Monthly Archives: February 2019

Pontiac renovations, part 14.

When I removed the engine from the car, I had undone some of the cylinder head bolts in order to attach the lifting chains. As such, the whole lot needed to be slackened off and re-torqued down in the correct order.

Collection of head bolts.

The bolts were all very randomly tightened, mostly due to dirt and rust in the threads, by the feel of it. I decided to remove them all, take the head off, give it an inspection and clean, chase the cylinder head bolt threads through in preparation for refitting.

Block side of cylinder head.

The cylinder head came off without any trouble. It doesn’t appear to have been leaking badly and the deposits were a little dark but still within acceptable range.

Head gasket.

The head gasket is in moderately good shape, although it appears to have been reused a few times already. I think I shall be purchasing a replacement. The head and deck facing surfaces were a bit dirty. One valve was stuck open (far right in the image below, no. 8 exhaust), as the coolant gallery had weeped past the gasket, drawn in and made the valve stem rusty enough to stick. I coated it with penetrating oil, freed it up and now it operates correctly again. I had noticed one cylinder was down on compression the last time the engine was run- this will be why.

Cylinder block.

The deck itself appears to be in good order. The top is straight and level, though it required a clean. With no compression the engine turns over moderately smoothly. I think the bearings have been replaced without the crank having been ground. It feels a little tight between power strokes, indicating mild ovality of the crank journals. I can turn it over with my 8″ ratchet, so I’m going to leave it as-is because the oil pressure was very good and there are no other issues.

Hone marks on cylinder walls.

Two of the bores show fairly heavy hone marks still.

Worn shiny bore; 0.040 mark on piston crown.

The rest are quite mirrored but are not scored. All of the pistons are stamped 40 thou’ overbore.

Clean piston crowns- pots 4 and 5.

A rag with some carburetor cleaner on was all the pistons needed to come up clean. I do not think this engine has seen many miles since it was last apart.

Gasket scraper.

I started to clean the cylinder head up and came to a rapid halt- the blade in my scraper was no more good.

New tools.

I went to the store and bought some more tools- a box of 100 #9 razor blades for my scraper, a big wire brush to take the black paint off the engine and a tap set to chase out rusty and dirty bolt holes.

Making a start on cleaning the cylinder head faces.

With a new blade, I was able to start cleaning the cylinder head. In the image above, the baked-on dirt in the corner between the bolt hole and coolant passage is visible still. Although very fine, this is enough to cause a new gasket to weep.

I also made a start on de-coking the combustion chambers with a brass brush. It would appear that somebody had made a half-hearted attempt at it, but had missed a lot around the periphery, where the gas flow needs to be smooth and uninterrupted for good power and economy.

Clean cylinder head.

The cylinder head started to come up nicely. I ran out of time to do any more but initial impressions are good. There’s no pitting, marking, cracks or any other problems to be seen. It just needs meticulously cleaning and then it will be ready to refit.

Spray protectant.

I bought a can of heavyweight oil, designed to sit and prevent rusting up of the internals of an engine that’s to be lain up for winter. It also works well to protect engine surfaces that are left uncovered (bores and mating faces) while they are disassembled.

Coating the metal to protect it.

Everything was given a liberal coating of oil before being left to sit up overnight. More cleaning is due. The engine is going to receive a coat of paint also. It should be a deep green, the closest I can see it should be is Brunswick green. I may have to buy John Deere green and Ford blue engine paints and mix the color myself.

Pontiac renovations, part 13.

Work started again on a cold weekend in February.

I jacked the car up to inspect the suspension and surrounding areas on this side. I also started to check for spiders and other biting creatures that may be inhabiting the dark, secluded spaces offered by the wheel wells and back of the radiator cowling.

Thankfully no critters were found. There was a lot of grime- mostly caked on dust, accumulated in old grease.

The car was pulled outside, jacked up and access was gained again by removing the road wheel.

Judicious use of my pressure washer saw a majority of the dirt removed from the underside. Inspection showed all of the metalwork in good condition, although a rub-down to remove surface rust and a new coat of paint are required.

The car was pushed back into the garage and the big drum fan put on in an attempt to dry the car out. This would later prove to have been moderately unsuccessful.

Final task of the day was to clean all the dirt liberated from the underside of the car off the driveway…

I then ended up spending yet more money. The purchase of a 2-ton engine crane, which helpfully folds up into a moderately small footprint.

At this point, work was halted as my (new) trolley jack decided to break. The handle came apart, the disc that the release lever fits into broke clean off.

My lifting chain was also in a worse state of repair- hanging outside but under cover, Louisiana’s climate has seen to the steel in an impressive fashion. There was no way I was going to trust that to lift nearly 900 lbs of metal.

Between times I made a start on removing the front grille and other items that were in the way of removing the engine.

The cross brace proved to be attached solidly to the front clip. I decided to remove the rivets holding it in, with them to be replaced later by bolts.

That just left the slam panel brace in place, which is held in with 4 large sheet metal screws.

I removed the pipework, clips, manifolds, fuel pump and carburetor from the passenger side of the engine.

Disconnected and tied up the accelerator and gear linkages on the driver’s side, removed the coil because it’s moderately loose in the holder (the original 6V coil was slightly larger in diameter).

A little while passed and a package arrived in the mail- the company who I purchased the jack from honored the warranty on it and sent a replacement handle.

This put the jack back into commission, and I tested to see if I could fit it under the back of the car and lift up on the base of the differential case. This was only successful if I first pump up the rear air suspension to raise the car a few inches.

Another special offer coupon arrived in the mail, so I purchased a load leveler to go with the engine crane. This added new chains and lifting eyes all in one go. I also bought a magnetic parts tray, as they are handy to have and it was $3.

I started the following weekend by raising the car up to see how well the jack fit with the leveler. The answer- just about!

I began to make preparation to remove the engine and gearbox. First task, remove the bolts from the front engine mount and clean them up.

Next, remove the last remaining obstruction on the front of the car.

Then, get up underneath and inspect the working conditions and how the propshaft comes off.

Next, remove even more spider webs. Last thing I wanted was to be sprawled under the car and have a spider decide to drop down onto me.

Then, put the back end of the car up on stands because the easiest method to remove the propshaft is to undo the bolts at the rear and slide the yoke off the gearbox end. The brown coloration on the underside of the vehicle is not rust- it is the color of the dirt where the car was previously driven in Mississippi.

I marked the position of the propshaft on the axle end, so it can be put back together in the same place.

The propshaft then pulled off the splines of the slip yoke and was set aside.

Upon jacking the front end of the car up, I discovered that the rear gearbox seal relies upon the slip yoke’s presence to be oil-tight. Not that it was particularly oil-tight when it was fitted, but this made it significantly worse.

I had wanted to push the car back a little before removing the engine but the front left brake had stuck on where the water had sat inside and rusted up the surface where the shoes were touching the drum. I decided I should have enough room, so began to connect up the chains to the engine, using the head bolts as attachment points as allowed in the manual.

I started to take the weight of the engine, then got up underneath and removed the rear engine mount and loosened the cradle. I also removed the speedometer drive cable from the back of the gearbox.

Up, up and away! Relatively painless removal with all obstacles not present.

Tilting the engine back to clear the oil pan put the gearbox at leaking-point. I deployed kitty-litter to the spill, which did a very good job of cleaning up the ATF.

There was a piece of flaky tape on the back of the gearbox, which I pulled off. Someone had masked up the data plate when they painted the gearbox, and never removed the tape. I assume that D51- indicates the gearbox was built in 1951.

Finally, the engine was set down on wooden blocks in a stable fashion on the floor. I am used to gearboxes dwarfing the engine, however in this case it is definitely the other way around, and that’s not because the gearbox is small!

I need to clean up a little, drain the fluids down and then investigate splitting the gearbox from the engine so I can work on rebuilding the valve block with new seals.