LD28 intake input

[81Z]

im looking for some input on my LD28 intake swap, its going on a P79 head. when laying the stock intake gasket on the LD28 intake, the stock injector hole slightly sticks past the intake flange witch would create a vacuum leak, i decided their are a couple options to correct this

 

1. weld on some extra material to the intake flange

2. move the intake slightly up, this would involve a lot more porting and would give a oval shape to the head and intake

3.  get an aluminum dowel and weld it into the head then port it to match still a lot of porting.

 

any input or wisdom? what would you do?

 

 

[81Z]

 

[Xnke]

I would cut the EFI flange off and weld it onto the runners, or move the injectors up to the bend in the runners and shoot straight down the tube.

[81Z]

i plan on moving the injectors closer to the plenum. i just cant decide the best way to make the ld28 flange cover the existing injector hole on the head.

[Xnke]

Weld it up and have it machined flat. If you aren't doing aluminum welding, it'll be less than cheap.

 

Is that the one from ebay last week?

[81Z]

I got it off eBay last week. I will be doing my own welding so thats not a problem. Your saying weld up the head?

[DAW]

Consider an L24 or L26 gasket (no injector cutouts).Trim open the intake port holes of the gasket if needed, to match the intake/head.

DAW

[DAW]

The bolt holes on the L28 gasket will be larger so use a leather punch or something to enlarge them.............but wait,

USE a LD28 intake manifold gasket!

(unless you are using a round-port head) I didn't notice that detail.

 

I built a hybrid LD28 bottom/L28E engine (opened the 10mm holes in the gas head up to 12mm and used secret outsourced head bolts/washers to pull it off).........the point is that I reused the old LD28 head gasket! There are different factory head gaskets fitted to the LD28 depending on deck ht variables, choice of c.r., etc. They are differentiated by the number of notches the factory put into the outer edge of the gasket up toward the pass side front of the head iirc.

 

The LD28 bore is only 84.5mm, so I relief eye-browed the top edge of each cyl bore where the exhaust valve would have collided (it would also be a barn door to flow without them).

 

I have used old gaskets so many times. I use the Permatex motorcycle grey goo on my 510 because I take manifold variations on and off of it a lot. Who knows how old that intake manifold gasket might be?

Cheers

Edited January 21, 2014 by DAW

[Xnke]

I'm pretty sure using the LD gasket isn't going to fix the problem; he'll need to either add material to the flange of the LD manifold (easiest way) Or weld up the gaps where the injector ports are machined. The gasket won't help if there is no metal to back it up.

 

However, since it does come with larger inlet holes, a little work with a razor knife and you can probably get a nice fitting carbon composite gasket  out of the deal!