valve stuff

Boris · Post by **Boris** » June 6th, 2006, 11:36 pm

Just wanted everyone's opinion on something:

I'm getting corksport miata cams. You can see em here http://corksport.com/store/category/4v9 ... ngine.html

My question is how necessary new valve springs would be for these cams in my 1.6 ... I was gonna go with stainless steel valves, and mazdaspeed valve springs (with retainers) but found out that the springs would cost me $1100 and the valves would be just under $200.

The engine I got only had 126000km on it, and the valves look pretty good actually. I always told myself that I would never buy cams without valve springs, but considering this is a $750 car I'm finding it difficult to dump huuge amounts of money into it.

Any input appreciated, thanks!
Boris

WingleBeast · Post by **WingleBeast** » June 7th, 2006, 12:15 am

it really depends. the only time i would be concerned with valve springs is 3 things

1. the stock ones are old and not gonna give the valve the nessicerry tension to work

2. the engine is rebuilt and is going to be revving up past 7000 RPM

3. heavy turbo or NO2 useage

any of those 3 things could cause valve float, wich is where the cam stops pushing on the vlaves, but because the springs dont have the nessicerry power, the cam lobe will actually lose contact with the valve, but the springs dont pust agienst the cam hard enough to close fast enough. next thing you know you send one of your nice new valves into your nice new piston. but of course if you dont meet any of the 3 things above... i wouldent worry

Yoda · Post by **Yoda** » June 10th, 2006, 10:05 pm

It also will depend on the grind on the cam. An agressive performance cam will need a stiffer spring for the valve to follow the profile of the cam lobe after TDC.

Boris · Post by **Boris** » June 10th, 2006, 11:39 pm

Well these cams would be .352 lift and 200 duration at .050 lift for intake and exhaust... pretty mild, isn't it?

IMO it would be much SAFER to go with valve springs, but I'm not forking out over $1100 for springs and retainers. If anyone knows where I can get cheap springs for a 1.6L (by cheap I mean roughly 300 CAD) please let me know

MechaManZero · Post by **MechaManZero** » June 10th, 2006, 11:41 pm

dude shell out the extra money. its well worth it in the long run dude.

torpedan · Post by **torpedan** » June 11th, 2006, 1:52 am

MechaManZero wrote:dude shell out the extra money. its well worth it in the long run dude.

For the price its questionable. Spec miata motors can usually be reved safely to 8k and that is with stock componets. Granted these motors are often thrown out after X amount of usage as well.

My suggestion to this thread though is to lay out a plan of how much power you want to produce and on what platform and do a lot of reasearch before sinking a lot of money into it.

Boris · Post by **Boris** » June 11th, 2006, 1:58 am

That's the thing...I'm not looking for much power. Putting a lightweight flywheel in, cams, port and polishing the head, CAI, headers, 2.25" exhaust... Don't know how much hp that will bring me but not a huge amount that's for sure. Not planning on turboing or nitrousing anything.

I will be putting in a protege ECU which will make it possible to redline it at roughly 7200 rpm... That's the main thing that worries me. I know I will be hitting that redline somewhat often.

MechaManZero · Post by **MechaManZero** » June 11th, 2006, 10:19 am

http://corksport.com/store/category/4v9 ... ngine.html

Check out the Eibach EVS spring kit. $213.00 for 16 springs

torpedan · Post by **torpedan** » June 11th, 2006, 2:56 pm

Boris wrote:That's the thing...I'm not looking for much power. Putting a lightweight flywheel in, cams, port and polishing the head, CAI, headers, 2.25" exhaust... Don't know how much hp that will bring me but not a huge amount that's for sure. Not planning on turboing or nitrousing anything.

I will be putting in a protege ECU which will make it possible to redline it at roughly 7200 rpm... That's the main thing that worries me. I know I will be hitting that redline somewhat often.

If you are going that route look into doing some ground wires and a Underdrive pully as well. The U/D pully (if its a nice one ie Unortherdox) will lower your rotational mass as well in addition to doing he underdrive bit so its a notaable gain.

Weight reduction to anything in the roating assembly will make a diffrence as well, going to a lighter wheel/rim combination will help too.

A lot of this depends on how much money your wanting to spend too, and honestly if your going above a certain amount you will get beter gains from just swapping in a diffrent motor or dropping in a turbo (i know its not what you want to do, just it might offer better bang for the buck).

mazdamx3sohc · Post by **mazdamx3sohc** » June 11th, 2006, 3:02 pm

also, it takes more pressure out of the flux compasitor...

Boris · Post by **Boris** » June 11th, 2006, 8:11 pm

Mechamanzero,
Those eibach springs are for the BP I believe.

Torpedan,
I am probably going to get an underdrive pulley... the only thing stopping me is hearing stories about the car dying at stop lights cuz of them. I work with a guy who put one in his truck, and at stoplights he has to rev his engine.

Gonna get lightweight 15" konigs within the next month, too.