Sinfulrelations

hello everyone, ive been thinking about doing a twin turbo 4.3l build, for my 92 camaro, i already have the 4.3 out of a 92 s10 that was mildly built, ie custom forged crank, h-beam rods, forged pistons, ported heads, and a megasquirt system all set up, for a n/a tbi build, i can easily convert it to mpfi and build hedders for turbos and get a custom grind cam to work better with boost, anyone think this may be a good idea, just looking for some input before i start tearing into modding this motor more than i already have, plus i think it would be wicked seeing turbos hanging of the side of the 4.3

fasteddi

iTrader: (2)

If you ask me... sure its worth it. If you can do the fabrication yourself, the cost wont be to bad. Ive seen some nice V6 swaps on here but I haven't really seen a 90* V6 one else then a 3.8L.

Drac0nic

The fuel system will be the weakness imo but it sounds like you have that covered. Should be wicked I would turbo with a 60 to 66. You may look at the yards they used tubular manis on some late 80s stuff that could be a good start to cut and weld.

Fallen2603

DO IT.

How much power you want to end up with?

Orr89RocZ

iTrader: (20)

As long as comp isnt to high, motor is already built to handle some power might as well use it if you cant go lsx or 305/350 swap.

Should easily make 300-400 whp with enough boost. Fun ride. How much you looking to make?

Single turbo in the arrangement like gn's syclone's or tta's would be cheaper and easier in my opinion

Sinfulrelations

i was looking into one of the build a header kits i can buy the flange that the turbo bolts to and make a good solid tubular turbo hedder

at this point its unknown, i know with the megasquirt system with the mapdaddy add on i can run up to 40psi boost iirc, i guess the proper answer would be as far as i can go till things go bust in the motor

as of right now the motor is running 11:1 which i will have to lower the compression a little before i go turbo, my car has the 305 in it i know most everyone goes for a 350, i just wanna be different, plus ive got a good starting point. plus if people around here didnt want an arm and a leg just for a block i probably would go with a 350 / 383 but seems like here where i live 650 - 800 is what everyone wants for a bare block

project89

iTrader: (1)

as long as u dont want more then 450-500 crank hp go for it.
the 4.3 is known to throw the crankshaft out the bottom of the block above those levels

its not cheap to convert a 4.3 to mpfi , i belive u have what 2 options either the marine manifold which is very expsensive or u can modiffy i think its the holley stealth ram again not so cheap


u could try using the tbi setup with larger injectors, it wont make as much total power but it will be alot cheaper


i also agree with a single turbo , though a pair of garrett t3's off a dodge shadow/crysler new yorker,dodge minivan or off some volvos and fords will do the trick as well and support enough power to spit the crank out the block

Orr89RocZ

iTrader: (20)

Good point, i thought there would be aftermarket efi intakes for these but doesnt appear to be

Fallen2603

Well, he's got a forged crankshaft, but I don't know if the mains will hold past what project89 said. I'm guessing if their 2-bolt mains, that 400-500HP will probably be their breaking point. Is it possible to upgrade a 2-bolt main 4.3L block to 4-bolt mains? That might give you some more room for power...

If you can only shoot for ~500WHP, a couple K04 turbo's off an LNF turbocharged Ecotec motor can probably be scrounged up for $300-$400, for BOTH, and COULD support up to 600WHP if done right. Getting 500WHP out of a twin-KO4 set-up would be EASY.

Sinfulrelations

The 4.3 can use the 350 splayed main caps didnt the newer 4.3 have mpfi? If need be I can custom make an intake manifold I have a few friends at a machine shop that could help me make something useable

Sinfulrelations

i just did some looking around, looks like around 95/96 they changed the 4.3 to mpfi, i found some intake manifolds on ebay for 50 - 60 bucks, does anyone know if they changed the block from 92 to 95?

Sinfulrelations

http://www.ebay.com/itm/1992-Chevy-Astro-Intake-Manifold-4-3L-Motor-/220772895627?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AChevrolet&hash=item3367170b8b&vxp=mtr
http://www.ebay.com/itm/92-93-94-95-...168b5a&vxp=mtr

found this, think it may work for an intake manifold i think i might just take this leap of faith and try this build,

jwfirebird

iTrader: (2)

the mid 90's and later 4.3's are crappy cpi and they will limit your fuel capability. most have to be upgraded to a form of mpfi but since its not the style that you can buy bigger injectors for that not the way to go.

Orr89RocZ

iTrader: (20)

If you can fab you can make a sheetmetal steel intake or alum if you can weld that lol. Alot of work but they sell rectangular runners. Just make a simple box plenum and run the runners to it. Drill heads for coolant crossovers instead of thru intake. Distributor hole would be like doin lt1 intake swaps on sbc. Need a machined ring at the right angle and height. Not necessarily easy or quick to do but if you wanted to have fun. Wouldnt cost much in material

Sinfulrelations

the nice thing about megasquirt is if i can figure out a good way to mount the trigger wheel and the sensor they sell i wont need a distributor i can use a coil on plug setup. that would greatly increase the ease of making the intake manifold

Orr89RocZ

iTrader: (20)

Yeah their new timing cover with cam sensor built in would help a ton. I am using their distributor shell for cam sensor. If their new setup works well i would consider swapping over

Drac0nic

The other thing I forgot to mention is don't discount blow through if you're handy with a carb. There are a few carbed intakes out there and if you're into a double pumper it may be the ticket for you. Just sayign it may be wise not to constrain your self to EFI.

Sinfulrelations

ive been looking around but havent seen this where is it at?

if need be i would go with a blow through carb, i just really like efi, easier cold starts and better gas mileage, and using the megasquirt system i can watch almost all of my sensors in real time

daverr

iTrader: (1)

You are totally wasting your time and money on the 4.3L. Go with a sbc/bbc setup its got 100x the parts available vs the 4.3L.Blow thru carbs are junk.

ZZ3Astro

I'm all for interesting engine combos but like Dave said, it won't be the most financially efficient way to go. I'm not a big fan of the offset rod throws on the 4.3 and have seen more than one break there. The downside of just 'trying' it will be six injectors, turbo too small for eventual V8 swap and of course the headers/manifolds and injector harness being wrong for hte same. On the bright side, tons of room in front of the engine for a turbo!

Sinfulrelations

i think im going to go for it, ive got most of the big stuff already done, with the forged crank and h-beams, ill make up my own intake and fuel injection system, worst comes to worst ill have fun and learn a few things, and have an awesome picture to show off

project89

iTrader: (1)

your best bet would be this
http://www.ebay.com/itm/4-3L-4-bbl-EDELBROCK-Performer-90-Intake-Manifold-2111-/281104929097?pt=Boat_Parts_Accessories_Gear&hash=item417328d149&vxp=mtr

weld in ur won injector bungs and make ur own fuel rails

then u can either get a 4bbl throttle body , or get a tbi adapter plate and use striped down tbi unit as the throttle body


i suspect that by the time u were done u would spend around 4-500 bucks and at the price u could have just bought a complete mpfi marine manifold


the very cheapest option would be to use the tbi intake and tbi and just upgrade the injectors to the largest u can find , which i think would be off one of the chevy big block 454's that had tbi

Drac0nic

A Grand National rail has the same port spacing as a 4.3L, or the 3.8L FWD incarnation. If you can get one for a decent price it should do the job if it fits with the Edelbrock intake. I had one off a hot air I played around with the idea of doing it on a cast iron qjet intake but never did. Both are 90 degree V6es and the width is almost identical at the valley.

I assure you someone has been faster than you will ever be with a blow through turbo system Dave. Not hating, but we he never stated his intentions with the car initially. Since it's sounding like a street car I can see the benefits of doing EFI but options for a 4.3L are um limited.

In regards to the TBI, I really don't know if I'd want to do that even with 454 injectors. I'm surprised the 60 degree guys haven't taken up that setup, but then again they have easy to get MPFI intakes as well. Power wise I'd bet even a properly set up 3.1/3.4 would max out the largest TBI injectors, much less a worked 4.3L. If it's a lower boost versus a "lets see what we can make" proposition I would go for it. With the HP goals he wants, I don't really think a set of TBI units will feed it. Maybe one of the Holley units Ford used adapted to a set of 160s (surprsied I've never seen someone do it honestly) But I don't think the Rochester 220 is that hot of a setup.

Sinfulrelations

what ill probably end up doing is machining a custom intake, something similar to what the mpfi 305 had, just a basic base plate with runners leading into a plentum i attached a picture of my idea, its not the greatest but i dont have solikworks on the computer im on gotta wait until monday for that

Orr89RocZ

iTrader: (20)

That should work. Taper it towards the rear will help distribution on front feed

oil pan 4

iTrader: (1)

The turbo 4.3L was a great concept that never went any where.
http://en.wikipedia.org/wiki/GMC_Syclone
GM used a 8 cm² TD06-17C, it was aftercooled with an Water to air unit and made 280hp and 350tq.
Maybe some parts off one of these would help.
I figured they would have just slapped a GMx serries turbo on there and called it good.

Drac0nic

The funniest thing about that engine to me is over all it seems like they "neutered" it. I suspect to keep it at the ragged edge of the rating of the 4L60 that was behind it. Not that they have an easy life in the Sy/Tys. At that time, the 4.3L HO was out that had a cam similar to a TPI engine vs the peanut cam they came with, and likely the CPI heads and cam would have been an option any of which would have increased output considerably. The turbo is capable but IMO mildly undersized and the intercooler is fairly restrictive compared to the massive TB ahead of it.

Some CPI heads, a 20G and the CPI cam and I think they would have had a significantly different engine on their hands. Likely something that woudln't be touched until the LT4 or LS generation of vettes. Truly a shame that the Syclones and Typhoons were a concept that the market wasn't ready for.

oil pan 4

iTrader: (1)

I don't know anything about that turbo but given the time peroid, pretty much everything that was turbocharged by GM had an undersized turbo.

Take for example the GM 6.5L diesel. When GM stated putting turbos on them they put a single 60mm GMx serries waste gated turbo.
Now us 6.5L guys have tried a lot of different turbos. The only thing any one has found that was too big was when ATA accidently shipped a kit using an HX55 sized turbo with the wrong grossly oversized turbine housing.

project89

iTrader: (1)

if u build an intake go with something along the lines of this shape

dont mind the crappy 2 min drawing i did while at work thats totally not to scale but it should give u the basic idea

project89

iTrader: (1)

btw there is a vortec marine manifold on ebay right now for 200 bucks , no injectors/fuelrails or throttle body
http://www.ebay.com/itm/GM-V-6-Vortec-EFI-INTAKE-MANIFOLD-MERCRUISER-VOLVO-OMC-/170949867230?pt=Boat_Parts_Accessories_Gear&hash=item27cd67f6de&vxp=mtr
edit

found another with tb and sensors looks brand new but no fuel rails for 300 shipped
http://www.ebay.com/itm/1996-2008-4-3L-GM-VOLVO-VORTEC-MARINE-MANIFOLD-INTAKE-MERCURY-MerCruiser-/360589803472?pt=Motors_Car_Truck_Parts_Accessories&hash=item53f4d3bfd0&vxp=mtr

diablizzard

iTrader: (8)

Here's a link for installing the marine intake: http://www.fullthrottlev6.com/forums...Helpfull-Hints

The only issue with the marine intake is that it is cast iron. But with it might as well switch over to the Vortec heads and put in a thicker head gasket

UR50SLO

iTrader: (1)

Blizzard and Project89 are on the right track...

That thread on FullThrottleV6 is mine.... We were sick of a 18second family hauler and I found a way to get it down in the 14's with out breaking the bank.

Anyway.... If you've got a mild built 4.3L with good rods ect thats' been a good runner definatly drop the compression down by putting in a set of dish pistons.

You'll need to put on a set of Vortec heads which do have a smaller chamber but flow much better than the Pre-vortec style... (us Sy/Ty) people switch over to vortec heads as a upgrade. Don't bother porting.. they work just fine.
The Mercruser intake is heavy but the cheapest way to MPFI a 4.3 by A LOT.

Twins/single? Eh ... Not much difference just more plumbing with twins... The Sy/Ty manifolds have been proven to low 10's. If you can find a set.. it's bolt on and go.

You can use the newer single serp. belt system on older block like yours... same block/head pattern... Much better layout and better Alternator/A/C.

You can use the Megasquirt on there... That'd be fine.

The 4.3L will bolt up to any standard chevy trans/4L60/700R some 200R's ect.

Duribility? Even with 4bolt mains the block is good to (as they said) around 500ish.

So you keep it in this area you'll be safe.
Need any help feel fee and good luck,
Scott
UR50SLO@aol.com

kmcn47

sub'd

JAYDUBB

I didnt read the whole thread but... Either Hot Rod or Car Craft built a 4.3 a few years ago with a centrifugal blower (i think vortec). It made 500 hp at the flywheel.

Fallen2603

http://www.hotrod.com/techarticles/e...l/viewall.html

JAYDUBB

Yep. Thats it.

And from memory... A dude showed up at Capitol Raceway a few years ago with a Turbo'd V6 Monte Carlo. We all thought it had a GN swap but when we looked, it had a 4.3 V6. It may have been a Typhoon/Syclone engine swap. IIRC, the car went low 10's/high 9's.

Im sure someone in here is from Maryland and just MIGHT remember that Monte Carlo.

kmcn47

monte's could have 4.3s stock, possible it was that engine

JAYDUBB

Well, it DEFINITEY wasnt the stocker but yeah, I forgot they came with 4.3's... LOL

Sinfulrelations

well havent posted here in awhile but here it goes, i recently picked up a 98 jimmy for the motor (4.3 vortech) im going to go ahead and start this build, ive got it figured out on how im going to (try) and do this, using the marine manifold and megasquirt, ill post here with how its going wish me luck

Sinfulrelations

and i have a question about this

http://www.ebay.com/itm/NEW-4-3L-Exhaust-Manifold-OMC-Volvo-Penta-Marine-V6-3857656-3852338-914899-/360795502834?pt=Boat_Parts_Accessories_Gear&hash=item54011678f2&vxp=mtr
anyone have an idea if a turbo could be bolted to this?

project89

iTrader: (1)

if the outlet isnt the exact size of the turbo flange u could easily modify it

Sinfulrelations

one thing im doubting though is clearance in the engine bay might just be easier to build a header that points toward the front of the engine to where the turbo sits right by the front of the block





as you can see the stock manifold doesnt have alot of room as it is, this is the motor still sittin in the jimmy

project89

iTrader: (1)

building ur own will be the best way to go, also ditch the belt driven fan , that will give u a ton more room up front.

what i would do is ditch the ac compressor and the power steering, u will need a manual steering box out of a 4 cyl s10

then u could get a vbelt setup to run the water pump and alternator only and u will have a bunch more room

AutoRoc

iTrader: (1)

Cool!! Don't ditch the power steering! I drove my car for 5 years without it and skinny gront drag rims//tires... putting it back on has been THEE best mod ever... With 275/40/17 front tires, it's damn near impossible to drive the car.. Requires both hands/arms/and a bit of finess as to not break the steering wheel coupler... They shatter easily.. My 85 camaro's did, broke off right in my hands..

I'll be watching the updates! Get after it!

project89

iTrader: (1)

with a manual box it aint that bad , now my tt iroc has the ps pump disconected and only have 225 width tires on the front , i have to muscle the wheel in parking lots. when driving i like it specially at high speed its hard accidently make the car dart left or right and loose control

with a manual box it will be much easier to turn at low speeds

Sinfulrelations

Update, the motor is out and on the stand, getting ready to disassemble the motor and freshen it up, and do some mods, ill be sending the stock crankshaft out so i can get a forged one made, ill be taking the manifolds to where i work and make a flange out of .25 steel then build my turbo headers off of that, and im also sending out the block to get a set of splayed main caps installed, plans for the intake manifold are im going to use the edelbrock carb manifold and make an adapter to mount the throttle body on top of it, along with injector bungs from diyautotune.com, that way i can run hard lines from a block mounted on the intake

Sinfulrelations

intake manifold
http://www.summitracing.com/parts/ed...make/chevrolet

injector bungs
http://www.diyautotune.com/catalog/w...ors-p-505.html

Injectors
http://www.diyautotune.com/catalog/d...owz-p-280.html

i figure that 95 lbs an hr is more than enough to meet whatever i can throw at it and with the style of injector bungs i have no major worries about making a fuel rail just gotta run lines from a block mounted on the intake manifold

project89

iTrader: (1)

u want a single plane style manifold makes doing the injectors 100x easier to do

UR50SLO

iTrader: (1)

http://www.ebay.com/itm/chevy-4-3-brodix-intake-manifold-/251403408283?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a88cf939b&vxp=mtr
Depending on what heads your going with... (The little brody's) are what I did have at one time. would work with this ... or convert it to Vortec.
Either way this is the intake I'd use.

Where are you having a good crank made? I'm sure the Sy/Ty guy's would be down for getting more made if they are a nice piece...
Hope that helps,
Scott~

Sinfulrelations

I'll be going with the vortech heads, ive got a couple guys around my area that can make the crankshafts but I'm likely to call up callies and see if they will design one