rcutclif's 1974 MGB-GT

In reply to Carl Heideman :

Oh my, that's really nice to look at. Is the B-pillar trim blacked out? In that last photo the roof line is highlighted so well.

This morning I did some staring and thinking while drinking coffee. Not much work done. I did pull the battery out and put it on the charger. 6v (its a 12v battery) ooops. 

Robbie (Forum Supporter) said:

With some other projects out of the way (jaguar brakes, building a standing desk for wife, building the closet barn door in the background, shoveling the driveway a zillion times, etc) I finally swept the shop today about 4 times and got the next patient on the table.

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Let's talk goals for a minute. I want to drive the snot out of this car when it is done. Like, not worry about taking it to a rallyx if I feel like it. Or not worry about tossing the keys to a friend if they are in town for the weekend. I want to wind it out frequently. 

I also want something that is daily driveable. So heat and interior at a minimum. I'd love it to be quiet ish inside and comfortable. Functional. 

I've already got the 1.6 miata motor and barring any significant issues that's what I'm going with for engine/transmission. I've also got a lot of other miata stuff that will probably find its way into the car. Pedals for example. Wiring harness (yes, I think I want to replace the mgb harness entirely). Fuel tank. Stuff like that.

Anyways. The car is dusty. Apply broom, then a couple rounds of water from a squirt bottle and rags. I thought I remembered paint under there...

Here's where I was under the hood.

Measure carefully:

I confirmed for myself that it should fit. The steering rack is going to be tight on the crank pulley. Then parts started flying.

If you're wondering what this stuff is, it is a home depot mismash of stuff I used a long time ago to make the mgb shoot a stomp rocket out of the grille. I fully plan to keep it (but maybe improve the system a little bit).

Next up, make a plan! (I'm already re-reading the grm stories on this swap, again).

I do intend to do similar to what I did last year with f-dat and spend the first hour each day working on this. I've mostly continued to do the first hour thing and it is awesome for getting projects moved forward as well as good for the soul. Maybe I'll keep track of time, we will see. Did about 4 hours today. I'll keep track of budget too, but this would only ever be a backup challenge car. I'd want to have no issues jumping in and driving it to the challenge and back, however.

Hey!  I've been shot by that damn rocket!  On your wedding day I was smote in the parking lot...

Lets take that contraption to 11.  I'm thinking compressed air, little more mass, laser pointer/red dot sight...

Popped the motor mounts off this morning, I'll be grabbing a new set so I might as well do it now.

Also I took the shifter off to ease the frequent install and removal program I'm about to start, but it was still full of oil so I put it back for now. I do need to order another one of these shifter boots.

Is it possible the shifter has different oil than the rest of the trans? I'm surprised to see oil in there when it's not leaking out the tailshaft...

Robbie (Forum Supporter) said:

 

Is it possible the shifter has different oil than the rest of the trans? I'm surprised to see oil in there when it's not leaking out the tailshaft...

Yep, separate oil reservoir for the shifter. I'm excited for this project! I love MGB GTs, not sure if I fit in them though.

Had both cars - a 72 bgt and a 90 miata.  That driveline is very much in keeping with the spirit of the car.  Did the whole HF engine stand rotisserie on the BGT...so...much...rust...sills, floors, bottoms of..well everything.  The laycock OD made it bearable on the highway, the 3.4 & T5 swap, moreso.   

If you are going to freshen up the 1.6, pop off the crank's toothed cog, notice that the woodruff key cutout in the crank snout is widening to the retarded side, slather a little loctite 660 on the mating surfaces, then reassemble holding the cog tight to the advanced side of the keyway, use a new bolt, torque to spec, let it set for 24 hours and you will be golden. The design is a tapered fit and there is almost just enough surface area to get the job done, but sometimes not.  Later years got a longer snout and larger diameters and problem solved.  660 sets in the absence of air and that cog will NOT move once it sets.  To remove again if you, say, use the wrong length bolts to secure the accessory pulley and hack up the front main seal (guilty as charged) heat it with a propane or mapp gas torch for a few seconds and it will slide right off.   Don't heat it, and you will bend a steering wheel puller trying.  Guilty again.   

As for Loctite 660,

In reply to BrianC72gt (Forum Supporter) :

good info! Does that apply to the "long nose crank" as well? I just double checked and my crank pulley has 8 slots. Must not be from a 1990 I think. 

cmcgregor (Forum Supporter) said:

Robbie (Forum Supporter) said:

 

Is it possible the shifter has different oil than the rest of the trans? I'm surprised to see oil in there when it's not leaking out the tailshaft...

Yep, separate oil reservoir for the shifter. I'm excited for this project! I love MGB GTs, not sure if I fit in them though.

The BGT is very large inside incredibly. Much larger than a miata with the top up for example. 

Ain't no turning back now...

Also, I'm going to just replace this hydraulic ram. Doesn't hold pressure anymore. Yes, I could probably take it apart and replace the seals. Not sure I want to mess with it right now. If it really was 12/2005, that's 15 years.

In reply to Robbie (Forum Supporter) :

I recommend the air over hyadraulic rams - makes lifting the engine quick and effortless.

Ain't no turning back now...

I'll be doing the same thing to my GT starting this weekend.  I've booked two weeks off to get the bulk of my Zetec swap done.  I'll be keeping a close eye on your progress to keep me motivated.

I just got the cheap $50 manual pumper.

Already tried 2 times to fit the engine and hit major snags each time. First time learned I needed to take the shifter off. So I drained the shifter oil (and the spring thing fell out - I assume the spring goes toward the plug...) And taped over the opening. Will need to improve that.

Second time I learned my engine crane isnt long enough. GRRR. So I'll have to pull the bumper to see if that gives me room. 

Also, my load leveler is an arm workout.

Getting there (haha).

Robbie (Forum Supporter) said:

...

Also, my load leveler is an arm workout.

Getting there (haha).

Weld the handle and a nut to the threaded shaft, then drive it with an impact driver. Give your trigger finger a workout, not your arm

Haha, have I inspired you to get back to the project with my 70?

Mark

autocomman said:

Haha, have I inspired you to get back to the project with my 70?

 

Mark

Yes! The build thread section of grm is one of the most inspirational areas of the internet.

Got the bumper off and the engine crane still isn't quite long enough. Nothing a prybar can't fix, but annoying. Might have to re-arrange and try to go over from the side.

I spent an hour or two yesterday and got the engine in "a" position. Need to start making some decisions.

Engine is raked back (nose high) 3 degrees, which I think is the spec mentioned by carl. I've pulled the driveshaft to check the angle of the pinion flange at ride height, since that will confirm or sent the 3 degrees. More on that later.

Engine mostly fits great. Alternator is close, may fit with some small clearancing. Steering rack and header are becoming close friends. From where I'm at the engine still needs to go over to the driver side about 3/8s inch to be perfectly centered.

The cutout of the clutch slave is like it was meant for this drivetrain.

And the engine could go backwards a bit more if needed too.

Even the shifter lines up purty good.

All that said, I've got to make some decisions.

1. Engine is still pretty high up front. I doubt the hood would close. I had a 3/4 inch chunk of wood between the oil pan and the cross member. Could maybe go down some but not much.

2. The bigger issue is the front pulley and the steering rack. Wasn't quite touching where I had the motor, but belt replacement wouldn't be possible. I could machine off the front pulley part - but I'd like the option to run AC in the future.

So options options options. I'm comfortable modifying the cross member. Not worried. But moving the steering rack is a pain. Gotta do all the work to check for bumpsteer and reposition the rack, but then also have to extend the pinion shaft and stuff. But many that helps with the header interference? I could just get the RB crossmember and steering stuff. Bolts in, and should have more room. 

I could move the engine back some. Would need to go back about an inch for the pulley spacing. That's starting to put the shifter further back than I'd like, but maybe a bent shifter could mostly make up for that. That doesn't help with alternator clearance much though, maybe makes it worse.

Maybe I can find someone who wants to swap crossmembers with me?

Regarding the crossmember and positioning, you've said it right:  Easy to notch to get the engine lower, but moving the rack and getting the geometry right is a lot of work (and a lot of compromises).  Also, when you get the engine lower, you're going to have more trouble with the alternator clearance.  That's why I've used the smaller ones from Geos. 

You can move the engine back to avoid the rack clearance issues, but then the shifter goes back further and the coils will hit the heater, so you'll deal with those issues.  

My strategy for engine positioning on a street car is to make the compromises that aren't too much work and allow for relatively easy servicing later on.  Perfect is the enemy of good enough...finding the perfect technical solution (far back and low) makes the job much more difficult.

That's why I think a chrome bumper crossmember is the easiest compromise.  Rack clearance, oil pan clearance, back-of-engine clearance and shifter placement are pretty easy.  Lowering springs are an easy way to bring the ride height back.

In reply to Carl Heideman :

I went back and re-read the article on steering you did, even with the RB crossmember. Is there a reason you went for the extra u-joint and extending the CB steering shaft VS just using the RB steering shaft that would match the crossmember?

I started the process of removing the front subframe this morning, and I have started the process of searching for a RB crossmember to replace it with. 

Robbie (Forum Supporter) said:

In reply to Carl Heideman :

I went back and re-read the article on steering you did, even with the RB crossmember. Is there a reason you went for the extra u-joint and extending the CB steering shaft VS just using the RB steering shaft that would match the crossmember?

The rubber bumper rack has a longer shaft that is matched to a different length steering column.  If you use the rubber bumper crossmember and rack with the chrome bumper column, the length and position isn't quite right.  I guess you could use the crossmember, rack, and column from a rubber bumper car (I've never measured it out or tried it).  But the rubber bumper rack is also slower than the the chrome bumper rack to make the rubber bumper cars have less steering effort.  I like the faster chrome bumper rack and don't feel the effort is an issue.  So the extra U-joint and custom shaft is a fairly easy way to deal with all of this. 

In reply to Carl Heideman :

oh, duh! the shaft actually would be connected to the 'rate' of the rack since the end of those shafts are twisted and that drives the rack. So you can't put the longer shaft on the early rack. duh. 

I wonder if the hubs are different then? because otherwise maybe I could just carefully measure where the RB crossmember puts the rack since I'm going to be messing with extending the steering shaft anyway. 

I think the RB and the CB crossmembers have the same rack mount locations relative to the rest of the front suspension, but I've never measured.  If the rack mounts were in a different spot, the bump steer etc. would change and I don't think the factory did that.  The stub axles, steering arms, etc. are the same between RB and CB, so the rack should be in the same relative position. The RB crossmember has a spacer welded to the top of each that raises the car up and also "lowers" the top of the crossmember relative to the oil pan, giving you more clearance.

Not quite sure what hubs you're talking about?  Stub axles (aka kingpins)?  Wheel hubs? As mentioned above, they don't change.  Just springs, rack, crossmember, brake hoses changed.

Now I'm really interested to see when I get both crossmembers next to each other. I guess I was referring to the combination of the kingpin, hub, and steering arm as the generic 'hub'. 

If the steering arms end (where the outer tie rod bolts in) and the same point relative to the wheel on both CB and RB cars, then the rack position relative to the wheels should be the same to not affect bump steer. 

I'm assuming the wheels don't move forward or back significantly with respect to the car on the CB to RB change, only down (raising the ride height). That means if the above assumption is true, then the rack also only moves down with respect to the car. It SEEMS like the RB rack is also further forward with respect to the car, but that is the part I'm interested to see. 

Robbie (Forum Supporter) said:

It SEEMS like the RB rack is also further forward with respect to the car, but that is the part I'm interested to see. 

You might be right--it's been awhile since I studied any of this.  One thing that was going on with rubber bumper cars was that they were using parts that they either designed to be in common with the V8 cars, or just plain left over from the V8 cars since they didn't sell many.  The motor mounts changed to the V8 style in 1975 and the inner fenders, radiator, fans, and radiator mounts were changed to the V8 style in 1977, after the V8 was out of production.  They may have moved the rack mounts forward and/or down to clear the V8 front pulley.  

Crossmember out!

Note the tube shock conversion that was done before I bought the car in 2004. I wonder if the lever shocks are still working too...