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.

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.

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. :cool:

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. :D
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.

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.

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

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.

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!!!

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.

This is a great thread, but...
 

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!!!

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?

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.

http://anthonyrawson.com/Cars/Rebuil...omparison1.jpg

http://anthonyrawson.com/Cars/Rebuil...omparison2.jpg

http://anthonyrawson.com/Cars/Rebuil...omparison3.jpg

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

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

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

I used an SC gaskets fpr under the carrera spacer.

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.

http://forums.pelicanparts.com/uploa...1105814957.jpg

http://forums.pelicanparts.com/uploa...1105814972.jpg

http://forums.pelicanparts.com/uploa...1105814985.jpg

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

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.

Excellent thread...

Great pics.

Now that you have everything in piceces and heads in the machine shop, why not go whole nine yards (right expression? :-) and machine dual-plug holes?

If you are going to run MS & Spark, it won't cost you anything more...just extra set of plugs, cables and wastefire coils. you could even drill those holes and plug them with spark-plags, to be used later when ignition is ironed out.

good luck!

Yes, the heads will be flowed when I am done with the initial porting work and that will be well documented and posted in its own thread like my balancing work.

My manifold only measures 40.5 mm but those damn plastic spacers are 41.5 mm. That kind of pisses me off but I will do my best to line up and match everything.

I have thought about twin plugging but with flat top pistons I think its overkill. I would much rather put that money towards the flame rings I am contemplating.

I had a chance to bore another head and do a little rough clean up on the intake ports today.

http://forums.pelicanparts.com/uploa...1106019356.jpg

Don't forget to post a link to that new thread in here for the people following your work. :D

Mad scientist, thank you for your substancial contributions to this forum. Real hard data and pictures are worth their weight in gold.

Well, since everyone loves pics I took a few more today when I bored out the remaining heads. Enjoy . . .

My Super Hi-Tech Alignment System.
http://forums.pelicanparts.com/uploa...1106431550.jpg

Target Locked !
http://forums.pelicanparts.com/uploa...1106431598.jpg

Let The Carnage Begin
http://forums.pelicanparts.com/uploa...1106431657.jpg

I Could Never Imagine Removing All This Material With A Die Grinder
http://forums.pelicanparts.com/uploa...1106431732.jpg

And a shot of all the bored out heads . . .
http://forums.pelicanparts.com/uploa...1106431803.jpg

Some of us did exactly that..

http://forums.pelicanparts.com/uploa...1106616456.jpg

How'd ya clamp the cylinder head down to the table, 350HP930?
Jurgen

I made a jig that bolted to the head that held it at the proper angle.

After that it was just a matter of centering the boring tool and making a 1.55" deep hole.

As the pics show it worked out perfectly. I have finished most of the detailed porting work so its almost time for me to post some more pics and begin flow testing my heads.

Your head flows should be much more consistant than ones done with a die grinder, although the difference with a die grinder between cylinders may only ammount to something on the order of 0.5% or less in HP variation. Nice job.

I too think that the consistancy of my intake bores and valve chamber areas should make for some very even flows. Though my porting work is not done yet as the pics below show all I have really had to do is blend the transition areas and remove some casting roughness.

I imagine I will have a bit of clean up work to do to the carrera manifold to even up all the cylinder flows though.

http://forums.pelicanparts.com/uploa...1107137100.jpg

http://forums.pelicanparts.com/uploa...1107137139.jpg

Very nice.

Question- on the top of the top photo is the short side radius. Is this smoothed and round as well? The reason I am asking is this is the place where I find most of the improvement in head flow. Do you find the same thing?

To clarify, if the port size is not increased I have found something like 95% of the flow improvement is just from smoothing out the short side radius. This increase is usually almost 20% when the radius is sharp. I understand that making the port bigger will also increase the maximum port capabillity, the flow will be larger but if the short side radius is still sharp you will be about 20 % below achievable flow.

Yes, smooth radiuses all the way around, especially on the short side.

My education in fluid dynamics has me paying a lot of attention to preventing 'detached flows'.

What I would give to have access to a decent digitiser and a good CFD program.

A good CFD program would be very nice, especially if it can be had for next to nothing. This should be possible. I was an independant consultant, purchased a top of the line Agelent tech. Microwave simulation program, now selling for about $110K plus. Once I retired I could not give it away. There must be the same sort of thing available on the CFD market.


I have to add this info somewhere so here it is. On the Caddy Northstar engine (1999) I am rebuilding. The piston rings are very very thin as they should be. The valves have half the sealing surface width the old engines had, eg about 0.025" on intakes and 0.030" on exhaust. The valve margins are next to nothing ie 1/10 what they were. The piston clearence is almost nothing at 0.001", the weight balance is all withing one gram. The head flows will support twice the advertized HP without any porting, ie just change out the cams. That means over 500HP with just a cam change. ( of course carbs or injectors must be compatible with the extra power). That folks is out of a 4.6L v8. The most amazing thing is that its all aluiminum, therefore very light. That means it can power A PORSCHE!!! I am opposed to 350 conversions to a Porsche, but this Caddy engine, being light enough and powerfull enough,is an other matter. I am seriously thinking about it.

There are lots of good CFD products out there, but they are very pricey. I could write my own program for purely laminar flows but I am interested in what could be determined by a program that would model the non linear stuff that I no longer have the zen to tackle myself.

Great thread. I just dropped the motor and tranny on my 930 to replace the clutch and will be ripping things apart for at least new gaskets, lines, possibly a turbo, etc. Thanks for such detail.

http://www.gasholes.com/smf/gallery/...30cleanup1.jpg

Edited to insert pic. I doubt mine will compare to this, so I promise to not post anymore here other than for questions.

Ugh, this was certainly the weekend for some messy work.

Now that the engine is about ready to come together I decided it was finally time to start prepping the engine compartment.

It was a big reminder of what an oily and dirty mess everything was before this whole project got started.

I spent a good chuck of saturday removing all the stuff like the A/C compresor, condensor, lines, relay box, oil breather and some trim in the tail that blocked off the grill slats that were not directly above the old intercooler and condensor.

Oh yeah, there were also all the old dry rotted rubber engine tin gaskets and the foam that was still hanging around from the insulation pad and pass through area for the plumbing and electrical stuff that needed to be removed too.

I still have a lot of cleaning and painting work to do, but at least all the big chunks are gone.

As usual I have pics of the progress . . .

It didn't take long for debris to build up under my work area.
http://forums.pelicanparts.com/uploa...1107755045.jpg

A better view of the carnage
http://forums.pelicanparts.com/uploa...1107755122.jpg

A lot of oil grime to go around too.
http://forums.pelicanparts.com/uploa...1107755213.jpg

And my pile of stuff I won't be using again.
http://forums.pelicanparts.com/uploa...1107755282.jpg

Great pictures.

When youall get to the alignment. let us know the final numbers. I use -1.25 degrees camber in front, and -2.5 degrees in the rear of my race car. Toe equal to zero both front and back.

When I pulled the engine in my 930, I got rid of that sound insulation above the engine. I like the way it sounds without it. And it gives better access inside the engine compartment.

-Juan