Bongo Fury

stop messin around you two, just find a same length bolt with a coarse thread, and pack the hole with the chemical metal stuff and wack it in,

Northern Bongolow wrote:stop messin around you two, just find a same length bolt with a coarse thread, and pack the hole with the chemical metal stuff and wack it in,

Woo-hoo!!!

Or do I mean, Yee-haa!!!

Or if you are serious.... can I tighten down on that stuff, would the bolt come out again or can you make it bind to casting but not bolt, blah blah. Before learning what a helicoil was, I though about something like this.

Why not investigate making some form or cap or rubber bung to fill the hole? If you did fix the bolt in place then if you ever needed to remove the head it could end up doing more damage.

Simon Jones wrote:Why not investigate making some form or cap or rubber bung to fill the hole? If you did fix the bolt in place then if you ever needed to remove the head it could end up doing more damage.

I agree - if there's 'repair' to be done then it should be proper, ie helicoil, rethread for larger bolt, or through hole with nut at a push.

Instant gasket under the flange of the bolt head would will 'seal' the hole. Whatever I do, if I don't tighten the bolt(s) down, then the gasket is going to be the weak link. But the oil's not under pressure.

Were you thinking anything other than blocking off the top of the hole?

Northern Bongolow wrote:stop messin around you two, just find a same length bolt with a coarse thread, and pack the hole with the chemical metal stuff and wack it in,

Took yer time didn't ya .
...and messin around??????? .....what ME?????????.....You know me too well
Any idea what the chemi stuff is called Ady?

widdowson2008 wrote:

Northern Bongolow wrote:stop messin around you two, just find a same length bolt with a coarse thread, and pack the hole with the chemical metal stuff and wack it in,

Took yer time didn't ya .
...and messin around??????? .....what ME?????????.....You know me too well
Any idea what the chemi stuff is called Ady?

Blu-tac?

Hi
Devcon :
http://www.itw-devcon.co.uk/index.php?/ ... m_putty_f/
Most excellent stuff...been around for decades
Cheers
Helen

Hi
If you can't find Devcon...Buck and Ryan in Tottenham Court Road used to sell it...Think they've moved now!
http://www.buckandryan.co.uk/aboutus.php
If the part / casing is as Steve shows, it is held onto the block at the front with studs/ bolts, so it's held securely...the skinny bolts i.e. your "bouncing bolt" is not really holding the head to the block, and chances are the casting may not have moved....have you poked a coat-hanger wire down the hole to see if it's a blind hole?...If it is, then a .22 cal pistol cleaning rod and cotton patches soaked in acetone, repeatedly changing patches till they come clean...stuff a bit of Devcon , and bolt in...and forget!...
Cheers
Helen

Driver+Passengers wrote: Blu-tac?

I wouldn't. The casting is bolted to the head so potentially very hot (not sure of temp but possibly too high for blu-tac).
The stuff/method Helen is suggesting is probably the way to go. Same as Northernbongolows idea I think.
Did you manage to look at the other side yet to see if that one is loose?

widdowson2008 wrote:

Driver+Passengers wrote: Blu-tac?

I wouldn't. The casting is bolted to the head so potentially very hot (not sure of temp but possibly too high for blu-tac).
The stuff/method Helen is suggesting is probably the way to go. Same as Northernbongolows idea I think.
Did you manage to look at the other side yet to see if that one is loose?

Yeah, right enough. Blu-tac gets softer when you heat it. 'White' is hotter than 'blue' - what about white-tac? Looking around my kid's drawers, plasticine or playdoh - which d'you reckon? There's more colour choice with the plasticine.

I've sealed off the driver's side A bolt with a bit of instant gasket, and went for a wee drive. Nothing on the back of the timing belt cover, which was the clear sign last time. I didn't clean off the oil on the block (around the engine number) well enough before driving to determine whether there was still a leak or not, so I'll get in about there and clean it up before I go for a drive next time.

I'm in two minds - if it ain't leaking any more, I'm tempted to let it be. If I find a continued leak I'll certainly want to replace gasket and make sure all head bolts are tight down, which will necessarily involve a repair to the threaded hole in the front casting. The middle way is to man-up and do the repair now. Assuming that all other head bolts are tight and gasket is fine (no indications to the contrary), what's the real impact of leaving the two A bolts "below spec"? Can't imagine the head warping because the last inch isn't being pressed down...

Note: I'm not looking for a shortcut - just trying to be pragmatic.

Also, between epoxy and helicoil, could anyone offer a rundown of the relative advantages/disadvantages? To my mind, the helicoil seems like the 'right' way to go, assuming there's enough 'meat' left on the casting. Does it fuse the bolt in there or once cured, does it leave you with a threaded hole? Ie. what happens when you (try to) undo the bolt - can you break the bond between putty and bolt leaving the putty intact? If not, it sounds like a one time fix. Please excuse my ignorance.

(She drives like a dream, though. )

I've used Araldite in the past to secure bolts by first dipping the bolts thread in thick oil or thin grease and then shake off excess, then applying Araldite to the thread itself, pressing it gently into the threads, then added extra Araldite to the stripped hole, finally insert the bolt into the hole. Wait for it to cure really well, then I have been able to undo the bolt as normal, sometimes its a bit stiff to get going the first time, but the grease normally provides sufficient protection and lubrication - just don't overdo the amount of grease otherwise there isn't enough room left to form a thread. The ones I've done have always been quite small in size i.e 8BA up to about 4BA, have been in Aluminium heat sink blocks that can run at anything up to and including 120°C . You also need to press the bolt into the hole and hold it in position under pressure as that will normally be the maximum depth you will be able to do the bolt up to in the future, otherwise you need to remove the bolt and insert a washer so that the bolt doesn't reach the end of the the "threaded" length.

Best fix is to replace the casting, but that involves a LOT of work and the Bongo being off the road for a few days.

As the front two 'A' bolts actually screw into the front casting, I would have thought that the epoxy route is the next best choice. Geoffs description sounds a MUCH easier route to take, and from what he says, Araldite will cope with the temperatures involved. I would think the important part is to get everything as clean as possible before application.
The Northernbongolow (Ady) solution sounds the same sort of thing but using 'chemical metal stuff' made specifically for the job (Ady's a pro you know ), as does Helens suggestion.
If you do choose this route, be carefull not to overtighten the bolt or you will be back to square one.

Would it be possible to do a dummy run by drilling a 9.98mm hole in a scrap lump of aluminium/steel and seeing how it performs?
Note: Just measured clearance hole in head for the bolt and it is actually 9.98mm dia, so a 10mm bolt would be too big. Seems a wierd (non-standard) size to me. Can you take the loose bolt out and measure it?


Helicoil? Good solution BUT personally I wouldn't be confident with this because it basically involves increasing the tapped hole in the casting, and without seeing the real thing I have no idea whatsoever how much 'meat' there is to play with.

in my opinion helens route, and geoffs, would both be suitable as the torque settings are quite low. araldite is quite brittle though
the release again factor is very important.
the product i use it a two pack roll(sausage) of soft metal around an activator, when the two are massaged together they have a curing time in which to use, after that it indesctructable.
i use it for perm repairs to metal coolant pipes etc. never had it fail yet. .
i just buy it off the shelf at the local motor factors.

Folks - thank you all so much for all your input into this.

Should it come to be that I take the head off to effect a repair, I will either source a new casting or perform a thread repair with a suitable compound. The latter stands up well in my mind against a helicoil. (I'll give the general process a go on some scrap in some spare time - cheapo 2 part epoxy, just for fun.)

My thoughts on what to do in the short term are as follows...

Regarding the other A bolt under the rocker cover - if it's been overtightened then either it's loose or it's damaged the threads and may become loose or it's holding fine. If that hole is also producing oil then it's ending up back in the same oil way. What I'm left with is the fact that I know I have (at least) one A bolt underperforming, but if it was both would it change anything? That's more or less my reason not to go and look, redo gasket, etc... Not that it's a huge deal to do it - just considering the necessity.

I will clean off the residual oil on the engine block and see if any reappears. If there is none, then (I assume) the head is sufficiently tight to the block and the gasket is performing well with respect to the more critical aspects of the operation of the engine. If there is a continued weep of oil from the return 'chute', I will review this thinking.

Added to all this, I must remember that I'm a novice and I shouldn't be too quick to decide to whip the head off (yet). Though a part of me wants to. Reeeeeallly wants to!

I'm not giving up on this and the assistance in planning an eventual repair is of great value (not to mention the unique BongoFury spirit on display!) Huge thanks/respect to you all.

Please let me know if you disagree with the 'wait and see' plan, but I don't believe I'm in imminent danger, do you? What I do next all depends on if and how much oil continues to weep. It should certainly no longer spray/blow.

Your plan sounds fine to me providing you aren't having to top up the oil too often (ie - not losing much).

From the sound of it, you are itching to get the head off for a look-see. Try and subdue the inquisitive side. I cannot stress how much work is involved to a novice. I have only ever changed ONE head in my life (spenners Bongo a few weeks back). Jeff had never touched a spanner in his life, and my experience taking cars to bits was VERY limited. The thing that did help us was the fact that I spent my working life in design engineering and could understand the various stages we were going through. I also relied heavily on verbal assistance from forum members Ady and Kirsty. Without this knowledge and assistance, I would have been stumped. Long winded way of saying 'Don't take the head off until you have to'.

Just spoken to spenner and he still has his old head bolts, so I'm picking up an 'A' bolt this week. If you need one to experiment with, let me know and I'll get one up to you.