Aussie Cams

[raman]

I am about to buy a new Cam, and I am just trying to find out what cam shafts are available in Australia, and if they are worth the money. I was looking at a Crow mild cam as i do a lot of driving. any thoughts?

Thanks

Ben

72 240Z

[Brett240]

i have a stage 3 crow cam in mine, its a bit of a lumpy thing, needs 1000rpm idle. mines nearly a daily driver. for this cam you'll need your choke to work properly because it wont run without it when its dead cold. it makes a nice difference though with the hammer down.

there is one problem with crow cams however:

there cam card does not state .050 valve timing and instead quotes .075. this is totally useless, and makes cam timing a hit and miss affair. if you ring up crow they still cant give you .050.

Camtech is a good brand that makes L series cams and their cam cards will have the correct info on them, give them a try.

[RB30-ZED]

I had a Camtech "702"in my old L28, cant remember the specs now , but it did have 13mm of valve lift idled at 800rpm and had very good mid range power and ran hard to 7000 rpm.

Steven

[g260]

I have attached a sheet for the specs for Camtech cams who are based in Sydney. They cost about $220.

HTH

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[RB30-ZED]

I see the valve lift specs are really the cam lift and has to be multiplied by the rocker arm ratio, which i think was 1.5:1

I would recomend the 702 with a good set of springs, was a nice cam when set up retarded 6 degrees from standard.

Steven

[Murph]

I'm also thinking of going a better cam for my L26. What sort of money are we looking for the other bits and pieces needed such as valve springs, rockers and lash pads?

Will the low compression of the L26 be a problem?

[halz]

Brett,

Can you explsin what you mean by:

state .050 valve timing and instead quotes .075

I understand lift and duration... but timing...

Hayden.

[Gav240z]

Ok here's how I understand things.

With a larger cam the duration is increased to which the valves are open this is ideal in higher rpm's because the engine needs to be open for longer to get rid of all the exhaust gases etc..

Setting the timing backwards would allow for the longer duration of valves being open? Not sure as I say I'm still trying to understand the concept.

My 240z has 10:1 compression but the cam i feel is very mild as the last owner stated and I run out of power around 5,500rpm. It hits the stock power limit. So I wonder if my stock cam was just reground.

I would very much like to install the 702 as I think it would be ideal for my car and driving. I can foot the $220 bill for the thing but I'm not sure how to install one and setting the timing I'd really like to learn etc. is it hard? is it best left to professionals?

I belive my valve stem seals are worn out as it's a little smokey after idling and take off so I planned on replacing these anyway and while I'm at it installing a new cam would be on the cards.

:classic:

[Alan Pugh]

Cams are a tricky thing to understand when you get right into the nitty gritty of it all, and thats why we all go to companies that manufacture cams to get them, because they have done all the homework and trial and error.

Every cam you buy or is fitted to a car as standard is a trade off in different areas. Variable valve timing is now standard in a lot of current day cars, which goes a long way toward solving problems with the valve timing, but the cam itself in these cars is still a trade off between driveability and performance.

Unfortunately it's not as easy as retarding or advancing a cam in the engine to get the performance you need, there are a lot of other factors you must look at.

Valve lead: The amount of time/rotation/degrees the valve opens B.T.D.C.

Valve lag: The amount of time/rotation/degrees the valve stays open A.T.D.C.

Valve overlap: The amount of time both valves for one cylinder are open at the same time.

The list goes on into a whole lot of technical jargin. I believe the best way to pick a cam is to decide how you want to drive your car and how you want your car to drive, and then go and talk to the people you want to supply your cam and talk to them, but I guarentee you will end up trading off somthing to get something else.

No point pulling up at the lights or being stuck in traffic and having to pull the kidney belt on.

Somthing to think about.

Alan.

[halz]

cam card does not state .050 valve timing and instead quotes .075. this is totally useless, and makes cam timing a hit and miss affair. if you ring up crow they still cant give you .050.

No one has answered my question(!) Advancing or retarding the camshaft would not change the duration or overlap (to respond to Gav240Z) but merely alter the open/close angles.

So, Brett240, what do you mean? Is it that aftermarket camshafts have a fraction or advance/retard built in when compared to standard ones?

[raman]

I have gone with the Crow 58640 Cam. It is a bit hotter than i had thought but seems OK for daily use. It just idles below 1000 Rpm but when you get to 2500 the car takes off. The car no longer likes to be started cold, but i can put up with that. I have had the workshop i go to setup the timing and they did'nt have any problems with it.