What are straight-cut cam gears all about?

YoungDub · Post by **YoungDub** » Tue Jul 01, 2003 2:31 pm

I hear about straight-cut cam gears off and on and I am a newb wondering what is so great about them, what do they accomplish etc...? Can they be used for all engine sizes or are they a big engine drag racing thing. Thanks for baring with me here!

-Grant

Muffler Mike · Post by **Muffler Mike** » Tue Jul 01, 2003 2:37 pm

What they really accomplis is to remove thrust load of cam off cam bearing when using big springs. they do free up hp, but very little. they make noise that some like.

If you are not familiar with the stock cam gear, they are cut at an angle, witch tries to pus the cam against the trust bearing and with a big enough load (springs) can chew that bearing up after a while.

normally found in race motors, because of big springs. found in a lot of performance street motors for those that want the best.

but can be used any where really,

fastoldvw · Post by **fastoldvw** » Tue Jul 01, 2003 4:30 pm

Also they are often adjustable so there is an option to "time" the cam, otherwise all the reasons Mike says.
Just dont forget that lovely racey Whine, you'll love it!!

YoungDub · Post by **YoungDub** » Tue Jul 01, 2003 4:44 pm

Cool, thanks guys I understand! I do see how the cam is cut at an angle I have my cam about 6 feet away from me and I checked it out! That makes sense... But they wouldn't help all that much on stock springs would they, unless you just wanted the sound? Probably used more with those dual super rev springs right?

I am going to have to keep an ear out for them

! Thanks again,

-Grant

zilch02pcusa · Post by **zilch02pcusa** » Tue Jul 01, 2003 4:46 pm

Can anyone link me to what they sound like? Is there a place on the web that has em? I mean, I've heard that they sound cool, like a turbo, yadda yadda yadda, but is there anyplace to see em in action?

I'm planning on putting em in my 2276, but I dont wanna wait that long.

69NoH20 · Post by **69NoH20** » Tue Jul 01, 2003 5:03 pm

Ive heard it described as a quiet blower sound and i think that is about the best description.

prerunner1499 · Post by **prerunner1499** » Tue Jul 01, 2003 5:27 pm

ditto on the blower sound

!!!!!!!! Way cool but may be annoying in a daily driver,,,, it also gives them ricers something to listen to as you drive past them in their FART CAN muffler cars.

zilch02pcusa · Post by **zilch02pcusa** » Tue Jul 01, 2003 5:55 pm

I think I may have found what it sounds like.

"Rapid" Russ Hare's '56 has em doesn't he?

That sounds NICE.

Do a search for "Kris Lauffer's Notch..." and click the link, find rapid's video.

1969dragbug · Post by **1969dragbug** » Wed Jul 02, 2003 6:11 am

zilch02pcusa wrote:Can anyone link me to what they sound like? Is there a place on the web that has em? I mean, I've heard that they sound cool, like a turbo, yadda yadda yadda, but is there anyplace to see em in action?

I'm planning on putting em in my 2276, but I dont wanna wait that long.

Listen to a race car,you will hear them. If you can find one running a muffler, like we have to do on sat, then you can really hear them.

george brown · Post by **george brown** » Wed Jul 02, 2003 1:42 pm

Straight cuts have slightly less parasitic loss.

But more important is the fact that crank end float does not create minor ignition timing variations. If your maximum advance will be set near the ragged edge of detonation straight cut gears are advisable.

Shad Laws · Post by **Shad Laws** » Wed Jul 02, 2003 2:20 pm

Hello-

But more important is the fact that crank end float does not create minor ignition timing variations. If your maximum advance will be set near the ragged edge of detonation straight cut gears are advisable.

There is _no_ distributor accuracy gain from straight-cut cam gears over helical ones. The reason why is simple: VW's aren't American V8's, and the distributor isn't driven by the cam

.

The distributor gear is 100% independent of the cam gear. And, it is effected by crank endplay. When the crank moves axially, so does the distributor drive gear, causing inaccurate timing.

There are two things to do that would help to reduce the amount of distributor inaccuracy due to crank endplay:
- reduce endplay as much as possible
- preload the crank one way. _Helical_ cam gears do a good job of this

.

Am I saying that helical ones are a huge help for accurate distributor timing? No... once you have your crank endplay down where it should be, the extra gain by preloading the crank one way isn't going to be much compared to the other things that effect distributor accuracy, such as the distributor driveshaft axial play, distributor mainshaft axial and radial play, etc.

Take care,

george brown · Post by **george brown** » Wed Jul 02, 2003 2:25 pm

Yeah Shad, the VW dist drive is off the crank helical gear; I must have been thinking in Chevrolet/Ford gearset drive mode.

John W. Kelly · Post by **John W. Kelly** » Thu Jul 03, 2003 11:32 pm

How well do straight cuts live in street motors? Or should I say, compared to stock?

green65bug · Post by **green65bug** » Fri Jul 04, 2003 12:18 am

Yeah, how long do they last ? I've heard for the little bit of gain with straight cut gears its not worth it in a street performance engines, cause they dont last as long as the angle cut ones, is this true?

sinikl · Post by **sinikl** » Fri Jul 04, 2003 8:12 am

zilch02pcusa wrote:I think I may have found what it sounds like.

"Rapid" Russ Hare's '56 has em doesn't he?

That sounds NICE.

Do a search for "Kris Lauffer's Notch..." and click the link, find rapid's video.

go here:

http://www.geocities.com/crgrapevine/videos.html