VW Question: CIS-E head on a Digifant 1.8

A previous owner mangled the cylinder head (on my 1991 1.8L Digifant Jetta) while trying to remove a broken exhaust manifold stud. He welded to the remaining stud and, apparently, warped the area around the exhaust port, so the manifold can't seat properly. I've tried filing it and using thicker gaskets, etc. Nothing has worked.

I have a good used cylinder head from a 1987 8V GTi. I also just bought a Techtonics Tuning 260-degree cam that I want to install. I want to use the exhaust leak as an excuse to upgrade my car...

That being said, I have to perform the cylinder head swap in one day, as the Jetta is my daily transportation. While I can certainly get that done, it's just a question of if the CIS head will work on my Digifant car.

So, does anyone know definitively if I can use the CIS head on my Digifant engine?

Yes it will. I put my ported and polished CIS-e head from my 86 on to my 91.

Just need to change to the Digifant injector cups and drill/tap one hole for the fuel rail. The head is machined flat where the hole needs to be, so it's minimal work.

You can, but the injector ports require different injector cups. I can't remember which cups to use though. But that is all that needs to be changed to go to a solid lifter/CIS cylinderhead

Cone_Junky wrote: Yes it will. I put my ported and polished CIS-e head from my 86 on to my 91. Just need to change to the Digifant injector cups and drill/tap one hole for the fuel rail. The head is machined flat where the hole needs to be, so it's minimal work.

I think that there is a gap beneath the digi cups that is supposed to be filled in a CIS head. The CIS cups have a lower piece in there.

The larger injector ports do not need to be filled. You can't put CIS injectors into a Digi head, but swapping the other direction is no problem. Just pull out the cis injector cups and put in digi injector cups. Ran mine this way for years.

In reply to Cone_Junky:

Fair enough, I hadn't swapped to a CIS head yet, was just going off what I had heard which prolly wasn't from someone with first hand experience.

Half of my spare 8v heads are JHs so this is good to know.

Yep, just change the injector cups. It works fine. The dealer can still get them.

I guess it's time to drop the GTi head at the machine shop and get to work. Thank you all for the responses!

• Brian