My 1.7TD Rabbit GTI project.
Posted: Sun Apr 06, 2008 3:12 am
Like I don't have enough projects going already,...
I've been gathering parts for this project for over a year now. I had a solid lifter TD block that was bored out to it's biggest bore and would need sleeves if i was to use it again. Going to 1.7 pistons would give it new life.... without using sleeves.
I got the pistons from a guy over on the GTD forum. Had them shipped over from europe. They are for the 1.7 TD, which uses the same rods in a KY block and I'm told was used in some eurovans.
Here's one side by side with a 1.6TD piston:
The pistons are so big that a 1.6 headgasket won't fit over them.... I'll have to use a 1.9 metal headgasket. This gasket works well with the later hydrolic lifter engines and last fall I was lucky enough to find an '86 TD Jetta with a hydro head.... so the 1.6 solid lifter TD block will need to wait for another project.
I started pulling the engine apart yesterday.
It's obvious some did work on it before it died. As we know, it's hard to give up on an '86 Wolfsberg TD Jetta. The head looks like it was rebuilt. The valves are very tight... with the cam holding them open there is very little side-to-side play. Only small cracks between the valves on a couple cylinders.
There were a few mistakes made by the previous mechanic,... maybe we can learn something:
Not a mistake but note the intermediate shaft seal is pushed out, due to internal block pressures/blowby.
See the red silicone he/she used to seal the waterpump?
Now you see it again, stuck in the passageways of the head.
This waterport gasket was put on wrong:
The headbolts were covered in granules. Not sure where they came from, probably the headolt holes. Not sure if it's just oxidation and salts that formed in the holes while the headbolts were in or they didn't clean the holes before they put the bolts in.
This is the top surface of the block:
Hard to see but it looks like they took a spinning disc to it, to clean it up before the new head, same swirls on the head. It was good to remove the head and see no valve marks on the pistons. It died a slow death, nothing catastrophic.
I'm seeing a few small cracks in the prechambers and the PCs stand up above the surface a little too much. I think it shows in a couple of the pictures above.
Also notice the punch mark on the prechambers. I only see these on known TD heads,... and I think the PCs are smaller on a TD head.
I got an '83 or is it '84? Rabbit body. 2 door, no sunroof. Mercedes ash grey,... solid body, almost no interior but I've been saving light blue interior parts from Old Blue (may she rest in peace).
So this project officially started today. The machinist gets the block and pistons Monday.
Rods get new ARP bolts and the bushings are just slightly smaller than the pins in the 1.7 pistons so I won't have to buy new bushings, just get the old ones reamed a little. I'm being told that new rod bolts means the rods will have to be sized, so savings in the bushings will go to that if the mechinist says it's needed.
I do worry about compression, with the larger pistons shoving more air into the prechamber and space at the top including the valve recesses it could be too high. I might go with the thickest gasket to help keep it low.
I've been gathering parts for this project for over a year now. I had a solid lifter TD block that was bored out to it's biggest bore and would need sleeves if i was to use it again. Going to 1.7 pistons would give it new life.... without using sleeves.
I got the pistons from a guy over on the GTD forum. Had them shipped over from europe. They are for the 1.7 TD, which uses the same rods in a KY block and I'm told was used in some eurovans.
Here's one side by side with a 1.6TD piston:
The pistons are so big that a 1.6 headgasket won't fit over them.... I'll have to use a 1.9 metal headgasket. This gasket works well with the later hydrolic lifter engines and last fall I was lucky enough to find an '86 TD Jetta with a hydro head.... so the 1.6 solid lifter TD block will need to wait for another project.
I started pulling the engine apart yesterday.
It's obvious some did work on it before it died. As we know, it's hard to give up on an '86 Wolfsberg TD Jetta. The head looks like it was rebuilt. The valves are very tight... with the cam holding them open there is very little side-to-side play. Only small cracks between the valves on a couple cylinders.
There were a few mistakes made by the previous mechanic,... maybe we can learn something:
Not a mistake but note the intermediate shaft seal is pushed out, due to internal block pressures/blowby.
See the red silicone he/she used to seal the waterpump?
Now you see it again, stuck in the passageways of the head.
This waterport gasket was put on wrong:
The headbolts were covered in granules. Not sure where they came from, probably the headolt holes. Not sure if it's just oxidation and salts that formed in the holes while the headbolts were in or they didn't clean the holes before they put the bolts in.
This is the top surface of the block:
Hard to see but it looks like they took a spinning disc to it, to clean it up before the new head, same swirls on the head. It was good to remove the head and see no valve marks on the pistons. It died a slow death, nothing catastrophic.
I'm seeing a few small cracks in the prechambers and the PCs stand up above the surface a little too much. I think it shows in a couple of the pictures above.
Also notice the punch mark on the prechambers. I only see these on known TD heads,... and I think the PCs are smaller on a TD head.
I got an '83 or is it '84? Rabbit body. 2 door, no sunroof. Mercedes ash grey,... solid body, almost no interior but I've been saving light blue interior parts from Old Blue (may she rest in peace).
So this project officially started today. The machinist gets the block and pistons Monday.
Rods get new ARP bolts and the bushings are just slightly smaller than the pins in the 1.7 pistons so I won't have to buy new bushings, just get the old ones reamed a little. I'm being told that new rod bolts means the rods will have to be sized, so savings in the bushings will go to that if the mechinist says it's needed.
I do worry about compression, with the larger pistons shoving more air into the prechamber and space at the top including the valve recesses it could be too high. I might go with the thickest gasket to help keep it low.