Zizi

JimLentz

See if this helps.

Zizi

WhiteC1

Zizi,
If you plan to follow the steps that JimLentz referred to, I have a few comments to add. I used this as a reference to modify my 94 Optispark, and ran into an issue. If you use the hose fittings off the bottom of the Optispark like the link shows, you may have clearance issues. In my case, I used a plastic elbow from the center hole on the bottom of the housing. When I tried to install the Opti back on the engine, the plastic elbow hit the front timing cover before the Opti could seat against the cover. If I had just tightened it down, I would probably have broken off the plastic fitting. So, instead I removed the plastic fitting, epoxied up all three holes underneath, and drilled a small hole in the side of the lower flange to intersect the driver side drain hole. Then I used a brass vacuum nipple from an old carb, and pressed it into the hole. The final port is in pretty much the same position as the production vented Opti, and it allowed the hoses to be hooked up relatively easily. Hope this description helps. If you need any additional info or pictures, let me know. Good Luck!

Regards,
John

Zizi

WhiteC1

Zizi,
Here are a few pictures that should help explain what I did (wrong & right).

Bottom Vent (outer holes epoxied shut). Flange on right side of picture is where I drilled the hole (horizontal) to intersect the drain hole. I left the epoxy in the bottom, and cleaned it out from the inside so there would be a path for the vacuum fitting. Then I removed the plastic elbow and epoxied up the center hole.



Bottom Vent, with vented cap installed:



Opti bottom vent interference to timing cover (viewed from driver side):



New side vent (carb vacuum nipple) showing clearance:


Let me know if you have any other questions.

Regards,
John

DGXR

^ that's an awesome response. I love this forum.