Loctite 5940 to bond/gasket KR500 dry sump bottom plate in place? On tour, have lost all oil, but not run with none.

[anthony1956]

Propose to use this, checking here if anyone has any experiences of information about this Loctite 5940 Product? http://tds.loctite.com/tds5/docs/5940-EN.PDF

 

This is an attempt at permanent replacement of the blue plate with the item from Simon Rogers. Loctite 431 is not available nor in the time available, which is camp site location, ramp has damaged blue plate fixings, helicoils and all to be replaced with Simon's part which I happen to have with me. Simon's comment about the 5940 is that it sounds as if it cures hard so is not ideal for long term use but provided not spilled over inside the region inside the sump, should be ok until next oil change and replace all then with Loctite 431.

 

So I am proceeding -0 but would dearly like to hear any views based on experience etc please.

 

The car btw seems fine, we had "low oil pressure", but not "no oil pressure" and upon return to camp site still had some oil in the dry sump, though not much but hard to say as of course it drains away after 60 seconds when readings become unreliable.

 

Needless to say this was the only time in ten years when I did not have any spare oil with me!

 

I sincerely hope this is no more than a short story and not the end of everything.

 

I am not yet told that we have the helicoils have been acquired, because "5mm Helicoils" are hard to get on a Friday in Toulon, France. I am at Le Lavandou, very nice if it were voluntary.

 

Anything urgent please text 0041795669857

 

Anthony

 

 

 

 

 

 

Edited by - anthonym on 23 Sep 2011 18:28:27

[anthony1956]

delete dup.

 

Edited by - anthonym on 23 Sep 2011 18:44:51

[anthony1956]

just had a chap telling me my english metric isn't the same as the french metric, I think he means the differences bewteen metric and the various british thread sizes, but we are changing (I HOPE!) the helicoils to French ones in a 5mm French sized hole set. So no longer 5MM British holes Slightly tongue in cheek here as 5mm = 5mm in any culture and as I understand it, renewing the Helicoils will remove any thread issues anyway, because the Helicoils will be French ones for French 5mm threaded screws (Allen key "French = BTR" heads)., howevere it#s a serious business, keeping the oil in my engine. Frightened the carp out of me last night up a mountain.

 

Another issue is whether to tap out the holes to 6mm and use 6mm screws, or maybe 6mm helicoils are easier to get.. on a Saturday. Silence about this issue is currently deafening, took all afternoon to find 15w50 oil in Toulon, nevermind 5 or 0w50.

 

Anthony

 

 

 

 

[Sheds Moderator]

Quoting anthonym: 

just had a chap telling me my english metric isn't the same as the french metric

 

Anthony

 

Well that's bollox! there are 2 metrics - coarse and fine. Either one is Helicoilable in M5. I forget which is most common - my money is on fine. M6 is very very common, whenever you see a 10mm nut or bolt head it will have an M6 thread on it. M5 though is a standard thread, anyone who tells you yours is different is talking out of his 🙆🏻.

 

Good luck sorting it out.

[anthony1956]

Apparently we cannot find helicoil

s anywhere l

[rj]

M5 is M5x0.8

 

M6 is M6x1, but is available as M6x0,75 out of the shelf.

 

If you can not find Helicoils have a look for "Timesert" which are from Würth - and a far better product.

 

Any well equiped motor factor should have Helicoils. Or a garage.

[Sheds Moderator]

If you can't get Helicoils (or similar) and there is enough meat in the casting then drill and tap it M6. Honestly, is your mechanic for real or is he a stuffed toy with Kermit and Miss Piggy dancing in the background?

 

In fact sod it, if your man can't repair a simple M5 thread then he hasn't got a bloody clue. He's a gibbon. Send him away and get hold of a mechanically competent human being.

[Sheds Moderator]

BTW if you can't get the right sealant then make a gasket from a heavy duty brown paper envelope and use this to seal the joint. I used to do this on my dry sump blue plate, I had more faith in Hermetite green and paper than I did silicone and its tendency to turn into gorilla snot and block oilways with disastrous results.

[jackb_ms]

I did an emergency gasket from the cardboard of a cereal box + hermetite green or orange

Worked well for a few month

 

Jack

[Sheds Moderator]

There's no reason why a cereal box can't make a gasket that will last indefinitely. It's just a piece of card, same as a commercially stamped out one. Same goes for paper ones or even cork - I'm very sure I could make a cork rocker cover gasket from a cork tile, but it would take me somewhere between half an hour and an hour and it's a bit of a chore when you can buy one that fits perfectly for under a fiver.

[anthony1956]

He's not a mechanic.

Its weekend in France.

I have no transport.

Probably should have called adac, in fact didso, Another tale still open.

 

Am tempted to find garage and get proper job done. Not kack of gasket worries me, it's 3 0f 4 screws and helicoils needing replacement.

[anthony1956]

My question is this: will the loctite 5940 hold the plate on even if the screws were not present?

 

[anthony1956]

Everthing is fitted, she is full of oil, engine runs fine. Wilk the plate stsy on, fall off or come loose?

 

Thats why I ha ve not driven her yet.

[anthony1956]

Just run the ebgine to oil check temp 50c and oil a bit full but ok, no leaks. There is a line of thought that this loctite 5940 is good enough on its own as a permanent solution, but not so sure I can place what for me would be faith in it. Maybe i wilk give loctite a call.

[Sheds Moderator]

I wouldn't chance it. Maybe you can get home on one screw and a bit of adhesive, but it's a bodge that has no place on a car like a 7. Do a proper job, get it to a proper garage in the morning and get them to drill and tap M6 or helicoil it.

[anthony1956]

Ok you voiced my worst fear. Having it helicoil drilled, tappped and wurth coiled tomorrow, to 6, hopefully. The bodge means I can drive ti the garage and I Malre

ady have another can of oil as I bought two.

 

Dannit the above means. M 6

 

CANNIT EFIT.

[anthony1956]

M6 is also a perfect fit for the new 7 tips plate

 

Question is why helicoil it snd not dimply tap it to 6mm and insert bolts, which will be permanent with new plate which has drain plug.

 

Is there enough metak to retap?

[anthony1956]

Right then, now car is at Antonio s garage Le Lavandou, originally for remove and replace 5MM HELICOILS WITH 6 mm and bolts to match.

 

Spoke with an engineer ar Caterham, who said sounded fine to retap to and replace with 6mm bolts and no heicoils, of course he was responding to my specific circumstances, so which points about these were salient only he knows.

 

My circs, resented to support my plan of action:

 

never tracked (very rarely, three times in ten years, slowly!)

never raced, ever.

Oil changes not often enough, blue plate looseness DISCOURAGES/d. I now am told I could not find 12mm long 5mm bolts because continental europe has only 15mm and 10mm lengths. Can it be true? (Think a la davids technicolour dream COAT). Anyway that's what I am told. I also gather they are called M5. and the 6mm will be M6. Why? The 5 and 6 are obviously the thread diameter, but the M? Mad? Mabel? Mercy? Metric? Does it also with its name define the thread frequency? I gather this is fine or coarse or 60 or 75 somethings. I will google it.

 

Helicoils are efficacious for use in soft metal, such as my magnesium or allow dry sump base as they offer good connection from that soft metal to the stainless steel M5bolts, for frequent removal and re insertion. Per Helicoil web site.

 

A race car engine is/may be oil changed very frequently, also the blue plate acts as a collector of any unpleasantness at the very bottom of the well. A drain plug is less effective, assuming it's plate is not removed entirely. Max engine revs of 9000 seem very persuasive to me of the blue plate idea (perfect oil sump cleaning, also of course very fast draining).

 

I reckon my car has had as many oil changes over its ten years as a race version may have in one season.

My car has also been scraped over sleeping policemen, Trailer lips, rocks, garage ramps, kerbs...that I can think of. So, about this and how it works in real life.

 

THis morning had to get the blueplate replaced with 7tipslated car out of the camp site over the hump that caused the damage in the first place. I exited the car and moved it by hand...scrawpy noise...stopped, insected, the blue plate screw heads are resting on the concrete. Push car back off hump. Install three paving slabs, one before and two after hump, right side wheels. Help has arrived, again push car slowly, this time screw heads clear the concrete.

Actually seeing how this happens is both interesting and painful. It is because the car is quite long that the front of the engine clears the hump, barely, then as the front wheels drop and the rear have not started to rise, the dry sump b

ue plate bolt heads are dropped right in to the concrete, they are simply not strong enough to Resist compression between the car and the concrete. IF it were tarmac then MAYBE it would tear a furrow through because asphalt is soft where concrete is not at all.

 

So this hump is different being a private one and not governed by a road authority.

 

To continue.

 

Having driven the car to garage to be 6mm helicoiled, I chat with a CC ENGINEER as above

(to whom my thanks if you see this), and it strikes me that 6mm tapped thread can later be helicoil tapped if needs be. So using 6mm thread now, leaves solution available in future to helicoil if these clearly (now I have seen just how much so) vulnerable bolt heads are again damaged.

 

6mm is also perfect fit for the 7tips plate, which as I understand it does not have to be removeD if simple tap outis tobe performed, it also acts as its own template, where there was a questionmark over new helicoils alignment.

 

So, we will see later.

Anthony

[anthony1956]

The 7tips plate inc bolts protrudes LeSS than the blue plate.

[Sheds Moderator]

M= metric. M5 = 5mm dia (that is the majot diameter). There is no indication as to whether the thread is coarse or fine, I think fine is the default choice.

 

Common sizes go M3, M4, M5, M6, M8, M10, M12, etc. I know of one M7 (K series flywheel, why I do not kn ow) and I have never heard of M9. After M8 they go up in 2mm increments, below M3 there are 1/2 mm increments IIRC.

[anthony1956]

thank you - I was always afraid to ask :-)

 

Guess what, I made the mistake of giving the impression my car is not urgent so the work has not been done! I think I mentioned sitting on the beech and paddling. Lesson of the day.

 

Anyway, I am told 5pm tomorrow Wednesday, for sure.

REALLY irritates me when they treat me like I am an amateur and they are pros and then basically turn their own reassurances into downright lies. Piece of my mind is reserved for after I get my car back, fixed.

 

I took the opportunity to ask why he is insisting the 5.8 (?) sized helicoil hole cannot be re-tapped for a 6mm thread. His response was pencil and paper and a diagram of holes. What he seems to be saying is there is not enough material to create a 6mm thread. Given we are talking .2 of a mm and I KNOW the old helicoils are really b***e*ed and indeed one has had half of the corner of the plate resting surface smashed off, (small piece but even so). I find it challenging not to have sympathy for a guy who wants to make sure the things stays in one piece by using a size he is confident will have enough grip (properly tapped), I know he wants to use longer thread reaches (bolt length) as well, having found there is lots of room up there.

 

His description of helicoils was colourful, if in French, I got the ideas he was imparting.

 

So what do I do? I decided immediately that as the mechanic on the ground, who has kept me well away from the car, there's nothing I can do but trust him to do a decent job. Bear in mind here it is for me a two hour round trip WALK to the garage. If my trust turns out to be unfounded, then regrettably my experience will be further re-enforced about so called professionals who claim they know everything and I know nothing. Me saying I could have told you so, is cold comfort.

 

Being an amateur and stupid are not at all synonymous - if I were stupid I would never ask any questions and I think sometimes the posing of questions can give an impression of stupidity, whereas often they are the gathering of further corroborating evidence in support of a proposed choice - or not of course.

 

He mentioned the M7 are Citroen bolts.

 

I am still by the sea, in a very nice cafe etc... not blatting.

[anthony1956]

found this http://www.engineershandbook.com/Tables/metrictapdrill.htm

 

looking at how much metal is needed to successfully tap out a new thread, I see there is course and fine, which we know, so let me see,

 

Fine is M5 0.5 is 4.5 tap drill

Crse is M5 0.8 is 4.2 tap drill

 

given we are already Helicoiled not sure this helps me yet.

 

Helicoil:

M5 - .8 _#5 drill 5.7mm tap drill

 

Fine is M6 0.1 is 5.00 tap drill

Crse is M6 0.5 is 5.5 tap drill

 

the M5 Helicoil tap drill size 5.7mm is bigger than the 5.5mm tap drill size for an M6 thread, Coarse - and also bigger than the 5.00mm tap drill size for Fine M6.

If this is as obvious as it looks, a hole tapped for M5 Helicoil, will be too big to be able to accept a tap for M6 bolt without being for an M6 Helicoil insert whose size would be: M6 - 1 _______6.3mm drill _________6.8mm drill which IS indeed bigger than the M5 Helicoil tap thread hole. I had believed that an M6 tap would be big enough to tap into an M5 Helicoil space, this is NOT the case, based on the above data.

 

To insert and M6 Helicoil would mean removing the already glued and sealed 7tips plate and all the oil, which when I fitted the 7tips plate, the oil had been allowed to drain for nigh on two days, meaning high confidence of no oil dripping on the plate when offered home for glue and sealant Loctite 5940 the subject of this thread (bought in Toulon 50km away by a friendly person). Having of course cleaned with a very niffy liquid substance much more potent than acetone (that was fun, good job it was open air camping.).

 

so to add to all that, what is going round in my head is that in the absence of constant removal and refit of hard metal threads into soft metal threads (which I think is where the Helcoils scored) so to speak, given I want a permanent fit with the already glued in place 7tips item, seems to me a hard thread bolt inserted ONCE into the soft metal recipient thread, especially a longer one than usual, and Loctited, is not going to budge regardless of vibration.

 

From what I am told the job I did gluing/sealing the 7tips item in place would hold it in place without bolts, but I want bolts so I can sleep at night. Bolt and braces.

 

from above M5 - .8 _#5 drill 5.7mm tap drill

 

Fine is M7 1.00 is 6.0 tap drill

Crse is M7 0.75 is 6.25 tap drill

 

so both M7 sizes are big enough to tap an M7 bolt direct into a previously Helicoiled M5 thread hole.

 

In fact if M7 had not existed I would have to invent it, to minimise the amount of boring out to avoid going up to M8. I want to avoid size increases so as to leave more metal available fro future solutions, should any be required.

 

Time for bed I suppose.

 

 

 

Edited by - anthonym on 28 Sep 2011 00:16:59

[Sheds Moderator]

Yes, that's how it works. Helicoils work because they are a steel insert, of course you have to bear in mind that a hole for an M5 Helicoil has to take the same screw size but have enough space to squeeze the insert in. It's straightforward addition, no rocket science involved, I'm surprised your mechanic is making so much fuss. We are talking about 4 threaded holes. That's it. Half an hour's work.

[rj]

Grant,

 

Head bolts of a K are M9x1.25

 

/r