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Cam gears- materials,design,failures

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FATGTS-R Experienced

FATGTS-R

Posted
Posted

One of the next things I plan to do with my car is install some cam gears so have begun to do some research.

MATERIALS:

Looking at the advertising speels a lot of companies (recently HKS comes to mind) promote the materials they use citing fancy metal names (duralymium sp?) that the layman has never heard of.

Why? Do cheaper, supposedly less quality gears brake, wear out etc? I ask as my car is from 1987 with what I assume are the original factory gears and they look fine. What are the factory ones made of?

DESIGN:

Cruising around the net looking at images of different brands of gears the one that stood out as odd was HKS in the fact they only have 3 bolts to tighten the adjustable part as opposed to most others having 4 or 5 and I think I saw one with six.

Isnt it obvious that the more securing bolts the better? Or am I missing something? Why would HKS, a supposedly reputable a/m parts supplier skimp in that area?

FAILURES:

Lastly, who has had a bad expereince with cam gears? Either failure of some sort, premature wear etc? What exactly happened and what brand were they?

Just hoping to get some decent feedback and maybe help a few others who want more than an anodised cog that matches there colour scheme.

Also would like to hear from people who have had custom cam gears made. Material used, pricing etc.

Thanks in advance.

Jayson.

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MSRB26 Enthusiast

MSRB26

Posted
Posted

Although not from personal experience i have heard of failures with HKS gears on more than one occation and it has always been related to the teeth on the gear as the material seems to be too soft and wears quickly. Has anyone else heard of this?

I am currently using Tomei and have had no issues.

Amaru Veteran

Amaru

Posted
Posted

On the "series 1" design of the HKS cam gears, the metal used for the teeth the belt sits on is too soft, and I have seen a few which have worn away pretty quickly (under 15,000kms). You can identify the series 1 design as having the purple center and blue outer edges.

The "series 2" design is made out of the same metals as Tomei's cam gears, and I havnt heard or seen any problems with the Tomei ones.

djr81 Grand Master

djr81

Posted
Posted

Duralium is simply a variant of aluminium that has increased wear resistance due to its hardness (As the name suggests).

Tomei have used it for ages & now HKS have come into line.

If you are worried about wear the answer is pretty simple: LEAVE THE TIMING COVER ON YOUR ENGINE!

predator Grand Master

predator

Posted
Posted

I would have thought a lot of the wank associated with the material would also be for weight reasons. Less weight = less reciprical mass on the drive system, which is a good thing.

I would have also thought 3 bolts was pretty strong to hold the whole gear in place, considering your tensioners only have one. Bolts don't often snap unless put under extreme heat, in front of the engine is relatively cool (otherwise the timing belt would also be not be made of rubber in this case)

If you are worried about wear the answer is pretty simple: LEAVE THE TIMING COVER ON YOUR ENGINE!

why? wouldn't it make more sense to leave it off so you can spot the wear? or is that what you mean??

Sydneykid Grand Master

Sydneykid

Posted
Posted

Leaving the cam belt cover off lets dust and dirt in, wears the belt and cam gears very fast. I have even seen a small rock get caught in between the belt and the pulley, ripped the belt to pieces. And many valves hit many pistons.

The Stagea needed a cambelt service, so I figured I might as well stick an adjustable exhaust camshaft pulley on there while I was doing that. I ordered a Tomei pulley from Nengun, but apparently they don't make them any more. So I opted for a HKS one made of the new material. It weighs 350 grams (standard camshaft pulley is 550 grams) which is quite a bit lighter than the Jun ones I have that are going on the new RB31DET.

I haven't done a propper hardness test on the teeth on HKS pulleys, but the scratch test comes up pretty good. I am not concerned with 3 bolts, I always use Locktite on them anyway.:cheers:

pnblight Mentor

pnblight

Posted
Posted
The OS giken cam gears are made out ouf the same material as the Tomei gears, but are alot cheaper in price, almost half the price.

damn you must be getting your os giken cheap cos i payed under $200 a piece for my tomei wheels

treo Collaborator

treo

Posted
Posted

i got my os giken adjustable cam gear $120 brand new in box privated on Firesport.com, i two used locktite however left my top cam cover off. I dont see this to be a problem dont live near salty water and i know not to put my hands there so i see there to be know real problem

Sydneykid Grand Master

Sydneykid

Posted
Posted
i got my os giken adjustable cam gear $120 brand new in box privated on Firesport.com, i two used locktite however left my top cam cover off. I dont see this to be a problem dont live near salty water and i know not to put my hands there so i see there to be know real problem

The RTA are resurfacing the road near my house, I found a small rock on top of my airfilter last week.

Be carefull:cheers:

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