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

After I made the changes I now had heads, rockers and push rods from the crate engine. A fellow Chevy buddy Barry cleared up the rocker/push rod issue. Seems that GM changed the heads sometime after 1979. The earlier heads had small push rod holes that helped keep the rockers centred (in the photo above of the original ’79 head the holes are narrow). The later heads had larger push rod holes and different rocker design which keeps the them centred on the valve tops. So when I used the old rockers and push rods couldn’t keep them in place. Good to know that there was a specific cause to the problem of mixing and matching heads, rockers and push rods.

A couple of test runs and all seems OK. So now I’ll re-attach the AC bracket – the bracket has to be loosened before the right hand valve cover can be removed.

I reconnected the lock up torque converter vacuum switch and did another test run. The trans is trying to lock up shortly after getting in 3rd gear and hunting when trying to drop out at moderate speed. It’s trying to work and only needs adjustment.

It is adjusted by an allen wrench in the vacuum input port. I am starting by turning it 1/2 turn in a CW direction which is supposed to increase the vacuum needed to trigger the lock up. Now for a second test run.

Ran the engine for a short time and it sounded like I had a loose lifter. Then the sound changed and I turned off the engine. this is what I found -again- on the #4 exhaust. The rocker to the left is also not centred properly.

#1 exhaust is also moving off centre!

The rocker on the left is from the crate engine and on the right is the one from #4 cylinder. It seems that GM became aware of the issue and modified the rockers to stay centred.

The push rod from #4 is slightly bent compared to one of the original units. I’ll use the old push rod as a replacement.

I’m now swapping out all the original rockers with the units off the crate engine – the crate engine had very little wear before it spun its bearings. I’m using a pad to tick off each cylinder as I give the lifters one turn down from zero lash. I’m following the service manual and adjusting half the valves at TDC and the other half after a full turn of the crankshaft.

This is the right bank with the engine running. All the rockers are staying centred on the valve heads. When the engine was warmed up some I reset the valves. Oddly enough I had to loosen the valves over 1-1/2 turns to get the valve to rattle. With zero lash I turned them down 1 full turn. Internet references often say that cold adjustment is fine, but I also found references saying that one full turn hot or cold is correct. I prefer to set them with the engine warmed up. Not so messy If you cut the top off an old valve cover and use clips for something similar to stop the oil squirting from the top of the rockers. I add an old towel over the exhaust manifold just in case.

Next: time for a test drive.

On about the third test drive and about 20 miles from home the engine starts to bang and clatter. Sounds like something isn’t right under the valve cover. So stop the car, call CAA and get the Chevy back in the garage. This is what I saw when I took off the right valve cover.

Something nasty going on here. Looks like a weakened push rod that decided to go south.

I have a used push rod from a slightly used ’86- ’90s crate engine. Newer style with welded in ends. I replaced the broken rod and re-set the all the lifters to one full turn after zero lash.

Ready to start up and see what happens.

My second bug was a buzzing sound on acceleration. I suspected that the exhaust system was contacting the body at some point. This is what I found. I had 1/4″ or less between the left tail pipe and the rear cross frame.

I needed to loosen the band clamps between the tail pipe and the muffler, the hanger clamp at the mid-crossover pipe and the band clamp (not showing) between the exhaust and tail pipes. This where band clamps come into their own. Once loosened the pipes can still rotate or move in and out easily.

I was then able to drop the tail pipe to match the right side giving 1/2″+ clearance.

Next: time for another test drive to check the engine and exhaust clearance.

Hooray! the seats are done and almost ready to be installed in the fibreglass buckets. The vinyl is buckskin and the cloth is matching period Chevrolet hounds tooth,

The only hitch is that the upholsterer didn’t realize the seats are held in place by the wires at four spots – seen here where the foam is cut out for that purpose. So the hog clips need to be removed from those four openings.

I dug out my hog ring pliers and some hog rings and attached the vinyl to the seat wire on either side of the mounting opening and then removed the problem hog rings.

Seat pads in place. Not the easiest thing to install, but once done that will be the end hopefully. The vinyl on the upper section is puckering some. To fit in the seat shell the upper cushion had to fit into a concave position for the wires to grab the seat clips. Something I will have to live with unfortunately.

Before the seats can go in the hinge covers need to be installed. The lower covers on both seats are hidden by the console once the seats are in place.

The decorative acorn nuts need to be driven on. I used a socket of the proper size with a small washer so that the nut is just outside the socket. They go on quite well with a sharp push using the palm of the hand. They seat with a snap and the hinge cover is held in place snugly. The old nuts are toast. You need to buy new sets of nuts each time the hinge covers are removed. Impossible to pull up the small tabs on the new style nuts (made in China) once they are removed.

A nice tight fit.

Seats in place. The new buckskin vinyl is a bit darker than the photo shows, but it is a good match to the carpets and to the seat buckets and console in the original beige tone. The buckskin is a tad darker than the original doeskin.

I’ve been waiting months for the seats so that I can start the test drives to work out any bugs. Since it has been so long I decided to spin the engine on the starter until I got some oil pressure ( I have an oil gauge mounted on the front of the engine).

The gauge is just behind the heater pipe in the red rectangle. After I got enough pressure the engine started right up as the carb had been filled. I ran the engine till warm and then disconnected the vacuum advance pipe and plugged it. I then set the initial timing to 10 degrees and found the total at 2500 to be about 30 degrees. I tightened the distributor and rechecked the timing. It moved the initial timing to 11 degrees and the total still at about 30 at 2500. Good enough for my initial runs which hopefully will start tomorrow. I’ve disconnected the lockup converter for the time being and I’ll re-connect it and make adjustments later. After all is working OK I’ll tackle the AC.

Needless to say I am a happy boy to have the “Chevy back on the menu”.

A few areas needed a second go-around with spot putty to fill in the spots were the first application of the filler shrank.

I’ve given the underside of the repaired cover a coat of white rustoleum oil based primer

Outsides with a double coat of white rustoleum primer. Good enough to paint. I’ll leave them for a day for the primer to set properly.

After a day I have put on two coats of sun yellow Rustoleum oil based paint. I’ll leave them for three days and then rough them up with 1000 sandpaper before adding two coats of Rustoleum clear coat.

All nicely finished in bright yellow that Studebaker V8s had from the factory. In front is a 1/2″ spacer for the AFB on the 289 R1 engine in the ’66 Commander. I’ll add it to the existing 1/2″ block under the carb to get a full inch that is supposed to be optimum for the original intake manifold. On a trip to PEI the Commander got about 22 mpg with the AC on. So maybe it will give me 23 w\o the AC. It gives me 17 on every day driving. So not bad I think. I don’t expect anything especially noticeable from the extra space except maybe a bit crisper response and a wee bit better mpg. It will be interesting to see how the engine performs when I swap in the 3.07:1 Twin Traction rear end – I’ll be doing that next winter along with a complete refurbishment of the ’79 Chevy front end.

Still waiting for my Chevy’s seats.

The left cover has a bad section of the inside gasket lip. It’s passable, but not the best.

I cut out the bad part of the lip and then cut a strip of 1/32″ steel as a replacement. The corner made it a bit tricky.

I don’t make any claim to be a welder. I don’t get to do it that much so I trained on a bit of scrap metal before attempting the job. Came out good enough to do the job. I drilled the strip with a 1/4″ drill over the spot where the original spot weld was located – about midway. I then welded the strip at that point as well for a solid fitment.

Sand blasted, repaired, spot weld ridges removed and spot puttied. I’ll leave them for a day and then get to the final sanding.

Next: Yet more valve cover work

Still waiting for the seats for the Chevy. The upholster lost his helper of 8 years and so is even later than expected. Seats were promised a couple of weeks ago. In this business you need to have patience otherwise best do something else!

In the meantime I’m restoring a set of Studebaker valve covers. I’ve twisted the spark plug brackets off the top of each one. They are rusted and it’s easier to remove them than repair them. I’ll be doing them up in yellow as was the originals from the factory. My plan is to make them up and let the paint cure longer. Last set I put on before a full cure and the paint took on oil stains that I can’t polish off.

The inside of one is OK, but the other will need to be sandblasted

I’ m scraping some of the easy crud off before sandblasting. My equipment is hobby class and so takes a lot to clean off old glue and hardened paint – even with “0” grade media and 100 psi.

Cleaned up nicely

Next step is to use the dremel with grinding burr to take off the spot weld remains on top and also the ridges and burrs on the spot welds around the bottom that hold on the gasket lip on the inside. The little bits of paint left after sanding blasting I’ll take off by sanding.

Next: filling and sanding

Still waiting for the seats for the Chevy. I called and they should be done sometime next week. After that I can get on with shaking the bugs out of the new engine trans setup. In the meantime…

I needed to get a replacement for the 7″ headlight that I burned out last summer. I like to keep one in the trunk. I thought it a good time to switch to halogen lights. I picked these up on Amazon for about 60 bucks. They aren’t a perfect fit, but they worked on the end. The rubber seals over the bulb connector had to be discarded and the bumps on the back of the glass lens didn’t match the grooves in the headlight pot.

The Chevy is patiently waiting in the background. It will be nice to have it back on it’s wheels!

Cover is back off destroying yet another gasket. The red sealant didn’t adhere to the housing even thought I wiped it carefully with alcohol. I was OK until I torqued the bolts down after waiting 24 hours for the sealant to cure. The torque caused the gasket to split at a few bolt locations and squeeze out from under the cover. I couldn’t take a chance that the same thing was happening on the inside.

This time the sealant came off the housing with no need for paint reducer to soften it. Oil must still have remained in the metal pores. I managed to keep most of the sealant and gasket bits out of the assembly. I dipped a piece of thin wood dowelling in oil to pick any small bits that got left behind.

Nice new FelPro gasket – thick paper. I’ll go with a dry gasket this time. If I have leakage problems I’ll replace it with a LubeLocker gasket. It will be easier to replace under the car if there is no sealant to scrape off.

Snugged down and then torqued to 30’# as per the Studebaker Shop Manual for Dana 44 rear ends.

Once again painted up. I’ll now tuck the unit away until next fall/winter when I’ll do the swap.

Next: Still no seats for the ’79 Chevy!!!

Cleaning up the cover and the matching casting with alcohol.

With a light bead of red sealant on both sides of the cover gasket I’m ready to close it all up. Two guide pins in place to keep everything lined up.,

I’ve numbered the 10 screws so that I can snug it all down evenly. Now I’ll just have to wait for 24 hours to give it a final torque.

In the meantime I decided to check the fit of the axles. I have a couple of used units for backup. OH NO! the axles won’t fit properly. They won’t go in enough to fit up against the thrust block and the bearings are half out of the housing! Major bummer:-(

Something isn’t right within the TT unit. So off with the cover which destroyed the gasket and leaves a lot of gasket sealant to be removed.

This is where the problem is. The axle shaft has to fit over two sets of splines. One on the spider gear and one on the differential side gear ring. Hard to see, but the two gears are slightly misaligned so the axle slips over the side gear ring, but can’t slip into the spider gear.

I had to loosen all the TT unit cover bolts and then wiggle the axle to get the two splines to line up. I did this on both sides and then re-torqued the bolts to 40’#.

Before replacing the TT unit I had to clear off the old gasket and sealant. I found that paint reducer on a scotch brite pad softened up the sealant and made it a lot easier to remove.

With this done I replaced the TT unit in the differential housing. I then snugged up the carrier bearing caps and put axles in both ends before tightening them to 80’#.

The axles now slip in properly. The bearings are sitting inside the housing – the cup is showing outside only because I don’t want to seat it and then have to borrow a slide hammer to get the axles out again.

A pain in the butt, but a whole lot less so that if I had discovered this problem when the unit was installed in the car. It would have been impossible to do on the car and I would have had to pull the unit out again to work with it on the saw horses. So definitely a silver lining in that cloud!

Next: Still waiting on my Chevy seats!!!