can you convert a cis 8v head to work on a digifant car?

[bpederndern]

i have to replace the 1.8 8v in my 88 golf , and don't have a spare digi head. i do have a late cis head that has the port for the air shrouded injectors. i know you could do the opposite and convert a digi head to work on a cis car.

i know that the injector cups need to be swapped out , but are there any other modifications that are needed?

[bpederndern]

after some deeper searching, it seems that as long as it is an 84+ head it should work after capping the air shroud port, and swapping the injector inserts for the efi cups that digi requires.


and tapping the two boss holes needed to mount the fuel rail

[Glegor]

but WHY?!

its MUCH EASIER to just get the right head..

most CIS heads dont have the cast in bosses for the digi fuel rail..

[bpederndern]

why? because i have a hydraulic cis head already......and not alot of $.....and no digifant cars in the junkyards around where i live. and did i mention i have very little $....you have no idea what i have been through in the past year.....to drive a pos base model 88 golf with an auto trans makes a world of difference to my life right now

[sandrunner]

Hmm, all three of my solid lifter CIS heads have threaded bosses for a fuel rail, including the "early" head with 24mm injector cups. Just lucky I guess.

[Glegor]

why? because i have a hydraulic cis head already......and not alot of $.....and no digifant cars in the junkyards around where i live. and did i mention i have very little $....you have no idea what i have been through in the past year.....to drive a pos base model 88 golf with an auto trans makes a world of difference to my life right now

you are preeching to the wrong crowd here..

when i dont have the piece i need, i find a friend that does have one, then i trade for it.

one thing nobody has touched on, is the threaded depth for the injector cups.. the CIS head has threads alot further down the bore. so, when your digi cups get tight, they will be too low to properly seal on the injectors..

trade your hydro CIS head for a good digi head.. or sell it and buy a digi head..

too bad you arent closer, i have a BUNCH of digi heads. they are useless to me, i would GLADLY trade you a CIS head for a digi head.

[sandrunner]

one thing nobody has touched on, is the threaded depth for the injector cups.. the CIS head has threads alot further down the bore. so, when your digi cups get tight, they will be too low to properly seal on the injectors..

I haven't seen any information on that and I would be very interested in knowing the height difference of the Digi cup bore vs CIS (CIS=17.5mm to upper edge). Anyone with a spare Digi head want to measure with a digital or analog caliper?

I used Digifant fuel rail and injectors on my MS swaps from CIS, but I had to fab up my own fuel rail mounts as I didn't have any factory ones. Swapped injector cups, made a block off plate for the air shroud port and bolted everything together. 50K miles on the '78, 35K on the '86 with no leaks or problems.

One interesting thing to note is that with CIS, 27mms of injector sticks out into the airflow and it's a good 10-15deg off of being pointed at the theoretical optimum of hitting the back of the intake valve. When I mocked up some spares, the Digi injectors only invaded about 3mm into the airflow.

[bpederndern]

just checked this thread , and wanted to say that i ended up plugging the aur shroud port with silicone, and swapping in digi injector cups. been running problem free since the motor swap.

[ps2375]

I had no problems with my solid lifter CIS head to use the digi cups for my MS change over. It even has the threaded bosses to mount the fuel rail. Go for it.

[onlyrotary17]

wow. this is totally the reverse of what i had to do on my motor. I put a '92" rebuilt gti (digi) head on my cis-e car. If only we were closer and in the same time frame I would have lined you up with a badass head. I did the swap back in september '12. Stupid thing about mine is, if i pull any of my injectors out of the head, the end cap will pop off and get lost in the valve-train..