Technical MOTOR, Flathead Tech - Installing a cam and adjusting tappets

I am using an Isky Max1. It is supposed to be a nice all around cam as well as a decent blower cam.

I obviously had to start by getting the old stuff out. This was a running motor so I didn't have to break out the heavies (in the left of the photo) to get the valves and guides out. They all popped out with no more effort than a typical wine cork. That's a Speedway pickle fork on the left and the other tool you see over there is a hook I made from a bicycle spoke to pull the retainers. I'm considering welding a nub onto the backside of the Speedway fork to more resemble other forks I've seen.

The stock cam is the one on the right in the middle of the valve assemblies. I sectioned my bench off so I could sort everything make sure all of the bits went back into their respective bores.

You can also see the stock fiber gear leaning against the wall. It looked to be in GREAT shape but I hear it's always good to replace them during a rebuild. I am switching my ignition from the posthole style to the early (crab) style anyway so I definitely need to replace my timing gears - late gears are cut the opposite direction and will put thrust on the distributor causing early failure.

The early timing gear was scabbed from an early motor and is already on the new cam. (left)

 

Next was the fun part. Changing the cam gear requires you to change the crank gear too. After trying several methods to remove the crank gear with the crank still in the block (any clearance for a puller is non existant) I opted to pull the front cap and smash it from the backside with a hand sledge and punch.

The first few blows shattered teeth and sent bits of shrapnel in every direction. But after the mess was swept away the work-flow settled into a solid blow followed by a half rotation of the crank to get a good hit on the opposite side. I basically "walked" the gear off of the crank.

A smart man would have covered the bearing surface while doing this.

So here's the empty space waiting for a new cam and gears.

 

And here's a picture of a big gear puller doing what it does. It's amazing what the right tool will do. I'm cheap but have no problem spending money on something like this. It's just vicious looking... savage. I bought this from the coolest hardware store in Kansas City. It (the store) is a recent find for me. I forget the name but it is right in the middle of downtown and has been in business since 1933. GREAT place.

FYI - A flathead crank fits pretty well right between the front wheel and split wishbone of your hot rod. Reach over and give the steering wheel a crank to keep everything in place while wrenching on the gear puller.

Look at the floor next to the water pump pulleys and you can see the ends of the five dollar puller in a tweaked and bent heap.

 

Not much to say here. Just a bunch of break in lube slopped onto the camshaft.

 

And here are the gears and cam installed. Things got a bit heated and I forgot to pick up the camera for a few steps but it went like this.

1) Give the crank snout a light coat of grease in preparation of installing the crank gear. I wanted to get the crank gear on first as I thought it would be much easier to spin the cam to line up with the crank than the opposite.

2) Realize you have nothing to drive the gear home. Search frantically and find a scrap of your old exhaust (made from EMT) and cut a 10" length off.

3) Slide it over the snout and keep hammering until the gear is fully seated.

4) Paint the piece of pipe red and hang it on your wall. It is now a flathead tool.

I had to spin the motor over to get the cam in the last half inch or so. Make sure to line up the timing marks on the two gears. My crank gear had a dot (on a peak) and the cam gear had a slot (in a valley)

 

Next comes installing and adjusting the lifters.

Again, I got in a hurry and didn't pick up the camera for a few steps, but all you would really be seeing is pictures of parts dipped in Isky lube.

I looked at the adjustables that came out of my motor and they were flat so I'm using Speedway adjustables. I've heard the various stories about soft lifters and to be honest, I didn't give it much thought when I picked up the phone.

I did notice that after I recieved the lifters I pulled a couple out of the box to find a nick more than big enough to catch a fingernail. It only happened on two of them but it was there. I called Speedway and their tech guy gave me some suggestions which involved emory cloth and assured me that if there were any problems after install they would be taken care of.

Thirty seconds on a friend's lathe with a scotchbrite pad and they seemed fine. I'll keep you posted.

 

Here are the tools from left to right.

Johnson tappet wrench. There is a left and right. You are looking at one of them - not sure which - the other is somewhere in the valley already.

Feeler gauge - .014.

Modified wrench. This has had some time on the green wheel to thin it down and shorten the throat so the ends don't extend past the adjuster when in use. So now it's high speed/low drag. I also chopped it off at the recommended five inches which seems like the PERFECT length. And yup, that's fuel line slid over the handle. Comfy.

Now look up above the intake port. That was a flat washer. I had initially forgotten to order a set of wrenches with my lifters so when it came time to adjust them I thought I'd just make my own. That piece you see got a test run clamped in a pair of vice grips and that's as far as it went. I ordered the correct wrenches that day.

I had heard the stories about adjusting flathead tappets with these wrenches and was prepared to start off by smashing the backs of my hands and knuckles into the corner of my workbench to get them acclimated to the work. Turned out not to be the case for me - read on.

 

No picture for this part. When you adjust each tappet you want to make sure it is on the heel of the cam to prevent negative lash. The absolute easiest way is to turn the engine over until the valve you are adjusting is at full open... now go another complete revolution and the lifter/tappet is now on the heel of the cam.

There are lots of formulas speaking to when corrisponding valves are just opening or have just shut, but I think the above method seems by far the most fool proof.

 

I've seen the drilled lifter bores and the other little tweaks to the block to make adjustments easier. And after fitting my modified wrench in the tight space left above the lifter bore but under the valve assembly I can see how av8's method of knocking the edge down a bit could be very beneficial. BUT, that is not to say I was bleeding tonight. I had a pretty easy time of it overall.

Now for those who have never seen it, here is a wrench in place. It's really pretty smart. The shape makes absolutely no sense until you see it in context. You have a bit that sort of snaps around a lifter and a bit which extends to the lifter next to it with a tab that reaches into a hole in the top of that lifter and holds it from turning.

From there you just use the modified wrench and fiddle with the adjustment screw until you have proper clearance. I turned until I could just slide the feeler into the gap with alittle push - and always made sure that when I wiggled it all I could feel was the flex of the gauge and absolutely no "rocking" sensation.

 

Silver Sharpies rule. I marked each valve after finishing. Be sure to remove the wrench before turning the motor over to make your next adjustment. I only had to make that mistake once.

 

That's it. Fifteen more times and you're finished. Keep in mind that the specs for my intake and exhaust were the same. Some cams require a larger exhaust gap. I that case I would do all of the intakes assemblies first and follow with the exhaust to keep cofusion to a minimum.