Ok I scared myself a lil the other day getting fuel. I forgot to add my mix and was about to drive off when I saw the bottle in the hatch, so Ive decided to go back to using the OMP. But there is a problem, dont have the stock setup at all, or anything remotely close. I am using (as many of you know) dual 40mm DHLAs and a TWM manifold, niether have anykind of provision for anykind of oil system. So just where do I start. I have the oil injectors still in my block but what about the other two lines that come from the pump, and is there a certain way that the omp controls need to move or is it just like an on off switch.

I have seen a couple of pics where people have drilled into the venturi of the carb and tapped in a small barb for the oil line to go, is this the best choice or is there a better way, I am trying to make this as reliable as possible.

EDIT: forgot this a ported 13b franken motor. Mainly S4 parts.

 

I know with the 12A motors where was a linkage to the omp, connected to somehow to the throttle, so the more throttle you give the more the omp opens up and feeds more oil. It is NOT a constant flow thing.

Sorry but thats all I can contribute.

 

Just put a little sticker note there to remind yourself to add the Idemitsu rotary lube pre mix. Put it inside the fuel door or the like.

 

I probly wouldnt go the venturi.....
you can tap the manifold for the other 2 oil inj
i think some 12As had 2 line omps and u can use this omp but 4s are better!!
the mechanical omp swing arm can be fixed at approx 3/4 of its full swing
the duty cycle of oil metering at 3/4 is not quite enough for consistent full throttle
but is just more than enough for all other throttle conditions,
just keep an eye on smoke at idle if its too much the back off arm slightly
If you go drifting or racing then fix arm at full swing

 

Drill and tap into the top of the float bowl.

 

Is this actually a good idea?

 

The way the OMP works is the more throttle you give the more oil it pumps out.

But who cares you have been pre-mixn and its what ever ratio you choose at idle or WOT. So I would just rig it 3/4 of the way or all the way which ever you feel better at.

IMO the intake mani would be your best spot for the oil.

 

I am going to set it up to close as stock opening and closing as possible. I am working in the arm for it right not but it keeps snagging.

 

use a bike brake cable, sheath , and a screw on bullet end

less than $5 and fixed right with no snatching

( sometimes will require a light spring added to the OMP lever to return it home as the cable doesnt have the weight of a link bar )

 

Holy hell why have I not seen or heard of doing this before. Heel with that set up I should not have to do anything to the throttle arms on my carbs because there is a opening on each end that one of these cable would fit into.

 

custom GM TB and linkage



routes however you want



standard TB
( spacer plates out of view to help clear LPG install necessitate the cable )

i use a small carb return spring down at the OMP arm
hooked to a wiring tab mounted off from the timing cover lower bolt to guarantee it returns freely and instantly