cam gear and under drive pully

[m92_MX3]

i have a 92 RS 1.6 SOHC and i want to know if anyone knows who makes a cam gear for it and if they make an underdrive pully for it and if they dont can i use a underdrive pully from the DOHC ?

Thanks

[Yoda]

Mazda made an adjustable cam pulley for the SOHC back in the early '90 because of the 1.5L SOHC uses in several classes of motorsport. The remaining inventories were sold off as scrap in about the summer of '00. I managed to get my hands on a few of these before the rest of the were purchased by a Dutch company. So unless you find one used you are pretty much S.O.L. On the SOHC it is better to use underdrive accessory pulleys rather than a u/d crank pulley. Before removing the waterpump all together I was using a larger diameter OEM waterpump pulley. On of my friend imports JDM parts and allowed me to poke around his warehouse. I managed to find a over diameter P/S pulley that was from a mitsubishi or nissan engine. Underdriving the Alternalor is taking one step forward but taking a step and a half back. Underdriving the alternator does reduce mechanical losses if the electrical system is at 100% but the problem is at lower rpm it is not charging the battery at idle and take at least 30% longer to top up the battery at higher that stock rpm. In reallity it takes the U/D pulley of the alternator requires more energy to drive than if it was running at the stock pulley ratios. The only time where a U/D alternator would be an advantage is in stock car or circle track racing where engine rpm's are going to be high and the car don't have EFI, elect. F/P, lights. etc that would put a heavy load on the alternator.

[m92_MX3]

so what your saying is that on the cam gear its not going to happen and wiht the u/p its not worth my time right ?

and thanks

[Yoda]

No that's not what I'm saying. The problem is that you were born about 13 to 16 years to late. The adjustable cam pulley did happen but were last manufactured about the time you were still learning to walk. With the U/D crank pulley it is not a good idea on any street driven engine. I was recently inspecting the crank nose on my KL-ZE and noticed some hairline fractures just behind the crank pulley.

Here is something you may want to look at
http://www.teamscr.com/pulleys.htm

My freeby U/D accessory pulleys maybe marginal at best according to the article but my dyno testing did show significant gains most at the top end. I have been told this is because the water and P/S pumps are optimized for what are assumed to be the average operating conditions the engine will see. Or about 3000 to 3500rpm. The guys that ran in the 323 Cup races way back when told me that at higher rpms both pumps will create hydra-dynamic resistance in there respective systems due to the pump is pumping more fluid than can pass through the hoses, thermostat, by-pass valves, etc. I don't have any dyno results with the water and P/S pump. But with the water pump removed and the P/S pump running at 1/2 speed I show almost no increase to about 3800-4000rpm then jumps up 6 to 8 hp at the wheels.

so what your saying is that on the cam gear its not going to happen and wiht the u/p its not worth my time right ?

and thanks

[BuGS]

Get a Cam gear made for the B6. HKS makes them and a handful of other companies make them. I had a HKS I played around with til I got my BP then I had another one so I had two for the BP.

Go here for more brands, prices, ect
http://www.clubprotege.com/forum/showthread.php?t=15379

[Yoda]

There is more that a handfull of companies that make them for the DOHC looking at my reference list there are(were) over 32 different companies.

If you were following the thread the question was asked about the SOHC engine not the DOHC

Get a Cam gear made for the B6. HKS makes them and a handful of other companies make them. I had a HKS I played around with til I got my BP then I had another one so I had two for the BP.

Go here for more brands, prices, ect
http://www.clubprotege.com/forum/showthread.php?t=15379

[BuGS]

And if you read my post the Cam gear for the DOHC fits the SOHC. I had one on my SOHC before going to the BP.