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JRSC CRACKED INLET

To add about the problems with the bolts

Basically the issue with the bolts is that it would appear that they have been zinc plated, and then they have not undergone a de-embrittlement process

this basically means that when they are zinc plated oxygen molecules form under the head of the bolt, and this weakens the head of the bolt and the heads pop off under stress.

Basically its using cheap crappy bolts, in the kits, best thing to do is either replace the bolts with different once or use the original ones removed when refitting and not the ones supplied.

If in any doubt then just go and buy some replacement bolts from any hardware shop / DIY shop.

Also not that if you try and use stainless bolts, into mild steel / plated holes you may have a galling problem where the threads will lock, this wont give you a problem fitting, unless you cross thread, but will be a problem in removal.

hope this helps a bit
 
It is nothing to do with the quality of the bolts. Nor of any kind of fouling. At least not in my case as the fittment of the charger was spot on with no contact anywhere it should not.

I first had the stock bolts shear two on the top right, and one on the bottom right, with symptoms as you described. I took it along to Abbey M/S and they repaced the bolts with ones a grade up in hardness. It was fine for a couple of months, then the same thing happened, this time with one head shearing off, and the other working loose (top r and bottom r).

Off to Abbey I trotted and left the car with them to do a bit of playing. The conclusion we came up with was that the charger was quite heavy, and was not sold to be fitted with the thick Hondata gasket that sits between the inlet mani. Over time this allowed for a certain amount of (very small) flexing, especially when doing full throttle starts, and engine braking (I had just changed jobs and when looking back my driving habits changed a bit as I drove on slightly more twisty roads, though that part is conjecture, as I had the unit fitted with no issues for nearly 20 months by that point).

Anyway, what Abbey did was drill wider holes into the gasket, then sleeve the holes with stainless, erm, sleeves...

This allowed the new bolts to have a firm point to grip against, and take any element of flexing out. And so far, 6 months on no issues...touch wood.
 
It is nothing to do with the quality of the bolts.
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It is, but Im not going to argue about it :)

I have worked in fasteners for over 10 Years :) so erm I do tend to like know what im on about, but basically the only reason a head will pop off a bolt is to do with hydrogen de-embrittlment

http://www.corrosion-doctors.org/Forms/embrittlement.htm

http://www.keytosteel.com/CN/Articles/Art120.htm

Basically when cheap as chips bolts are manufactured in large quantity and then Electro Plated there is Hydrogen embrittlement, the bolts then have to be heated in a furnace to remove this hydrogen, as this obviously costs money and is an extra process some manufacturers may skip this process / or the bolts are a fualty batch.

This will cause the heads to pop off

Just to add, the bolts on my charger have never failed broken, due to the fact that when it was fitted I took one look at the bolts supplied all bolts are stamped with a class and normally a manufacturers mark) and I knew they were only grade 8.8 and were from a crappy far eastern manufacturer, I changed them for some grade 10.9 Bolts and have never had a problem.
 
I will not also argue with you, as I am sure you know more about fastners than I do.

However I DID replace the bolts with stronger ones, and they popped as well. They were still 'only' grade 8.8 (iso r898), but they were also aircraft grade alloy steel, quenched and tempered with a proof load of 85,000 psi, and whilst that is not quite the 120,000 load of your 10.9's their tensile strength is still 120,000. I think 10.9s are probably overkill, but I guess if you have em why not. And to say the "only" way a bolt will shear at the head is due to de-embritlement is being rather narrow minded.

Of course it would have nothing to do with the fact that at that point...the head, is where the most stresses take place :), I also know a we bit about metallurgy, a smattering of chemistry and a degree in physics, so I am not totaly thick in such matters :p

Of course if it was soley due to the bolts, then there would be a greater instance of them failing, not less. So other factors are likely to contribute, as I am willing to bet not everyone has changed their bolts.

I also know you drive like a girl, so the charger is unlikely to be put under much stress, so there :p
 
I also know you drive like a girl, so the charger is unlikely to be put under much stress, so there Razz
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LOL Trust me if a bolt is going to fail it will fail under the head, for a bolt to fail in the thread is very very rare, yer it can happen but is very doubtfull.

also I will guess that the bolts used would have been cold formed or cold headed, and not hot forged.

I also guess that they would have had rolled thread and not cut threads, rolled threads give greater strength than cut threads and so are best used in this application.

But like I have explained the problem is Hydrogen De-embrittlement as the bolts were zinc plated, its nowt to do with the strength of the bolt as when zinc plating takes place the hydrogen will form under the head of the bolt and this will make it as weak as a piece of toffee unless they re heatreat the bolts.

This is why they fail, because of this Hydrogen De-embrittlement :)
 
And as I said, this did not apply to the second set I fit, you are making assumptions.



hey, considering we were not going to argue about it, we are doing rather well :D :D

All I know is (which is a lot, I can tell tell you) is that old bolts snapped, replacement bolts snapped. Abbey mod and same bolts as before, still going strong.

Of course it could all be karma...
 
Of course it could all be karma...
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Probably is, all I was saying is that the reason the bolts snap is dembrittlment, in the heads.

If abbey have replaced with Stainless like you have said then de-embrittlment dont happen with stainless as you cant plate it :)
 
I never knew there was so much I didn't know about bolts! :lol: A very informative non-argument guys, has made interesting reading. :D
 
Peter Pan said:
Of course it could all be karma...
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Probably is, all I was saying is that the reason the bolts snap is dembrittlment, in the heads.

If abbey have replaced with Stainless like you have said then de-embrittlment dont happen with stainless as you cant plate it :)
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Indeed, that was my point the second set were stainless...however just to throw a spanner in the works, the heads of the bolts I am using now are rusty, though the integrity seems to be un-affected. So I am guessing infact that the three sets of bolts were infact all different. I thought the set I am using now were the same as the last ones, but I guess not.

They do seem to be doing the job combined with the gasket mod. Do remember that afaik the JRSC originaly came with a regular thin gasket, not the Hondata one.
 
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