Printable Version of Topic

Posted by: John90290 Nov 2 2018, 08:52 AM

I pulled the 1.8 L motor in order to fix all the rust in hell hole which of course gave me the opportunity to fix a few things.

Pulled the heads as the lifter tubes were all leaking oil profusely.

Heads/Valves: Looked to be in good shape with minimal carbon buildup. I was surprised.

Pistons: Look OK I guess... not sure what they’re supposed to look like? They had light carbon buildup on the top of the Pistons but otherwise seems to be OK.

Questions:

Do I buy a new stock pistons and cylinders? if not should I at least change the rings or does it matter?

Can I upgrade to a slightly larger piston without changing the heads and using the original FI?

Should I get one of those modified type 1 oil pumps to replace the oem?


I just want this to be a reliable weekend driver that I can drive through wine country and go coffee and cars.

Posted by: bretth Nov 2 2018, 09:07 AM

If you have water in your air cooled heads there is a problem. I tried to read this post but I think you need to retype it.

Posted by: John90290 Nov 2 2018, 11:22 AM

Retyped the post...sorry, I used my phone to post this originally and it was all screwed up.

Added some photos of one of the heads, valves etc.


Attached image(s)

Posted by: John90290 Nov 3 2018, 07:23 AM

Added pictures.

Posted by: tvdinnerbythepool Nov 3 2018, 08:46 AM

Following this. I'll be in the same situation with my 1.7 shortly.

Posted by: ClayPerrine Nov 3 2018, 09:03 AM

You can use stock pistons and cylinders from a 2.0 on a 1.8. They bolt in with no issues. Been there done that. You get an extra 2mm in piston diameter, and a bump in compression ratio because of the wrist pin hole location is different on the 2.0 pistons. If you don't mind premium gas all the time, use the 2.0 flat top euro pistons. That gives another slight bump in compression ratio, hence the premium gas.

It looks like you already have the valves out of the heads. Have your local machine shop put 2.0 stainless valves in the heads so the engine can breathe a little easier.

If you are going to split the case, then change the cam out for something more aggressive. If you are running the stock L-Jet, put in a Raby 9590 cam kit. You will need to put in bigger injectors, but they are easy to find. FLAPS carries the injectors, you just have to know what to ask for. Get 4 injectors for an 80s NA Nissan 280ZX.

Find a throttle body for a VW bus and convert it for use on a L-Jet system. http://www.914world.com/bbs2/index.php?showtopic=244849 It will let the engine breathe better.

The bigger oil pump is a good idea too.

Posted by: John90290 Nov 3 2018, 09:43 AM

Awesome info!! Thanks!! Would these be the flat tops you suggested,


Attached thumbnail(s)

Posted by: Valy Nov 3 2018, 01:08 PM

When you buy pistons, make sure you get the correct pin height. The 2L has a different measure due to the longer stroke.
There are 94 and 96 pistons for the 1.7/1.8 crank, if that's what you want to do.
Regarding the oil pump, the type 1 has no advantage over the type 4. On the contrary, it's a bit of a headache to get the right one and to make it fit. It also has more places to leak from. The only reason for a type 1 is if your type 4 is bad and can't find a new one (NLA)

Posted by: Valy Nov 3 2018, 01:15 PM

You probably want these if not planning to replace the crank.
https://aapistons.com/collections/porsche-piston-cylinder-kits/products/vw-porsche-96mm-big-bore-piston-cylinder-kit-914-bus