Hey guys. This is my first time posting on this forum, but I've been absorbing some great information from it for years. Anyway, I was searching for information on how to port the l92 intake manifold, but could only come up with very limited information, so I decided to jump in with both feet on an extra l92 intake manifold that I may or may not end up using depending on whether I can make the inner support work and get it to seal effectively. I have read that this intake in stock form outperforms the ls3 intake, and in radically ported form will even gain additional power.
Here's what I started with.


I used a sawzall and a dremel tool to get the top off. Plan on this taking at least two hours. The inner posts were a huge pain, but a longer sawzall blade would have saved a ton of time.


Sorry if these pics are huge. Again, this is my first post and I don't know what to expect.

Thank you dremel tool.

Here it is after some sanding. This is not a radical porting job. I don't think that my stock lq4 bottom end/l92 top end (stock unported heads) needs anything too radical. I just wanted to open up the flow for some good top end while leaving the long intake runners for good bottom end torque.


I went out to my garage looking for whatever pieces of garbage that I could find to make an inside support out of. I once saw a youtube video where a guy had a ported l92 intake where the inside was unsupported and it looked like a big black lung that would expand and contract with the engine's revs. Anyway, this is just a long bolt welded to another piece of junk that is bolted to a piece of scrap metal that I cut out with a hole saw.



I used my dremel tool to cut out an insert for the bottom of the support rod to drop into. I will most likely epoxy it as well so it stays put when it's under the stressful conditions that occur inside of an intake manifold.


And this brings me up to where I am now. I hope that this info. has been helpful to anyone looking to do this job themselves. I am also looking for suggestions as the best epoxy to use to put this thing back together. I will be cleaning everything up and smoothing everything out before I put the final seal on it, but at this point I have no idea what I'm going to use to seal it up. Also, any thoughts on whether my "support beam" will do the job? Thanks in advance for any suggestions.

 

I did something similar and plastic welded it back together and then finished it up with PL premium which is paint able.

 

Will plastic welding hold up better than epoxy? How is yours holding up?

 

plastic welding will absolutely work better than epoxy. the only thing is making sure you have the right plastic to weld with. you need the same type of plastic the manifold is made from so if you have an extra intake or piece of one that would work best

 

Thanks for the tips. I'm glad I waited before trying to epoxy this bad boy back together.

 

Do you have a L92 manifold you would like to get rid of?good luck with the project.

 

I will be starting a trailblazer i6 to 6.0 swap soon. The ly6 engine that I bought for the swap has a stock one, but I'm going to hold onto it until I'm sure that the ported one is going to work without issues. I will let you know if I want to get rid of one. By the way, I just found out that the one that I ported came with the flex fuel 50# injectors. Bonus By the way, I was originally going to throw my lq4/l92 engine into the trailblazer, but that is now going into my firebird ws6, the ly6 is now slated for the trailblazer.