>does anyone here use this kit ?
I have the AFR #1032 LT4 heads and was wondering if I should get this too .

I upgraded my engine to a forged 396cid (3.875" Callies crank ,4.030 bore,5.850"Oliver rods,custom JE pistons,and a Vortech T-trim)

 

Sorry I don't have any info on your question, but that's going to be a hell of a ride!

 

I haven't used AFR's kit, but I've used rev kits before. They're great if you want to turn high RPM without having to worry about the lifters puking out early in life.

 

I seriously thought about it on my 383. Most people who have one give it a thumbs up, though a couple said they couldn't tell any difference. Probably just depends on the particular valvetrain and where the weak spots are.

You may already know, but really, all the HydraRev does is put additional spring pressure in place to control high RPM valve float. The trick is, it does it by setting it's springs directly on the lifter body. So there is absolutely no additional stress on the lifter's plunger, the pushrods, the valve springs, the valves, the retainers, the keepers, or the valve seats. That's a lot of stress saved. Of course, the cam still has to deal with it, but I don't think it minds too much on a roller.

If you've already got enough spring pressure to control valve float at your highest desired RPM, I don't think you would even know the HydraRev is there. That's going to be a decision somebody makes in the process of assembling your heads. Most people just get high dollar RRs and lifters, then slam some serious springs on. Not as elegant, but it seems to work.

Do you know what your seated and full open valve spring numners will be? That would help.

 

BTW, what pistons and what -cc relief did you go with? What's your target compression ratio?

 

I know the co-owner of AFR and inventor of the Hydra-Rev. I asked him if I would need it in my upcoming install of LT4 heads and intake with a 230/236 112 lsa cam. He came back with a definite "Yes." He told me that in most of his testing of his (AFR's) heads, valve float became a problem at some point. This was his solution - and it works.

Guy (his name) is helping me for free and wasn't trying to sale me anything. I trust him. If nothing else it will reduce the stress on my already overworked parts.

AFR

 

I can attest to that. Why? Because LT4 heads have LT4 springs, which SUCK. I have LT4 springs on my car with a 224/232 and these springs float at 4500ish RPM. The springs are very poor at valve control. So the rev kit would do wonders for me here. I'm using Comp 987's now, and even though the rev kit wont help alot it's just extra insurance. With a stiffer spring like a Comp 977 the rev kit wouldn't really even be necessary.

 

The main advantage I see to the kit is tha it allows you to run a lighter valvetrain but still control float.

 

You mean heavier? A heavier valvetrain has more inertia which makes it harder for a given spring to control the mass.
Also let's you run more aggressive cams/ramps without having to worry about the lifter launching off the lobe, or the valve bouncing off the seat from lack of pressure, which is what valve float is.

 

My heads were set up by Total Engine Airflow, and I'm smooth as glass to my arbitrary 6500 RPM revlimit. I just picked that to play it safe till I can get to the dyno and dial the car in.

The car is perfectly smooth to redline and feels like it's not even trying really hard at 6,500. No power dropoff, according to my SOTP meter, but you can't really trust that. Dyno time, but at this point, I'm thinking around 6,800-7,000 RPM is going to be the ideal redline on this setup. At 7,000, it might be HydraRev for me, just to play it safe. I bent an intake valve, back in the day, on a Ford 428 SCJ, doing about 140mph. That was not fun. Or inexpensive. The valve broke off of the stem before I could get slowed down, then dropped into the cylinder and cracked the piston, which cracked the cylinder wall. Not good, seizing the engine at 100 mph.

I'm betting the answer to "Do I need a HydraRev?" is always going to be "maybe". Depends on how your valvetrain was set up and how high you need to spin before your engine stops making power. There is not a one-size-fits-all answer. But OTOH, I don't see how it could hurt if you have the $$$ and want to spend it. And it might help.

 

Not sure of the lift numbers for your cam, but it looks to me you're stretching the bare limits of those LT4 springs with that cam. They're only rated to around .520" of lift I believe.

Jason

 

OH YEAH. Lift numbers are .502/.510, and I was using stock rockers. I just used the LT4 springs because that's what was available. Perhaps good for a stock or LT4 motor cam, that's it. Wont even use it for a hot cam now. My LT1 feels like a TPI motor...serious power dropoff where it should continue making juice. So I have a swap to a cc306 and Comp 987's planned when I get home with my timing chain and opti conversion

 

im using CC987s and 10 degree locks and stock lifters and going to 6500 all day long with no float with .555 lift. LT-4 rockers and valves.

 

You have realize that its cheap insurance, if a pushrod goes, or a rocker goes or even say your valve spring break & just the inner valve spring is there trying to keep up, the hydra rev will do a heck of a job keeping the lifter on the cam & taking the lifter weight off the whatever is left of your valve spring.

Just think its good to be there, I doubt it serves much for valve float problems if you have a good valve train, but with all that can happen at 6500-7000 rpm I wouldn't do without.

 

He has a point...
if a valvespring breaks up high without a revkit, it can mean