LLY Intake plenum

[James Hess]

Hey yall i was just wondering i know there are a few different things you could call an intake on these engines but my quesiton is this, on these engines is there an actuall intake plenum with individual runners that you can have ported and polished. I figure there has to be a plenum for it to work so could it be ported and polished or has anyone done that?

Also along with that question could the seaperate little pieces and parts have the same treatment or no. Just trying to get some info to if it could be done(trying to get as much uninterrupted smooth airflow as possible).

[hondarider552]

This a LBZ air intake manifold and Y bridge. A LLY is a little bit different from the Y bride to the intercooler, but you get the idea.

[neversatisfied]

I don't know of much that you could port on it. I think your best bet for an lly would be to put the lbz runners and bridge on for a little more flow.

[ripmf666]

I was thinking of a sheet metal set to work on both and a sheet metal bridge.I just need to get a set of junk heads to work with,I have a extra block here.

[James Hess]

Brian could you get a pic of the underside of the runners, id imagine they should be individual so why couldnt ya take that set up and have the pipes and then the runners proted and polished. is there just no room or not enough material?

Also is the LBZ setup a direct fit for the LLY head wise?

[blksmok]

I understand the benefits of porting and polishing a normally aspirated intake, but on a turbo/super charged application where the intake is pressurized, would you get the same benefits?

[neversatisfied]

Brian could you get a pic of the underside of the runners, id imagine they should be individual so why couldnt ya take that set up and have the pipes and then the runners proted and polished. is there just no room or not enough material?

Also is the LBZ setup a direct fit for the LLY head wise?

It is not individual. It's all wide open.

The LBZ bill bolt right up to the LLY or LB7 heads.

[neversatisfied]

1524

[James Hess]

Dave if i am correct any and all airflow will always benifit from a smoother flow that causes less restriction in a sense"friction" from the rough cast on the inside i could be wrong though.

On a NA set up you will definatly notice a change like this and on a boosted set up it will still benifit from it as the air is moving along easier IMO again i cold be wrong. i just figure the same concept applies here as it would in any airflow situation NA or boosted.

Well that sucks about the underside :mad: any idea why it is set up that way? Wouldnt ya figure it would give better efficiency and performance from less turbulant air with individual runners? i would think so anyway, talk about a way to save money in production.

What are your thoughts.

[neversatisfied]

I think not enough space is the main reason it is setup how it is.

[hondarider552]

2 intake manifolds will be cheaper to produce than 8 individual runners.

[ripmf666]

If we could have are heads made like the 4.5 dmax that would help us alot.exhaust on top and intake on the outside.Mount twins in the valley.

[James Hess]

HAHA i was talking about individual runners in the intake(like a gasser intake) not 8 individual runners by them selves.

I know that Banks offers an intake that is set up with the 2 inlets and then has the individual runners but that is alot of work to route everything and its alot of money.

Anyway i was jut curious as to if it could be ported and polished every little bit helps.

[OTHRGRL]

Another main reason that the intake manifolds/runners/plenums are not individual runners is that we have direct injection. In a gas motor you are adding the fuel either through a carb or TBI and then seperating the mixture into 8 runners so it can atomize on the way into each intake port, or you have an injector in each intake runner (multi-port injection). On a direct injection engine you are only trying to get air in the intake ports so as long as there is air available when the valve opens it doesn't matter if the intake runners aren't seperated.

I do agree that every little bit helps and porting and polishing all parts that you can will only help things (even if not by much). I wouldn't recommend tearing into your motor to get the runners off for a port-polish job, but if you are building a motor and have the time why not. I rounded off all the corners in my LBZ runners then smoothed out the castings and polished them a little inside and out. I'm also running stage 2 heads.

[hondarider552]

James are you going to port and polish your intake runners?

[James Hess]

At the moment i am not tearing into te motor but i will keep things mum for now, that is the reason i was asking cause while everything was apart why couldnt i just have them PNP'd and get a little more flow.

I see what your saying about the gasser compared to ours and it makes sense seeing as how its a boosted setup so there is constant pressure on the valves from the air trying to get in. for some reason i was thinking that it wasnt a very efficient setup cause of the air being turbulant in there but if its being forced in it doesnt really matter that close to the valve anyway.

If it had an intake that was set up in that way yes i would have tried to have it PNP'd but since its not ill probly just go with the LBZ set up and have everything but the plenums PNP'd if possible just to add that little extra ya know.

[MAXLLY]

hey James.

When you take it all apart you'll see what its all about. IMO- the port and polish is high hanging fruit... alot of work for a very small benefit. Take a look at all the kinks, restrictions and small ports. Get rid of them and part throttle response is much improved.

James