Goodness I’m tired! Saturday was a long day but I got close to being back where I should be. Let’s see, where to begin. So I got the piston/connecting rod that was in backward out and took it to Norman Racing Group on Thursday afternoon. Dan Marvin agreed to check the rod for straightness and pointed out that the piston was making contact with the head, something Tom Sahines told me to look for. I brought the head along too so they could tell me if there were problems with valve clearances etc which was a good thing as it was needed to cut the pistons down to clear the head. I asked if they could do a one day turn around on Friday so I could reassemble everything this weekend if I got the other three pistons to them first thing Friday morning. They said they would try.
I left their shop and pulled the other three pistons. I can’t complement Norman Racing Group and Dan enough. I had my wife drop the pistons off on Friday morning about 10am and they were ready when I got there at 430 to pick them up. I guess the bag of pastries she brought them probably helped but I doubt they were necessary. He gave the backward connecting rod a clean bill of health. I bought a new head gasket and set of Viton oil passage seals and away I went.
I like this shot because you can see the crank journals through the liners. Coolant drip drip dripped out of the bottom of the liners without the head there to hold them down hard. Tom and Dan both told me that it was normal for this to happen.
So Dan and Mike told me that an easy check of the clearance between pistons and head is if the pistons clear the head without a headgasket installed they are good. So I dropped the head on without a head gasket and no cams installed. The pistons still hit the head! I called the Tom Sahines Tech Hotline (he’s the ARA tech resource) and he told me to put a thin layer of clay on the pistons, install the head with an old head gasket, install the cams, cam chain etc then turn the engine over once and open it back up. Theory is that if anything is not clearanced correctly it will be visible in the clay.
I inspected the clay after turning the engine over and I couldn’t see any interference but I called Tom anyway. He basically said if there was no interference I was done and should button it up and that it wasn’t uncommon for an engine to have interference with no head gasket but none with a head gasket. The head gasket is pretty thick so this makes sense.
Two weeks ago if you asked me about setting the cam timing on an Alfa engine I would have had this black magic sort of image come to mind and I would have talked about it like it was some super technical process. Today I set the cam timing twice. Once for the clay test and once when I set to and reassembled the engine. I learned a lot of lessons and things went well.
Here I am installing the master link. If you don’t put a rag over the opening you will drop some part of the masterlink into the engine. If you do have a rag you will have steady hands and it will go smoothly.
I never claimed to be good at any of this and apologize for using big vise-grips to hold the cams. I just didn’t know what else to do. The dial gauge seen here was borrowed from Laurence Anderson to determine TDC to within a fraction of a degree.
So it goes like this. Push the cam chain tensioner in all the way and lock it in this position. Loosen the cam sprockets by removing the vernier lock pins and bending the lock tabs back. Loosen the big nuts at the ends of the cams. Find TDC. Line up the cam marks with the number one lobes pointing outward. Verify that this TDC has the rotor in the distributor pointing to number 1. Loosen the cam chain tensioner so it takes all the slack out of the chain and tighten the cam sprockets and reinstall all the vernier lock down bits.
I feel like I am really starting to understand what needs to be done and how to do it at this point. In the next few days I will reassemble the oil pickup, windage tray and oil pan. Reinstall the carb and hook it back up as well as the exhaust. Refill it with fluids and start it up again. It will be really nice if the engine purrs quietly, I don’t know if I can go through this again without a break. Oh wait, I have a rod knock in the FIAT to investigate as soon as this is done. Oh well, so much for a break.