tuney

Piper UK have Vtec Cams, has enyone fitted similar to their S2000?

Piper are Quoting 15-20bhp increase in power.

The Reverend

I have heard similar claims about Toda's cams (they're not available yet). But it surprises me. Usually, with VTEC engines, the cams are tuned for maximum power given the current redline. I guess that's not the case. Anwyay, are the piper cams regrinds or made from fresh blanks? Toda uses fresh blanks. Regrinds will often bend a valve or screw up other things in the valvetrain.

tuney

With Piper u can have regrinds, or from a blank, which I think is most sensible.

The Price is about 400GBP, and Piper have been modifying cams for years, usually with Fords such as the Escort Cosworth etc.

The guys i talked to said they could get a hell of a lot out of the Vtec, which may be just sales speak, but who knows!

I am thinking of SC the car, so I guess a cam is out of the question anyway.

Bobway

Rev- Why do regrinds screw up otheer valve train components? Please explain.

The Reverend

Think of it like this... The idea of an aftermarket cam is to let you open the valves farther and for more time to let more air/fuel in (basically). To do this, you just need a bigger/broader lobe on the cam (once again, basically - it gets more complicated, but that isn't necessary to get into to show the problem). So how can you grind metal OFF of the cam to make a bigger lobe? Well, there's two ways people go about it. One is to weld more material onto the cam and then grind it back down to where they want it. I hope I don't need to tell you that that is ghetto and just not a good idea. The oter way is to grind material off of the original cam so that the lobe stays where it was originally, but everything else is cut down closer into the axis of rotation. You now adjust the rocker arm to sit closer in to the cam and then the lobe is farther out in relation to your starting point and the valve will open more. But in the process, you've thrown off all the normal geometry and ranges of motion in your valvetrain because everything sits in the wrong place from what it was designed for. Add to that the fact that most regrinds aren't made to exact enough standards and you have lots of manufacturing imperfections to really screw things up. The end result is that the opening and closing of the valve is not a smooth motion and you can often bend a valve (along with other things that can break as a result).

HTH.

[Edited by The Reverend on 02-27-2001 at 01:42 PM]

Pinky

Thanks Rev. I always wondered about that. Im like....regrind. You want more metal not less! Very helpful.

Bobway

I agree that just removing metal from the lobe for a regrind is suspect, but welding up the cams and then regrinding has been done for years, and is very much a solid process, not "ghetto " at all. Especially with welding techniques of today.

But thats why I asked, I have only had good experiences with regrinds, and have never heard a story of damage as a result yet. It just seems that when someone hears a part is remanufactured, they assume it is a piece of crap.

cmnsnse

I have had cams repaired and re-ground by Crower :

Exellent job, not any smaller, just different specs.

Sime

Cams in the VTEC do give great power gains! I put the Civic Type R cams (made by Mugen) into my B16A CRX.

The improvement was unbelievable, and VTEC smacked you in the back!!

However, I don't know if, to get the power they did from the F20C, Honda already did put a 'Type R' equivalent cam into the engine. Therefore, an aftermarket cam may prove to provide little to no gain at all. It might even provide you with a loss

Cheers,

chinkys2k

i'm going to wait for the toda spec cams to come out. Have got to say they're the best things in the world. My friend's crx with a itr motor in it has the spec C cams. The vtech doesn't engage until 6600 rpm but when it does kick in it's the greatest feeling in the world. My friend also had the ctr cams in his car so I know the difference between the two. The ctr cams are nothing compared to the toda cams. With the toda cams it really does feel like a turbo kicking in. I'm planning on getting the cams when they come out and i'll surely be posting my impressions.