getting ready to port my l92 intake manifold and i was wondering if someone could give me a bit of direction. I am going to port match the runners to the heads but i am a bit lost at what i should do inside the plenum.

afraid to grind on that big bump with a hole in it towards the rear of the plenum. I obviously dont know all the dynamics of the airflow so i was wondering if someone could help me out. I dont want to end up with something worse than i started with.

i was planning to enlarge the hole in the bump and narrow down the post on top of it. sound like a good idea?

of course im also going to open up the inlet a little, but what else is there i can do?

 

I have no experience porting these, but it seems as if the guys that were getting decent numbers out of them were cutting them apart to port them and then plastic welding them back together.

 

I know that would be the best way to do it, but i am against cutting it apart and epoxying it back together because i really want to just keep it simple.

So id like to port whatever i can reach inside there

 

havnt heard of alot of ppl proting these i know people make good power with ls2s ported

 

The "simple" solution is to buy a F.A.S.T LSX intake manifold . . .

The "inexpensive" solution is to try to port you L92 manifold . . .

The "compromise" solution is to send your manifold out to have it professionally ported.

 

Without cutting it open ,you can not get any substantial gains. But you can open up the throat and port the runners tho. As far as the hole at the end of the log , I would leave it alone, unless your going to open it up and try to do a radical port job. Peakspeedshop a sponsor on here does good work, take a look a some of their pictures and you will get an idea of the work involved to get good gains from porting. They earn every dollar they charge, its takes proper tools and alot of time to do one properly.

 

thanks that was what i was looking for.

I have been looking at peak's pictures, if i planned to stay NA i would definetly send it to them but the motor will be getting a whipple soon so it would kind of be a waste for me to send it out or spend the time to hack it open and risk it not sealing properly.

I think I will just port the runners and open up the inlet a bit, keep it simple and easy.

So you wouldnt enlarge that hole at the end at all? in peak speedshop's diagram of the airflow they show how that piece at the end of the log is restricting flow. So i have been wondering if it would be beneficial to enlarge the hole a bit to allow more air to flow past that huge bump.

Or is there any way that enlarging that hole would hurt flow? Im afraid to mess with it

 

If your trying to get more airflow to the back cylinders, your not going to get it by enlarging the hole. Peakspeedshop has got more flow because they have removed the roof of the log, which can only be done by opening up the intake. The area behind the hole is a dead area. I know its difficult to tell from the pics, but if you saw one opened up you would understand better. Leave the hole alone.

 

thanks, will just do a port match and open up the runners as far in as i can reach. the inlet will be smoothed out as well

 

that is what i did to an l92 intake i had. i was happy with my work . but before i installed, i came across on a deal on a ls2portworks ported l92 intake and jumped on it. love it even though i have never dynoed my truck, it runs very very good

 

Did you do your ported intake swap along with other mods or just the intake buy itself. The problem with comparing, is alot of guys do other mods along with intake so its hard to tell if or how much a ported intake helps. If it was just a intake swap tell us if there was a seat of the pants difference in performance. Most of those Ls2 portworks are good for 10hp gain or more.

 

I hear ya,
I will not have a useful comparison at all. The motor is getting stroked and cammed at the same time. the manifold was already off so i decided i may as well port it.

I wish i could have done it on it's own to know if it really made it run any better.

If i can get half of the gains from a professionally ported intake i would be very happy. il bet it would be worth 5-8 hp or so, especially on a stroked l92.

It is practically free horsepower too, just the time it takes me mess around for a few hours with a dremel with flexshaft and the cost of a few sanding rolls.

 

I would not expect that much of a gain. How much do you plan on removing from the throat area. PM me if you want any tips on method and tools I would use. Post up pics when your done.