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Qingdao 12-14-2019 05:02 PM

4.3 Supercharged Chevy
 
Finally got my hands on a cheapo boxster. Its a pile LOL, BUT $1500 seemed about right for a strait chassis and clean title.

Now I just have to wait for the half off weekend at LKQ. I am gonna shove a 4th gen 4.3 Chevy engine in this thing with an Eaton M90 blower.

I think I'm gonna draw through an edelbrock, but I might go with a Holley. Haven't decided yet.

At anyrate, I got this thing, but now I have to go on vacation... Sucks cause I'm going to be off with the wife and not at home in my garage. :lol:



Well here is the pile... (yes I do body work too)

http://986forum.com/forums/uploads02...1576375343.jpg

Qingdao 12-15-2019 04:38 PM

Didn't take long. Got a nice cheapo Eaton M90.

$100 and after I get back from vacation I can get a rebuilt snout from Ebay for $300.

Rebuilt blower for $400 not too shabby. :D



http://986forum.com/forums/uploads02...1576460312.jpg

78F350 12-15-2019 06:12 PM

Looks like a cool project. Lots of the guys on the forum wouldn't touch a $1,500 Boxster, but at that price you've got nothing to lose and a lot of potential fun if you like playing with cars. I'm looking forward to the progress.

Qingdao 12-15-2019 06:38 PM

Quote:

Originally Posted by 78F350 (Post 608247)
Looks like a cool project. Lots of the guys on the forum wouldn't touch a $1,500 Boxster, but at that price you've got nothing to lose and a lot of potential fun if you like playing with cars. I'm looking forward to the progress.

2 years ago I wouldn't have either. My wife had an auto and that thing was super fun even though slower than a heard of turtles. That car's gone now its my turn.


Got a bit of inspiration off of YouTube. This guy went ham with the intercoolers. I don't think I'm gonna have to use two belts, but who knows at this point.

https://www.youtube.com/watch?v=L_FRdIjGkgg

^^^ Apparently I'm not the only idiot who wants roots noises emitting from their V6 engine.

78F350 12-15-2019 07:54 PM

I had an M90 that I thought about blowing down into a VW VR6 with. After laying it out and looking at what it would take to do right, I passed the whole project on to someone else.

http://986forum.com/forums/uploads02...1576471956.jpg

Do the M90s have a stock mounting on the 4.3, or do you have to fabricate it?

Qingdao 12-15-2019 08:30 PM

100% gonna have to fab.

I was gonna just do a piece of 1/2" aluminium. Tap some holes in the top to bolt the eaton to it and bolt the bottom to match the 4.3 intake. That'll also give the ability to position the snout where I want it in-between the alternator and A/C compressor.


Accessory position is the reason why I've chosen the 96-02 chevy 4.3. The accessories on the 4.3 almost line up perfect with the accessories on the German H6 engines. So all I have to do is break out my line lock crimp tool and fab up some hoses. (that's a big fingers crossed there LOL)



As for engine building I am just going to put a healthy cam in it and some good pistons and rods. Maybe some light weight rockers for show. Nothing too spectacular; I just want about 300whp maybe 350 if I'm lucky. BUT the torque should be to die for.



One question I'm wrestling with is weather or not to buy new springs. I like the stock ride height but I don't know how much the original springs have sagged over the 20 years of life. Especially since this thing has like original struts on it (its a motor boat) so I'm sure these springs might be "sprung out". Just don't know if its worth the cash to toss in some new oem springs.

Qingdao 12-19-2019 07:11 PM

I'm thinking this might be the way to go for mounting the edelbrock (I'm dead set on another eddy) on my Eaton.

http://986forum.com/forums/uploads02...1576814934.jpg


The best irony I can think of... using an adaptor that is supposed to convert a carb intake manifold to a throttle body; to bolt a carb to a throttle body. LOL its perfect.


I still might weld up my own intake. Just for fun. :D

itsnotanova 12-19-2019 07:19 PM

I love engine swaps so don't take this wrong, but won't you have a huge issue with how tall the motor is? Let alone with a blower on top

Qingdao 12-19-2019 07:37 PM

Quote:

Originally Posted by itsnotanova (Post 608502)
I love engine swaps so don't take this wrong, but won't you have a huge issue with how tall the motor is? Let alone with a blower on top

I hope so. I'm gonna build a plexiglass top. :D I wanna see this...thing.


I do want to do the "cayman style" hard top as well. So I don't need room for the convertible top. That whole rear trunk area is probably going to be substituted by a series of square tubing supports.

If the blower, carb yada yada are to far aft/high and I can't close the rear trunk; I might turn a pair of elbows around 120* go with a pair of SU carbs on top of the valve covers. One conveniently placed in front of each of the side intakes.

99Roadster 12-23-2019 05:48 AM

Respect your initiative for taking on this project.....Whatever you do just keep us informed of your progress if you would please.....And good luck!

Qingdao 12-23-2019 03:24 PM

Quote:

Originally Posted by 99Roadster (Post 608672)
Respect your initiative for taking on this project.....Whatever you do just keep us informed of your progress if you would please.....And good luck!

Well I'm trapped in a forced vacation with my wife ATM. I'm so glad to be getting back to the garage in the next few days. Then I can start mocking things up, and poking the car.


I think I am just gonna buy a $125 4.3 off ebay for starters and toss a cam in it. Not even gonna upgrade rods.

I got the blower, and I found a used eddy on ebay as well for $100. Manual choke :D


Honestly, for the growing crowd of IMS failure guys. I think the 4.3 is the way to go. Naturally asperated and carbed; you won't have to worry about wiring (there are electric chokes but I like to pull the nob). Its 4" shorter than an LS motor so you won't have to cut up the firewall. With a simple cam and an intake you've got almost 300#s of tourque which is more than the 3.4 Porsche engine. And they are CHEAP and plentiful; Kennedy adaptor and a bit of angle iron added to an engine/cam/carb/intake is less than a 3.4 Porsche engine.

JayG 12-23-2019 03:50 PM

Quote:

Originally Posted by Qingdao (Post 608703)


growing crowd of IMS failure guys. .

really ??????

Qingdao 12-29-2019 03:02 PM

I took a crack at trying to replicate a part out of foam.


I put my M90 in a bag....

http://986forum.com/forums/uploads02...1577663787.jpg

Then I covered it with great stuff...

http://986forum.com/forums/uploads02...1577663839.jpg

Then I took the M90 out of the bag...

http://986forum.com/forums/uploads02...1577663893.jpg

Then I filled that void with great stuff and Styrofoam...

http://986forum.com/forums/uploads02...1577663940.jpg

The end result...

http://986forum.com/forums/uploads02...1577664012.jpg


I took the end result out of the plug way too soon because I noticed the great stuff wasn't curing on the outer edges of the plug. I tried to drill an air hole and the bit caught the bad and made a royal mess....

I think I am on the right track but I need to use a card board box to retain the negative. I should be on my way to scoop up a 4.3 tomorrow. :D

Qingdao 12-30-2019 01:47 PM

Well... to hell with making a foam copy. This thing is gonna fit no problem. I might have to hack the fire wall some, but not any more than you'd expect.

And OoooHMYgod does the Eaton sit perfect on top of the 4.3.


http://986forum.com/forums/uploads02...1577745562.jpg


http://986forum.com/forums/uploads02...1577745624.jpg


All I should have to do is hack down the back of the M90 just a hair and tig up a square bore plate. Adapt the M90 for the 4.3 LIM; drop the carb on it and call it a day.




As for the size constraints here is the skinny...

http://986forum.com/forums/uploads02...1577745801.jpg


The 4.3 is 22" long from flex plate to W/P... The 2.5 Porsche is about 23 ish (I can't exactly see down in there).

The 4.3 is TALL from the bell housing up its gonna be a whopper of 12" and after about 5 inches forward of the bell housing its gonna be about 16" (cause of the carb). According to my rough estimates that puts me at about right at where the top of the rear storage bin would be. Another words this is gonna fit under the glass.... BUT JUST barely under the glass. :D :D :D

Qingdao 12-31-2019 02:00 PM

Cut down the M90 some more. It almost sits flush on that LIM. Cool cause now all I need is a good 1/2" thick aluminum adaptor plate.

http://986forum.com/forums/uploads02...1577833118.jpg



If I'm able to get the carb low enough I'll slap on my buddies old Duel fuel carb hat. How cool would that be having a duel fuel Porsche!!


http://986forum.com/forums/uploads02...1577833211.jpg


I also put my vehicle make emblem on it; fits perfect.

Qingdao 01-04-2020 02:12 PM

Damn waiting for pieces. I ordered a 3/4" plate for the adaptor and carb, but it won't be in till Monday. In the mean time I'm twiddling my thumbs.

I did cut out this portion of the firewall. Hoooooo boy what a smell when the grinder met the old sound deadening material. It might also be my grinder is 60 years old and ready to retire.

http://986forum.com/forums/uploads02...1578179296.jpg



Do any of you guys know for sure if these are the P/S hoses? They are right behind the drivers seat. They snake under the A/C compressor.

http://986forum.com/forums/uploads02...1578179367.jpg


http://986forum.com/forums/uploads02...1578179415.jpg

Qingdao 01-20-2020 02:47 PM

I don't really want to flood this thread with needless updates so I've stayed away for the moment. But the engine is out and for sale if anybody wants a boat anchor or coffee table. LOL

Seriously I think it might be a "re-builder". The oil filter didn't seem like it had an excess of metal shavings... IDK Doesn't matter


http://986forum.com/forums/uploads02...1579563749.jpg


The Harbor Freight engine hoist which normally is quite inadequate when it comes to length did VERY well here. Just used a long chain and whola the engine is free.




http://986forum.com/forums/uploads02...1579564004.jpg




Still waiting for my buddy to finish (or even start) welding my M90 so I can fit it to my 4.3 and get to rebuilding that engine.

Qingdao 01-21-2020 06:56 PM

Well I hit a brick wall. Kennedy doesn't make an adaptor for a 4.3 with an aluminum oil pan for a 5 speed boxster. They wrote me and said something about the starter not having a place with the adaptor plate.

Ah poooo.

I messaged them back to see if I could use an 88-95 4.3 engine. I mean if its the aluminum oil pan that's in the way I can work around that. Shoot mild steel is easy to work with.

I don't see the difference between a 4.3 and a SBC and the difference between the LS and SBC is .400" of bellhousing spacing. So buy an LS adaptor and add .400" of spacing???


One question I do have for any high output boxsters out there; what clutch's are yall running? I'm not seeing too many aftermarket options out there. How much power can the stock clutch hold?

itsnotanova 01-22-2020 08:42 AM

They probably did you a favor. The five speed can barely handle the power from a 2.5/2.7. The five speed won't last that long behind the torque of a supercharged 4.3. You're much better off using a 986 or 987 6 speed.

Qingdao 01-22-2020 03:42 PM

Its cause they use a proprietary starter they make in house and where they put it the starter conflicts with the aluminum oil pan.

I have a friend who, if you get on him hard enough, welds aluminum. Worst case I buy an older 4.3 and use an older block. But more than likely the oil pan is going to be custom.



So 5 speeds can't take the torque?

I have decided to tone it down a bit on the engine. No aggressive cam, light boost, stock or dish toped pistons, and only a 25 shot of nitrous at best.

I'd say 300#s on a good day.

itsnotanova 01-22-2020 08:16 PM

Quote:

Originally Posted by Qingdao (Post 610459)
So 5 speeds can't take the torque?

I have decided to tone it down a bit on the engine. No aggressive cam, light boost, stock or dish toped pistons, and only a 25 shot of nitrous at best.

I'd say 300#s on a good day.

I'm guessing you're a chevy guy? The audi/porsche 5 speed is like a T5 and the 986/987 6 speed is like a T56 in terms of power it can take. What you're doing is like connecting a SBC 350 to a T5. Sure it might work, but it won't last if you try doing any kind of aggressive driving. You're kind of limited to power with the 4.3 cast crank but even in stock form I think it's too much for the boxster 5 speed

maytag 01-23-2020 03:28 AM

Quote:

Originally Posted by Qingdao (Post 610459)

I have decided to tone it down a bit on the engine. No aggressive cam, light boost, stock or dish toped pistons, and only a 25 shot of nitrous at best.



I'd say 300#s on a good day.

I'm all for creativity, and even mods just for the sake of modding.

But I gotta ask, gently; if the goal is 300.... that's a poop-ton of work for 300..... so,.... why?
I mean.... I've done my share of gm v-6 stuff... mostly 3.8's (wasn't the 4.3 the truck motor?) And I get the fascination with turbos on 'em.... but otherwise?

It just seems like SO MUCH WORK for a 10% hp increase over a Porsche 3.2 that bolts right in.
?
Respectfully, of course.

Sent from my SM-G970U using Tapatalk

Qingdao 01-23-2020 06:28 PM

Quote:

Originally Posted by maytag (Post 610483)
I'm all for creativity, and even mods just for the sake of modding.

But I gotta ask, gently; if the goal is 300.... that's a poop-ton of work for 300..... so,.... why?
I mean.... I've done my share of gm v-6 stuff... mostly 3.8's (wasn't the 4.3 the truck motor?) And I get the fascination with turbos on 'em.... but otherwise?

It just seems like SO MUCH WORK for a 10% hp increase over a Porsche 3.2 that bolts right in.
?
Respectfully, of course.

Sent from my SM-G970U using Tapatalk

I can understand confusion. LOL

Most of this work is for the blower right behind my head. Just want the VEEEEE sound. Addition of power is a side effect. I'm a strange one.

I'm toning it back to about 300 because I don't want to spend more than I paid for the car on a transmission. At least not right away. ;) … Who knows in a few years once I get the body and suspension the way I want them I might re-visit the trans and engine output. Typical Chevy problems; engine's got more potential than any trans can handle.

Work yeah, but have you priced a 3.2 lately? If I went to the larger tranny and pumped up the 4.3 to a respectable output I'd still be paying less than swapping the engine alone. (side note after the clutch/adaptor purchase I'm in $3500 car purchase included)

Another reason for the 4.3 is I got one when I bought my garbage scow of a pickup truck. I'm about 100% certain it has jumped timing, and it still runs (I just advanced the distributer so it only pings a little). Well 2 years of driving essentially broken and it keeps ticking gives me the impression that its a VERY robust and well built engine. What better engine to put in a car that is less than easy to access the engine?

I am reminded of building my RX 5 years back. The trans always is the compromise area. I had to limit my output on that engine too. But like then I want the engine noises from the blower now; at that time I wanted the wooosh noises from a turbo, the power increase is a side effect.

Qingdao 01-23-2020 06:36 PM

Quote:

Originally Posted by itsnotanova (Post 610477)
I'm guessing you're a chevy guy? The audi/porsche 5 speed is like a T5 and the 986/987 6 speed is like a T56 in terms of power it can take. What you're doing is like connecting a SBC 350 to a T5. Sure it might work, but it won't last if you try doing any kind of aggressive driving. You're kind of limited to power with the 4.3 cast crank but even in stock form I think it's too much for the boxster 5 speed

Never really was a Chevy guy, but working in a shop for almost a decade now I respect their engines. Everything else about GM is garbage, but there engines are nothing to shake a stick at.


Hmm.. It just costs so much to swap that trans. Other than the longer shift cables, does it require different axles?

I think I'm going to try the 5 speed for now and then later on swap over to the 6 speed when it breaks. I mean I have a 5 speed now. Why not have some fun and break it. \m/ :D

maytag 01-23-2020 06:58 PM

Quote:

Originally Posted by Qingdao (Post 610545)
Most of this work is for the blower right behind my head. Just want the VEEEEE sound. Addition of power is a side effect. I'm a strange one.

Actually, that makes total and complete sense to me... maybe I'm strange in the same way, but I fully support all sorts of machinations for the right sound...

Carry -on!

And yes, the 6-spd has different axle flanges. I'm told that they can be swapped over though. Also a different input shaft, so clutch would need to be changed as well. (Disc only, if you start with the right clutch)



Sent from my SM-G970U using Tapatalk

Qingdao 01-23-2020 07:28 PM

http://986forum.com/forums/uploads02/gggg1579839985.jpg



http://986forum.com/forums/uploads02/jjj1579840008.jpg



This is the level of crazy I am at. :D

That's my dually RX7. LOL


https://www.youtube.com/watch?v=FjH_e1V_PYc

^^^ this is my inspiration for the mid engined blown car.

itsnotanova 01-24-2020 12:07 AM

Quote:

Originally Posted by Qingdao (Post 610546)
Hmm.. It just costs so much to swap that trans. Other than the longer shift cables, does it require different axles?

I think I'm going to try the 5 speed for now and then later on swap over to the 6 speed when it breaks. I mean I have a 5 speed now. Why not have some fun and break it. \m/ :D

Axles, uprights, calipers, transmission mounts and somewhat the aluminum belly pan but that can be modified easily. That's if you go with a 986 6 speed. A 987 6 speed requires modifying axles too

Qingdao 02-12-2020 05:11 PM

Waiting for Kennedy...

I started working on the subframe. I figure I don't need the engine in place to start on that.

The plan is to run two of these square tubings from the cross member by the bellhousing strait forward and then bolt them to the under body of the car (with a substantial backing plate of course).

Then to give it some more strength I am going to run a bar from where the aluminum skid things on either side of the body and attach that bar to the two running the length of the car.

These are the bolt holes that will secure the subframe to the body. I inserted some steel pipe to give the square stock some "anti-squanch" power. The backing plate I am going to put inside the car (under the seats) will have two M12 bolts welded in place. In my head it should be easy to bolt this subframe up, but its just in my head atm. :D



http://986forum.com/forums/uploads02...1581559594.jpg


http://986forum.com/forums/uploads02...1581559624.jpg


On a side note I sold my M96 at a whopping 580#s. I was just looking for a cheap replacement engine when I went with the 4.3; I didn't expect to loose almost 150 pounds of weight.

robdelorenzo 02-13-2020 07:30 AM

“I love engine swaps so don't take this wrong, but won't you have a huge issue with how tall the motor is? Let alone with a blower on top

I hope so. I'm gonna build a plexiglass top. I wanna see this...thing.”

This line had me howling:D
Gotta love the enthusiasm and creativity on this forum.

There are so many people that know these cars well on here that it’s not even always about budget or $$

Anything is possible with a little imagination.
Well done, enjoy the car!

Qingdao 02-14-2020 05:04 PM

Well that cross member isn't as strong as I remembered when I took it out. Its quite thin if you don't know. So I made it stronger as it is going to support an engine that weighs almost 500#s. This is just tacked on for the moment (ran out of wire feed and I don't like my skills with my arc), but the bolt holes match up.


http://986forum.com/forums/uploads02...1581732161.jpg


http://986forum.com/forums/uploads02...1581732194.jpg


http://986forum.com/forums/uploads02...1581732239.jpg

Qingdao 02-15-2020 03:46 PM

Welded my little triangles in there.

God help me I kinda like the red paint. lol


http://986forum.com/forums/uploads02...1581813904.jpg


http://986forum.com/forums/uploads02...1581813932.jpg


http://986forum.com/forums/uploads02...1581813961.jpg

Qingdao 02-16-2020 03:07 PM

Tacked under the car. :D

http://986forum.com/forums/uploads02...1581897714.jpg


There is a reason why this stuff was $10 for an 8' piece... lots of not only rust.


http://986forum.com/forums/uploads02...1581897880.jpg


Once again... the red paint.

http://986forum.com/forums/uploads02...1581897940.jpg




Now just one more brace across the middle, like east west.

Qingdao 02-22-2020 02:40 PM

Subframe is done; well for the most part. I want to make it into two pieces cause its a nightmare to put it in place, but for now it will serve until I get my adaptor from Kennedy.


I'll say this you can't say **************** about this car and rear structural rigidity. :D


http://986forum.com/forums/uploads02...1582414747.jpg


http://986forum.com/forums/uploads02...1582414778.jpg


http://986forum.com/forums/uploads02...1582414807.jpg

Qingdao 03-02-2020 02:28 PM

This thing fits almost well.

I was hoping it would be shorter, or I'd have more length to play in. But looks like I'm going to have to re-work the trans mounts. Oh well so much for stock drivelines.

The oem subframe connector thingy doesn't even have a prayer of going in with this engine. So gonna have to re-fab that up. No big deal there, cause I already made that angle iron piece; just have to grind the welds off of it and use it solo. I might possibly just go another direction... Haven't made up my mind yet.



Do any of you guys know which direction the coolant goes ?????

Is this the hose going to the radiator from the engine like hot out of the engine???


http://986forum.com/forums/uploads02...1583191261.jpg


Does this heater core hose go into the heater core from the engine? or is it the return from the heater core to the engine?

http://986forum.com/forums/uploads02...1583191669.jpg

Qingdao 03-02-2020 02:34 PM

Oh yeah, here is the old girl in the engine bay.


http://986forum.com/forums/uploads02...1583191837.jpg


http://986forum.com/forums/uploads02...1583191877.jpg


http://986forum.com/forums/uploads02...1583191962.jpg


http://986forum.com/forums/uploads02...1583192056.jpg

Qingdao 03-09-2020 04:34 PM

Almost final product. I didn't have enough gumption to put it back under the car and take some pics... maybe tomorrow.

http://986forum.com/forums/uploads02...1583800364.jpg

Qingdao 03-10-2020 06:35 PM

There she is no chains no straps. Perfectly level side to side, and the trans sits at the OEM height (just back an inch and a half).

Gonna get my hockey pucks soon enough and I can fab up the trans mounts.

Then the fun can begin.. Exhaust fab, coolant lines, ac and power steering. :D

http://986forum.com/forums/uploads02...1583893933.jpg


http://986forum.com/forums/uploads02...1583894065.jpg


http://986forum.com/forums/uploads02...1583894095.jpg

itsnotanova 03-11-2020 05:08 AM

Will your shifter cables reach the transmission? I think the 6 speed cables are longer but don't quote me on that

Qingdao 03-11-2020 05:02 PM

Quote:

Originally Posted by itsnotanova (Post 613112)
Will your shifter cables reach the transmission? I think the 6 speed cables are longer but don't quote me on that

I've been wanting to check that, but I've been pre-occupied with making the trans "cradle". In one hand they route over the idler pully in the same manner as on the flat 6 and they should sit right in the V almost lower than the H6. BUT the engine is a bit taller so IDK.

I figured the V8 guys don't have too big of an issue worst case I can route 6 speed cables the same way the V8 guys do (under the V???)

Qingdao 03-13-2020 05:24 PM

Quote:

Originally Posted by itsnotanova (Post 613112)
Will your shifter cables reach the transmission? I think the 6 speed cables are longer but don't quote me on that

So yes, 5 speed cables can be used... you got me motivated to route them. :D

They slip under the V with no fuss.

http://986forum.com/forums/uploads02...1584148845.jpg


http://986forum.com/forums/uploads02...1584148876.jpg


http://986forum.com/forums/uploads02...1584148913.jpg



This is the start of the trans "cradle" or whatever. I made this thing that grabs the trans nice and tight then used some flat bar to make a mounting area for a pair of hockey pucks. The pucks will be supported (where my hand is) to a cross beam of some kind (that will be made at a later date... tomorrow???).



http://986forum.com/forums/uploads02...1584149036.jpg


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