Lapping The Valves

Lapping the valves should not be absolutely necessary after a valve job but I did it anyway to see where the valves contacted the seats. The heads had been modified quite extensively so I did not want leave any doubts about the valves fitting them.

Lapping itself is really simple. I bought some lapping compound and a lapping tool that is just a stick with suction cups in each end. The grinding compound had coarse and fine paste and you start with the rough stuff. I spread it on the valve face, pushed the stem in the guide and attached the tool.

I rotated the lapping tool back and forth between my hands while pressing it lightly towards the head. After a few rotations I tapped the valve with its seat a few times to get more paste between them. After doing this I got a nice grey ring on both surfaces. Then I needed to clean the valve and seat and do the same thing with the fine paste. It took a few hours to lap all 16 valves.

All seats were fine but the contact area on the intake valves was quite near the edge. Should be fine but there is no room for any more machining.

Comp Cams Camquest

To get some kind of estimate for the power level in my engine, I toyed with Comp Cams Camquest page. I entered the requested parameters and the app spat this kind of graph for me:

Calculated peak HP was about 260 @ 5000 RPM and peak torque 330 @ 3500 RPM. This was using all the stock parts like carburetor, intake manifold, exhaust manifolds etc.

To get some kind of idea which parts would have the largest effect on the engine, I went through some of the options one by one. Better intake and bigger carb added about 25 HP and 10 ft-lbs but changing the original exhaust manifolds to headers gave a huge 50 HP and 35 ft-lbs boost!

Combining the intake and carb with the headers brought in another 30 HP and 10 ft-lbs. If the Camquest simulation is even close to real life results, I think first item on my upgrade list would be the headers. But for now, I'll go with the stock parts.

Compression Ratio

After selecting my cylinder heads, I could now count the compression ratio my engine would have. There are dozens of calculators in the web but I used the one on Summit page. The needed facts were:

Cylinder bore	4.030 inches
Stroke	2.870 inches
Combustion chamber volume	50.5 cc
Piston volume	8 cc
Piston deck clearance	0.01 inches below deck
Head gasket height	0.039 inches

This gave me a compression ratio of 9,73 : 1. Should work pretty well with my combination of parts.

Valve Spring Tests

First order of head jobs was to find the correct valve springs. For this I had borrowed two test springs and solid lifters so I could measure the installation and open heights. As I would have to bolt the head on the block, I also decided to measure the valve-to-piston clearance. So, two valves went in the head.

For the piston clearance I placed some blu tack in the valve reliefs.

And I was ready to bolt the head to the block. I made sure to follow the correct order for torquing the bolts and then installed the lifters, push rods and original rocker arms. Before adjusting the lash, I rotated the crank until both valves were closed and then tightened the nut until the push rod just started to feel sticky. Time for measurements. Results were:

-	Intake	Exhaust
Installation height	1.80 inches	1.75 inches
Open height	1.33 inches	1.28 inches
Lift	0.47 inches	0.47 inches

Now I was able to find correct valve springs. Not that surprisingly after a phone call to US-Parts, we came to the conclusion that I should buy what Comp Cams suggests for my cam: Comp 942-16. They had the correct pressure and height so I went and bought a set. Their required installation height was 1.7 inches though so I would have to measure every valve and add shims to get it correct.

Finally I removed the head and checked the blu tack.

The valves had hardly even touched it. After cutting both in half, I measured the clearance to be 0.25 inches. No problems there.

Head Games

I got my cylinder heads back from the machinist so time to go through them. First issue with them was deciding which heads to use. I had my engines original pair and the heads from the crap engine that I bough earlier.

The original heads seemed untouched and had never been restored. This probably meant a lot of work like valve guides, valve seats, valves, springs etc. Really expensive and in the end I would just have original heads with small valves and poor flow.

The second pair of heads had been worked on quite extensively. They had bronze valve guides, they had been machined for larger valves, the intake and exhaust runners and bowls were ported, they had screw in studs and they had been lowered a lot. Sounds really good but they were not without issues:

• Even the replaced valve guides were a bit loose. Not as bad as in my original heads but still.
• They had been lowered so much it would raise the compression ratio and might cause problems with the bolt hole alignment in the intake manifold.
• One of the studs was just a normal bolt that was even bent.
• The installed valves were too small! Standard size valves had been put in and they were really deep in the seats. I can't believe someone would have actually run the engine with them.
• Were they just cracked junk heads that had been put together to make the crap engine seem whole?

Comparison of original (top) and ported combustion chambers. Note the way too small exhaust valve.

I showed pictures of both heads in FMOC forum and one member agreed to go through them for fair price. He had tools to machine the valves and seats and experience to inspect the heads. So I delivered them to him and waited.

Some time later I got a call that the heads were done. I drove over and we checked the damage. He had inspected both pairs and suggested that I use the ported heads. They needed new valves and springs but that was small compared to the original heads which needed pretty much everything. He had also acquired used but almost like new valves for me. Their sizes were 1.9 inches for the intake and 1.62 inches for the exhaust. That just left the springs.

Stainless steel Ferrea valves

Comparison of original and new valves

The valves and seats had been machined and surfaces checked for straightness. He had also measured the combustion chamber volume which was about 47 cc. That's 7 cc smaller than original! The heads had really been lowered a lot. This would make my compression ratio pretty high so he ground the chambers back to 50 cc. Hopefully removing material from around the valves also improved flow.

Machined combustion chamber

Ported intake bowl

Chamber with the new valves installed.

Nice amount of room around the open valves

Even with the machining done, I still had a lot to do before dropping the heads on the block. I would need to find the correct springs, measure the valve-to-piston distance, lap the valves, paint the heads and finally assemble them. Oh, and hope that the heads would not be cracked and ruin my day when first starting the engine.

Wiring Harness Connector Pin Repair

Now that my engine bottom end was about done I turned my gaze to the heads. They needed some work that I could not do myself so I dropped them to a machinist that would inspect them. This would take a week or two so I had some time to do other stuff with the car.

When I was preparing the engine bay for painting, I removed the wiring harnesses. Unfortunately one pin in the main connector broke when taking it out. I checked a wiring diagram and it was the main power wire from the engine bay to the cabin. This is quite logical as it carried the most current so it would also corrode fast.

I did some Googling and found others that had the same problem. The discussion had some good instructions on how to fix the broken pin so decided to try it. I began be drilling a hole to the connector so I could screw in a new pin.

I had a small hook that had threads in it. I screwed it in the hole.

To make sure the pin had good contact with the wire in the connector, I melted some solder on it. I was not worried about the neatness at this point as I would have to add some more to solder the stud on the pin.

I used a small Dremel like rotary tool to cut the hook.

For the stud I cut the head from a bullet type connector.

The stud slid nicely over the pin and I added some more solder to keep it in and to ensure a good connection.

The repair felt pretty solid and should suffice for now. I might have to do more electrical work later but at least I should have electricity in the cabin again.

Engine Assembly: Water Pump

I noticed a small problem with my oil pan: the threads were pretty much gone from the drain plug hole. I do not want to risk it opening during driving so I'll have to fix it before installing the pan. Perhaps by welding a nut to the inside of the pan.

I let the pan wait and installed the water pump in stead. It had a small problem too. I had opened the back plate to inspect the insides but it seemed that the gasket there was not included in any of my kits. Neither is it included in my friends "complete engine gasket set" so I had to visit the parts store to get it. Just remember to get it separately if you plan to open the pump...

To seal the back plate to my cast iron pump, I spread some Hylomar on the gasket surface...

...placed the gasget on it and added more Hylomar to the other side...

...and installed the back plate. To make sure it was located correctly and to give the sealer time to dry, I added a bunch of bolts and tightened them to squeeze the gasket in.

After letting the back plate settle, I removed the bolts and installed the rear gasket. It had to only seal the water passages so I added Hylomar around them and set the gasket on it.

Finally I placed the pump on the front cover and located it with the bolts. I used new locking washers on all and torqued them to 15 ft-lbs. Pump installation done!