BXProject

[charlie]

right back for some more advice

have got the exhaust manifold, inlet maniflold etc etc off

and im now starin at the camshaft cover, block and sprocket

soo before i jump in just wanted to check....

accordin to haynes ive got to take the sprocket off,

then after the cover has come off, undo the bolts, then the camshaft carrier comes off (with camshaft in it)

then take the assorted rockers and their guides out (to be put back in the same place) out with the hydraulic tappets and small oil filter

is this about right cause i dont really want to mess anything up??



how far do i have to strip the block down cause im going to have it skimmed??

ta

[Vanny]

dont strip the block down, let the engineering people do it unless they will charge a HUGE amount less

[Bx Bandit]

Not knowing the engine mate it's hard to say...Doc or Dave are probably in the know. Personally, I probably would take the camshaft carrier off...maybe best to find who's gonna do the testing/skimming and see what they want/quote.!

[Way2go]

Mmhh........just realised this is open forum so need to be restrained about any post to the controversial Charlie! (:idea: must avoid another slap from Vanny! )

[docchevron132]

You dont have to take the cam carrier off (as it goes I have a spare one I think) to remove the head, and any engineering shop that isn't shit shouldn't charge more than £20 to remove it and refit it for a skim.

Be very careful about the skim though, make sure they use a new stone and tell them at the outset you will not UNDER ANY CIRCUMSTANCES accept milling marks in the surface.
Equally, be aware that there is only a finite amount of alloy you can actually remove before the head becomes scrap.

IF you're going to re cut the valve seats and lap the valves in yourself, then yes it's probably best to remove the cam carrier, rockers and valves before you get the head skimmed.

Also, whilst it's off, check the pre combustion chambers, they can crack very badly on D12's to the extent lumps of them fall off and glue themselves to the piston crowns.

[charlie]

cheers one and all for de advice and as always spot on

have got the bandit coming down tomorrow for the final push

just the cylinder bolts to remove

then lots of finger pointing and photos of the old gasket

oh and yes decided to take the injectors out and have them tested to see if ok

ta ta

[Bx Bandit]

cheers one and all for de advice and as always spot on

have got the bandit coming down tomorrow for the final push...

Have you? Fuck, the shit you rope me into dude! Yes mate, I'll be there for the final push.........push you over the edge of insanity by saying things like " Oh fuck Charles, Camshafts are meant to be in one piece" or "That's sawdust that is mate, sawdust! This engine is fooked!" etc etc and other useful comments

Oh, thank you for the bottle of Vodka, but if you do it again my liver will personally drive to Cardiff and.......er........um.....trample on your flowers and.....er....stuff. So there!

[Vanny]

vodka, that explains tonights posts!!

[charlie]

finally got to the head gasket!!!!

but as always things in charlies world are never straightforward

decided to strip rockers and followers off (valve springs still in place cause i havnt got anything to take them out with yet) cause didnt really trust garage to put them back in the original position

on three of the rockers there are signs that they've been making contact with the valves themselves,

when we seperated the head the first thing that we noticed was the amount of crud/shit and rubber in the water ducts.

most showed signs of a build of this crap, some where half closed, some almost completely and in one it was blocked with a 4 inch long piece of rubber. me and the bandit assumed that this was some sort of additive to stop leaks !!!!!

i was expecting an old paper gasket but it was a laminated jobbie, two holes. so i assume that the heads been done before.

though it must of been done some time ago cause of the amount of shit thats gathered on the gasket

in the pre combustion chamber there are a couple fine cracks but there're still in one piece

and one of the seating dowels is missing

and have taken the injectors out to have them checked over

i just wish that the bandit wouldn't laugh so much cause hes supposed to be helpin me like

and not pointin and shoutin things what the fuck have u done

bastard

ho hum

[Bx Bandit]

I godda laugh mate...else I'll cry in pity! Only jesting mate...
There was uneven wear on one of the camshaft lobes as well. The water ways were uber fucked tho', full of crud and rusty crap so it's no bad thing to have gone this far. I rekon it's been skimmed as well, there are lots of small irregular swirl marks (as if finished by hand with some wet/dry). In two of the corners on the head there are is a sunken circular patch with a textured finish...do they signify the deepest skim to be had? I rekon there's only about 1/2mm depth.
I guess we need to be certain if it has been skimmed
If it can have another skim
How to identify the correct gasket...

[docchevron132]

Yes, the two circular indents in the surface show how much can be skimmed, once you cant see them anymore the heads had it.

Gasket thickness is easy, get the thickest one they do!

Since the valves will be removed then it would pay to resut the seats and lap the buggers in anyway.
Now, you could cut the seats back and recess the valves to original tolerance in which case you could use the thin gasket, but in my opinion using the thickest one is always the way to do it.

Cant say I'm surprised about it being full of radweld shite to be honest. Most of them are by now..

It's not at all uncommon for the cam lobes to wear quite badly on D12's, especially if they have oil delivery issue's to the head, but if it's worn through the hardening then the cam will have a short life.
Rockers always show signs of wear but are made of the hardest metal from the planet Krypton, so I wouldn't be too worried about them.

[Vanny]

Rockers always show signs of wear but are made of the hardest metal from the planet Krypton

that will be pure unobtainium then?

[docchevron132]

:lol::lol::lol:

I like that!

As it goes rocker and cam sets are available off the shelf.
But it's cheaper to have a machine shop metal spray and heat harden the old units..

[Vanny]

The sort of job it want to be done in a mettalurgy lab where they have the gear to check its right, cos if you get it wrong you'll get shards and fragments of very very very hard stuff wizzing around!

surface layer deposition for the win!

[charlie]

Since the valves will be removed then it would pay to resut the seats and lap the buggers in anyway.
Now, you could cut the seats back and recess the valves to original tolerance in which case you could use the thin gasket, but in my opinion using the thickest one is always the way to do it.

more info please,

the gasket im gonna use is citroens own repair gasket (5 hole) and its as thick as me

where does that that leave me in the seating of the valves

ur got to excuse me ignorance but never done this before

soooooooo can anyone can point me to an idiots guide

[Bx Bandit]

buy one of them wooden sticks with suction cups on the end, some carberundum pasted and get calluses for the next 12 weeks!!

[charlie]

i said i wanted an idiots guide

and hey presto who appears

the banditoooooooooooooooooooooooooooooooooooo

:roll:

[Bx Bandit]

see, this site is great!

[docchevron132]

Since the valves will be removed then it would pay to resut the seats and lap the buggers in anyway.
Now, you could cut the seats back and recess the valves to original tolerance in which case you could use the thin gasket, but in my opinion using the thickest one is always the way to do it.

more info please,

the gasket im gonna use is citroens own repair gasket (5 hole) and its as thick as me

where does that that leave me in the seating of the valves

ur got to excuse me ignorance but never done this before

soooooooo can anyone can point me to an idiots guide

A 5 hole gasket should be thick enough.
Really depends how much metal gets removed from the head during the skim.
It may be easiest to get the machine shop to recut and seat the valves after the skim, then you aint gota worry about the head depth of the valves..

[Philhod]

Yeah Bandit said the depth guides were 1/2 a mill deep

That`s ....err.....20 thou in english
Are you going to skim the block as well ? If so it`s worth checking them both out on a surface plate, to determine the accuracy... then take just enuff off them both to true up....it can be as little as 5 thou between them
or less, run with a fine grinder on the miller.
Agree with Doc.... get the seats re cut 2 thou deeper than you have taken off in total.. they can do it accurately ...you are only guessing with the hand cutter