Straight Cut Gears

[DKK Ted]

Am curious, who makes or has made the straight cut gears with aluminum cam gears.

Ted

[Cheesepanzer]

original magnum sets had the aluminum cam gear.

[DKK Ted]

This is the gears in question.....

Ted

[Diederick/DVK]

i now have an aluminium Magnum cam gear installed.
unfortunately i did not yet get round to testing it as someone else blew the fun for me...

[ibg]

I have a set of the old magnums (aluminium on steel), does any one know how much spring these can handle. I would like to use 350 lb with 1.45 rockers.

[stealth67vw]

DG part number, maybe Dyna Gear?

[DKK Ted]

I checked other forums, seem that Dyna Gear were cast gears. I had pulled these out of a motor I'm doing for a friend, replacing them with CB's all steel gears.

Ted

[Kaferdog]

I know I was told that aluminium on steel is "loud"as far as straight cuts.... thats why I sold my old magnum gears

[Donny B.]

I had a set of Magnum aluminum and steel straight cuts in my Berg 1776 when I first put it together for my '66.  I found the aluminum gear wore prematurely.  Not sure what was going on, but I found small chunks of aluminum in my Oberg.  It was very quiet but I replaced it with another set of Magnum aluminum/steel straight cuts and didn't have any more problems.

I now run steel/steel Magnums in my 2165 and they are not very loud.

[Cheesepanzer]

Ted, not sure of the brand, but the finish of the aluminum cam gear looks like its a cast gear.  I've seen other cast gears shatter from RPM and spring tension.  I wouldn't recommend running those.

[DKK Ted]

Yes your right, it is cast, not running them, going to use steel on steel.

Ted

[Pierside Parts Unlimited]

way back in the olden days, while working at gb enterprises, Gene had the race motor on the dyno and if you ever saw gene dyno a motor, you knew if the motor made it thru that, you were good to go.
anyway, after a couple mid rpm pulls and some tuning changes he ramps it up to like 8K, and holds it, then suddenly, silence.
as we tore it down, we realized the aluminum straight cut cam gear had no teeth left,
after that, you never saw aluminum straight cut gears around gbe again.
Ti valves, empi slipper skirt pistons, pushrods and tubes, custom split port heads all toast.
the motor was running chevy springs, the motor had been run with duals and triples no problems but the chevy springs were too much.
Get a good set of CB, magnum or bugpack gears, cheap insurance.
Happy holidays!
Greg

[rick m]

I run CB straight cuts and I take a lot of time filing all the edges of each tooth on the crank and cam gear...then I dress them with a 220 1/2" sanding cylinder.  You cannot tell have straight cuts in my motor. They are very quiet. It is an age old thing Dean Lowry showed me years back. It works.

Rick M

[bugnut68]

I run CB straight cuts and I take a lot of time filing all the edges of each tooth on the crank and cam gear...then I dress them with a 220 1/2" sanding cylinder.  You cannot tell have straight cuts in my motor. They are very quiet. It is an age old thing Dean Lowry showed me years back. It works.

Rick M

I bought CB's for my 2017... went right on the crank after heating five minutes, but for the life of me I could not get the crank gear off with my puller, broke the tool in the process.  Is this common with CB gears? Just wondering.

[Taylor]

Bugnut, it's not always that it is too tight on the crank circumference.   I have found that most often the key doesn't slide through the broach.   You have to fit it by hand.  Also making sure inside diameter is smooth and apply anti-sieze. Taylor

[neil68]

I run CB straight cuts and I take a lot of time filing all the edges of each tooth on the crank and cam gear...then I dress them with a 220 1/2" sanding cylinder.  You cannot tell have straight cuts in my motor. They are very quiet. It is an age old thing Dean Lowry showed me years back. It works.

Rick M

I bought CB's for my 2017... went right on the crank after heating five minutes, but for the life of me I could not get the crank gear off with my puller, broke the tool in the process.  Is this common with CB gears? Just wondering.

I've experienced the same tight fit with my CB straight cuts.  I've installed them first on a CB 78.4 crank, and now a CB 84 crank.  Both times I had to heat up the gear on the stove burner in order to get it to drop onto the crankshaft.  The previous hot oil technique that I had used for years, did not work with these straight cuts...they needed some extra heat.

[bugnut68]

Bugnut, it's not always that it is too tight on the crank circumference.   I have found that most often the key doesn't slide through the broach.   You have to fit it by hand.  Also making sure inside diameter is smooth and apply anti-sieze. Taylor

Wish I'd known that before... I'lm going to take it to a buddy's automotive shop, hope he can get it off without busting any of his tools...lol. 

[Steve D.]

Wish I'd known that before... I'lm going to take it to a buddy's automotive shop, hope he can get it off without busting any of his tools...lol. 

If you have a really tight set of gears that don't want to come off the crank, blast the gears with a mapgas torch (or I guess it would be mappro or whatever they call it now- the one in the yellow can) before you start putting some force to them.  I've done this before with an extremely tight set of CB gears and a borrowed crank gear puller that I wanted to return without damaging it. 

[Taylor]

Grind it off!

[rick m]

I agree with Taylor. I personally go over everything on the gears before installing them, no matter who made them. It is just a good preventative measure. Do the same with everything in your motor. Trial fit before assembly and check all clearances, including ring gap, axial play (side clearance on the rods when hung on the crank), lifter to cam clearance in the case.  Don't just trust that everything fits.  It is worth the time to check every clearance on every assembled part. Obviously you should be checking deck height (to ensure the barrels have the same clearance when set in the case, etc., etc., etc.  It all makes for a very dependable motor and miles of hassle-free driving, no matter what size the engine is.

Rick M

[bugnut68]

At this point, I'm just trying to get the gear off so I can a shipping quote to a dude interested in buying my bottom end.  I'm thinking my buddy should be able to get it off, hoping without destroying it.  Gears have not been run yet, bought them when I was still intent on finishing this engine but that ship has sailed.

Awhile back I likened building VW engines to being a clockmaker... obviously there's not a part out there that can be relied upon for precision fit out of the package.

[DKK Ted]

Hey Ryan, just use the gear puller but without the impact, use a wrench with a long cheater bar, and just turn it slowly, it will come off. Make sure it is in a vise, had the same problem, used my Berg puller at the time and sheared the lip. Bought a cheapy one and just used what I told you, and came right off, just take your time.

Hey, and MERRY CHRISTMAS!!!

Ted

[spanners]

Ive had a failure on my own motor , steel on steel, expensive,  and seen others suffer , so i now life them and log the hours, in fact, ive gone back to stock helical on many builds, another problem is excessive back lash as vendors seem to only offer a one size fits all product that is often too slack, the debris from the failure punched thro the gear case under the camwheel, luckily it welded to a good repair, plus the usual bent valves/damaged pistons. to be fair, the gears were old and had about 100 race hours on them at a guess, i would certainly life them at about that figure, not what you want for a daily tho..