As well as playing engines we have also been playing diff’s. The diff we had was a 12 bolt posi with a ratio of 4.56 to 1, this really isn’t the ratio for a 71 year old, old fart, and also it had the wrong saddles on it. Thankfully for me after telling a few club members of my problem, Craig Armstrong said that he had a 3.08 gear set that he would give me, I accepted gratefully. I striped the diff down to the bare housing, removed the saddles and cleaned up the housing
Then all the bits were taken to Con at Diff Techniques at Rockdale, where he welded on the new spring saddles and straightened the housing, I then collected the housing and along with the backing plates and the diff cover, had them all powder coated, then back to Con to be setup. Once again the brown stuff hit the fan.
Firstly, the posi carrier had been butchered big time to allow the high ratio to fit; it was the right series carrier for 3.08 but had been machined to suit the 4.56.gears. So to cut a long story short Con fitted a new “Auburn Pro Series” posi carrier, replaced the wheel bearings and set all the clearances.
Before the diff can be fitted to the car I have to sort out the rear springs. The car was fitted with a mono leaf spring set up, which I am replacing with a set of 5 leaf multi leaf springs which I have to have reset, which, at this stage hasn’t been done. My Dilemma is that I don’t know the setting for the spring, I am thinking that the front will be about 1.5” lower dew to, at this stage not changing the front coils and the extra weight of the big block, and I don’t know what the height settings the second hand springs that I bought of ebay are. I was hoping that I could have the springs set to lower the car 1.5” then have them powder coated and that would be the end of the story, but it looks like I will have to wait until the car is finished, fit the springs, check the height, them take them out again and have them set, and then have them powder coated.
Since my last entry a lot has happened, as I said earlier I was looking forward to receiving the motor from Chris ready to install, that didn’t happen. After totally dismantling the motor, Chris told me that the motor was beyond repair. The reasons were that, water had entered the block and damaged a bore, the casting numbers on the heads were different, and water appeared to have damaged a piston, and that the pistons were .060” over.
A week or so later, after the language had settled, we started to look at Crate Motors, 502 seemed to be the logical replacement, but I really did not want to go down this road, and Enid suggested that I ring an old mate from Dubbo who has had a lot to do with big block
Chev engines in boats and one of his statements was that a 396 chev engine has no problems with .060” over so long that the correct radiator, fan and fan shroud is fitted.
After this chat, I took the engine (which was in a number of boxes) to a highly recommended engine machinist for him to clean, and then measure at to make a recommendation.
After about a week he rang and said that the engine was rebuildable with no problems and that he would do all the machining and supply all the parts but he would not assemble the engine. and that I would be able to pick it up in a week.
About Four weeks later the engine was ready to be picked up.
I won’t go into detail about what he did, other than to say he did every thing and supplied every thing from a mild Isky cam to valve collets also total engine balance from the new harmonic balance to the pressure plate. Due to the fact that the heads were different they were CC’d (whatever that means). Once I got the block home I spent a few hours grinding out some of the casting marks hopefully this would give a better finish when the block is painted, then back to the machinist for a thorough wash and clean.
The workmanship and attention to detail was brilliant, what are we going to do when these sort of craftsmen are not around
The guy that I really wanted to assemble the motor for me was the guy that has always done work on the Mustang’s and the Buick but unfortunately he has retired and could not be convinced, one more motor would be alright. Also SMS was reluctant to put his name on it.
The last motor that I put together was a long time ago, but I can still hear the old guy that helped me then,” make sure every thing is surgically clean, take your time, and check at least twice before you lock it up and use plenty of STP during assembly.” So I thought bugger it I will do it myself, it can’t be that hard as I have a toolmaking back ground and know all about clearances and tolerances, and I have all the tools that I’ll need (I think). So I set up an assembly section and bite the bullet.
The first thing I did was to gap the piston rings, I had bought a gadget made especially to gap piston rings and it works like a charm, I had to take about .025” of each ring, to give an end gap of .020” roughly .005” per inch of bore
The next thing I did was to install the crankshaft using heaps of STP on the bearings then in went #1 piston. With #1 piston in, I was able to check the deck height; I put a piece of plasticine on top of the piston, layed the head on the block and turned the motor 1 complete turn, then removed the head, it showed that we had clearance and reasonably high compression.
I then installed the cam after coating the lobes with the special lubricant that came with the Isky cam and again STP on the bearings. I then installed the timing sprockets and chain (double row roller) I then installed the rest of the pistons and again STP, I think I have ‘top dead center’ right, but I will double check when I borrow my friends dial indicator. This point I was finished for the day, and extremely happy with the way things have gone so far, and if I can offer any advice to this point it would be, think about what you are doing, take as much time as it takes, and after every bolt is tightened turn the motor to confirm that there is no interference.
I reinstalled the diff and before I fitted the motor in the chassis, I remanufactured all the hard brake lines, had them all cad plated and then they were fitted along with all new
flexible lines
The motor is now complete, the gear box fitted, and set into the car. Tail shaft and starter motor temporarily fitted, and the car was taken to Liverpool Exhaust to have a complete custom system fitted, this took about six weeks but the wait was well worth it, they did a fabulous job and I would have no hesitation recommending them to other club members.
Phone 02 9829 5072
Phone 0438 658 458
Phone 0432 136 333
