Straight cuts

[modnrod]

I thought I'd ask here as there are a few US tuners.

I'm looking at straight cuts, and although the tool steel are always cool, these aluminium ones caught my eye........
http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC%2DC10%2D5401
Possibly reduced noise, anyone have any experience with any backlash or softness issues?

[Donny B.]

When I built my 1776 many years ago I used the aluminum on steel set for the reasons you stated.  I found the aluminum gear wore prematurely and I had to replace the gears.  I wasn't pleased when I tore the engine down at about 60K miles.  In my current engine I am running Magnum steel on steel and they are not very loud.

[DWL_Puavo]

Am I reading correctly that Donny's engine got 60000 miles (96500km) and that big alu gear was "prematurely worn"?

For me it doesn't sound that bad at all, but I'd still note that I've also seen too much alu chips for my taste in the oil, just after break-in with "normal" helical alu cam gear. With steel straight-cuts there isn't (visually) nearly as much metal in the oil after first break-in.

[neil68]

I thought I'd ask here as there are a few US tuners.

I'm looking at straight cuts, and although the tool steel are always cool, these aluminium ones caught my eye........
http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC%2DC10%2D5401
Possibly reduced noise, anyone have any experience with any backlash or softness issues?

C10 denotes EMPI parts, so you may want to search on several forums, or Google, to get a better picture of EMPI's aluminum gear reliability.

[modnrod]

C10 denotes EMPI parts, .........

Oh.

Loud it is then! 

[nicolas]

if it were me i and noise was the issue, i would go for a set of stock gears. the noise is far less, and they are not so hard on one another because of the helix cut. i use them in my type3 because i didn't want the 'whining' of straight cuts. works without issues.

[modnrod]

The whine of straight cuts is music (along with a lump at idle).
The whining of ex-wives is bloody irritating though. 

Just considering the ally gear may have less harmonics, although I've never seemed to have an issue on ACVWs.

[nicolas]

 

[pupjoint]

sorry to hijack, been looking at straightcuts too, having issues finding Magnums, who sells them nowadays?

has anyone ever used the new gears from CB Performance ?

http://www.cbperformance.com/ProductDetails.asp?ProductCode=1400

[wph]

http://www.webcamshafts.com

part # 00-483

Web Cam seems to have Magnums in their webshop, I wouldn't hesitate to use CB either.
Built in crank spacer is a nice feature too...

Pekka   

[type149doug]

   I'm happy with the Competition Engineering straight cuts I've been running.