Discussion in '16-valve' started by Nige, Feb 11, 2009.
This is a really clear guide, Thinking about upgrading my cams so this thread will be a great help
Markings to refit cams and belt
I am in the process of rebuilding a 16v (ABF) engine and is not sure of the following:
1. If I align the twp dots of the cams to be in line with each other, the line mark on the inside of the cam pulley does not align with the side of the valve cover. I notice the no4 inlet valves is in the process of opening, meaning that if I turn the engine to TDC the valves may not allow no4 piston to do it.
2. If I fit the cambelt, what procedure should be followed to ensure the valves not catching the pistons. I need to use the factory marks as it was not marked on removal.
My Cams dont look aliagned!
I read your thread and have used it to look to take the Cams out on our Golf Mk 2 gti 16V. I have found that when the No 1 piston is at tdc that the timing belt sprocket marking is not quite at tdc, also the forward (fuel inlet) cam appears to be one tooth out.
I attach some photos to show what I mean. Haven't taken anything else off at moment, wanted to get your opinion.
It seems not to be quite right bit it has done one track day and seemed to run ok.
Your guide to cam removal and refitting is really clear so thank you (so much better than haynes manuals 4 lines) , so I have used it to remove mine to replace the cam/sprocket oil seal that is leaking.
I have put No. 1 cylinder at tdc, however the notch on the timing belt sprocket is not quite positioned at 12 o'clock and the fuel inlet cam is also not quite aligned (seems to be one tooth out from the markings on the cam gear).
We have done a track day with the car and it seemed to go ok, apart from the temp getting quite high (120deg C). I also noticed that the plugs are quite white.
I attach some photos to show what I mean. Haven't loosened any of the cam bolts yet, as wanted your thoughts before doing anymore. I think it needs resetting up....any help/advise appreciated.
The notch on the timing belt should line up with the mark on the cam cover. From memory, I don't think that's 12 o'clock. I'd suggest you need to reset the timing, or at least recheck it, with the cam cover temporarily put back on. Just use a couple of bolts to make sure it's located properly.
When you're trying to find TDC, there's a flat spot at the top of the travel, where it's hard to tell. I'd suggest you use the TDC dot on the flywheel to confirm (not the V mark).
I've figured this out the hard way in the past - if the cams are timed nearly right but not quite, it makes a big difference to power, and tends to cause a lot of top end rattling as the cams rotate (I was convinced I had a tappet problem, but when I rechecked the cam timing, the noise miraculously disappeared.)
For future reference, this thread is for information, rather than fault diagnosis. If we get a load of enquiries on it, all Nigel's work will be diluted by the size of the thread. Please post any queries in the 16v engine forum. Feel free to post a link to this thread, if you think it will help.
i used most this guide to help me do a head gasket for the first time. thanks
Great concise guide with excellent images.
This is indeed a very useful guide. I also used it for fitting my Schricks, although it's a bit different. You don't have the dots on the chain wheels, but the ends of the cam shafts have to be in one line. I don't think this is the same for all aftermarket cam shafts, but for the latest Schricks this is how it has to be:
It's import the K-numbers (K12 in this case) are on top of the line, on both the shafts! It's also useful to compare the position of the cams, with the original one.
It's also a bit harder to fit the shafts, because of the higher lift. I also had stronger valve springs, so this makes it a bit harder as well, I think. How I do the trick:
- Put the cams in right position, with the ends in one line. Watch out the chain doesn't move while the shafts are fitted.
- Now it should be possible to put on cap nr. 5. Tighten the two nuts a bit, until you have enough thread to put on the nuts of cap nr. 6. Now tighten these nuts...
- I did this for the caps 5 till 8.
- Now it should be possible to put on the two nuts of bearing cap nr. 4. This is the hardest one to do. It's important to be careful with the nuts, so you don't lose one in one of the holes of the head. There isn't much thread when you try to fit them!
- Once cap 4 is on it's place, it's easy to fit cap 3, 2 and 1 (and the other caps at both sides of the cylinder head)
Don't tighten the caps too hard! Once they're fitted, they still have to be tightened on time (15Nm!).
So for clearness:
How I fit them first:
How they should be tightened:
Had to change my head gasket for second time (buy cheap buy twice, lesson learned) and followed this amazing guide again, sadly have hit a snag, with head back on I could turn crank fine until timing belt added, then she went rock solid and (stupidly) I forced and now have a toothless pulley, any ideas as to why this could happen?
(no plugs in so no pressure on system)
A cap on backwards or in the wrong place ?
all taken off in sequence and put back same, might have been 1 tooth out on alignment but that shouldnt cause an issue should it?
I've got a spare head en route so if push comes to shove, just wish I hadnt spent a day cleaning and polishing it to get rid of casting errors lol
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