1915 Engine Rebuild

Straight cut cam gears are used in performance engines due to the tendency of the helical gears trying to push the cam out the backside of the case and hence wearing the cam bearing out, in short order. Higher lift cams with stronger or double springs makes this much worse in non stock engines. Helical cut gears are certainly better for stock....that's why VW used them.

What Jim said +
Stock VW helical cam gears will survive with stock diameter dual springs. They don't hold up to triple (double with a flat damper) or Chevy style (larger diameter and wire thickness) springs. IIrc Gene Berg said that they wore out cam thrust face on a set of dual thrust bearings in one day of drag racing with their Chevy springs.

PS (another note on cams)- a lot of CB's cams have long, soft ramps and a 50' spread between the 2 dur figures, and if you only look at the adv dur # the cam will look more wicked than it actually is. If I ever have the opportunity to chat with Pat Downs (CB's main engine development guy) that's one of the questions....

x2 on the "talk to Pat Downs" suggestion. He's an easy person to talk to.

I have eliminated the straight cuts from the build.

This is where I have ended up with my build:

Reuse case, weld no. 3
CB 044 heads 40x35.5 valves
Dual springs
CB 2242 cam
Stock cam gear
1.25 ratio rockers on solid shaft
Chromoly pushrods
Windage pushrods tubes
Dynamically balancing crank, flywheel, pressure plate, pulley, rods and
Pistons
1 1/2 qt extended oil sump
German tin except for 36 hp style SCAT shroud
019 distributor with petronix ignition
Dual 40 dells with Gordon's linkage upgrade

With any luck I'll be able to purchase Tigers Sebring style exhaust 1-1/2"

Let's talk compression ratio. I was thinking 8.5. CB said that should be fine. After running the numbers on my original build the CR came
Out to appox. 9.7. It always ran in the hot side in the summer.

Is there a perfect CR for particular set ups?

I like Ron LaDow's writing style, and often read his words just for fun. He has a bit of worthwhile reading here:

http://www.porsche356registry.org/resources/tech-articles/troubleshooting-and-repair/452-why-should-i-care-about-compression-ratio.html

The 2242 has 248' @ 0.050" and using 1.25 rockers adds another 4-5' to the original figure, so in reality the cam/rocker combo gives 252-253'. The motor should rev to 6000 rpm (or a little more! where's the laughing devil face when you need him?lol) 8.5 is safe and forgiving; you won't always have to be on top of the tune. At 9:1 there will be a little more power all around, and if there are no sharp edges in the combustion chambers (including spark plug threads; check that they don't potrude before installing the heads) the only things to be aware of will be to make sure it gets good gas and it may be a little more sensitive to the tune (you may have to fiddle with it a little more often, which isn't necessarily a bad thing). On the Samba you will find guys that say even 9 1/4 is safe, but I think that may be pushing it. I would lean toward the 8 3/4 -9 range. I want to hear what you think of it when it runs!! Al

PS- You will have to make sure the engine compartment has enough air intake, or overheating problems will rear their ugly head. There is a way to measure engine compartment vacuum with some clear aquarium tubing (it's actually cheaper here at the local hardware store) and a glass of water. This is a good test for any aircooled car that seems to run fine around town but has oil temp troubles on the highway. You may be surprised at what you find and how easy it is to fix...

Cory- that looks like a good article; I've bookmarked it for reading later..

Another PS- Paul, did you read the Hoover case, lifter and rocker arm modification article http://bobhooversblog.blogspot.com/2007/05/hvx-mods.html that Stan talked about earlier? If you haven't, take the time to go through it; getting more oil to the heads, (along with piston squirters) are the 2 best ways ensure longer engine life.

Long block is back together and the engine tin is being picked up from the powder coater tomorrow morning in the AM. With any luck... ill have this motor back in the car this weekend. This is the longest ive been without this car on the road. Spring is taking on an entirely new level of excitement. I really realy hope i can feel a difference in the seat of my pants. standby...

Just don't get to jiggy with it right off the bat. Somebody needs to post proper break in techniques here to ensure it lasts you.

Is driving it to Atlanta (12 hour trip) getting to jiggy with it? I leave in 10 days. I will get a good 500 miles on the motor prior to leaving. Oil Change, valve job and hit the road.

Make sure you drop by my place. We're overdue for a run to Annapolis, and my car is tentatively grounded. I'm waiting on new shoes to arrive.

I finished a motor install once at 4AM, left Vancouver at noon and talked a gas station attendant into using his hoist for it's first oil change just south of Portland Oregon that night. Adjusted the valves the next morning in the rest area parking lot where we had crashed and then drove non-stop to LA (hit Bug-In about 6AM). Take it easy and vary the rpms. It'll be fine.

ended up with a aprox. 9.1:1 compression. I was hoping for the lower side of 9.

Some pics, not anything y'all havent sean before. I hope im going to feel a difference. some people seem to doubt that I will.

Cory, ill swing by for sure.

Is the deck height low enough that you can add a 010" spacer under the cylinders? If not, it will be fine. Have you modified the tin to fit over the brass 90 degree oil return fitting into the case? If not, take a file to the top of the fitting and round it off some; it makes a real difference in how much you have to bash the tin to fit around it. Good to see it coming together.

pretty sure the deck was cut to .060, i ground down the brass fitting and pounded out the stock german pulley tin prior to getting everything powder coated. I dont think we will be breaking it down to add a shim at this point. thank you for all the advice along the way.

This was not an easy process, but a great learning process. still much to learn, its a start.

Very cool project, Paul! I'm also interested how much difference you'll be able to feel in the drive!