I'd like to know if anyone has actually seen any improvements by installing a Hydra-Rev kit..... Rather it be by dyno, or quarter mile times. I've spoken to several professional engine builders, and they all seem to have differing opinions about them. The idea behind them seems to make sense, though.
I'm not going excessively radical on the cam. It's a CC305 with 1.6 rockers. I know Brian (ProjectZ) is running the same cam, without the kit, and doesn't seem to have any problems with valve float.

Frank

 

Dont know if you saw this, I dont believe it, the concept makes sense for durability issues, but I definitely do not see it increasing HP much if at all, let alone 100hp....But thought Id post it incase you didnt see it.


http://www.airflowresearch.com/pages/hydra_rev.htm

 

I don't think they are claiming an increase of over all horse power. I think they are stating that the HP will not drop off.

For instance if your car dynoed at 400 Peak RWHP at 5000 RPM & at 6500 RPM your car read 300 RWHP, they are claiming to be able to maintain that peak HP higher in the RPM range. This would make a bit more sense to me. I could be wrong though but that is what I get out of it. If your car dynoed 400 rwhp I don't think they mean you will now have 500 rwhp..
Just my .02

 

I dont think the rev kit will ever give you more power. It will just stop you from losing power due to valve float.

 

Thats what Im saying, but it says (probably just them lying but put something in small print somewhere saying they were lying) installing this kit gave an overall gain of 100hp.

 

From what I've read and gathered, I think Smokn 94 Z and atljar have nailed it on the head. It's not a HP gain, but a sustain in your peak HP.

I don't think the CC305 is too much of a cam to worry with it, but for $249, it ain't a bad idea. I think it'd be a MUST on a cam with a larger operating range, but that may just be me.

DJ

 

if you have the correct valve springs then you shouldnt need a hydra-rev.

 

That isnt always true. Some very steep ramp rates can and will collapse lifters. The rev kits takes some of the pressure off the lifter.


IMO, the 100 HP gain is looked at like this. You dyno a car, it puts down 300rwhp, with the valves floating. You install the kit, it now puts down 400rwhp. Yes you gained 100 hp, but not really. The engine always had this power, just now it was able to fully harness it in a way.

 

Again...I agree. Good example/points.

DJ

 

ok then...the correct springs and lifters to support them.

also all the hydra-rev does is supply presure directly onto the lifter body..not the pluger like a pushrod(im sure you know this) now what i dont see is how a hydra-rev takes spring pressure off the plunger. if you have springs stout enough to keep the lifter on the lobe then a hydra-rev will do nothing to keep that pressure that spring is supplying off the lifter. the way i see it, if a lifter will collapse without a hydra-rev..it will with one too.

 

nice to have u back around frank

Thanks for the help with the trans-
one problem
it doesn't like going into OD
the tranny shop said it might be a lazy soliniod and they will replace it.

thanks

 

Brad is correct.

Especially in this case, the cc305 is very mild, don't spend your money on it unless you're a road racer or that bad at shifting.

 

Phil should i get it with my cam?
I want to rev to like 6500 although I'm fairly certain it can rev to 6900.

I'll probobly take it 6900 once or twice to get my bests though

 

My cam pulls to 6,900 on the dyno without power dropping off at all. Maybe it's the Hyrdra-Rev.

 

Thanks for all the input guys. The springs I'm using are Comp 986 double springs. They're rated for up to .560" lift. I'm only going to have .544". Did I forget to mention that I'll also be spraying another 150 HP on it via an NX kit? Excessive Motorsports suggests using stiffer springs than the cam calls for when using nitrous. Anyone have any thoughts about this? The cam numbers may seem small by comparison, but I know the cam works...Just ask Brian (ProjectZ). 11.9's with stock heads, t-body, injectors, bottom end, etc. kinda sold me on the cam#. He made peak power up to 6600 RPM's on the chassis dyno.