Graham’s Corvette Blog and Studebaker bits ‘n’ bobs

One primer coat and two of GM opulent blue. It is a rich blue with hints of violet. Doesn’t appear to be a metallic.

The remains of the big dent filled with two part tiger hair body filler. It is a bear to sand if left to dry fully. I”m using some kind of cutoff wheel I picked up from my Dad’s shop after he passed away. I used it to remove the remains of the original repair and it did it quickly. Not so quick taking off the epoxy, but it got the job done – I used it like a big sheet of sandpaper. I didn’t want to use an electric tool as it will fill my garage with dust. So a little muscle and time and it turns out OK.,

Epoxy sanded and some spot putty out of the tube to fill in the last of the small holes.

A truly fiddly job getting the door taped off – one reason I don’t like body work. Just about ready to prime and paint. One issue I’m having is that my tape does not want to stick to the door rubbers. I coat my rubbers with silicone and that’s the problem. I don’t want to re and re the rubbers so a little patience and I was able to get some newspaper tucked in between the rubber and the body.

L48 news: I’ve got a lead of a good used high mileage 305 in a ’79 Caprice. It’s a 4 bbl 175 hp model. Would work nicely while I do over the original motor.

Primed and painted. I’ve done all around the frame even though I’ve just shown the back edge.

Second go around with the filler. I’m trying to get the door curve just right so the repair won’t show.

All primed. I’ll sand the primer when dry.

Sanding the primer revealed a dent I missed – bummer!

On the Chevy front – I’ve decided not to give up on my 4 bolt main low mileage block. I’ll wait until R&D engine builders are not so busy in the early summer and take it in for an evaluation. I can’t find any cracks between the main oil holes and the sides – magnaflux may find some. It will be interesting to find out just how much higher the crank will be in the block after a line bore and just how much that would affect a double roller cam setup or even a gear conversion. Piston height may be an issue, but a thicker head gasket should take care of that.

Next: more body work.

I had to drill a couple of access holes to get at the back of the big dent. I then put a short piece of wood with piece of scrap steel on top and used a long punch and maul to bang out the dent somewhat.

I ground everything off the dents and then used rust converter on the remaining rusty pits.

Next I fibreglassed over the four unwanted trim holes in the bottom of the door.

I was planning to install the rear vent windows that I picked up at Gary Payne’s Studebaker salvage yard before it was closed down. However, they need new rubbers and no one makes them. So I’ll leave the door seals in place as they are passable and just sand and paint the inner door edges with the final car colour which is Corvette opulent blue.

Next; more door work

All the Chevy and Studebaker trim has been sanded and some primed and painted. My shop is too cold for painting now so I will have to wait for the first warm days of spring to finish the job.

So on to servicing the Commander – tire rotation, grease and oil.

My oil of choice is the local Canadian Tire brand. It is 10W30 high mileage for older engines – it is supposed to contain some zinc and phosphorus. To be sure I add some Riselone ZDDP additive – one bottle per oil change.

I normally use STP which apparently has enough ZDDP for an oil change, but my engine is already running higher than normal oil pressure so I don’t want to make it worse. The pressure relief valve spring must be a little to stiff. I installed a new spring when I built the engine.

Next job is to do over the rear doors. I will repair the dents and then prime and paint with satin black until it gets its paint job.

The rear doors are a bit of a pain to remove. In the end I had to unbolt the front seat, move it forward, remove the door post panel and then unscrew the hinges. There are ten screws on the post and on the door and two were missing – one from the top inner that only had two to begin with. Didn’t find any rattling around so they must have not been fitted at the factory – maybe it was closing time on Friday or maybe assembly man was keen to get off for coffee and the car moved down the line without the two last screws.

Next: more Studebaker work before I tackle the dash work on the Chevy.

The machine shop checked the crank and it is bent .030 and so is toast!

Two of the main bearings were spun on the crank. That gouged out the mainss at least .005. I had a chat with Darrel at R&D Automotive about the possibility of line boring the block. I hate to scrap a low mileage 4 both main block. Apparently it would be very expensive to build up the damaged cast iron mains and do a line bore. Also the spinning of the bearing causes a lot of heat and that often causes block cracks between the main and the oil gallery. So it looks like my block is also toast – all that reaming and honing for zip.

The crank was so distorted that it rubbed a noticeable groove in one of the pistons.

Three of the rod bearings spun in the journals. These can be bought for about $35 each.

One of the pistons got added wear on both sides of the skirt. Again these can be bought cheaply.

At first glance the cam and lifters looked OK. But closer checking revealed that the cam had pits on all the lobe tops and the lifter tops were mottled. I’m getting enough toast here to do me for a week – hahah!

Again cams and lifters are available, but I would rather not have had to put out another $300- $400 on this temporary engine. As it turns out I won’t have to!!!

So my little 350 crate motor short block is destined for the scrap pile. However the heads, valves, pan, most pistons and rods’ etc are all OK. I just need to find a good short block. Even a good 2 bolt main bare block will do me just fine.

Still lots to do on the Studebaker and the Chevy while I get the engine thing straightened out.

This is my bore hone of choice. My buddy Don lent me a ball hone, but I’m comfortable with this unit.

After running the hone up and down quickly to get a cross hatch pattern I noticed these dark marks on every cylinder. A careful check to detect any ridges with a dental pick and I found I needed to do a better job of ridge removal. A ball hone wouldn’t have brought this to light.

A little extra with the ridge reamer and all the ridge is gone.

A final hone and the cylinders are all done.

Heads resting on the block and all ready to be tucked away until I get the crank back from the machine shop.

I even found bits of destroyed journal material in the oil filter fitting valve – see the triangular bit on the right of the valve opening.

I pulled two frost plugs and found very little in the way of corrosion crud. I’ll let the block dry out completely and then use high air pressure to blow out any rust residue.

The bare block and the starting point of the rebuild 🙂

Using the ridge reamer I removed all the ridge material from each cylinder leaving a smooth surface for my hone.

With the ridge cleaned up I checked the top and bottom wear. Each cylinder showed less that .0005 – that being the max acceptable.

Next: honing the block.

Buddy Don loaned me his ridge reaming tool. I took off just enough to get the pistons out of the bore.

The pistons all appear to be fine. Some pins are looser than others – some floppy and some downright stiff. I’ll have to check that out.

The harmonic damper was very tight on the crank.

The timing gear and chain looked fine. I may keep it as it is a low mileage engine. I have a dual sprocket unit for the engine that will be coming out of the L48. This is a failed engine so I’ll be looking for any causes.

Mains out. Nice to have a 4 bot main block. All bolts packages and labelled. Centre caps are all marked to go back in as they were removed.

Crank and cam out. Can’t really get a shot of the cam bearings, but there is noticeable wear. I”ll be buying a set of cam bearings and also the tool to extract and install them.

The crank is in poor shape. Three rod journals and the three centre mains are all damaged enough to require a grind job – likely just .010 under I hope.

Looking at the crank, rod and cam bearings leads me to think that the engine was run on low levels of oil and maybe even next to no pressure. If the truck had an analog gauge the problem might not have been noticed soon enough. That and maybe no oil changes – just topping up – may have caused the excessive wear.

Next: more checking

I borrowed this heavy duty valve spring compressor from fellow car buff Don. It was needed as the valve springs on this engine are very stiff.

The springs are doubled with an inner spring. Two were extra hard to compress for some reason. They happened to be the only two with damaged oil seals. Oddly there was only the O ring style rubber seals in place – no umbrella seals at all. The number relates to the cylinder they were taken from.

Lots of carbon especially on the intake valves likely from absense of umbrella seals on the stems. The Exhaust has more than normal carbon deposits. The faces look OK.

The valve chambers are not carboned up and the valve faces don’t look too bad.

I cleaned the valves with my electric wire wheel being careful not to his the valve faces. I then lapped the valves with proper lapping compound and a lapping suction cup on my drill at low speed. I ran it for a bit until the sound of grinding stopped then I lifted the valve to get more compound on the face and lapped again. I did this for four times then added more lapping compound and did it again. There are a some dark spots on the exhaust valve, but the intake is nice and clear.I will try lapping the exhaust valve a few more times to see if they clean up a bit better. If not I’ll go with them as is. This is not going to be a high mileage engine and since I live in the country it should run clean.

Next: ridge reaming and checking the cylinder run out.

Checking the lifter wobble. Less than .001 so all’s good. The face of the lifters is shiny and not showing wear. I suspect the cam will be OK too.

I checked the lift on an exhaust and intake valve to verify the cam and I got a reading close to .401 and .383 resp. that is listed for that crate engine.

Other than a minor bit of surface rust on a couple of cylinders all the combustion chambers look OK.

Next: on to the valves.

Tim arrived with the engine in the back of his truck. We off loaded it with an engine hoist and then I got it onto an engine stand.

The engine block # 10066036 is a ‘hencho en Mexico’ GM Goodwrench crate 350 from around 1990. The heads are #93417369 (or 33417369) also made in hencho en Mexico. They are 76 CC heads with 1.94″ intake and 1.50″ exhaust. This engine as it stands is supposed to make 250 HP @4300 rpm with 350 lbs of torque. Respectable as a donor for the Chevy until I can get the original motor rebuilt.

First thing removed. I was surprised to find out that it is an aluminum unit. I’ll save it in case someone needs a 4 bbl intake.

When doing over an engine I like to keep all the bolts, etc marked in bags. The lifters, and push rods are all marked so they go back in as they came out.. I”ll likely use the original cam. It is supposed to be good for low end torque – something like a stage 1 replacement cam which is often used to improve towing. They is a replacement truck engine so that makes sense.

Heads off and time to check the cylinder wear – ignore the numbers on the pistons.

This is my handy-dandy cylinder checker. I was gifted it from an old mechanic friend Arnold Legrow of Springhill, NS who sadly has passed away along with the love of his life Doris.

The bar on the bottom has a number of collars of differing sizes. I used a combination that gave me exactly 4″ between the uprights. I then used a combination of gauge extensions so the gauge fits between the uprights. I then set the dial to 0 and I was ready to check the cylinder wear. I’ll use it also to check the top to bottom cylinder wear when the pistons are out.

I checked each cylinder one at a time while rotating the engine. All the cylinders ranged between 4″ and 4.002″ Satisfactory for a re-ring with the original pistons.

Using a compression calculator I came up with a ratio of about 8.9:1 Which is quite respectable. The parameters I used were 4″ piston, 3.5″ stroke, 4.03″ gasket bore, .026 compressed gasket, 76cc combustion chamber, dish depth -5 and deck clearance of .025″.

The gallery is quite clean and free of sludge. there was however quite a bit of sludge in the pan. Also in the pan were bits of rod bearings – not all showing.

Next: more engine evaluation.