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which fixings HAVE to be replaced?

Posted: Tue Jul 18, 2006 5:47 pm
by wibble_puppy
hey guys,

so the engine is out of the van and I'm playing happily unbolting various bits from it and cleaning them up (eg water pump, thermostat housing, timing mechanism etc).

I'm keen to retain all the original bits I can, down to the washers if possible! but I am hazily aware that there must be some bits which are placed under strain, torque or other pressure and which it would be a sensible idea to replace. I'm thinking maybe head nuts and studs, for instance.

Can anyone tell me whether this is right, and if so which fixings I should be replacing rather than restoring?

(I'm not doing anything to the main block of the engine but 3 of the head nuts do have to come off as they need longer studs.)

Grateful for all advice! :D

juliet xx

Posted: Tue Jul 18, 2006 11:29 pm
by Kevin
With all the effort you are putting in Juliet replacing the studs and nuts is probably a very good idea as they can stretch with age and you only want to be doing it once, it may also be worth replacing your timing chain with a duplex one as they last much longer and do away with the timing chain rattle that starts much sooner with the standard chain.

Posted: Wed Jul 19, 2006 12:28 am
by bigginger
You'll need to countersink a couple of bolt heads for that. Do a search on here for tips - it was covered fairly recently.

Posted: Wed Jul 19, 2006 2:18 am
by Packedup
I seem to recall the timing chain was mentioned by someone in the past....

And the answer came back that it apears to have a duplex fitted, from what I remember!

Posted: Wed Jul 19, 2006 9:30 am
by wibble_puppy
nah, i looked again t'other day (now that i am starting to know a leeeeetle bit more than nothing at all :wink: ) and it's a single one, so I'm getting the duplex kit. But what's all this about countersinking bolt heads????? In metal :o ????? I can do all this stuff in wood but metal is not my native element!!!! Can anyone point me in the direction of the thread BG's mentioned? Pweeeeease? *makes Bambi eyes*

Changing all the head studs probably makes sense to you guys who would whip a head off as soon as look at it (reminds me of various periods in history) but as you know i'm juuuuust slooooowly begiiiiiining to learn about this stuff and am by no means familiar (except in theory) with anything deeper in than the rocker cover. To replace the head studs is it just a question of whipping the rocker cover off (which i can do) and hoiking out the nuts? I'm guessing there is no way of replacing just the ones outside the rocker cover, given the torquing sequence and all that :-?

NONE of the several books i have, three of which are specifically about restoration of MMs, talk about this stuff. And none of them say, "jolly good idea to bung new studs in while yer at it, what what!" Pah. :evil:

And is there anything else I should be replacing rather than renovating and reinstating? :D

Thanks for all your help, guys, it is much appreciated :D

juliet xxxx

Posted: Wed Jul 19, 2006 11:03 am
by bmcecosse
If you are not taking the head off (and you should be doing so) then leave head studs/nuts well alone. Unless you are upgrading the engine the existing studs and nuts will be fine - although they do benefit from having a thick washer under the nuts - but only if you have the head off. Why is the engine out of the vehicle if you are not doing an overhaul ? Ideally - it should get new big-end and mains shells - crank reground if necessary - pistons and rings examined/freed off/replaced (maybe with re-bore) - new oil pump - head cleaned and valves re-seated - and all re-assembled with new gaskets !!

Posted: Wed Jul 19, 2006 11:55 am
by wibble_puppy
yup - ideally.

the engine is out because you can't do a bare shell strip and repaint, including taking cab and rear section off the chassis and getting that blasted and flame-sprayed, with the engine still in the engine bay.

I know nothing about engines (outside of books) and I'm not going to "have a go" at doing mine and ruin it, it's been running perfectly well. I certainly can't afford to pay someone competent to do it for me. Nor in fact can I afford to buy new bearings etc etc. Hopefully in the longer term I'll get hold of a crock engine and learn how to do stuff using it - and then maybe strip my own one down and sort it out really thoroughly. But at the moment I'm just concentrating on learning what's necessary to get all the bits cleaned up, restored where appropriate (eg carb) and put all back together again so that I can enjoy driving my lovely van again and not a moment too soon.

Thanks for your advice to leave the head nuts and studs alone, that agrees with the advice I've just got from Steve @ ESM so that's all good 8)

Posted: Wed Jul 19, 2006 1:13 pm
by bmcecosse
Si fractum non sit - noli id reficere!

Posted: Wed Jul 19, 2006 1:23 pm
by wibble_puppy
absolutely :D

Posted: Wed Jul 19, 2006 4:09 pm
by Packedup
If you can arrange to pick it up, I can proban;y sort you out with an unknown condition 1098, a very clean 948, or a totally stripped and parts monst likely missing 948. Or a smattering of a 1098 with various parts missing. Would give you a chance to explore the depths of engines, and you never know you might get a useable one you can rebuild at your leisure :)

It's really not tricky to do things like bearings with the engine out, and they're not all that expensive (compared to other engines I've replaced them on). Besides, however good the consumables on your engine are, they are less than new so I'd b replacing them now as it's easier than later. At least think about a clutch plate, oil pump and water pump while it's on the bench so to speak :)

Now gearboxes, those are a black art that should never be opened up.