Intake mani and dual feed side feed stock rail build

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Jmoore124
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Intake mani and dual feed side feed stock rail build

Post by Jmoore124 »

So I started putting together a intake manifold for the KA the other day. Basically aluminum sheet with stock runners. I bought a brand new IACV I will mount on the rear of the plenum and I intend to install an AN fitting on the rear to accommodate my vac manifold. The two main reasons I am building this is due to the stock design, it makes the right side of the motor difficult to get to. Making heater hoses, IACV hoses difficult to work on. I beveled the edges of the plate that I welded to the runners so that it acts as a velocity stack and calculated the volume of the plenum just over 2x the displacement of the motor (ideal from what I understand)

I am also creating a stock side feed fuel rail with dual feeds. I bought a couple fittings from Mcmaster and turned them down to fit inside of the rail. So the rail will have two AN6 fittings on either side and a single return to a remote mounted FPR. I did this to avoid replacing my 850cc side feeds with a top feed/rail setup that I can't afford for my build atm. And to get around the issue with the stock rail leaning out on the last injector at higher horsepower.

Let me know what you all think, any suggestions etc.

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Still a ways off from being complete, but ill keep it updated as I go along.
Jmoore124
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Post by Jmoore124 »

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supakat
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Post by supakat »

I have not search but do you think you may have some issues with pressure differential? Your gonna have the two feeds working against each other which could make uneven pressure on one side of the rail.

If you have proof that a setup works like this, please enlighten me.
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beercandrifter
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Post by beercandrifter »

so, wasnt this just the inherit problem of using the stock fuel rail? it cant push enough fuel after about the 800cc mark?
just curious how you came about finding that the 4th injector was leaning out or if it is just an assumption.

have seen a couple people do this on other motors, they end up welding the an fittings to the rails because they didnt fit, seems like a challenging weld. seems you did a nice job on it
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Jmoore124
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Post by Jmoore124 »

Honestly this was just an assumption, and listening to things I have heard. I have no idea if they would have actually leaned out. Just when I got to thinking about it it was not something I wanted to deal with. It seems to me like it would have been impossible to tune out, and probably would have been something I sat around scratching my head trying to figure out.

Honestly, the welds were not that difficult. I took the NPT side of the stainless AN fitting, slipped it in the lathe and cut it down to a point where it would slide in to the middle and either side of the rail. After that I just TIG'd it (no filler rod). Pretty simple stuff, but it is nice to know there is a work around other than getting a top feed rail. (or a godly expensive side feed)
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I think I actually get my stainless welds a bit too hot. But it Is solid regardless
mewantkouki
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Post by mewantkouki »

What exactly is the benefit of this..? The ability to use an adjustable fpr?
Jmoore124
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Post by Jmoore124 »

When using the stock rail in original configuration and large injectors many have claimed the last cylinder to get fuel actually will lean itself out under WOT.
Also for the use of a external fpr.
mewantkouki
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Post by mewantkouki »

What size injector are you running? I've found that side feed injectors in general are potshot. On my next build I'm going to use ID 1000cc top feeds and an aftermarket rail.
Jmoore124
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Post by Jmoore124 »

Im running 850s now. I know a few people making big power with side feed injectors. So I don't know about the 'pot shot'
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