Why do the simple jobs go wrong.......

Dom J uttered summat worrerz funny about:

There are to my knowledge at least 2 different gaskets for a V8 (I'm making an assumption here as to what your working on)

I have a new pair in the garage for our Disco which are rubber with inserts in them where the screws go through...

Then you get the old cork ones ala Earlier V8's certainly up to around 1983 if not later.

I think you need either one or the other and there is some suggestion they aren't interchangeable when I picked up mine.

You say the new rubber ones thicker... was the old one rubber too?

Lee D

Opps forgot to mention what engine it is. 3.9Efi on a M plate.

I've got the rubber ones with the inserts in like Lee mentioned. The old ones were the old cork type which were absolutly buggered. Bloke in shop assured me they would fit my vehicle ok.

Dom J

This has got me thinking. Can i fit the rubber gaskets or do i have to fit the cork ones?. The rubber ones appear to fit on the cover properly.

Dom J

Sounds like the bloke in the shop is a bit of a tosser. If he told you that they would fit and they don't, you are clearly entitled to your money back - sale of goods act, unfit for purpose sold. Don't suppose you'll need to get that heavy though, I hope he'll change 'em for you

TonyB

I fitted rubber ones in place of cork ones on my 86 3.5 V8 a while ago - straight swap, don't remember changing the screws. I'd never go back to the cork ones again even though the rubber ones are dearer.

As for compatibility, I ordered them from the LR dealer using the number for the cork ones and they said they had been superseded by the rubber ones.

Andy Fox

1986 110 V8 1990 205 1.9 GTI 1975 Hillman Imp

Are you sure it's not 1/4" UNC?

As you say, definitely 1/4" UNC and as Andy says the rubber ones are a direct replacement.

Martin

Double check that you have located everything correctly as it very easy to have the rubber bunch in places it's not meant to and screw things up so the short bolts are had to locate. I must say your bolt lengths SOUND right but it'd too dark to go out and check. As others say they are listed as direct replacements and I've never had to use different bolts. Try again!

Regards

William MacLeod

On or around Sat, 21 Jan 2006 16:54:31 -0000, "Dom J" enlightened us thusly:

hang on, ISTR that the bolts are longer one side of the cover than the other

- the ones on the valley side are different to the ones on the exhaust side.

worth checking up on before going hunting more bolts.

And FYI most of the bolts on the V8 (except, perhaps, the Thor variants?) are UNF or UNC - the rocker cover ones are probably 1/4" UNC which IIRC is a

20 TPI thread.

Cue one very embarresed AFL user...........

I was reading through all the replys to my origional post and came across William Macleod's reply. Off i went to the Disco thinking 'it can't be as simple as that....can it?'. hey presto within 10 mins rocker cover on using the same bolts!. As Homer might say Doh!!!. To all who replied, especially William, thank you!. Oh and yes the bolts are 1/4 UNC as well.

Dom J

Dom J uttered summat worrerz funny about:

Thanks for the feedback Dom, It's put my mind at rest as I have the rubber but not certain whats on at present, hence querying with the geezers at the local suppliers.

They can be a bugger to fit. I sealed the 101 ones on the day before fitting to rule out some problems.

Discos gotta be done, it's making a hell of a mess of the drive. Not looking forward to it though with all the clutter including LPG gizmology in the way.

Lee D

I found it's just possible to get the drivers side rocker cover off without too much trouble. Just need to lift, sldie forward and down a bit and then push the dipstick for the autobox back into the bulkhead and it just about comes out. Not sure about the other side though. Can it be done without removing the Plenum chamber etc etc?. One down, one to go.

Dom J

FWIW, I regularly replace cork gaskets with the later rubber ones if the customer so requests, and I've never had any issues with bolts being insufficient length. The bolts are 1/4 UNC thread, BTW, even the later ones with a bi-hex 8mm head! Badger.

Plenum has to be lifted, doesn't need to be completely removed but it's easier if you do. Remove the 6 allen-headed screws, throttle and kickdown cables (if auto), unplug the idle speed control valve stepper motor and pull off it's feed hose and disconnect the vacuum line to the fuel pressure regulator. leave the throttle body water pipes connected and flip the plenum over towards the front of the passenger side inner wing. Clean off all traces of sealant and reseal using ONLY blue hylomar sealant as petrol vapours will eat into silicon sealant. Badger.

We've all done something similar :-) Glad you got it sorted

Regards

William MacLeod

In article , Badger writes

The mind fair boggles when you remember the "U" stands for "unified".

I have visions of the fledgling US engineering industry with 20 different not-quite-matching variants of the same threads. Must Google for the real history of these some time. Incidentally, my dad and various other engineers have always said that the old non-metric thread forms were better for different applications than the metric 'compromises' (his word). I'm not well versed enough to know, but I can see some sense in it - Whitworth, for example being designed to undo even when badly abused or gunged up, or so I was told.

Regards,

Simonm.

Whitworth was the first bloke to realise that standard threads would mean you could use any right sized nut and bolt from any manufaturer to do the job - up till then each made their own non-interchangable ones (see Fred Dibnah on the subject) - so easy to undo or not was not a primary objective.

The difference between UNF/UNC and other imperial/metric standards is "Not Inveneted 'Ere" by The Usual Suspects.

Richard

On or around Fri, 27 Jan 2006 14:25:56 GMT, SpamTrapSeeSig enlightened us thusly:

The whitworth thread was "designed" by Whitworth who took and average of a selection of threads he had to hand at the time. Later the BS lot got a hold of it and at some point people decided that Whitworth was a rather coarse thread, and so you get BSF as well. When whitworth derived his standard, bolts were typically mostly rather coarse and crude, I suspect - witness the fact that most modern whitworth bolts have nuts and heads the next size down - the 1/4" whitworth spanner (about 13mm) fits bolts with a

5/16" diameter, and you hardly ever see 1/4" bolts with that size head.

Meanwhile, other people came up with other standards, such as the SAE (Society of Automotive Engineers), which had different thread forms and different head sizes - measuring the head in inches across flats (which makes more sense, really). At some point, someone decided that it would be nice if all the inch-size threads fitted a common standard, and you got UNC and UNF (Unified Coarse and Fine), although plenty of threads continued to be used such as BS Cycle which used, IIRC, a whitworth thread form but with a standard pitch of 26 TPI irrespective of size) and BA (British Association

- of what I forget) which are a law unto themselves but were for a long time used on electrical stuff - BA threads have a very narrow thread form, IIRC

37.5°.

The people who were doing metric threads had less of a checkered history I think, probably mainly 'cos they started later and had the prior example of the muddle of imperial standards to steer clear of...

somewhere I have a damned great document which lists almost every thread there is sorted by size.

.

BA threads ARE metric. They were one of THE first metric screws, with highly convenient logarithmic changes in diameter with "number" from

14BA (1mm OD) to 0BA (6mm OD) and very good properties for fine work, like electrical and instrument applications.

Is an interesting read...

Its a great shame that people who should know better pushed the modern metric SI thread form and series, because for those of us who work in fine mechanisms, getting hold of BA screws is getting very tricky.

Steve