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Engine Specific Info and Questions => IDI Engine => Topic started by: wpinnix on November 25, 2012, 01:36:19 pm
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Hello,
I have a 1997 AAZ that I put in my 1981 VW pickup. REcently the coolant system was getting overpressurized so I'm going to change the head gasket. I have a new AAZ head (Kolbenscmidt) and ARP studs that I am going to install. I am running 14 psi max boost with a giles pump (adjustable pulley), and K03 turbo.
I'm looking for any tips on the install.
My proposed process:
-Put engine at TDC prior to removing timing belt
-Mark pulleys and belt and rear timing belt cover to get things back close to where they need to be
-Pull belt off cam and injection pump pulleys; remove pulleys
-Pull old head and gasket
-lightly clean up block, tap head stud holes, blow out any debris with compressed air
-Install ARP studs
-??Apply hylomar to all 4 mating surfaces??
-mount gasket,
- ensure cam is at tdc in head and mount
-torque ARP nuts according to ARP torque procedure
-lube cam and followers with oil
-Put everything else (intakes, covers, belts, etc.) back together
-turn engine over by hand to ensure no interference
-start engine
I have a couple of questions:
--If the cam lock is in place, is the cam at tdc? I want to be sure the head is static timed before I put it on the engine
--is oil sufficient for lubing the cam and followers?
Any other input or tips would be greatly appreciated!
Thank you,
Bill
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-Mark pulleys and belt and rear timing belt cover to get things back close to where they need to be
No need to mark pulley's or the belt, you will be starting fresh when you install the new head. At least, you SHOULD be. The "mark and pray" method is the worst possible way to do it. The crank and pump pulley are the only two that are key way'd and only go on one way. If you set the engine to TDC prior to, then you know the crank and pump will sit at TDC for the time being.
-If the cam lock is in place, is the cam at tdc? I want to be sure the head is static timed before I put it on the engine
Yes. The cam lock will only go in one way, and that is #1 TDC on the compression stroke.
-Put everything else (intakes, covers, belts, etc.) back together
I'd probably hold off on re-installing everything until I rotated the engine. Just in case you gotta tear it back down again. You only need the timing belt on and locks out of the engine to turn it over. If everything goes well from here you are solid to continue putting everything back on. In fact most leave the cam cover off as well so that they can verify everything comes back to TDC after a few revolutions by hand.
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Awesome, thanks for the reply!
Any thoughts on using oil as initial lubricant for cam lobes and followers?
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If its good enough to use for the engines several hundred thousand km life span, I don't see why not ;)
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Before you take it apart, practice timing the engine a few times so you get used to the procedure.
Also, when you install the head, rotate the crank a few degrees forwards or backwards so that the pistons are not at TDC. this will help prevent any accidental valve/piston contact while you are finessing the head into place.
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Thank you for the replies.
I've timed this engine a few times, and timed my old n/a 1.6 a bunch of times, so am comfortable with that process.
thanks for the tip on rotating the crank....should I leave the cam at tdc when installing the head or is there a better position for it to be in?
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As for cam position I think no matter what at least 1 valve is open so it's best to go close to TDC #1.
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I would go dry if it's an MLS gasket, and it likes a fine finish.
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When stripping a head off a block I always pull one of the two small coolant hoses going to the waterpump housing to make sure the block drains of coolant properly. Just pulling the large bottom hose to the radiator will not drain the block as the thermostat holds coolant in the block.
The reason for me doing this is to make sure no coolant spills into the bores when the head bolts are undone and the head removed. You do not want coolant sitting in the bores or around the piston rings for any length of time or it will water mark the bores.
Also make sure the head bolt holes are cleared of any debris or oil prior to installing the new head. You can hydraulically crack the block by screwing in the head bolts if their threaded holes in the block are full of oil or coolant due to fluid not being compressible.
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Another great tip, thank you. I've removed the thermostat housing to drain the fluid. I'm hoping that sufficiently drains the block and head.
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That should be sufficient as it is the lowest spot for coolant.
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You could have a shop vac handy just in case ;D