Cambelt let go at 6000rpm!! what r my chances?

[andrewdowd 0]

Ok not quite the cambelt it was the bottom pulley, the locating lug is still wedged in the crank salvagable by the looks of it, but i'll need a new bottom pulley, if anyone has a spare one let me know am worried however at the state of my valves n pistons im running a piper fast road cam so chances are its gonna need 8 new valves, a head job seems immenent :)

Let me know your views n horror stories

[h100vw 0]

Buy yourself a new bottom pulley from VW and get a DX crank bolt and washer.

 

2 ways to go here IMO. Fit the new pulley, bolt, belt and tensioner and see if it turns over by hand. Then try for a start. This is what I'd do myself.

 

Depending on what happens you may need to follow on below if it doesn't run.

 

You can pull the cam and see if all the valves return to the top on their own. Any bent valves will get stuck and not return all the way.

 

If they look ok drop the cam in and try a compression check. The slightest bend will stop the valve seating and drop the pressure in the check although you will probably see something on the gauge.

 

It might seem involved but you are saving the cost of a head set and a skim, which is going to be 100 quid or thereabouts.

 

Or 2 rip into it blind, which isn't sensible and will cost money and waste time.

 

Gavin

[andrewdowd 0]

yea was gonna run compressions and go from there, im pretty optimistic i blew a ford cvh cambelt b4 stuck a new belt on and away she went, i class my self as lucky

[h100vw 0]

I hope so mate. Not a killer job if it does bend a few valves, just the inconvenience.

Keep us posted

Gavin

[VEEDUBBED 0]

Depends also on the cam's lift,on a normal 8v G60 the valve's won't touch,i know because once i tried turning over the engine whilst changing the cambelt and the crank turned freely with out hitting the open valves,also tried it on a scrapped Passat G60,same thing no interferance...

If you need a compleat head let me know because i've got one left,cheers,Andrew.

[stevemac 0]

VEEDUBBED, G60 pistons will touch the valves. The fact that yours didn't depends on position of the cam, while you were turning the engine over. If any of the valves are fully depressed into the engine, they'll hit the pistons.

 

Several G60's have been known to bend valves, as they were hit by the pistons.

[CoxyLaad 0]

thinking about it as soon as the cambelt snaps the tension will go from the valves and the springs will withdraw them to their fully closed position?

[olly elworthy 0]

thinking about it as soon as the cambelt snaps the tension will go from the valves and the springs will withdraw them to their fully closed position?

 

think again, the cam will still be in the engine pushing some of the valves down, only way all the valves will return into their seats at the same time would be if no cam was in the head,,

[andrewdowd 0]

Bit are on order new pulley £24inc the vat.. new bolt £2.57 inc the vat.. the look on my face when the thing runs?? priceless!

[Henny 0]

The problem with the belt going at high revs is that the cam doesn't just stop dead, it slows down first which means that you'll get a period of time while the pistons are going faster than the valves are opening and closing. When the cam stops, you're left with at least one set of valves open and normally with the pistons still moving at this point...

 

VEEDUBBED, the G60 engine (in both PG and 1H flavours) IS an interference engine. Snap the belt while the engine's running and you have a VERY high chance of valves touching pistons... how hard they touch is a matter of luck. When my bottom pulley went it only bent one valve so I was lucky, but when Bananaman's went (again at around 6Krpm) it took 3 (IIRC) valves.... A mate of mine's went at high revs and actually damaged a piston too... :|

 

andrewdowd, As gav says, fit the new pulley and belt, and do a compression test (DON'T just try firing it up as this could do even more damage to the head...) to see what the score is... you may have been lucky...

 

Good luck!

[VEEDUBBED 0]

How is it that the camshaft can still be turned 360 degrees?,whichever way you look at it some valves will remain fully open,the engines should have locked up but they didn't,and i was turning both crank and camshaft in different directions without the belt installed,strange...

[CoxyLaad 0]

thinking about it as soon as the cambelt snaps the tension will go from the valves and the springs will withdraw them to their fully closed position?

 

think again, the cam will still be in the engine pushing some of the valves down, only way all the valves will return into their seats at the same time would be if no cam was in the head,,

 

ah fair enough - I knew someting wasnt right with my post

:)

[Henny 0]

VEEDUBBED, put the engine to TDC and then turn the cam 360... the valves will just touch the pistons.... Now add in some oil pressure so that the tappets are at the correct height and suddenly that touch becomes a hit which will do damage... ;)

 

It's only just an interference engine, but when the oil pressure is up, it most definately makes contact... :(

[andrewdowd 0]

Well, got my bits today ran compressions and got a big fat 0 on all 4 cylinders. in the middle of pulling the head off now, (by the way does anyone have any tricks on how to get the down pipe off? inlet manifold bolts are rounded off so i gotta take it off in one go) checked the vales as i took of the rocker cover and at least 2 are jammed open, this ones gonna be fun by the looks of it, I sense a big head porting job coming up :D

[Henny 0]

if you go under the car with a LONG extension bar, you can undo the manifold to downpipe nuts and leave the manifold on the head... it's by FAR the easiest way of doing it... ;)

 

The trick is that the middle bolts need a wiggle-woggle joint (technical term) up by a deep socket to be able to get on to the nut successfully... ;)

 

Oh, and they're likely to be TIGHT, so use a BIG bar... ;)

[andrewdowd 0]

Ace thanks i got a big breaker bar, fun part is im on my back outside, havnt got a wobble ext bar or a deep socket tho :( have to go ask a friend

[stevemac 0]

Well, got my bits today ran compressions and got a big fat 0 on all 4 cylinders. in the middle of pulling the head off now, (by the way does anyone have any tricks on how to get the down pipe off? inlet manifold bolts are rounded off so i gotta take it off in one go) checked the vales as i took of the rocker cover and at least 2 are jammed open, this ones gonna be fun by the looks of it, I sense a big head porting job coming up :D

The whole lot can be removed in one lump - just detatch the front pipe from the CAT. You'll end up removing a dirty version of this -

[andrewdowd 0]

Looks loads easier, cheers for that steve :) bit of a wiggle to get it all out tho i guess? ;)

[2cc 0]

Mods, can we add "wibble wobble joint" to the glossary? I'm lovin it :lol:

[MillSpeed 0]

Buy yourself a new bottom pulley from VW and get a DX crank bolt and washer.

 

What's the deal with these DX crank bolts then?

[h100vw 0]

http://www.the-corrado.net/.archive/forum/viewto ... crank+bolt

 

Gavin

[MillSpeed 0]

Cheers fella!

[stevemac 0]

Looks loads easier, cheers for that steve :) bit of a wiggle to get it all out tho i guess? ;)

No worries m8 - like you say, just wiggle it around a little. Pull the whole assembly forwards & upwards & it should come out fairly easily.

 

Do the same when you come to re-fit it all. Build it all together before fitting the head back onto the engine. Just be careful not to damage the new gasket.

 

BTW - be sure to use a metal head gasket. There are some dodgy gasket kits around with paper head gaskets. The kits that GSF sell are from the same manufacturer as the VAG ones - you'll be okay with one of those. Only gaskets that don't come in the kit are the throttle body gaskets - VW only.

[Henny 0]

oooh, didn't know that'd clear Steve... good discovery there... 8)

[stevemac 0]

oooh, didn't know that'd clear Steve... good discovery there... 8)

Yeah - virtually the whole top-end comes off in one piece.

 

I discovered that after I'd snapped an exhaust manifold stud & rounded off 2 downpipe nuts, trying to seperate the manifiold from the head.

 

If there's an easy way - I'll usually find it .. :lol: :lol: