Removing the crank cog bolt on ABL engine?and rebuild advice

[vwt4]

ok guys, I m in the process of stripping my engine down (1.9TD ABL code) and have the head off. Valves have contacted with 3 pistons   and one of the pistons has a nasty impression of the valve in it, leaving a 2mm ridge I can feel with my finger.

The bottom half of the engine turns over smooth as a whistle and I have crack tested the pistons and they all seem fine:?!!!

So my plan is possibly to deburr the piston, clean it up, recon cylinder head etc... though I am concerned that a conrod may be bent, but I cant see visual evidence of it, as the pistons  come up to TDC correctly etc

 and a recon ABL engine will cost me nearly $2800....

so Im not going that route! this one is being repaired...but is it worth new piston(and possibly rods? if needed)

BUT// I still dont have concrete info as to why the timing slipped OR a valve bent for no reason? causing the carnage...

So I am going to remove the cog/pulley from the crank nose (its the cog that drives the timing belt) as I suspect the woodruff key is gone or the keyway damaged (and hence timing slipped)

Anyone got any bright ideas about getting it off as I dont have compressed air supply and it is on very tight it seems.... Ive tried putting the T4 in gear and it makes no difference?!

I was thinking of wedging the flywheel somehow

But all ideas appreciated before i have to go out and hire a compressor! (ive got an impact gun)

[vwt4]

Also, ive got a stuck/damaged lifter...and it is well and truly stuck in the lifter channel in the head. it is in the down position so I cant get a good grip on it.

has anyone got any secrets to getting them out so I can remove the valve and inspect the damage?

if I have to I will drill it and try and get a hook in there somehow to pull it out!! but Im out of ideas besides that..

[arb]

Did you heat it up ? I'd try that first. If you are going to destroy it to remove it, you could spot weld a small bolt to it to pull on.

[arb]

You could also try slapping a super magnet on it after you heat it. It might be salvageable. These magnets are also used in computer hard drives if you want a free source. Be careful you don't pitch your finders.

[vwt4]

Did you heat it up ? I'd try that first. If you are going to destroy it to remove it, you could spot weld a small bolt to it to pull on.

Thanks ARB

Hadnt really thought about giving it some heat  :?

I like the welding a bolt on idea but alas I dont have a welder presently although I could borrow oor acquire one if it comes to it.

The super magnet is tempting though, I never realised they were in hard drives??!
How 'super' are these magnets!!! Ive tried a couple of magnetic pointer tools at the same time and they didnt touch it  :cry: Are these super magnets really quite powerful? as Ive got a hard drive lying about thats corrupt  

[arb]

Here's a site that sells / describes them http://www.unitednuclear.com/magnets.htm

If you have more than one, and they are of the larger size, they can be out right dangerous !! If you have an old computer with the 5.25" hard drives ( 20 megabytes typical ) they will have rather large magnets in them. If the 2 are place with opposite poles toward each other, they can slam together with enough force to break your skin. If you have a flat one (some are curved) and put it on flat steel, you will not be able to remove it by hand. You will have to slide it off. Be careful not to get it near a computer monitor or TV as you can cause long lasting damage (color distortions).

I bet the heat will be enough with a magnet.  Drilling you might damage the head and the chips are not nice anyway.

[vwt4]

Here's a site that sells / describes them http://www.unitednuclear.com/magnets.htm

If you have more than one, and they are of the larger size, they can be out right dangerous !! If you have an old computer with the 5.25" hard drives ( 20 megabytes typical ) they will have rather large magnets in them. If the 2 are place with opposite poles toward each other, they can slam together with enough force to break your skin. If you have a flat one (some are curved) and put it on flat steel, you will not be able to remove it by hand. You will have to slide it off. Be careful not to get it near a computer monitor or TV as you can cause long lasting damage (color distortions).

I bet the heat will be enough with a magnet.  Drilling you might damage the head and the chips are not nice anyway.

Thanks for the info!

Thats the only thing left in my arsenal!!

ive tried heating it gently with oxy, no luck, Ive tapped teh valve back home and it pushed the bucket out a bit, but I still cant get a grip on it.

THeres no way I can drill it as its very tough indeed and the shiny surface doesnt help!

The more I look at this mess, the more I think Im going to end up needing a new engine  :cry:  I will know for sure when I get the crank bolt off hopefully tomorrow.

if the keyway is fine I will be shocked!!

Take a look at these pictures guys....the inlet valves have contacted all pistons to some degree.... Piston 2 is only a carbon mark, the same for 3 and 4 surprisingly. Ive since cleaned the pistons and there is no imprint damage to 2,3 or 4.

But piston 1 is the one that has damage. It has an actual imprint of the valve about 1mm deep!!! and there is a raised lip of iron around the edge of the valve imprint.

Im not sure whether to de burr the edge and (if the crank is ok) rebuild with a rebuilt/new head.
Or full stripdown or new bottom end which I really cant afford the time or cost to do at the minute. Especially as I hav a 1z conversion planned early next year.






The bottom end turns over sweetly and theres no visible conrod damage (TDC and TC piston height measurements are all the same) so my only concern is hidden conrod or piston damage or there being a problem with squish seeing as there is a new imprint in the piston that breaks in to the exhaust valve recess

What r your thoughts guys

[zukgod1]

If the Dent from the valve hasn't deformed the ring land you can run it.

I've seen some pretty bad pistons run just fine. Of course if you already plan on replacing them then no biggie.

Smooth out the damage and run that suka!

(take some pics when you get it out)  

[vwt4]

Weld a bolt to the lifter and pull it out.

Andrew

Thanks Andrew. I had thought of that but dont have a welder currently
but having said that, there have been so many times i could have done with my own welder recently... that Im going to buy one tomorrow and try and get that sucker out  
A new (recon pattern head) head will cost me $600
A decent(ish) 150 mig welder will cost me $4-500 but i will have it for lots of other jobs.... and it wont feel as bad as having to buy a new head!!! lol


zukgod - thanks a lot for your input  :wink: That has made me a feel a lot better about running the beast with the slight piston imprint!!

Removing the piston will mean taking the engine out fully, which is not a job Im very keen on at present as its freeeezzzzing outside here currently and I cant work on the engine inside until I have removed it from the vehicle and put it in the workshop!..hence Im not overly keen on replacing the piston if it will run fine as it is! (which Im hopeful it will)

I will definately post photos. If this engine does go back together and run sweetly when all the top end damage is fixed....i will have a new found respect for the bulletproofness of VW dervs  :lol:

[VW_Commuter]

Honestly a welder is, hands down, THE ABSOLUTE #1 POWER TOOL I HAVE EVER GOTTEN.  I know that they are expensive, but that is one expense I have never regretted.  

Andrew

I agree with Andrew 100%.  I own both MIG and TIG welders and they have both been very useful.

[VW_Commuter]

Alas, my TIG is only DC and I can't reverse the polarity so no Aluminum for me but it has served me well and when I have time to practice can lay down a beautiful bead.  My friend Oaf (I know, funny nickname but one of the greatest buddies you'll find) can weld a razor blade to a boat anchor with a TIG welder.  He used to be a 'nuclear' welder at the Puget Sound Naval Shipyard years ago and can weld anything you want and make it look pretty.

[vwt4]

Cheers guys

I needed that encouragement as a pep up prior to getting the wallet out in these hard times  :?

Im sure this welder will pay for itself in short order...I hope!