93 Opti-spark issue
Thread Starter
Intermediate
Joined: Apr 2013
Posts: 45
Likes: 8
93 Opti-spark issue
I took my Optispark out and apart and as expected it was rusted and corroded inside, I don't know how it ran at all based on what I see.
I have all new (Delco) now but my question is should I seal off the three vent holes in the bottom to prevent this happening again? If not, what is the best adaptation
Thanks, Bob Smith
I have all new (Delco) now but my question is should I seal off the three vent holes in the bottom to prevent this happening again? If not, what is the best adaptation
Thanks, Bob Smith
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
You don't want to block vent holes. Also modifications may effect warranty. You want to modify water pump wee hole. So if water pump fails coolant will leak away from opti spark. Ideally you want a drain tube or hose to run beside and empty below opti
Instructor
Joined: Feb 2015
Posts: 234
Likes: 20
From: Stuart Florida
I have a 1994. There are three vent holes on the bottom, in the aluminum frame. Most people on this forum recommend adapting those holes so they function like 1995 and after models that come with a vacuum vent from the factory. It involves drilling the holes out, attaching hardware and vacuum hose. Just do a search on opti conversion.
Thread Starter
Intermediate
Joined: Apr 2013
Posts: 45
Likes: 8
Thanks for all the suggestions. I did modify the NEW water pump to accept a drain tube away from the OS. I am still unclear about the three holes though, what will happen if they are sealed. Better yet can I seal two and run a vacuum line to the third and if so which of the three? This is such a bad design and I don't see how water/moisture is getting in there. It is sealed all around (except for those three holes) and looks tight as a clams ***. I hate being a pain but I do NOT want to go through this again, easier to pull the motor I think
Race Director
Joined: Sep 2001
Posts: 14,686
Likes: 753
From: NEwhere Ohio
I took my Optispark out and apart and as expected it was rusted and corroded inside, I don't know how it ran at all based on what I see.
I have all new (Delco) now but my question is should I seal off the three vent holes in the bottom to prevent this happening again? If not, what is the best adaptation
Thanks, Bob Smith
I have all new (Delco) now but my question is should I seal off the three vent holes in the bottom to prevent this happening again? If not, what is the best adaptation
Thanks, Bob Smith
buy a 95-96 vent harnss (it includes flow reducer and check vavle).
drill out one of the three weep holes to 1/8" and epoxy in place a straight vacuum fitting to create an air outlet nipple.
seal off the other 2 holes. i sealed mine off with self-tapping metal screws and epoxy around the screw- for good measure
buy a gen 2 (95-96) optispark cap bc it will hav an extra fitting on it for the air inlet.
connct up the vent harness
tee of the weephole side of the vent harnss to a vacuum souc somewhere
tee off the other side to the air inlet (behind filtered air, so it wont suck any debris in that could clog it).
good luck!
put rtv silicone around the perimeter
Last edited by dizwiz24; Jun 19, 2016 at 09:29 AM.
