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Other items for sale / Gear Shirft Knobs
« Last post by amgba on June 12, 2019, 01:25:17 PM »
Custom, hand sculptured, gear shift knobs of ebony and another hardwood; drilled and threaded. $42 plus shipping. Samples in photograph. Special orders available.
Cars for sale / 1974 B Roadster V-8 conversion
« Last post by amgba on June 01, 2019, 01:05:53 PM »
1974 MGB Roadster V-8 Conversion. Orange PPG acrylic enamel, new chrome, rubber, black canvas top/boot/tonneau. Hardtop. 4-liter aluminum V8, 9.5:1 CR, S-10 rear end (3.07), aluminum D&D radiator, Edelbrock 500 low-profile carburetor, Borg Warner T-5 transmission, Michelin 195-60s. New interior panels and carpets. $20,000. More info/photos:, 310-275-8156, CA.
Other items for sale / Rover V-8 Engine 3.0 L
« Last post by amgba on May 29, 2019, 01:41:43 PM »
Rover V-8 engine 3.0 L.  Aluminum block & Heads. 6M Bell housing bolt pattern,  dissembled, cleaned & cack-tested.  Rods balanced, heads polished, valves resurfaced.  Complete w/hardware, brackets, pulleys. No manifolds or flywheel.  Good crank & cam.  Ready for reassembly to give your MGB 300 hp.  304-268-9440. WV
Electrical Items / Re: Heater Motor Will Not Run
« Last post by Art on May 12, 2019, 11:34:57 AM »
Good to hear from you again, but sorry for your troubles.

Based on what you're seeing with the trouble shooting you've already done, I'd say the obvious fault is a break or short somewhere along the wires from the switch to the fan motor. 
That you are getting no power to the fan lead makes a grounding issue less likely to my thinking, but you should check that once you've got power to the fan lead.

You can check this with the fan motor reinstalled.  You can take power on a lead directly from the fuse box and see if the motor runs. 

If it does, that eliminates any grounding concern.

Clearly you're getting power from the fuse box to the switch and both the switch and motor appear to work properly.  On some cars, there is a resistor in-line before the fan. 

Make sure you've checked if you have power before that to the fan.  You do, the resistor has some issue.  You can also bypass it with power direct to the fan motor to check.

A car this old, I'd suspect and check for any bullet-&-barrel connectors to make sure they are tight, not corroded or broken.  I've been chasing these kinds of issues on occasion over the 30 years I've owned my B. 

In the past, I've had to replace them with newer crimp type bullet connectors, making for some unoriginal looking repairs that work well, but are not as the car was built. 

Original style replica barrel and bullet connectors are now available individually or as kits from most of the catalogs.  Generally it's the thin metal barrels that fail. 

They're hidden within plastic tubes as either single (1 bullet connection at end) or double (2 at each end) so other than having fallen out, faults are hard to see or detect without getting hands-on.

The excerpt from the 67 MGB wiring diagram I've attached shows at least one in-line (circled).  I know on my 74, there's at least (1) at the motor, but another elsewhere in the harness itself.

I hope this helps you.  Keep in touch and let me know how you make out.
Safety Fast!
Art Isaacs
Electrical Items / Heater Motor Will Not Run
« Last post by amgba on May 12, 2019, 11:18:20 AM »
It has been a while since we have corresponded but now I have a new problem. The heater motor wonít run. Hereís what Iíve done so far:

Removed the motor and bench tested it. Ran fine.
Checked the switch. OK (I did this with a multimeter on the wires coming through the fire wall. Switch off no voltage, switch on 11.8V

Ran jumper wires from the wires through the fire wall to corresponding wires on the motor. Nothing.
Checked jumpers with OHM Meter. OK. However Iím not getting voltage thru the jumpers! However I tried testing with the leads from the fire wall directly touching the leads on the motor. Nothing.

The only thing I havenít tried is to ground the motor but since it bench tests OK Iíve kind of ruled that out.

Any ideas on what I might have missed or something else I might try?

Sorry I forgot to mention this is a Ď67 MGB roadster.

Jim Kraft
Morehead City, North Carolina

Engine Related Items / Re: Changing the Distributor
« Last post by amgba on May 12, 2019, 11:38:12 AM »
More on Distributor Replacement

Our first diagnostics was performed in the street outside the Retirement Community where I live.  The ďBĒ fired up, as usual, and was happy to drive around the property.  After about ten minutes, it died.  So we popped the bonnet, pulled the gas hose off of the filter, and turned the key. 

The problem appeared to be in the ignition system. That could mean coil, electronic module, or distributor.  My car still had an old style electronic module on the wheel well.  We putin a new coil while waiting for the new distributor.  No improvement.   Car would still run for about ten minutes, then die.  The starter would spin the engine, but no sign of life for five or ten minutes when it would come back to life.

When the distributor arrived, my son and I prepared to swap it out.  First- check the timing. Then, following the directions weíd received, mark the wires (spark plug and those going to the coil), mark the position of the #1 wire on the distributor, photograph the distributor and the coil wires with cap on and off the distributor, then unbolt and remove the old distributor. The new distributor didnít seem to want to go all the way in, but finally it went home.  A little tightening, then we hit the starter.  It fired and ran, a little grumbly.  The distributor was rotated the timing was back where it had been, and the engine was fine.

 Today was warm enough to run the car. It ran for about ten minutes as I drove it around the property, then died as I was backing up to turn in a tight spot.  But I tried it again in a couple of minutes; it started.  So I drove it around for another ten minutes and decided that it was worth taking the risk. 

First order of business: see if I could get it to the local emissions testing shop to renew the TN license.     But, just to make sure I was paying attention, it stalled when I had to slow down for a car turning off the road a mile or so down the troad.  I pulled off the road, crossed my fingers, hit the starter and away we went. 

 It passed inspection, and drove home very happy.  I have a little work to do on the idle as the gas and the engine drops down to a couple hundred rpm then climbs back up to about 1000). Iíll need to drive it a bit more before Iím totally comfortable but I think the problem is now resolved.
Thanks to all for the support provided. 

John W Philbrick
Brentwood, Tennessee
Engine Related Items / Changing the Distributor
« Last post by Art on October 29, 2018, 01:43:08 PM »
Changing the distributor on a B is fairly easy, especially if you have good mechanical ability.

Unlike American cars, the Lucas (or replacement aftermarket) distributors can only go in one way.  They don't have gears on the bottom, but keys and slots that are different from side-to-sided, so the rotor will always point in the correct direction.  The trick is to reasonably align the number 1 spark plug wire as it was originally.

Also, some aftermarket distributors require reusing the drive (keyed coupling) from the old distributor.  Not a daunting task, but the roll pin that retains it has to be punched-out and the coupling properly aligned on installation to the new unit.  It should be keyed to the shaft, so that becomes easy.

Little tricks:
- Mark all the park plug wires on the cap.  If you don't have the the electrician's numbered bands, a piece of masking tape with the number written in dark ink (Sharpie or gel pen) number works fine.  Make sure the number one plug wire is especially clear.
- Mark the block where the number 1 plug wire is positioned on the distributor. Just helps to get the new distro positioned so the car will start to be able to set the timing with the light.
- Take at least 2 photos of the old distributor before removing it.  One with the cap on (so you can see the #1 plug wire and Vacuum advance pot positions) and the other withe cap off (to see the rotor direction).
- Remove the cap, primary leads (with the CEI you have to also remove the module), the 2-bolt clamp that retains the distributor and just pull it out.
- Remove the clamp from the old distributor (single bolt length-wise across the split side of the clamp) and check the clamp is not bent and the bolt is free and can be adjusted. Repair or replace as necessary.
- Reinstall the retaining clamp to the block with the adjustment bolt still somewhat loose.
- Install the new distributor with the rotor in place.  The rotor should automatically line-up as the keys in the bottom of the distributor should only fit the same way as the old one did.  Determine where the #1 wire would be (that can vary between distributors relative to the vacuum advance pot) and set the body of the distributor so that it is in the same place, either using the photos you took or the mark on the block.

Now, depending on which way you went on the replacement distributor determines what you do next.   I'll follow the 45D4 installation with a Pertronix kit as that's what I'm most familiar with.  The others, being completely different, should come with full instructions, but will only differ in the controls and associated wiring.

With the distributor in place, rotor and cap off, install the Pertronix unit.  A sensor cap goes over the cam that actuated the points on the shaft just below the rotor. 2 screws that used to hold the points in place now secure the reader unit to the plate. 
The kit comes with the wires that replace the primary lead and power source and they have to be snaked through the hole in the lower distributor body the primary lead had gone through.  Instructions are provided.  Make sure in ordering the distributor and Pertronix kit that they match by model.  The kit for a 25D4 will fit the points plate, but the wiring harness is very different and won't fit.  And caps and rotor are not interchangeable.

Fit the cap, wires and vacuum advance line and start the engine.  Once warmed-up, remove and plug the advance line, adjust the idle, fix your timing light and set the timing.  Once set, adjust the idle, tighten the clamp, reconnect the vacuum line* and done.

My personal advice here is a reminder that, with a turbo, the vacuum advance my be hooked up differently or bypassed entirely.  The intake manifold is now under pressure from the turbo, so it won't work conventionally.  With a draw-through set-up (carb before the turbo) it can use fittings on the carb to work pretty much normally, but if you have a blow-through set-up (carb after the turbo), the carb is now under pressure, so no vacuum. 

This could influence your distributor kit purchase, as it may be best to get a fully mechanical advance type distributor, like the one from Crane.  Check and make sure what you have before buying anything.
Moss sells their supercharger kit, so see what distributor they use on that.  Also, sources, like JEGS or Summit Racing carry aftermarket distributors and Pertronix kits for the MGB that may be better suited to your application. 

They routinely work with supercharged and turbocharged racers and hot rods.

Safety Fast!
Art Isaacs
Engine Related Items / Re: Noisy Tappets
« Last post by JohnTwist on May 12, 2019, 11:41:39 AM »
Roger,  Torque the head first to 55#.  Loosen one nut at a time, back it off several turns, oil it, and pull it down to torque.  Follow the spiral noted in the workshop manual.  Then adjust the valves.

Iíve always used the factory setting of 0.013Ē hot.  Now it doesnít matter if the engine is hot or not as the expansion of the pushrod is only 1/10,000 or something Ė but I always adjust them hot.  Once youíve made the adjustments, and I have a good YouTube video on that, then start up the engine with the valve cover off.  Use a 0.010Ē feeler and move down the line, inserting the feeler between the valve stem and rocker at each valve.  If there is a noisy valve (or more), that tick will cease with the feeler in place. 

You then have the option of rechecking that lash or accepting that the cam and lifters need replacement, which is often the case with a noisy valve.

John Twist
University Motors Online
Engine Related Items / Noisy Tappets
« Last post by amgba on May 12, 2019, 11:24:46 AM »
Hi John, we have never met. Brian Woodhams, a good friend kindly shared your email address.

I have watched many of your videoís with interest Ė well done on sharing so much. 

More recently I was fortunate to acquire a 1980 MGB with very low millage (50,000 km), but I seem to be struggling with the tappets which in my opinion seem quite noisy.

In your videon tappet setting, TD/TF example, you seem to refer that on the later model cars a variation of method is required, but I have not been able to find any further information.

I would really appreciate your insights on the method you would use on the 18V series engine.

As part of my quest to make improvements I have fitted a new rocker shaft and checked that the ďstressĒ shims were in place.  I have not checked anything lower down on basis that the mileage is very low, but still 39 years young.

Roger Lewis
Cape Town
Engine Related Items / Re: Carburetor Adjustment
« Last post by JohnTwist on May 12, 2019, 11:42:40 AM »
How are you venting the float bowls?  They should be connected to the charcoal canisters but there must NOT be a low point in the hose.  If there is, then fuel can collect there and prohibit atmospheric pressure from pushing on the gasoline in the float bowls.  Sometimes I see those lines plugged Ė sometimes I see them connected to each other.  WRONG on both counts.  They must be open to air pressure.  If they are connected to the canisters, disconnect them to see if thereís a difference.

Fuel pressure should be low Ė maybe 2-3#.  If itís too high then the carbs overflow and thatís not your problem with this miss.
Float height is critical. Use 90 weight in the dashpots.

After all this, try changing the needles.  You can make a determination about the mixture by examining the plugs after a run at a certain rpm.  Just donít let the car idle after the run.  Pull off the road and check the plugs right there.  Black is too rich; tan is just right; white is too lean.

John Twist
University Motors Online
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