Rebuilding My 930

[snowman]

Originally posted by beepbeep
Whooa, hold it there. It's not so trivial.

Just making oval hole bigger is easy, but port-matching the injector notch isn't.

to make good flange seal (in case you do a full poprt-job on the notch) or keep the notch little smaller, which will disturb injector spray-pattern once Carrera intake is bolted-on.

Question-- is the whole problem not to disturb the injector spray pattern or is there more to it? It seems that the injector is located in a "dead" area that dosen't affect the flow so any other port matching (in this specific spot) would not be overly important.

[350HP930]

I have verified that the injector angle and location is the same but I am awaiting my new carrera phenolic manifold spacers to verify this fact.

Once they are here I will post some pics of how the unmolested 930 port matches up the to carrera manifold and spacer, looking in from where the intake valve should be.

There is a chance that the notch shown in beeps pic may have been overkill since its located in an area where the injector spray pattern is still narrow.

I should have an update by the weekend if my package arrives tomorrow as it is supposed to.

[350HP930]

Ah, I almost forgot to link to my seperate balancing thread . . .

http://forums.pelicanparts.com/911-engine-rebuilding-forum/200123-930-engine-balancing-results-post1696485.html

I am also flattered to see that I now have the second most popular thread in this forum, right behind reringing alusils.

[Saintly]

Originally posted by 350HP930
I am also flattered to see that I now have the second most popular thread in this forum, right behind reringing alusils.

I don't have a 911 but i subscribed to your thread when it was mentioned elsewhere. I find it interesting and enjoy the pictures and debate over the different stages and upgrades.
I also like the DIY nature of the rebuild rather than the "i gave them $$$ and i got my car back in a month" type of process.

[350HP930]

Originally posted by Saintly
I also like the DIY nature of the rebuild rather than the "i gave them $$$ and i got my car back in a month" type of process.

LOL, why thank you.

Even if I had more money to throw at my project I would still prefer to do everything myself. Part of it is the satisfaction of being able to produce my own automotive magnum opus and the other is that it would be hard to find someone else who could put the same level of workmanship into such a project for $$$.

When I started my project and this thread I was a recently laid off engineer who was more concerned with paying my bills than getting this all done but I knew in my heart that I would eventually prevail. In addition to my employment woes I also had to deal with a divorce and defaulting on some debts. I am happy that is all now behind me and I am to the point where I am nearing the end of this phase of my porsche project. Its a nice change I must admit.

Even though my skills were a little rusty after not working as an automotive machinist and tech for almost a decade fate was certainly on my side when I landed a job at one of the best automotive machine shops in the southeast. Talk about a godsend for this kind of project.

Depending on the size of my tax refund I might actually have enough money to wrap things up soon. Once I get all my W2s I will know more for sure. My spread sheet says I am about $4K away from completion and I currenly have about $2K in the bank.

I will just cross my fingers and do my best to keep my PP bretheren updated on my trials and tribulations.

[snowman]

Its good to have people who still like to get their hands dirty.
From an ex but still quite mad rocket scientist who can't even get spell check to work on this stupid thing.

[350HP930]

I am too lazy when it comes to spell checking what I post on the web.

[beepbeep]

Originally posted by snowman
Question-- is the whole problem not to disturb the injector spray pattern or is there more to it? It seems that the injector is located in a "dead" area that dosen't affect the flow so any other port matching (in this specific spot) would not be overly important.

It all depends on injector spray-pattern. He's swapping out K-Jet injectors for EFI injectors and changing the position as well.

Different EFI injectors have different spray-patterns depending on their design. Pintle, disc, 6-hole injectors...they all have different patterns.

Easiest way to avoid trial-and-error is to install same type of injectors as OEM Carrera injectors, port the heads so they match the intake just as Carrera does and then bolt everything at same height.

If not, he could check injector pattern on the bench, note the angle and try to find out how they will spray once installed in his particular application.

Some of you might find this overly ambitious but I think it's worth doing while everything is in pieces anyway. There are cold-start, emission and some subtle power-benefits of optimizing this and manufacturers spend lot's of time/money on optimizing injector position. Fuel should be atomized as well as possible before drawn into cylinders. There is a risk of condensation if spray is directed so some of it is spraying intake walls.

[asphaltgambler]

You gotta really respect a guy who is going through a divorce, almost bankrupt, jobless and still puts his priorities in order!!

OK, ok ........got all these personal problems...but I GOTTA get my 911 freshened-up!!

YOU GO SON!!! YOU MAKE ME PROUD TO BE A MAN!!!

[350HP930]

Yeah, it always saddens me when I see tales on this board about people giving up their beloved car due to personal or financial reasons.

No matter how bad things get a man always needs a good car.

[FastDave]

I can't believe we have an "English teacher" commenting on anyone's spelling errors!

quote: "Its good to have people who still like to get their hands dirty.
From an ex but still quite mad rocket scientist who can't even get spell check to work on this stupid thing."

This is a great thread!!!

[snowman]

I ain't never been no english teacher and I was commenting on my own (in)ability to use spell check. can't youall read?

[350HP930]

Originally posted by beepbeep
Whooa, hold it there. It's not so trivial.

Just making oval hole bigger is easy, but port-matching the injector notch isn't.

Take a look:

After doing my own research I would like to post my data since it differs from the bee['s pic. Whoever did the above marker work was a bit sloppy in how they represented the FI notch. I also have a view looking right up the intake port in the direction of the injector spray direction to show how little material actually needs to be removed from the notch, which isn't much.

[beepbeep]

Well that's great news then. You might not need to deck the ports after all?

[David]

My plan is to epoxy the spacer to the head since the Carrera gasket will still not cover the stock 930 port.

[350HP930]

That gasket is so oversized I am just planning on making my own that will better seal the spacers to the head.

[dean]

I used an SC gaskets fpr under the carrera spacer.

[350HP930]

I finally had a chance to bore out one of my intake ports on the mill today. One down, five to go. At least I know what I will be up to during my lunch breaks all this week.

As the pics show my bore angle calculations were dead on the mark. For anyone who might attempt this on their own the hole is pointed 3.2 degrees towards the combustion chamber.

The new port size is now 39.5 mm.

There is still a little blending to do but the end of my headwork is near.

As the marker shows the area near the injector port will be a little narrow so I will probably add some epoxy to that area for a little extra safetey margin.

The most hair raising part of this operation is that the reamed out intake port comes within 0.15" of the valve spring seat.

So far so good at least.

[snowman]

Good info. Are you going to flow the heads? If so please post data. Tnx.

[David]

I bored mine to 40mm, not realizing the Carrera intake is really 41mm. I had to go back and do some hand work to match them.