1970 MGB GT supercharged beast!

Well work in progress.  New to the forum.  I always had good responses at the MG forum i normally post at, but this time not so much, so here I am.  Bout me real quick, been in the industry over 20 years, worked at independents, spend 5 years at Icon 4x4 as their electrical engineer.  I redesigned the harnesses in the Bronco, FJ, designed the harness in their Thriftmaster, Restos, Derelics etc etc.  Now I do 'transportation wiring'  as a buisness.... @wingnutwiring if your interested...

Onto the build!  1970 MGB GT.  bought it as a roller, it had a rotary in it 2 owners ago, and it has a ford 9" with 4.86 gears an a traction lock.  Im pretty sure it was a drag car.  But it wasnt butchered, and it was complete and very rust free.  Only issues I can find as far as body goes is rust in teh dog legs and bottom of the outer door skins.  Not even that bad, the body is in really good shape.  So it was the right price, and a clean straight body.  That was the big requirement.  I am trying to keep the budget under control in this one.  It will most likely be sold after I enjoy it for a bit.  To make a couple of $$.  In the end, I really wanted to do a GT.  I have a bugeye sprite with a 1275 and a turbo stuck on it, crazy fun little beast.  Ive also done a few MG midgets before.

Since this one was sans engine, and I didnt wanna do a stock 1.8l 4 cyl car anyway i looked into an LS swap.  But honestly, more work than I wanted to do, and with the price of everything byt eh time I get the engine, trans, harness etc etc it was more than I wanted to spend.  There is a company tha makes a drop in kit for the GM 60 degree V6, 2.8, 3.1, and 3.4.  But Ive never been a big fan of those motors.  And power is well, eh.  Also, simplicity and drivability/ease of parts for years to come is super important.  The engine control for those engines is old and not something I wanted to play with.  In comes the buick 3800.  You can literally trace it back to the 215 V8 which is what Leyland bought for its rovers and everything.  You could get an MGB with that V8 in it.  The fireball v6 from buick was a derivitive from that, and the 3800 which yes it had a huge redesign by the series 2, was based of those motors, so it makes sense.  They also maze a bazillion 3800s.  Goto any junk yard and find any GM FWD vehicle, it will most likey have a 3800 in it.  They built the motors till 2012.  Lots of parts, support etc etc.  Good economy, cheep and dead nuts reliable.

So, why would I just do a 3800 when there is a supercharged version out there that just a bullit proof.  So motor is coming from J and J.  Gotta say to see a video of the running car, verified mileage and getting a complete drop out is the only way to go.  Especially with an older engine like this.  There are 3800sc in the junk yard, but I didnt wanna take a chance on that with this one, also they mostly likely have well over 200k on them anyway.  T5 from a 4th gen camaro.  A/C from vintage air, interior and a respray its gonna be sweet.  Everyone does a v8 and I felt this was different enough not to be overlooked and to stand out.  And more efficent.

So, interior gutted, started with the A/C.  Cut the cross brace which is just a 3/4 square tube.  Box mounted, reworked the brace and set it up to be bolted back in.  Console center bracket flipped around and slightly reworked.  The console tucks under the edge of the dash now, and is angled up which is much more pleasing.  The dash angle is pretty much where it was, no room for error with this, its a very tight fit when its all done.  But I didnt wanna cut the firewall like so many people do.  All this brought the console farther forward but it shouldn't cause any issues.  Also stripped the foam from the pillow dash.  Dash needs massaging, holes filled in, same with the console but this is a good place to stop for now.  Im gonna dump the fat plastic rocker switches for the old school Lucas toggles.  I dont wanna stray too far from the original feel.  And I dont want it to seem like I did too much.  I want it to feel like a 1970 MG when you get in it and not go woah thats all way different, even though it totally is.  Its a delicate balance.

So yeah, hopefully this is more appreciated here, I think it will be.  And I like to share this kinda stuff.  Now, pics, there is a lot....

    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
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Hell yeah! This will be a cool little rig!

You will definitely be among friends here. Only social media I connect to! 

Great build, and we love pictures!!!

 I also am a huge fan of the 3800. 

Oh my!  

Nice project ! 
 

welcome. 
 

if you worked At ICON, you must be local. I just picked up a center console from TLC/ICON for my 60 

mr2s2000elise said:

Nice project ! 
 

welcome. 
 

if you worked At ICON, you must be local. I just picked up a center console from TLC/ICON for my 60 

Yep, Socal born and raised.

Lookin forward to the build and the new community!

Great ! Nice to see another local member. We have 5-6 local guys in the forum that post regularly 

looking forward to more of your projects 

BGT is on my list of swap candidates, someday.

1973 in the grosh ......toying with an Ecotec , T5 , 8.8 ford.......or a full on Typhoon /Syclone mash up........regardless  sitting quietly  observing......welcome aboard

Love the split bumper goodness.  I built a 72 GT  like this back in the late 90s with a 3.4liter fuel injected V6 and T5 from a 93 Camaro.  Used  an earlier PCM  sumptin sumptin 727 chip burner...a nuisance.  In hindsight, probably better to go with the stock one and a VATS bypass box (some kind of simple square wave signal)  or a standalone.  V6 swap parts & suspension upgrades from a couple of spots.. Bill Guzman  http://www.classicconversionseng.com and Brian McCullough  http://www.bmcautos.com .  Impressive work on that AC solution.  Looking forward to your build.

Man I love the positive support!  Thanks everyone.  I pondered the 3.4 swap, but the ECU was part of the reason I didnt do it, that and its just old and other than the 3100 GM didnt really use much into the 2000s.  The 3800 im using has basically an LS ECU in it, I dont remember the part number.  The EFI is just so much better in the later stuff than in the 90s.  Aside form turning off VATS and some codes for the secondary O2 and other emissions stuffs, and a VSS recalibration it shouldn't need to be retuned at all, thought ill prolly do a street tune with my usual guy.

Project will have only a few major challenges.  Accessory relocation, removing the P/S pump and moving the A/C compressor, im pretty sure it wont fit in the frame rails.  Building headers, Ive never done it, but I have a buddy who has that will help me.  Im hoping I can go down hugging the block and not through the inner fenders.  And lastly the throttle body is on the wrong end.  I dont know how close it will be to the firewall.  Hoping I can put a 180deg boot on it and be done.  Worst case Ill have to move the throttle body with a 180 pipe and some flanges.  Good thing I know some people with a CNC ;)  This is what people do when they build a far with one of these in a RWD application, or 3800sc swap an F body.

Suspension will be stock for now, new everything of course.  And yeah, love the split bumper goodness.  Im actually gonna have the one bent one fixed and rechromed which is not cheep.  Also the dash is a bit of a challenge.  I need to build an eyebrow on the top, never done that kinda thing before.  Need to hit the craft store to find the right kind of foam.  It will get covered in black vynal.

Will be watching  

Cool project! Dash looks much better without the padding. Looks like you're not planning on using the 9", are you interested in selling it? I'm guessing it might be about the right width for my mk1 Capri.

In reply to Racingsnake :

I am not using it, with the 4.86 gears I'd have to regear it.  Also the axles were 5 lug and the front still 4.  Yes I could upgrade the front brakes to match but that ment a set of wheels.  Stockers I think look great and they are cheep and easy to get.  So that would mean redrilling the axles.  Also the u bolts were stock for the old axle so they were too small.  In the end it wasn't cost effective.  The stock rear is infact a truck rear end and it will put up with around 300hp.  I have new shims for the spider gears and new seals so it should be fine for this project 

The guy I bought the rear from actually wants the housing and axles so that's not available.  The center section is however.  It's in really good shape, pretty fresh inside, infact all you would need to do is gears if you wanted, you shouldn't have to touch the bearings.

Welcome to the Buick V6 minority community! Proof that LS and Miata are NOT always the answers.

I have at least three Buick 225/231 builds teed up. Never got up to the 3800's as I'm "Allergic" to computers. ;)

You will want a WC V8 Camaro trans for better first gear, they are now a bit hard to find and overpriced. After looking at new prices vs used condition at nearly the same I think I will buy new trans from now on. 

As a member of the Buick v6 minority (3400 from a Buick rendezvous stuffed in a miata) ill be watching!

In reply to Dusterbd13-michael (Forum Supporter) :

Technically, despite coming out of a Buick, the 3400 is the 60deg. V6 has its roots in the Chevy 2.8. The Buick 3800, (90deg.) has a much more interesting history than that! I’m a fan of the 90deg. Buick, but I’ve heard good reasons to like the Chevy V6’s from some folks on here. 

Watching with interest, supercharged 3800 is perfect for this car.

It'll be interesting to see how this conversion turns out compared to my own. Different priorities and requirements. My interior was untouched but I also pulled out the stock AC components. I was willing to put the headers through the wheel wells because, well, there's no way they would have fit any other way.

One of the fun things about building an MGB is that there are so many parts bin games you can play to make it look just the way you want it. The body on mine is a 1972 but I mixed and matched grilles and badges and taillights to get the right feel.

It's got a GM V, but has too many cylinders for a 3800 ;)

In reply to autocomman :

Can we be friends? My shop is quite messy right now, but I'm working on that.

In reply to Robbie (Forum Supporter) :

Haaaa you saw the X1/9 in that one pic.  I was wondering if someone would catch that lol.  That's mom's project car.  She had a 74 new and it was her fav car, but it was the worst car she ever owned.  Years ago I got one for her again.  It's next on the chipping block for a full resto.  I have a 1500 with a euro head and cam and a 5 speed.  But that's a project for another time.  There is also a classic mini on a rotisserie in the garage waiting for body/paint $.  An 82 olds custom cruiser that 95% done. That's got a stock interior, stock exterior with wood grain and the wire hub caps, and an LQ4 under the hood with a 4l80e from an 03 silverado.

So yeah.  I just saw a B on facebook marketplace with a 3.8 and it looked like the exhaust went next to the block not through the fenders but I dunno.  Hard to tell from the pics.  So we shall see.

03Panther said:

In reply to Dusterbd13-michael (Forum Supporter) :

Technically, despite coming out of a Buick, the 3400 is the 60deg. V6 has its roots in the Chevy 2.8. The Buick 3800, (90deg.) has a much more interesting history than that! I’m a fan of the 90deg. Buick, but I’ve heard good reasons to like the Chevy V6’s from some folks on here. 

Yup! I was just being a dork. The 90degree v6 stuff is neat, but i think the 60 degree stuff packages better and sounds better. With the obd2 ecu, hp tuners is wide open. My miata is running 14.2 at 96 all moror at the challenge,  and is daily drivable. So, its DEFINITELY worth the time to investigate. 

However,  forced induction is all aftermarket though. No commonly available factory stuff. And the roots blown 3800 is just a FUN engine. In a Pontiac gtp. Only experience ive had with one. 

autocomman said:

In reply to Robbie (Forum Supporter) :

So yeah.  I just saw a B on facebook marketplace with a 3.8 and it looked like the exhaust went next to the block not through the fenders but I dunno.  Hard to tell from the pics.  So we shall see.

My car has an LS1 in it, so it's a 90 degree instead of a 60. It's also a larger displacement engine. So it may be possible to keep the headers inside the fender wells with the smaller engine. In my case, I had to go with a smaller diameter steering column to keep from fouling the head bolts.

In reply to autocomman :

Shame about the housing, pm sent on third member to avoid cluttering up your thread.

60 deg v6 you can keep the headers tucked.  Infact classic conversion engineering sells em, along with a bolt in kit for the 60 deg.  The 3800 is supposedly 1 inch narrower than the 215 v8.  Aldo my car has had the firewall massaged flat like the V8 cars did by the guy who put the rotary in.  So I don't have to do any of that leg work, another reason I bought it and went with the 3800.

Motor came today, props to J and J, motor looks great, no wiring cut, strapped securely to a pallet and drained of all fluids.  Also the vids on their site proving mileage and why it's at their junk yard, good stuff.  Also got the fuel tank and pump.  Getting a stock replacement tank with a tanks inc GPA-A sending unit and a delco EP381 pump.  Should be fine for a stock engine.  I dont like external pumps either so this will work well.  I did the same setup in the turbo sprite, and that tank was below the min height they said I could do it with.  Takin a break this week.  There will be progress come the weekend

@racingsnake, I'll PM you soon as mods give me access.  I only just signed up for the account so I gotta wait for it to all be legit, so says the magic being in the box that says I have to wait to PM