I am in the process of an engine swap and have it down to the short block. In it's current state, it would be real easy to convert the OMP to use a dedicated 2-cycle feed. I've read what's out there on the subject, mainly on the FC forum, that range from deleting the OMP entirely to leaving it alone. I’m leaning towards keeping the OMP (along with pre-mixing) for added protection, but keeping it stock due to the cost and hassle to convert it to use 2-cycle oil and the fact that it will be primarily tracked so I’m thinking carbon buildup shouldn’t be a problem (the high RPMs and heat will burn off what little amount of oil that's injected). Are there any thoughts on this?

Car is a '94 FD BTW

Thanks, Tom

 

I run the omp with 2-cycle oil. I figured I didn't want any engine oil to get into the engine. I also pre-mix as well. I do 1 oz a gallon but probably is a little too much. I am going to cut it back to .5oz or so per gallon. Time will tell if what I am doing will work. I did change my plugs after 4,500 miles or so and the plugs had oil on the threads of them showing a nice amount of oil in there, hence why I am cutting it back a little. Car runs great, idles great, and I haven't fouled a plug.

I am running redline synthetic 2-cycle race oil.

 

Do you have a Mikuni OMP or USDM?

 

usdm

 

Any fitment issues? I've read that's the problem with the USDM OMP and stock twins.

 

After some more research, there doesn't look like there's any simple solution.

Stock: Simple, but may lead to carbon build up

Premix (OMP Delete): Complicated. Requires modification to the OMP in order to not send oil nor fault signals to the ECU

OMP Conversion: Compicated/Expensive. Req adaptor to feed 2-cycle oil as well as oil supply tank.

At first, i was thinking of leaving it stock, then i read multiple posts about carbon build up, so then I thought to delete it entirely, the i read about ECU issues, so right now I'm leaning towards installing an adaptor and feed tank, but then again i'll probably be upgrading my ECU soon so i could go ahead and delete the OMP, but not before the engine goes back in where it will be a pain to delete it.

Why do i subject myself to this mental (and financial) torture. I should just sell it and buy a Mustang (or any other domestic car that's simple and cheap to operate)

But that's rationale thinking

 

I have a single turbo, I have an omp adaptor and separate tank.


you can run a little pre-mix, keep the OMP and it might break up some of the carbon build up. You can also do some water injection treatments every once in a while (when you need to change your oil) to burn off some of the carbon in the engine.

 

That's the course i'm thinking. Anyone out there with stock cats running 2-cycle thru their OMP?

I'm a little leary about running hose for the turbo oil return which is what's req'd to fit the OMP adaptor with stock turbos

 

This is way I did mine. Make the shaft bore as tight as possible (light press fit).


A Polaris snowmobile tanks works great for a tank.... with breather and low level float.


Barry

 

That looks like a great alternative to the RA adaptor. It looks like you fab'd a block off plate for the oil feed on the block side and tapped a hose connector for the 2-cycle feed.

Thanks for the tip!

 

Definitely liking the end result, it's tidy and well sorted. Now you got me thinking about doing this to my 20B

 

This is what 50k miles looks like. The soft soft carbon wipes off with your finger or rag.

 

How often do you need to fill that tank? It looks huge

 

It's only about a quart. That is about 5 fuel tank fills or so.

I drove to Deals Gap from New Orleans and back without a refill.

The low-light is on the column top and gives a second heads-up display on the face of the tach.

Barry