rcutclif's 1974 MGB-GT

Turn the alt backwards. Works regardless of direction of spin 

Great progress man!  Looks fantastic!

On the alternator, I would agree with chopping the frame rail and reinforcing/boxing it back in.

The MGB's projected use case would likely permit and justify such a modification. 

In reply to RACEC4R :

Thank you! 

Yeah the cut and notch is the first try because it is by far the fastest and easiest route to a solution. 

Here's the results of the recent exhaust work. I'm very happy with the results!

And how it fits

And now I'm digging into the rest of the exhaust since it's handy and I had success on the first piece.

Small update here: about 10 days ago I took 2 parts I will never use because I have a GT (tonneau top boot, and some tonneau bows with felt bag) and put them up on eBay for $5 starting price no reserve auction. To my surprise, both sold, and while the tonneau bows only sold for $5, the boot sold for $130!! 

I just got the payment from eBay, so I can 'recoup' $119 of the $150 I spent on those parts. 

Dusterbd13-michael (Forum Supporter) said:

Turn the alt backwards. Works regardless of direction of spin 

Electrically yes, but the fan to cool it does not.

Radiator is pretty easy to move forward.  You can use sheet metal to make up new brackets pretty easily.  I did this in my v6 project

Well, I got the entire front suspension swapped over from the old crossmember to the new crossmember, and got it bolted back up to the car. Everything was super-nasty with old grease from the oil leaking old B motors. 

Both my shocks were 100% blown, and I think I'm going to re-do it a little more thoroughly before making this a full driver. It would probably be good to replace all the bushings and stuff. 

But more importantly, everything fits with the motor! I marked the header where I will have to beat it back some for steering rack clearance. Next step is to get the car back on the wheels so I can roll it outside and pressure wash the engine bay, then onto the alternator work. But all of it might take a backseat for a while, since I'm going to have to put the Jag under the knife for a little bit.  

Had a few minutes so I put the car down and gave it a few "jounces". Quite the large space now between the top of the tire and the fender with the lighter engine and the new crossmember. I think the term here is "mind the gap" - woof.

Anyway, rolled it off to the side for now, need to make space on the lift for a few other jobs.

Robbie (Forum Supporter) said:

Small update here: about 10 days ago I took 2 parts I will never use because I have a GT (tonneau top boot, and some tonneau bows with felt bag) and put them up on eBay for $5 starting price no reserve auction. To my surprise, both sold, and while the tonneau bows only sold for $5, the boot sold for $130!! 

I just got the payment from eBay, so I can 'recoup' $119 of the $150 I spent on those parts. 

I've been in shop cleaning mode recently and put 10 more parts up on ebay. 4 sold last night for another $70 or so, so we can safely say this parts lot is 'fully recouped' and the parts I wanted were 'free'. 

Love the build, I have a MGB-GT slated for the garage in the next two dream builds. 

In reply to TheWraith :

Thanks! It is a classic shape.

In other news, I also happened to find another builder who is doing a Miata diff swap. So I need the front half of the Miata driveshaft and he needs the rear half.

Better than a sharp stick in the eye...

Here I am lining up a relatively straight cut.

More pics of the bandsaw setup?  I'm fairly happy with mine, but I could always use a slightly better setup.

Mr_Asa said:

More pics of the bandsaw setup?  I'm fairly happy with mine, but I could always use a slightly better setup.

I thought I posted a whole post about it but I cant find it. I did mention it in this thread:

https://grassrootsmotorsports.com/forum/grm/ims-bandsaw/179808/page1/

Here are some other pics:

keeping this for later

https://grassrootsmotorsports.com/forum/grm/small-light-alternators/186056/page1/

Following along!

Updates?

metty said:

Updates?

It's been a while for sure, and I will get back to it soon. I have my x1/9 up on the lift currently waiting on injectors and then once I have those I'll better be able to make a plan for it. 

Robbie (Forum Supporter) said:

metty said:

Updates?

It's been a while for sure, and I will get back to it soon. I have my x1/9 up on the lift currently waiting on injectors and then once I have those I'll better be able to make a plan for it. 

the x1/9 has injectors now but also a laundry list that needs completed before the challenge. 

HOWEVER, today marks my 9th anniversary, which also means it has been about 9 years since I last drove this car. I'm setting a goal of driving it again before 1 decade of sitting. 

Good goal.  We will push you. 

Like physically if necessary.  Gumby and I can probably get it up to nearly 10mph it's a fairly light car.  

Well, didn't make my "drive it once every decade" goal, but I did get back at it today. 

First, I happened to have an alternator for a Mazda 12a here in the garage and they looked similar, hmmm.

12a on the right

And the 12a one is a bit smaller:

And wouldn't you know if it fits! Better to be lucky than good is what my mom would say!

I still will trim the "frame" rail a bit for tensioning clearance, but for now I'm quite happy. The 12a alternator also uses a smaller pulley so I might just get a shorter belt. Or u also may be able to swap pulleys.

Next I also started making space for the radiator to move forward. It wasn't as hard as I thought, dunno why I was so hesitant to start this. 

I also pulled out my late mgb fans and covers and stuff so I can start to finalize the radiator position. That will be next.

Today I assembled the fans and the shroud. Looks like it will all work (as expected, since it is all mgb stuff). 

That said, the radiator I have is not exactly straight, so I might try to source a better one before I make mounts. We will see. 

Then I turned to the clutch system. I pulled it all apart and started measuring. The Miata master cylinder looks like it will fit really nicely in the mgb pedal box. I had originally thought I might swap in the Miata pedals and stuff but after looking at it I am convinced the simple solution is best. 

And then since I'm using Miata master and slave set, then the math is very easy. I just have to measure the full throw of the pushrod of the Miata pedals, and then modify the mgb pedal to give a similar throw.

I measured 11/16ths approximately as the Miata throw. Mgb stock throw is very near 1 full inch. The stock distance from the mgb pedal pivot to the pushrod is about 2 and 3/16. 

So, 1 over 2 3/16ths = 11/16 over x, means x or the new pivot to pushrod distance should be about 1 1/2 inches. That's shortening the distance about 11/16ths. 

Because I had it handy, I quickly checked the semi recent copy of grm that covered this exact swap and this exact math. They say shorten by 5/8ths is good, and ideally they'd go a tad more but it gets a bit hard to lower the master too much. I'm glad my measurements and math worked out to the same figure!

Robbie (Forum Supporter) said:

 

Next I also started making space for the radiator to move forward. It wasn't as hard as I thought, dunno why I was so hesitant to start this. 

Well, last time you were working on this was before a lot of F-Dat hackery? More comfortable with it now?

In reply to Mr_Asa :

Quite possible. I remember being concerned that I wanted to make it similar to how the mg factory did on the 78-80 MGBs. 

I think I also got over that feeling!

Please discard the original MGB fan set for a modern fan that won't seize its bushings the next hot day. I understand why they fail, yours will. Lucas used an iron rich alloy in the syntered "bronze" bushings. Too iron rich from the way they gall the shafts. All Lucas motors of the era.

TurnerX19 said:

Please discard the original MGB fan set for a modern fan that won't seize its bushings the next hot day. I understand why they fail, yours will. Lucas used an iron rich alloy in the syntered "bronze" bushings. Too iron rich from the way they gall the shafts. All Lucas motors of the era.

I don't like to disagree with Turner as he's got a lot of wisdom, but, hey, this is the internet. First, I think the factory dual fan setup flows better than any modern aftermarket fan, so I vote to keep them. In my experience, the replacement fan motors are very reliable, but Turner is right about the original being very quick to fail. I imagine you're going to keep the budget low and use original units and my advice is to take them apart and if the bushings are good, liberally grease them. The front bushing is the one that fails, not the rear, and the easy button to keep them long-lasting is to squirt a little oil on the shaft/bushing twice a driving season. I've had my 1978 MGB for 35 years and taken it from 20,000 to 80,000 miles on the original fan motors due to the regular oiling.