Warped Injector Housings

[LGAFF]

A few years ago I took some prototype injector housings and siamesed the runner. The walls were much thinner than stock and I Epoxied them were it was thin. In Prep for my new powdercoat I had them sandblasted and they turned into swiss cheese. I was just going to go back with Epoxy, but the PC guy talked me into "doing it right"....by TIG welding

Alittle welding and now they are warped pretty bad, the gasket seems to make up for it and they seem to straighten when they are bolted down. However, not sure I would trust that the gasket is compressing and how they might react to heating and cooling cycle. Biggest fear is coolant getting in the intake....

guess its time to get a set of injector housings from the basement and start porting

[mike100]

How warped are they? If you have a machine shop deck them and remove say... .010-.015, would they sit flat? you may have to recheck the geometry of the "concentricness" of the ports, but I figure it would be less of a mess thant the misalignment of intake manifolds on small blocks after machining heads for more compression

[LGAFF]

probably off by 1mm or more...toast. Only thing I can think of is to heat it up to 500 for a few hours and then bolt it down to see if it gets with tolernances of milling

[cvette98pacecar]

Lee, next time make a jig and bolt the IH on both sides so the flanges cant warp. Take the set you have to a machine shop and have them deck both flanges. should not cost more than a C note.

[Paul Workman]

DITTOS ON THE DECKING! A mm is a little more than 0.04", but unlike a head where valves are involved, "40 tho" isn't a big deal. However slight, the plenum my be slightly tilted, (one side shorter than the other) unless you deck BOTH flanges...Just a thought.

[LGAFF]

I am going to take it to my machine shop. Using heat and force/pressure is a common way to straighten a head. We did have them on a jig of 1/4 steel, but it still managed to warp

[LGAFF]

Well, I tried checking the gasket compression with a new set of gaskets...could not see a mark...but looks like that was because they are new. Took some Gorilla tape and put it down, the Inj Hs are leaving deep marks on the tape.....so Gorilla Tape is 1/4 the thickness of Jerrys Gaskets.....I think I am good....any thoughts.

I believe the warp is in the center of the IH, so if you tighten down one side of the IH is amplifies the warp

I am think get them milled and ready to go

[cvette98pacecar]

Well, I tried checking the gasket compression with a new set of gaskets...could not see a mark...but looks like that was because they are new. Took some Gorilla tape and put it down, the Inj Hs are leaving deep marks on the tape.....so Gorilla Tape is 1/4 the thickness of Jerrys Gaskets.....I think I am good....any thoughts.

I believe the warp is in the center of the IH, so if you tighten down one side of the IH is amplifies the warp

I am think get them milled and ready to go

Lee, If you are anything like me they will be fine until you are 300 miles away from home. I would get them shaved and be done with it.

[LGAFF]

I am going to do that, but was ready to just toss them, still debating one whether to use them or do another set....

[LGAFF]

Injector housing bolts on the left side only...Gap is .070
http://i134.photobucket.com/albums/q115/lgaff/DSCN5724.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5724.jpg.html)

Installing the five center bolts the gap is .022

http://i134.photobucket.com/albums/q115/lgaff/DSCN5720.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5720.jpg.html)

Once the end bolts are installed the gap drops to .007
http://i134.photobucket.com/albums/q115/lgaff/DSCN5721.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5721.jpg.html)

[LGAFF]

Well I measured a gap of .022....looks like they were milled .025.....will see what the plenum fit is like

[LGAFF]

.016 gap in the inside of one side of the plenum to IH....I think I can live with that and a.060 gasket. Thoughts?

[mike100]

.016 gap in the inside of one side of the plenum to IH....I think I can live with that and a.060 gasket. Thoughts?

Depends where the distortion is. These things are somewhat prone to oil weapage of the PCV vent passages as the gasket tends to saturate in time and squeeze out the edge.

[LGAFF]

Plenum to IH...the IH were machined top and bottom....no PCV issues with the plenum to IH....that's the IH to the head.

I would think with .016 gap......and a.060 gasket....I would have enough gasket crush to seal.

[mike100]

ahh- I missed that detail... if it won't leak air or water, why not?

[LGAFF]

Ugly day, putting the 90 back together...used 2 gaskets between the plenum and the IH. Everything went well but the first two bolts were off by about .5mm, maybe alittle less. had to grid the bolt hole to get the plenum on.

Not to sure this is going to work

[LGAFF]

Its up and running, 900rpm idle...