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wearymicrobe
wearymicrobe SuperDork
7/8/15 12:22 p.m.
Boombeartree wrote: In reply to wearymicrobe: I have a worked on building cars with big block mopars, fords, pontaics, and even olds engines but never a big block chevy that's one reason for the 8.1 and also the 8.1 we are getting is really cheap and runs so it was hard not to use it. but yea the 8.1 is pretty heavy will be doing lots of weight reduction to keep the car under the 2500 lb goal.

I will be following it that's for sure. I have been thinking of doing a Triton V10 manual in my next 28 roadster so fitting big engine in small space is a theme around here.

Good luck.

Boombeartree
Boombeartree New Reader
7/8/15 1:22 p.m.

In reply to wearymicrobe:

nice ford v10 i really like those engines i have been working at a ford dealer for over 14 years now and have only ever replace one v10. We have a 5.4 dohc navg motor sitting at home too but it's really large for a miata.

Kenny_McCormic
Kenny_McCormic PowerDork
7/8/15 4:22 p.m.
wearymicrobe wrote:
Kenny_McCormic wrote:
wearymicrobe wrote: If your going to go nuts go all the way and put a quickchange in the rear at least then blowing up cheap spider gears is the only thing you will do.
And a 4 speed dogbox.
Looking at the pictures and where you have the structure hacking the entire tunnel and footbox out and replacing with some sheetmetal. I have a cobra and that footbox looks even smaller then what I have at this point. Trust me it will be un-driveable without the extra space or you will have to offset the steering wheel and seats which make for some interesting issue.

Can't be any worse than a 7 pedalbox, can it?

psychic_mechanic
psychic_mechanic Dork
7/21/15 9:28 p.m.

We found a BBC mockup engine, dredged up from a sunken boat.

 photo DSCF0085_zpspl8fehb6.jpg

Probably need to do some more work to the framerails to get exhaust in here.  photo DSCF0082_zpsx4gykucs.jpg

 photo DSCF0081_zpsjtm4pdq6.jpg

We've got some plans for a transmission. We were looking for a strong cheap manual trans and just happen to have several A833's. They actually put this Dodge trans behind chevy V8 engines for a couple years so we can get a compatible bellhousing cheap and easy.

erohslc
erohslc Dork
7/22/15 11:08 a.m.

Apparently mockup had the rare recyclable fiber composite valve covers ;)

GTXVette
GTXVette New Reader
7/23/15 11:35 a.m.

In reply to psychic_mechanic:

If its a boat motor (mercury) that IS the block/crank/pistons I would use, the Heads May also be Great BB heads Post the Numbers

TIGMOTORSPORTS
TIGMOTORSPORTS HalfDork
7/24/15 6:40 p.m.

High five for the 8.1 motor. Be different. Smoke some tires, Pass the others............

psychic_mechanic
psychic_mechanic Dork
8/1/15 10:12 p.m.

We found an actual engine to swap in. We spent $550 and got a 2002 8.1 engine, flywheel, most of a harness and modules. This leaves us around $1300 left of a challenge budget so far.  photo DSCF0119_zps7sfxoplk.jpg The relatively low mileage dump truck we got it out had a fire in the heater box and got a bit of the harness toasty. I think I have a few coils laying around somewhere.  photo DSCF0120_zpsxwjy1sqd.jpg

moparman76_69
moparman76_69 UltraDork
8/1/15 10:21 p.m.
psychic_mechanic wrote: There's just something so twisted about having nearly 500 cubic inches under the hood (mostly).

Like the unibody?

psychic_mechanic
psychic_mechanic Dork
8/2/15 7:22 p.m.

The new engine fills the engine bay nicely.

 photo IMG_20150802_182753_9961_zpsaktciqdz.jpg

We've got the position where we want it and started roughing in some cardboard motor mount brackets. The final one will have the gussets on the forward and backward edges and the outside open for access.

 photo IMG_20150802_182812_6251_zpsgubpjg9x.jpg

patgizz
patgizz GRM+ Memberand PowerDork
8/2/15 9:13 p.m.

keep at it. i want to see it run

Kenny_McCormic
Kenny_McCormic UltimaDork
8/2/15 10:03 p.m.

Awesome,I take it the stock exhaust manifolds don't fit?

psychic_mechanic
psychic_mechanic Dork
8/3/15 8:17 a.m.
Kenny_McCormic wrote: Awesome,I take it the stock exhaust manifolds don't fit?

One of them didn't fit well, we're going to try modifying the outlet a bit to see if we can get it to tuck in better. If it fails all we're out is a manifold we can't use anyway so we're no worse off than now. We may still end up making a set of headers to fit, so if you know anyone with a cheap set of BBC headers send them my way.

DirtyDiesel
DirtyDiesel New Reader
8/4/15 3:06 p.m.
Jambo wrote: Psychic, here's another idea for you that I've been tossing around (albeit for a much bigger, heavier car): since there's not much in the way of support for the 8100, how about a single turbo Vortec 454? That would be the last gen of the big block, and according to Wikipedia anyway, they even made an HD version with a forged crank, rods, and pistons. I would think that one of those bad boys with a slightly thicker head gasket and a big turbo pushing low boost would be pretty powerful and long lasting (unlike the 8100 when pushed hard from my understanding.) Other fun references: Car Craft ran a budget BB series with a lump from Demon engines in CA and they were able to put down some serious numbers somewhat cheaply. Also, on BangShift, they featured an 80s cutlass wagon with an 8100 and a Doug Nash 5 speed that was done on the cheap. Best of luck with whichever direction you go with. We'll be anxiously awaiting any updates!

I love it!! Thanks for the heads up on that project, 340hp/500tq sounds sick, especially behind a manual trans!

http://bangshift.com/general-news/videos/car-feature-the-secret-weapon-a-1980-olds-wagon-with-496ci-of-vortec-big-block-and-a-doug-nash-5-speed/

TRX
TRX New Reader
9/11/15 4:20 p.m.

My first thought is, "needs turbos..."

A friend of mine has a C4 Corvette with the old 265hp Tuned Port 350. He found an article on the "Big Dog" 454 conversion GM did, found that it was in the Corvette Museum in Bowling Green, and schmoozed them into bringing the car out of storage for us to go look at. I took several rolls of 35mm, this being some time ago...

I can tell you this: that big block fits the Miata at least as good as it fits a C4 Corvette. Minor items like the exhaust ports nearly sitting on the upper control arm pivots caused... issues.

Anyway, in the spirit of demented gearheads everywhere, I hope you continue with this...

psychic_mechanic
psychic_mechanic Dork
11/12/15 6:31 p.m.

Took some time away from the miata, the weather being one of the main reasons. We have located, cleaned and mocked up a NP440 (the chevy bellhousing'd version of the venerable dodge A833 trans). The trans was sourced from a junkyard for $300 and came with a shifter and a bellhousing. We have couple more A833's laying around, so if we spit any gears out the side of this aluminum case the cars getting a cast iron trans. The shifter location ended up being about spot on the stock with our engine set back where it fits.

 photo 1112151733a_zpsav8bacbe.jpg

 photo 1112151736_zpsesmqaeza.jpg

We also located and purchased a parts car for the princely sum of $700. It has what appears to be an almost new top, a 135k 1.6 engine that had a timing belt, water pump and clutch done less than 5k miles ago. It runs and drives fine, but it's in the next state over from here. I must be growing up or growing old because we're going to tow it back on a trailer instead of driving on illegal tags.

 photo 1108151519d_zpspyuyx0pm.jpg

We did tear down our mockup 454 to see what it looked like and found a cracked cylinder. Since the block isn't really anything special I don't think it's worth the cost to resleeve, but it can continue to be a good mock-up block when we need one.

 photo 1020151715b_zpsfibuju2t.jpg

psychic_mechanic
psychic_mechanic Dork
12/13/15 8:13 p.m.

We've been working on the designing the front subframe and trying to fit exhaust in the car. We've narrowed the front frame rails to use 2x3 box as the main load bearing structure. This gained us some much needed clearance around the exhaust ports. These are some used headers we picked up for $70 so they might get modified to fit better.

 photo 1213151520_zpsghgbfkhr.jpg

 photo 1213151520a_zpsb6dpyata.jpg

The headers do want to occupy the same space our steering shaft needs to run though.

 photo 1213151520b_zps2lj5vw6t.jpg

The stock manifolds fit OK though or we may try to find some tri-Y headers or really close fit headers.

Jambo
Jambo New Reader
12/14/15 4:40 a.m.

Awesome.

BrokenYugo
BrokenYugo UltimaDork
3/21/16 10:34 p.m.

Any news?

Acme Lab Rat
Acme Lab Rat Reader
3/22/16 9:51 a.m.

Yeah, fill us in!

Rostamon8
Rostamon8 New Reader
10/8/18 10:43 p.m.
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