Durango_Boy

iTrader: (1)

I was not sure which section to post this is as I did not see anything specific to the Gen V and Gen VI big blocks.

I'm working on a project to put a fuel injected 8100, or 8.1L 496 in a 1974 Corvette.

Here is the proposed outline:

FI 496 - TH200R4 - 3.55 Rear End

I understand the 8100 will share the old standard big block exhaust manifold bolt pattern as well as shared motor mount locations.

I will need to know specifically if the 8100 will bolt up to a TH200R4 with the multi fit case.

Does anyone know the compression and total height of the motor from the center of the crank to the top of the manifold?

Any extra tips are welcome.

Thanks guys?

DB

Durango_Boy

iTrader: (1)

Bumpity bump bump...

bczee

iTrader: (12)

The bolt patern of the bell housing is the standard Chevy and should bolt up to your TH200R4. I hope that this is a built unit, cause that is a lot of torque coming from that 8.1L to that little TH200R4.

I not sure about the crank to the top of the 8.1L intake, but bottom of pan to top of intake is 30.5".

LS1MCSS

iTrader: (18)

I don't know anything about the 8100. The LS1 will bolt up, but you have one bolt left out. If the 8100 uses the older style exhause pattern and motor mount locations, my guess is that it will bolt right up to the tranny.

Durango_Boy

iTrader: (1)

Thanks for the insight guys. I'll want a crank center to top measurement so I can tell what my hood clearance problems will be.

The TH200R4 will indeed be built, as I'll do that myself using a kit and some instructions I have seen passed around. I've done a TF727 and I don't imagine a GM trans will be much harder.

bczee

iTrader: (12)

Are you going to use the Truck intake or a aftermarket intake (EFI or Carb) ?

tirefryin_s10

iTrader: (3)

lol my mildly built 200r4 handled over 550 rear wheel ft lbs no problem with the right mods they are avery stout trans for an overdrive

Durango_Boy

iTrader: (1)

I will be using the stock EFI intake if possible. The hood is a stinger hood and there is more room at the back. What I'm thinking of doing is flipping the EFI manifold so it's drawing air from the back of the hood at the cowl.

Durango_Boy

iTrader: (1)

Yeah there are a bunch of guys on my Corvette forum that have non-built TH200R4s behind high HP motors...some even race, and they hold up fine. Very stout transmission.

Speartech

iTrader: (14)

Looks like 21" from the crank centerline to the top of the intake:

Durango_Boy

iTrader: (1)

Awesome man, thanks so much. Looks to me like you have the inside scoop on this engine and I will for sure be hanging on to your number. Thanks again.

By the way, I have a cam thread open about this very same motor and was wondering what options there are to replace the cam with something a bit more 'lopey' that will improve performance and give me that choppy idle I love where the car shimmies a bit.

Thanks so much.

Durango_Boy

iTrader: (1)

Is the 8100 a roller motor?

ryanvv355

iTrader: (17)

I don't know about you guys but I'm pretty involved with the Oldsmobile community, the only OD trans that we have, short of a gear vendors, is the 200. With big torque motors like BB BOP's and in this case the 8.1, the 200's don't hold up, except for the real high dollar units with aftermarket forged parts inside. Maybe in a light Vette it wont be a problem, after all it isnt a 4,000lb 442. Just my $.02

Durango_Boy

iTrader: (1)

Yeah, my Vette, after some lightening, is right around 3200.

Durango_Boy

iTrader: (1)

Would it be better to have the stock harness and computer modified or buy and go through the Megasquirt process? Aside from the cam swap I won't be trying to squeeze every last bit of HP out of it as I can. I like lower RPM cruising mostly and will enjoy the torque more than the HP.

Rodder

iTrader: (2)

Use the stock harness and PCM, and buy HPTuners or EFILive to tune it.

Durango_Boy

iTrader: (1)

Thanks. I wonder how hard it would be to modify the stock harness myself. All I will need is engine management stuff. I know I'll be deleting anything I can like VATS and EGR and SMOG and transmission control so I hope all that's available.

wannasupra

i believe megasquirt can be set up for v8's. as long as you're good with electronics. that's a fairly popular ems in the srt community. if you don't want trans control, don't build it in.

Durango_Boy

iTrader: (1)

Yeah, I guess I'm not sure about that part. I will be using a TH200R4 and it may or may not need control. Any insight there?

93Polo

iTrader: (5)

I believe the 8100 is a tall deck so you may have some problems fitting it in a C3, a normal BBC is rather cramped.

Megasquirt has been hooked up to an 8100. http://www.lt1swap.com/ has some info and the owner does post on here. Also the 8100 was not built to spin high rpm. If you do plan to mod it you may want to consider new rods and pistons.