Intake port design / manufacturing optimization.

Yeah, I do like that about the LS motors, Chevy dropped that shared port thing.


Unfortunately, all that is available for the 4.3 are just factory Vortec heads. I forgot the flow rate, but it boils down to a max of about 50hp per cylinder with stock heads N/A. Not too bad, but that exhaust is definitely a restriction. I just look at the glass half full and say it saves my transmission some heart ache :D

FWIW my cam is just large enough (212 duration at 450 lift) to give me optimal air flow without being a burden on excessive lift. I should be able to hit a good 7k RPM and still make power.

OOOH boy the shiz is getting real.

I got my block back from the machine shop. Just need pistons .060 over; this ain't no 4.3 its a 4.4. lol I round up.


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Of course rustoleum black.

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AND I added a second pane to the back glass. I was not satisfied with the sound/heat deadening that a single 1/4" piece of plexiglass can provide. I also put about 15 pounds of sound deadener to the firewall under the carpet.

I also re-did the window tint. While the pre-cut stuff is easy to use; it was short. Like half a cm short on the bottom so when the window closed all the way (door closed) there was a strip of non tint on the bottom.



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Very nice. I guess nothing really can go wrong on such a classic OHV V6. Unless you blow it with a big charger ;) Btw, what happened to the original motor?

I wouldn't say the M90 is too big. Its no Detroit blower after all. I'm hopping to get about 6 or 7 pounds of pressure.

No idea about the original motor. Guy I bought it from said that it was an IMS failure, but IDK about that guy, same guy used a rag to adjust the headlight... I honestly didn't really care enough to check it.

Pistons should be pressed in tomorrow. :D

The Box is all like "Please be gentle good sir" and that Chevy is like "HELL NA; I'MA RAM IT DOWN!"


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But seriously I'm so close gotta get longer push rods and figure out a correct belt length... then its just a matter of sliding this bad boy in that purty gurl.

O M G... Everybody talks up Kennedy engineering.. Oh man Kennedy is the bomb digity. Oh Kennedy makes some sharp shiz. BUT Dagnabit (I'm using softer words) I was gonna do some real hatting on Kennedy the other night.

I went to put in my trans on the KEP adaptor plate. I had previously (as seen on this thread) mocked the engine and trans up in the car. No problems right??? But when I went to put the trans back in for real this time I ran into a big snafu. One of the bellhousing bolts for the SBC is in the same spot as the Porsche bellhousing. I know thats not necessarily KEP's fault, but at least they could have not made a hole there or made some kind of note about it. SO I took the trans back out (what a pain). Cut a chunk out of the Porsche bellhousing.

THE Next attempt at re-installing the trans... I had it all bolted up with all the bellhousing bolts in place. And I went to put the starter motor in. CLUNK :confused: I hit the Porsche bellhousing. Apparently you have to cut out another chunk of the Porsche bellhousing to get their starter to fit. OH man I was cursing when I took the trans back out.


ANYWHO, alls well that ends well. I cut my chunks out and re-installed the trans.


http://986forum.com/forums/uploads02...1602557650.jpg

^^^ Thats the area in question that anyone following me (I doubt there are those as crazy as I***) can use as reference on where to cut.


Here is the old girl sitting all pretty in that engine bay.... I just wanna cry its so beautiful.

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So I asked on FB and someone politely responded to my inquiry, but I'm retarded and even more so when it comes to electricity. What color wires, or which pins do I need to make wires go to to make this sensor work. I feel like this is a VSS which is something I want and I accidently hacked it off. Does anybody have a wiring diagram I can follow the VSS wire to a source or know off the top of their heads which pin on what I need to make a wire to make this work?



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***Or just touched in the head??

Not sure if that helps you any way, but on my car this connector is blank, wasn`t used and capped off. The only cable that comes from the tranny is the reverse gear switch. Perhaps it`s optional and the speed signal for the speedometer is coming from the ABS sensors?

The connectors on the trans is/are either the neutral safety switch, and/or the reverse lights switch. The speed comes off the ABS reluctor on the hubs.


Badass project. I love the supercharger sticking up. I can't wait to hear it shriek.

I guess you guys are right. Its not like me to just toss out a connector; especially not one that came off the trans.

Shriek it will, soon enough.

I got all the coolant things sorted. I have the coolant temp sender in the heads. I don't know what kinda temps thats gonna read; I might move it to the intake manifold as thats the OE location on the Chevy truck.

Looks like I'm just held up by a clutch slave cylinder. Then I just have to re-assemble the exhaust, drop the car off the jack stands, and wire it up.

It sounds good... Just like a well muffled truck. Just what I wanted. If you're in a parking lot and I'm idling you'd be looking for the S10. LOL

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I did unfortunately blow out like all of my intake manifold gaskets with backfire... Might have something to do with my nitwit plug wiring, but that gives me time to make some new ones. Also, gives me some time to trim the UIM down a little to allow for better timing control (the big distributer can't do a full 360).

All the wiring is done; just have to wrap it and tuck it. To give a tentative timeline I'd say a week or two and I'll be on the ground ready to tune the old edelbrock. :D

Wow, you are not wasting your time for sure. Post a video if you have one, looking forward to seeing how it runs! :cheers:

What`s that gauge on the charger? For measuring boost pressure?

Its just an oil pressure gauge. I have the Porsche low oil pressure light hooked up for the dash, but I knida needed something to "plug the hole". Figured a gauge would be nice. I was gonna put it facing forward so I could see it in my rear view mirror, but the tint is so dark.

You could use an MSD distributor like the link below which would give more clearance and a timing box which would improve performance and look really good doing it.

https://www.holley.com/products/ignition/distributors/chevrolet/parts/8597

I got a skinny one... But I kinda LOVE the clean look of the single wire distributer. I mean the 12+ wire hides under the lip in the back so you can't see it; then the 6 plug wires just come out. SUPER clean.

Its just a little grinding anyways. ;)

I found my coolant leak; dunno if I mentioned that. Apparently I broke some kind of outlet or something on the overflow reservoir. Well it isn't used in my application anyway so I sealed it off. :D


With proper wiring it fires up every time, just as a SBC should. I'm tickled pink every time I fire it up. But cause I destroyed the adaptor plate gasket it doesn't run for long. I'm gonna have to take the SC off and re-make the gaskets.

As soon as Amazon delivers my super cool Mr. Gasket heavy duty gasket paper I'll be able to let it idle and play "find a wire" with the tachometer. Figure thats the simplest way to figure out how to get the tac working. Just strip the wires from the harness and plug in the tac signal.


I can't get a video to upload here... IDK why. Maybe I can try a link from FB?? oh well.

Careful. I cooked a Chevy diesel truck tac I got at auction doing it that way.

I can't think of any other way to get tac signal to the gauge cluster. Like every tac information out there is how to put a silly aftermarket tachometer in a car... nobody wants to use the oem tachometer with an aftermarket engine.

I got the tac to blip once when I was testing the wires coming out of the DME. So I figured one of them if energized will make the tachometer move as it should. After all I have 6 pulses for every 360 degrees... just like an H6. ;)

I grabbed a wire with stronger output than my tac could handle.

Ah, I see. Na, I am trying to get the tac signal from the distributer and send it to the Porsche gauge cluster. I would hope that the signal from the GM distributer is pretty light, but IDK.

When I was testing the wires a few months ago some of them, when put to ground through the multimeter (just testing for voltage) would give a blip on the tacho. ME THINKS that means if I give some of those wires a blip from a tac signal off the distributer they will make the little Porsche tac come to life.

This is what happens when you have the plug wires in the wrong spot and your engine says "CHECK YOUR TIMING" and you are like "F YOU I'm gonna pour more gas in the carb". Oh well I really shoulda clear coated that adaptor plate anyway. :D

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And I picked up a piece of garbage on the side of the road today... then I put it on my car.

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Well, I was thinking that air, being a fluid, would find the vacancy in the engine bay of my car the path of least resistance... then slap a Z-art top over that vacancy and I'll get all kinds of rumblings that I don't want. SO I wanted to make a belly pan of sorts (to keep that naughty air going out the back of the car). I found a washer machine on the side of the road near my house and I picked it up. Fits pretty well, I just need to do some trimming and paint. BUT I think its gonna do well back there. It fits under the OEM plastic trans tunnel (??) panel; so I don't think any excessive air is gonna really find its way into the engine bay.

BUT at the end of the day I know its just gonna look like I have a washer machine under my car. ROTFLMAO :D :D :D

https://www.facebook.com/james.dallis/videos/10158000595343732


Dunno if that will work for you guys... :rolleyes:

She's on the ground and I charged up the A/C. Now its just a matter of fixing a 2007 Mitsubishi Eclipse before I can back the boxsterado out of the garage. My wife's car warped the head and is currently blocking me in; gotta fix that first.

http://986forum.com/forums/uploads02...1604353892.jpg

It looks so mean when its off the jack stands. :D

Yeah, looks sharp! I loved the belly pan solution, very genuine :D

Further in the saga of LISTEN TO WHAT YOUR ENGINE IS SAYING. LOL

Yeah, roots blowers don't allow for backflowing of gasses. Apparently I've been running on 5 cylinders ever since I first started the engine. LOL

I'm not mad, I'm actually impressed. That push rod made it through a rocker. :D

Oh well. In about an hour and a half I had both the heads off stripped and I'd ordered new headgaskets, rockers, and lifters. God I love this engine in this car, its like insanely easy to work on. Everything is so easy to fix and right there. Imagine having an engine on a permanent engine stand with 2 feet of room to work on either end; that's a SBC in a Porsche. :D



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Ahhhh yeeeeah; She moves. BUT got some questions...

The DME apparently does NOT like this situation. The A/C doesn't click on because the computer doesn't think the engine is running (oh boy its running LOL). So I have to hard wire strait from the climate control box a wire to the A/C clutch. Does anybody here know off the top of their heads which wire kicks the A/C on?


Also, cause the computer is not getting all the info the cooling fans aren't coming on... Thats an easy enough solution. I'm just gonna get a thermo switch and hard wire them. Not really looking for an answer here; just sharing :D


And third problem. The Porsche designers didn't make the throttle cable long enough for an edelbrock carb. WHAT WERE THEY THINKING???!! LOL



Other than those issues... its fun. Just fun to be out of the garage finally. Even though I'm happiest when in the garage. :D

For the A/C: there are at least two points where you can hotwire the system: the A/C pump relay, and the A/C control unit. Based on the circuit diagram probably you can trick the control unit such that it thinks the engine is running. Do you have the Bentley service manual? I`m uploading the respective diagram here, just in case, I hope that`s allowed:

http://986forum.com/forums/uploads02/ac21605071626.jpg
http://986forum.com/forums/uploads02/ac11605071644.jpg

Hope that helps.

Hmm.. Looks like it got resized, I guess you can`t see the text. I can send it to you in the original size, that`s readable, lmk if you need it.

Got it.

I think I'm gonna try giving the crank angle sensor some voltage from the tach wire. I'm hoping that might trick the computer to think that the engine is running. I think that might cure what ails me.

If not I guess I've gotta wire stuff up. :(

Last image dump.. The body isn't gonna change much at this point so picture viewers can sign off now. :D

I have the "tuning top" on the car right now. It makes it soooooo much easier to make carb/timing or other tuning changes when the hatch isn't on the car.

OK sitrep I have cooling fans when the engine gets up to temp. The problem is the fans cool off the radiators... and the radiators are 2 meters from the sensor. Maybe some day in the future I'll wire up an electric water pump to turn on when the fans do. That way if I shut the car down the fans won't run FOREVER. ATM I wired them to turn off when key is in the off position.

There is NO power to the relay 2 box. I'm gonna try to hot wire the relay 2 box tomorrow. That might give me A/C voltage.

As for the tac... I'm still up in the air. I think I might honestly just get a Porsche CAS and glue a picup sensor to my flywheel. Kind of a jerry rig situation, but who cares. :rolleyes:




Anyways, she is lookin suuuuuwweeeeeet. [You're supposed to read that with a good southern inflection]


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PS: yeah, I know that right fender is fubar... the door is questionable.

The propane diffuser fits. :D

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Too much compression... too much boost... Too much timing... not enough ring gap... not enough fuel...

Muy muy mallo...

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Its all good though. I sorta clocked myself working on the boxsterado this time. It took all of 4 hours to get from running engine to pistons out. Granted I am a "professional" mechanic, but even by my standards thats a pretty easy engine to work on.

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The washer machine looks good though :D

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Well lesson learned; I got some deep dish pistons on order and I said to hell with it and ordered some Eagle H beam rods. Cause why not. :D

So, after some maths, I found out that my CR with the old pistons was about 11.1:1. TIDAK BAGUS!!! I mean I could run E85, but no, just no. I could have just run strait propane, but I like the versatility of gasoline. I mean when you are camping and you need to start a fire you just unplug the fuel line and BOOM instant fire. LOL


With the new pistons and eagle rods my CR should be about 9.7:1. Which IMPO is still kinda high for boost, but definitely doable with 93 octane. :( I really wanted to be able to run like 87, but oh well.


Just gotta hone out the block and slap these buggers back in there. :D

1k mile update
 

So after 1000 miles I think this machine is about in its final form.


I ditched the hot air intake and made this cold ram air intake. I blocked off the original hole and made my own in where the top would normally sit. In theory this should shoot cold air from the side intake into the conic filter that feeds the carb. In reality it makes cool intake noises from the side of the car. :D

http://986forum.com/forums/uploads02...1610232345.jpg


My fear of a VERY unbalanced plenum is put at ease a little bit by making this "gutter" to feed cylinder #6. Its just a piece of steel in a gutter shape that is bolted to the intake; then the piece is welded to the bolt. All the parts are larger than the intake runners so I'm not afraid it will get sucked into the engine. But it should help charge #6 as much as 1-5.

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http://986forum.com/forums/uploads02...1610232606.jpg



And lastly I finalized my A/C situation. I just jumped strait off the A/C cycling switch to a toggle switch to power my A/C compressor. I have a toggle switch to turn my A/C on; not too happy about that. BUT it works and cycles under pressure changes, and the HVAC works just as stock otherwise.



And after driving for a while now I can say its a hoot. Yall already know how spectacular the handling is, and the creature comforts are just as amazing as I remembered them to be. The car is not as powerful as I'd wanted, but much more than a stock boxster. Butt dyno measures 300hp at the wheels. More than a boxster S; which is plenty. If I really want more I can always put a shot of giggle gas on there; lord knows the IRON block will take it with stride. :D

Very cool! Thanks for the updates.

Pretty cool! Can we request a video of how it runs when you have the chance?

Can't figure out how to upload here. I mean I am a cave man running a carburetor LOL


I just noticed I hadn't made any update since the little detonation party I had in cylinder 3.

To fix that issue I got some deeeeeeeep dish pistons and some forged eagle con rods. Compression should be on the high side of 9.4:1. Before the compression was about 11.1:1; thats kind of a lot for 93 octane and 8psi of boost. There is a weee bit of detonation now; only after a good heat soaking on the highway. I might be able to dial the ignition timing back a hair and fix that. I might be investing in an ignition box to control timing a little better, but for now its good enough.


Fuel ratios are a little fat. 8:1 at wot... I'd like 10:1 but I wanna get the ignition sorted before I start pulling fuel out. This is my first roots blower, and from my experience so far the heat soak is real LOL. You do a few pulls and everything is super, then the intake gets warmer and warmer.... :(

Just create a youtube account and upload your videos there, very straightforward.

I know; to be honest its a lot of work for the 8 people interested. LOL

PM me your email I'll send you a video or two, but I'm gonna warn you my wife and I are TERRIBLE camera operators. :D


EDIT: oh and I think I'm just gonna live with the glowing headers at idle... I mean they don't seem to mind being that hot at idle, and if thats the ignition timing required to keep this thing from pinging then thats what it takes.

Haha, yeah, I hear you, PM sent. :cheers:

Wouldn't too lean of a fuel mixture cause the headers to glow?

Yes, but in this case its timing related. I was trying to run a locked distributer using vacuum advance at idle retard enough to correct for the timing needed at WOT.

As of last night I've given up with that idea. I ordered an MSD boost retard control box. Supposedly it takes out 1, 2, or 3 degrees of timing per pound of boost made at the turn of a dial. It cost a pretty penny so I hope its worth it.

I was almost about to take the heads off and check which cylinders are pinging the hardest. I was under the impression that 1 & 3 were/are running harder than the rest due to the supercharger's location. I also wanted to maybe lower the compression some more. BUT I took a syringe and actually measured the dish of my new pistons. They are 18ml of dish; with a 4.120" X 0.040" HG, 64ml of head volume, and nominal deck to piston I should have about 9:1. Thats a lot lower than I was guessing at. Actually measuring things helps LOL

^^^ after that revelation I decided to buy a better ignition system; regardless of its astronomical cost.


Cost aside it is a really nice unit. It records boost pressures and timing maps. I might be able to get it to communicate with my LM-2 wide band system.

Oh yes, this is the ignition I shoulda been running from the get go. Totally tunable, I can adjust ignition on the fly with the retard nob. It lets me go full retard or just a little retarded.

I was full retard with the locked distributor; and we all know "you never go full retard". LOL

http://986forum.com/forums/uploads02...1611800528.jpg



The MSD does provide LOADS of spark too. Doesn't really help much power wise, but starting is like 1 000 000 times faster.


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I also gave my little box 'o' small blocks a nice hair cut. :D

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