Jump to content
SAU Community

Recommended Posts

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.

Link to comment
https://www.sau.com.au/forums/topic/73956-cam-gears-materialsdesignfailures/
Share on other sites

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.

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.

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!

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??

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:

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

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

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:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...