Durango_Boy

iTrader: (1)

Thanks. There is a guy locally that installed a GenV 454 in his C3 under a stock hood. I understand the 8100 is taller, but I am looking into either an L88 hood or a Stinger hood. Both will get me some extra room.

Also, I prefer cruising at low RPMs so the torque of the motor is the draw for me, and the 'WOW' factor. I won't play at the high RPMs much at all.

93Polo

iTrader: (5)

if it is a tall deck, you will need tall deck specific headers as well. The Gen V and VI 454/502 crate motors are the same deck height as a traditional BBC. A 572 crate motor is also a tall deck IIRC.

I think it is a cool project

Durango_Boy

iTrader: (1)

Yeah the headers will be Hooker side mount headers and side pipes so it'll be cake to get a set so long as they make them for the tall deck BBCs.

2500avalanche

iTrader: (1)

I have one of these beasts in my 2500 avalanche. It is a great motor. I am interested in putting an LS1 into a 1st gen s-10, but I would love to put one of these 8.1 (496) into it! Has anyone done this before? If the 8.1 uses the same motor mounts as a old small/big block (thanks 93 polo for the link) it should be possible, with fabrication, of course! Anyone?

gnx7

iTrader: (28)

Isn't the 8.1 all iron.... meaning it would weigh around 800lbs+ with accessories? http://www.gm.com/automotive/gmpower...4_8100_ind.pdf

The late 60's/early 70's Vettes with iron big blocks were some of the poorest handling.... flexiest cars around. That weight up front was a killer for vehicle dynamics. After 1971 they truly began to loose power due to emissions. If your engine is fairly stock.... then upgrading even to a mild LS1 with cam/headers/tuning would knock your socks off.

Why would you swap in a big block that is rated at 325hp/450tq and is known as one of the thirstiest engines around ..... when a mildly massaged LS1 will surpass that, get 2x better fuel economy, rev higher, have perfect driving manners and is a true perfomance engine. If you want torque build a 416 stroker all aluminum LSx motor.... but with your lightweight Vette you don't need gobs of torque to get it going anyway.... You can help manipulate that with the ring gear choice out back.

The 8.1 is a low rpm big grunt behemoth meant for towing in heavy rigs. Big off idle torque is what that thing is all about. Putting that in your 2200lbs Vette doesn't make sense as it doesn't need gobs of torque to get going. A fully dressed LS1 (all accessories/wiring harness/PCM) is 475lbs approx. That is a 325lb+ difference.

Do you know what 325 additional pounds does to the driving characteristics when placed on the front end of a car, when it doesn't need to be there? ... it becomes a plow at speed vs. a nimble car.

Also.... A built TH200-4R may last for a little while with no traction.... but why not run the 4L80E that came behind the 8.1 if you just have to have that setup.... as it is essentially bulletproof. The stock 4L80E convertor weighs a ton as well..... (hint on the TH200-4R... you want the BRF valvebody in it from an '86-87 GN TH200-4R.

I would think this engine swap thru just a little further. In all honesty the 8.1 may look glamorous.... but when you add it up.... you are going backwards in the available technology choices you have at your disposal at just about any auto dismantler.

If you want torque in a smaller package you must research the '86-87 Buick GN 3.8i turbo/intercooled V6! This will certainly turn heads and keep people wondering! The GN engine is one bad ****.

$1500 into this combo would put your car solidly in the 11's and get 25mpg+ highway running near stock parts. You could even get away with 3:08's with how light your car is http://gnttype.org/techarea/recipes/foxrecipe.html

Other recipes:
http://gnttype.org/techarea/recipes/recipepage.html

Grr

iTrader: (2)

im gonna have to agree with ^^^^^ this guy on this one. Going with an all iron big block is like stuffing a flat head v8 in there. Pretty pointless and very ancient tech. The main reason being the weight. You could do a straight, stock LS2 6.0, with a 4l60 in that car, and have all the electronics and trans wiring right there. I bet it would be a TON faster, and actually come out of the hole faster as well. If you havent driven a LSx swapped car thats around 2500lbs, you should PM someone local to you on this board and do it. You will change your mind so fast, the feeling is unreal. You want torque? a tune and headers on that LS2 will be putting down 425lb-ft and probably 440hp. Might be cheaper as well, as big blocks are always spendy, and the shipping (weight) will be a couple hundred more.

Dont do the GN swap, theres a reason i went with LSx over the V6, no sense going back to a motor that was designed in the 60's like the 3.8. Man they make tq/hp thogh.
Gary

ghettocruiser

iTrader: (17)

Sounds to me like he doesnt much care about weight or tearing through the twisties. And he already stated that he is a low RPM cruising kind of guy. Plus...Im SURE this isnt his daily driver, so MPG concern probably isnt even on his radar. Seems like from what he is saying he wants a brutal torque monster WITHOUT having to build it from a smaller motor. Put a cam, or no cam for that matter, in the 8100 and you already have the torque monster... Plus it will be different. No one will expect to see that under the hood.

I think its a cool project, and will be a challenge for you, which is good! No fun in just being able to plop something down and have it instantly work...if you are into making things work that is. haha.

Good luck with it. You will get/are getting great info from this site. I see speartech is helping you out with some measurements. Im sure he can hook you up with a custom harness so that your motor is basically plug and play. Personally, I would either modify the stock harness or get Speartech to send you one. Just makes for a nice neat install and its custom. Im not sure what you would do about gauges...Im not a vette expert, but I imagine there is something out there to either make your stockers work...or you could go with a custom gauge setup and take the easy way out. haha.

Keep us posted! How about a couple pics of the vette??

Justin

Durango_Boy

iTrader: (1)

You nailed it. Low RPM cruiser. Just as much as I want all that torque, I want "Wow" everywhere I go. There are a TON of guys on my Corvette forum that have an LS motor and while everyone is happy and blown away by it's performance I do in fact want something different and awe inspiring.

Here's the car.

ghettocruiser

iTrader: (17)

Damn dude... Im not totally a fan of that generation vette...but that thing is HOT! Love it! You already have something different awe inspiring in my opinion. But like I said, its definetly your choice, and for what you want, the 8.1 sounds like a decent choice, and will definetly not be the norm. Plus, after you swap it in, if you decide you want to go a different route, its no big deal. You can get good money for the 8.1, and will have all the know-how you need to swap in something else. Assuming you dont go carbed...in which case its cake.

Anyway when you get started Ide like to see some progress updates!

Justin

bczee

iTrader: (12)

I agree with Ghetto... its his choice and you really have to be a BBC guy to understand why some people just love those BIG Blocks ! I am sure that this thing will just burn up tires without trying, with the correct suspension setup and tires... I am sure that the 1/4 mile times will pertty good !.

And Remember Torque is just another form of HP.

Durango_Boy

iTrader: (1)

Thanks so much guys. This project is coming soon. I intend to buy and pickup the motor early next week. I will procure a TH200R4 and either have it rebuilt or do it myself. I will need a new set of headers and will maybe have my harness made or ordered. Once it in and driving I will have the rear gears swapped out for 3.55s and I will for sure post as many pics as I can.

doorslammer71

Hello, We've done two 8.1 swaps. The one that is closest to your deal is in a 1956 chevy 210. I've got lots of pics. There are a few things we ran into that you may also find to be a problem. The first is the oil pan, it is cast aluminum and it does NOT interchange with a mk IV or gen 5/6, the pan is fairly deep but it is nice and thick, relatively easy to section and modify as needed. We were having trouble getting everthing under the hood, so we kept dropping the motor lower and this required pan work. It was imperative to the customer that it looks stock from the outside. The front drive stuff looks like traditional big block but the water pump is different and there is a nasty, heavy cast iron water crossover manifold off the front of the heads. I threw all this in the garbage and used a reverse rotation aluminum long waterpump, made a nice aluminum crossover with remote thermostat and our own serpentine setup. Keep in mind this car has a intercooled whipplecharger kit designed for a HD GM pickup. It also runs with same belt. The 8.1 is a tall deck, kinda, it actually is around 10.450 and the exhaust port is raised on the cylinder head. The bolt pattern is the same (but metric) but I highly doubt any off the shelf header will work unless you find something for a Brodix/Dart/AFR .750 raised exhaust port race head. The stock cam is pathetic, on the dyno this thing is DEAD at 4800RPM, the customer insisted on the stock cam though....smoooooth idle. The valvetrain is non-adjustable and there is not alot of room for more lift. Check valve guide - retainer clearance closely. For a stout cam, look into Crane, they originally made GM HP2 and HP3 496 marine cams, these motors were intended for off shore powerboats and supposedly as a crate motor but never made it. Crane did alot of development work and has a couple of cams, roller rockers, metric rocker studs, guide plates, etc. Also, we remote mounted the coils and installed different valve covers, one bolt hole per side needs to be "ovaled" slightly but they fit nice. The fuel system is pretty straight forward, I used 42lb Motorsport injector and modified the fuel rails for a remote booset referenced pressure regulator from aeromotive. We used a 4l80e from a 2wd 6.0l pickup, trans is stock except for a freshen and RV shift kit, and the 6.0 converter is a bit smaller and stalls around 2400 in this application. For wiring, we struggled with BigStuff3 on the first swap but quickly realized this was an expensive PITA for what we were trying to accomplish, the second used a S&P street rod harness, set up for the 4l80 and a throttle cable (ALL 8.1's use drive by wire, which you can too, you just need the pedal and couple of pieces under the dash. Speartech can set you up with all this stuff and the harness). Then we put the car on a chassis dyno and used LS1edit to tune it. This thing is an absolute brute and a freakin' blast to drive. It made 368rwhp at 4700rpm and 564 ft/lbs of rwtq at 3400rpm!!!. It absolutely destroys the 295/50r15 tires on the street, and with the stock cam, dual three inch exhaust and four mufflers, it sounds like some street rodders 2bl 307 cruiser!? If you've got questions or want to bend my ear, drop me a line. Glad to help out, JJ@BTP

GreenBlood

iTrader: (6)

i am of no help on this, but it sounds like a bad *** project, good luck with it..

ghettocruiser

iTrader: (17)

Wow dude... GREAT information. Good for you for typing all that out for the guy. Sounds like even with the stock cam the motor made some decent numbers and the car is still fun to drive. I personally would love to see him drop the motor in and finish it up...because Ide like to see some videos of that sucker gettin it on the street.


Justin

Durango_Boy

iTrader: (1)

Doorslammer71 - I sent you a PM. Thanks so much for the info.

hannes_slanec

Finally my topic is here, before some months I asked for help for my 1968 Impala SS Convertible - 8.1- Project but nobody had a hint.
Actually I did not know that the 496 engine I have bought is that new and needs a lot of electronic as it was not complete. After understanding what I have bought I loved the engine much more as I like the swap to EFI engines.
I will also need a lot of work with this project but I think a 68 Impala with vortec 8100 will be really cool.
I am after the alu heads of GMPP which are used by the guys who built this coolside truck but I cannot find them. With those heads the engine will gain performance and loose weight. If anyone knows about the heads please give me a hint. All I know about is:
GM PERFORMANCE PARTS ALUMINUM HEADS GEN V/GEN VI (12363409)
Link to the coolside project:

http://www.pickuptruck.com/html/auto.../coolside.html

I would like to copy this engine, does anyone know a reason why it would not be the right modifications for my Imp or would it fit for that car?
Tranny will be a 4l80E or 85E and I have already bougth a 3,08:1 12 bolt PosiTraction rear end.
That combo should be good for endless dual rubber strips behind my car!

Greatful for any advise

thanks and best regards

Hannes

big2bird

I find that hard to believe.

big2bird

You bought Curtis' car?

DJ Dep

Hey Bird....do you think that Vette has SPYDERLITES and TWO ALTERNATORS???
This place is gonna need a detector if this guy is posting here.

big2bird

Yep. Don't worry. A Vette weighs over 3,000 lbs. I am not aware of ANY C-3 that light. Maybe he filled it with Helium?