engine rebuild trouble

[agnew1985]

yes i can and will! Thanks!

[silverbullet]

Hairline cracking is quite usual and yours isnt that bad. What is the blue gunge on the jacket seal? It doesnt look like Dirko to me (what you get in Elring kits, alloy-safe non-acidic sealant)
Got to ask: why does the water jacket face of the head looks so oily?

[silverbullet]

PS I have just gone back to your first post.
Tappet preload only applies IF the cam followers are "dry" and not full of oil, in which case any oreload will simply jack the valves open and you will have no compression at all.
I have just finished an engine which had new hyd lifters on a new cam, 6 of the 8 were dry (apart from a bit of packing oil) the other two were solid, so I had to pop the clip out and drain them before reassembly.
If you can't push the little piston down in the follower and feel it spring then you can't set the preload with any degree of certainty.
I only give them 1 turn preload, that equates to 1mm of wear at cam or a lot of valve recession!
Crank the engine with the plugs out and coil disconnected to get oil pressur up and everything full before attemptung to run it.

[itchyfeet]

On page 1 we came to the conclusion they were solid tappets but now you have the head off pull one out and check.

While the head is off put a bag with a cable tie around the barell and see what the compression is like.

[agnew1985]

silverbullet thats good news about the cracks. I thought that was the case but thought I'd better check. The blue gunge is the blue rtv silicone instant gasket as the gasket set I bought didn't come with any sealant - I was told it would do the job. As for an oily jacket face, I think it's just wet. I took the head off with the engine still in so I think its just coolant. I know its dark but if you look at the pics on page three it was like that before I put it back on and I hed really scrubbed it. Itchyfeet, I will definately do that to check compression on the pistons. Thanks so much again.

[agnew1985]

put some paraffin in the combustion chambers and watched it all drain past the valves today! Spent a while lapping them in again but no improvement. Its really hard to tell just by looking but I think they are slightly bent. The head of one of the exhaust valves is very slightly not quite round. So i think new valves and then see...

[itchyfeet]

Put marker pen on valve and seat, then grind in with fine paste briefly, should show if an area is not touching.
Engineers blue is better
http://www.ebay.co.uk/itm/Stuart-Engine ... 0405691880" onclick="window.open(this.href);return false;

[ermie571]

Really impressed with your dedication Agnew!!


Keep going...it'll get there eventually!

x

[agnew1985]

Thanks ermine, I really hope so! Itchy feet I will definitely do that before ordering new valves, thanks.

[Ian and Lins]

Glad the method gave you a result, even if it's not the one you want! As I said before, valve heads may be only slightly bent (really slightly bent) to lose compression.

[agnew1985]

Yeah you're right. At least I've got something positive to work on tho! Did itchyfeet's test and there were clear spots where the marker pen wasn't coming off - pretty conclusive! I have ordered new valves for the side I'm working on and they should be arriving tomorrow. As I have compression on the left hand side I thought I would leave it for now and see how it goes. I'm probably going to replace the exhaust some time next year so If the van runs ok when I eventually get it started, I may well do the other side then.

[itchyfeet]

Do yourself a favour and buy dirko rather than that blue stuff

need new compression seals also but I'm sure you knew that

[agnew1985]

Er... No! Compression seals?!

[itchyfeet]

Are you saying you didn't fit them top of barell to head
http://www.vwheritage.com/vw_spares_Gas ... tartPage=1" onclick="window.open(this.href);return false;

looking back at your pics I think I can see them.

[agnew1985]

Oh! Phew... Yes of course I did! They were new when I rebuilt the engine, do I need to replace them again if it hasn't started yet?