MGA Guru Is GOING MOBILE -November 16

The MGA With An Attitude
MGA Guru Is GOING MOBILE - (November 16 - November 30, 2024)

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Saturday - November 16, 2024:
While waiting for paint to dry, I had time to update a Restoration tech page for Boot Floor Panels. You can now buy this one-piece restoration panel from Jon Thompson at Sports Car Specialties in Ada, Missouri.

Sunday - November 17, 2024:
Strip off the masking tape and pull wadding out of ports and tapped holes. Looks ike an engine block with nice paint, so yes, begin assembly.
We oiled the inside of the block first, just in case it might be longer than anticipated before it might be running, and keep everything clean. Three main bearing half shells with oil,then the crankshaft nicely oiled all over. Three more half shells in the min bearing caps, center cap with thrust washers, give it a spin to assure it turns freely. Then the front and rear caps with more oil, and give it another spin with fingers. Notice this MGB 18G engine has locktabs for the main cap nuts,different than earlier engines that had lock washers here.

Oil the camshaft journals and heavily grease the cam lobes before sliding the cam into the block, then test spin with fingers. Temporary fit the front plate, and scribe the rear surface at sides of the block.

Remove the front plate to remove paint from the rear side where it will mate with the paper gasket, just to assure it will have flat surfaces for a good seal (not gasket over paint). Install the front plate with paper gasket and the cork strip at bottom corner of the front main bearing cap. RTV sealant was applied, because this cork seal had small end gaps. Once it was bolted firmly in place, we trimmed the cork seal flush with a razor knife.

Take a short break to paint a new MGA water pump, as it was the net thing out of the box. Then we encountered an odd problem with a new timing chain tensioner, something I had never seen before. The traditional tensioner shown at top of next picture, with the new tensioner immediately below. The new one is three pieces only, no backing plate, no gasket, no bolts or locktab, no internal anti-back out step cam, no rear plug or locktab. Also no alignment spigot at the oil inlet port, and no drill hole to allow oil through the rubbing foot to lube the foot and chain. Additionally, the rubbing foot is made of soft plastic you can impress with a finger nail, or poke a hole in it with a screw driver. I am skeptical if this new tensioner can be functional or if it might last more than a few thousand miles before self destruct. And "Made In Taiwan" is not reassuring.

I will set this issue aside for more consideration over night. Meanwhile we did install the camshaft retaining plate and timing chain and sprockets (sans tensioner).

Monday - November 18, 2024:
I placed an order with Moss Motors this morning for a new Rulon timing chain tensioner (along with a few more parts). I have so far never been bitten by failure of this part, and I don't like the idea of installing another skeptical looking cheap replacement part with unknown service record. I also called the vendor to offer my comments on the odd new tensioner. Of course the response was that we have never heard of any problem with this part, and I'm the only person to ever report any concern with it. The rest of the conversation was not encouraging (or convincing). The new style part is supposed to be from a Datsun 1500 Roadster engine. I just don't feel like serving as Guinea Pig on this one. Been having too many other poor quality parts problems recently. -- Much of the day spent posting the photos and notes above, and there was a John Twist Zoom tech session this evening on "Setting up MGB Front Wheel Bearings".

Tuesday - November 19, 2024:
Big surprise. The Moss order placed and shipped on Monday arrived Tuesday afternoon, one day delivery from UPS. As it was projected to be 2 to 3 days, I wasn't looking at tracking information, so didn't know it was here until Wednesday morning.

Wednesday - November 20, 2024:
Back to work. Punch the old oil seal out of the timing cover to install a new seal. Notice this early MGB timing cover is same as late MGA 1600-MK-II style, with the seal inserted from outside. As such, it uses the same cup shape oil thrower ring as all MGA. We cleaned some paint off of the engine front plate to assure that the paint wouldn't interfere with the cover gasket.

We installed a new timing chain tensioner, Rolon brand, similar to the OEM part, and put the oil thrower in place before closing the cover. install a new gasket with a little sticky stuff, and install the cover with loose screws. Install the crankshaft cover temporarily to centralize the cover seal on the pulley hub. Tighten a few screws to hold the cover in place, then remove the pulley before tightening =all of the cover screws, and reinstall he pulley. In this case we installed the harmonic balancer that was original for this engine (beginning mid production of the 18GA engine), with a new locktab and original hex head bolt (for now). Left the bolt loose and locktab not set, anticipating installing the MGA dog nut here (once it comes out of the car) so we can continue to use the MGA starting handle.

Roll the engine on its side and get on with installing pistons. While removing the old pistons from the conrods, #2 gave us some problems. The wrist pin was seized so tight in the piston that it wouldn't move tall. We ended up clamping the piston in a vice and hammering the conrod to move it to one side for access to the pinch bolt. Then lay the piston on its side and use thick punch and heavy hammer to drive out the wrist pin. After that ordeal, the old piston was dropped into the nearest dust bin, along with the rest of the old pistons. Installing new pistons on the rods, installing rings on the pistons, pushing pistons into cylinders and connecting big ends with oil in the bearings was more standard fare. We soon had a new oil pump and pick-up screen installed, as well as the pressure relief valve and side plug. The crankshaft still turns easily with a short lever and one hand, with only nominal resistance from new springy piston rings dragging on freshly honed cylinder walls.

I was going to install the new water pump when we discovered the new bolts procured with a recent parts order were all too short. The two longer bolts were close enough to use in place of the two short bolts. Hunting for longer "long' bolts when we decided to call it a night and come back tomorrow.

Thursday - November 21, 2024:
Back to work on engine assembly, we're getting there. Finally found some 1-3/4" long bolts for the water pump, ran out of threads in the blind tapped holes in the block. Ground 1/8" off the tips to make 1-5/8" long. These bolts could be a smidge shorter, maybe 1-1/2" would be good. -- Installed the sump temporarily with six screws, no gasket. Thinking we may need to install the cork seal strip at back and bolt on the engine rear plate before final installation of the sump, but the rear plate we need is still in the car until we will pull the old engine out. And we ultimately want to set the engine upright before installing the right side engine mount parts. Still thinking about how to install the sump with rear cork strip before the rear plate.
Time to replace the spigot bushing in rear end of crankshaft, as the clutch alignment tool would wobble some in the old bushing. I pulled out a new busing just received from Scarborough Faire, slipped that onto the alignment tool, and the new bushing wobbled some on the tool. Say what? The new bushing also looked a bit rough,not as smooth as I am used to seeing for a good Oilite bearing. Measuring the bushing ID with a dial caliper shows the bore to be 0 .629" where it should be 0.625 to fit with the 0.623" spigot on the gearbox input shaft. Curses, out of spec bushing. We then pulled a spare bushing out of the Magic Trailer. That one had a Moss Motors part number, looked smooth, measured 0.625" ID exactly to spec, and fits well on the alignment tool. We will install this one, and see how far I can throw the out of spec S/F bushing.

I have this neat tool for pulling the spigot bushing with a slide hammer. I think it was originally a fender pulling hook. Many years ago I ground it down for this special application. First used to pull a 15-mm needle spigot bearing from a Mazda RX7, it is a tad small for the 5/8" bushing, but still works a treat.

There is a neat trick for installing an Oilite bearing, so you don't need to soak it in oil for 24-hours. Set the bearing on end on your finger tip (or thumb), and fill it to he top with oil. Place thumb on top to seal it, and squeeze until you see the bearing "sweat" through the porous sides. Instant lube for the Oilite bearing ready to install immediately. Push or tap the bushing gently into place. Start with a flat face tool to drift the bushing in until flush, then you can use a wrench socket to drift it home to the shoulder in the crankshaft. With oil on the clutch alignment tool it should be a perfect fit, no wobble, and a nice vacuum tight "pop" when you pull the tool out. If you accidentally put a small burr on the edge of the bushing bore, it can be easily cleaned out with a rat tail file, no need to use a 5/8" reamer.

Time to install the tappets. We have kept them in order with numbered tape on each one, although it likely wasn't necessary here. Pretty sure this reground cam and new tappets have zero running time, all new stuff. Notice the tappets are ground with a slight crown on the "flat" end. With a thin film of oil it gives a nice mirror reflection of my fingertip. Oil the bores and the tappets, and drop them right into place.

I was going to install a new shaft seal in the tachometer drive housing when I began running into some dead ends and confusing blind corners. the tachometer drive housing on the engine can,in theory and in common practice, use the same seal as he speedometer drive housing in the gearbox. It should be 5/6" shaft, 9/16" housing bore, 1/4" wide seal. BTDT multiple times with my MGA, both speedo drive and tach drive. I have (had) a spare seal in the Magic Trailer since five years ago (procured from Moss Motors), and I recently ordered another one from Scarborough Faire (which was maybe missing from the package on delivery). While navigator was pulling the spare seal out of the trailer, I was disassembling the tach drive from the MGB 18G engine, removing the shaft, seal retainer and seal. The seal removed looks like a standard O-ring (hard as a rock), tight on the shaft but loose in the housing. Guessing this is not factory issue. -- The new seal was correct size to fit in the housing, and he pinion gear shaft of course fit in the housing (because I had just pulled it out). But the shaft did not fit through the new seal. Huh? Measurement shows the MGB tach drive shaft to be 3/8" diameter, and the housing bore as well.This means the tach drive shaft and housing and seal have to be different part numbers for the early MGB 3-main bearing engines. Go figure, new to me, and I don't have a seal for it. -- Seems like the expedient fix will be to transfer the tach drive assembly from MGA 1600 engine to MGB 18G engine. If I do that, there will be forever the issue of keeping track of which parts were used to build the Frankenstein engine. And this will suck up more time for documenting the dimensions and part numbers for the MGB tach drive parts. Such is life.

Still going, we installed the head studs in the bock, and the left side engine mount bracket and rubber mount. Installed threaded studs for the tach drive, and on left side of engine in the dummy (blank not machined) space for a mechanical fuel pump (not used for MGA or MGB). These studs are used to attach the draft pipe and fuel vent/overflow pipes from the carburetors.

I finally figured out how to handle the cork strip seal at he rear main bearing cap to sump gasket joint prior to installing the engine rear plate. Bit of finesse to insert the strip seal on edge, slobber sealant on it and hold it in place (push, push, push) while tightening the sump bolts. I used a thick cork gasket for the sump, gluing the gasket to the sump flange with sticky stuff, and greasing the top side of the gasket for easy release next time it might be removed. -- The tappet covers got new bolts with rubber covered flat washers and silicone rubber gaskets (Michael had them handy). I'm usually happy with cork gaskets here, but the cork parts seem to shrink a lot in storage making them sometimes difficult to install if they are not fresh issue. A few years go I had to make my own cork gaskets from two layers of 1/8" cork hand cut and glued together, kind of a pain. So in the future I may carry silicone tappet cover gaskets for spares.