cross flow block and vice versa.
The bolts should thread into either block.

[dakazman]

Yes they do Galvin. 
According to the bolt gauge it’s a 7/16 x 1.5 tpi . The gauge does not have an independent M11
Once I get the correct tap I can determine the depth of the damage in that cavity. (Hole) and order the correct helicoil insert or other manufacturer of inserts.
I’ll post some pics a little later .
 
 

[dakazman]

  Galvin go on my Instagram and check out my backlash videos on the two gearboxes.

If anyone else wants to comment see ,”Christine.Kaczmarek.71”. on Instagram.
What do you think?
Dakazman

[GavinT]

Hey Dave,

Please abandon imperial measurements when dealing with metric stuff. It hurts my head. 
It's an M12 bolt, not 7/16 inch.
As such, there can be no "TPI" - threads per inch.

Metric fasteners are specified by their nominal diameter and the distance between adjacent threads.
The bolt we're dealing with is 12mm diameter with 1.5 thread pitch. That is, the distance between threads is 1.5mm.

OK, now if the bolts which we've both compared and measured to be nominally 12mm, and they fit in either block, what exactly is the issue?

Something else going on, methinks.
Is the 12mm tap you bought 1.5mm pitch or the more common 1.75mm?

I'd be wary of running an 11mm tap into those holes for fear of damage.
Does anyone even make an 11mm bolt?

Sorry, I don't have an Instagram account . . hurrumph.
Put them on YouTube?

[dakazman]

  Galvin,
Thanks for the TPI lesson.👍
  Check out the pics.
1. Tap 12m x 1.5
2. M12 tap in hole.
3.Head bolts
4. Head bolt in proper hole 7/16 or m11 according to conversion table.
5. Head bolt in M12 hole (very loose)
6 head Bolt with 11 marking 🤷🏼‍♂️   
7 wedge bolts marked 12 thread into holes of all blocks , in 7/16 m11


The M12 does not thread into any of my 3 blocks.
Dakazman

[GavinT]

1. Tap 12m x 1.5

Cool, the tap appears to be correct.

4. Head bolt in proper hole 7/16 or m11 according to conversion table.

"I'm sorry Dave, I can't let you do that” (said in my best HAL 9000 voice) 
   

7 wedge bolts marked 12 thread into holes of all blocks , in 7/16 m11

"I'm sorry Dave, I can't let you do that” 

The M12 does not thread into any of my 3 blocks.

Let's do process of elimination:
Drill a 10.7mm hole in a piece of scrap ally, steel or whatever and tap a thread with the 12mm x 1.5.
See if the head bolts screw into that.

[BDA]

Most hardware stores have internal and external thread gauges. I don’t know if they get that big but it might be worth a try if your tap doesn’t match.

I’m with Gavin. I can’t imagine a scenario where a Renault engine would have English threads. In fact the bolt heads you show are metric. Rather than use a plastic bolt gauge (I have one too that I almost never use), I would measure the diameter of the threaded section and use a metric thread gauge (like you get with a tap set to figure out what you need.

Something I don’t think was mentioned yet is that where English thread pitches are in threads per inch, metric thread pitch is I mm per thread.

[Richard48Y]

Yes they do Galvin. 
According to the bolt gauge it’s a 7/16 x 1.5 tpi . The gauge does not have an independent M11
Once I get the correct tap I can determine the depth of the damage in that cavity. (Hole) and order the correct helicoil insert or other manufacturer of inserts.
I’ll post some pics a little later .

I've had much better luck with Keensert than Helicoils.
Keensert is a solid threaded sleeve that is swaged into place while roll-forming the internal thread in the final step, much stronger.

In fact a DSR racer I used to know "Repaired" every thread of his KZ1000 engines using the Keensert method before an engine ever went into the car.

A bit more expensive, but so is a Lotus!

[dakazman]

 Thanks Richard,
   that’s the name I was looking for. I also believe they have a higher torque rating.

   I’ll see what my machinist says! He definitely has done more in his career than I have.

Galvin, and. BDA  I have some specialty shops close by and grainier about 20 miles away. I can go there .  Below is a cross section of the holes, the m12 tap only goes down to the tapered section and they do not go any further.
Here is the German Renault manual I have on PDF comparing 807/810/ 843/697/841 models. I wish I could read German because this book is payed out very well.
Dakazman

[GavinT]

Dave,

Yep, your pics in the German manual show different bolt lengths for the wedge head.

Please follow the process of elimination and drill / tap that 12 x 1.5 hole in a piece of scrap.

You've confirmed an 821 head bolt screws into your cross flow block and vice versa.
If a head bolt screws into the test piece, you'll have further confirmed that the bolts screw into the test piece as well.
As such, all bolts, block holes are the same and that they're 12 x 1.5.
Therefor, the 12 x 1.5 tap should fit the block holes.

Please check me against reality because the concern I see is:
1. You say the 12 x 1.5 tap doesn't fit.
2. On page 80, you show a piece of damaged thread as noted by JB and also talk about an "extended M10".
3. On page 80, you also say you've "quickly cleared the last block head bolt hole"

Was the "M10" a typo?
What happened there?

[dakazman]

  No typo , but I could have been clearer!

   When I first disassembled the engine the threads in that hole came out with the bolt and I wrote I may have to place a stud it that hole. That was three years ago .
  When I said I cleared the hole I meant I drilled an undersized hole thru the , “debris” then with the M10 tap slowly removed more of the material, the threads pictured. I only cleared hole to get to the bottom and matched it with the other holes. The M10 was used in all the other holes to lift out tons of crap that was jammed under all the bolts.
   Going step by step , the depth of the hole was discovered.
 That’s when I took JBs advice and ordered the M12. The M10 just got me started. The M11 I just ordered is an uncommon size but is going step by step . It will lightly ream out the threads that I’m hope are still undamaged.
 
  I appreciate all your advice and will try your method. As far as I know is what the gauges are telling me and slowly moving forward to order the correct anchor if needed.

Dave

[GavinT]

Ahhh . . . I must have missed the part where there was lots of crud in the holes.

I'd still be wary of using an M11 tap to clear it out.
Because M11 is so undersize, there's a very real chance it'll cut into the existing threads and damage them without you even knowing.

On occasion when I've needed to chase threads, I've used an old bolt with slits cut into the threads to resemble a crude tap. This lacks any real cutting power but is sufficient to clear crud from the threads.

[dakazman]

    With all the festivities this week. I managed to get some time in the garage. My 336-56 gearbox is setup correctly backlash at .006-.007 . I guess it should be strapped down to get a perfect reading. Pull check at about 1.5n .
  The 336/66 gear pattern was nicely centered on the gears, however it’s original lash was in excess of .024 . The pull test was under 1n .  The adjustment nuts were easy to turn . I’ll take a small miracle...
I’ll be replacing the seals on it so I left everything as it was until the seals come in.
 
  Galvin, I listens to your instructions and drilled a 27/64 hole in a 2x4 clear thru. Then used the M12 tap thru the entire hole . I was surprised it did a nice job inscribing the threads . Then I grabbed the long head bolt and threaded it into the hole.  Even though it grabs slightly , the bolt wobbles about an 1” when threaded 1 1/2 “ into wood base.  It was worth a try and I would have been rude to not have given it a go. I’ll keep you posted when the M11 arrives.
Dakazman

[dakazman]

  With my Holiday chores completed, I’m ready to proceed with the assembly of my original motor with a few modifications. Today will be timing cover , oil pan, fill cam valley with oil and install head.
 Found a pic of an R8 with a similar mod, then to make it all fit and as BDA says make some noise. 😃
Dakazman

[BDA]

Looks good, D’man! You are going to polish the bolt heads, aren’t you?