Trying to go though my parts to get back on this LT1 build. I bought a crane rev kit a while ago and was thinking of using it. Anyone ran one of these? Now the tricky part, i have as of of crane solid roller lifters and I have a set of comp solid roller lifters. The rev kit wont work with the cranes because the top of the body tapers off, however the comps it will work like a champ. Any input is appreciated.

 

Rev kits are to keep the roller on the cam at high RPM when your springs/lifters/pushrods cannot handle the pressure needed to do so, since it adds the pressure to the body of the lifter instead of the plunger.

If you spec'd the proper springs and pushrods for your combo, you will not need a rev kit.

 

yes and no.

 

Does anyone even still make an LT1 specific rev kit?

 

Afr has one. Not sure if it's specific to the ltx. Mine required a small amount of clearancing.

 

Ive heard that rev kits are band-aids over the years. Some people believe in them and some dont. I can see how it would help a radicial HR but not a SR. Can you please expand on your last reply?

 

It's not necessarily a band aid. It can be used as a band aid. But the biggest reason to use one is durability of the valve train. It takes a fair amount of stress off everything above the lifters. I run one with a big hr. Still have the components I put in it back in 2002.

The clearancing I did was around the corner were the head gaskets stick out.

 

Ive been doing some reading on them. Ive heard they can add power from 10-100 HP and Ive heard that they hurt hp from 5-50. What I did read that makes the most sense is that with a rev kit there is always pressure on the lifter and that lifters will last a lot longer. Makes sense because the valve lash could cause the lifter to bounce. also Ive read that you can get by with a little less spring pressure. Big question is is will a comp lifter hold up to start with, since I cant use the crane lifter with the rev kit

 

Ive been thinking of getting one myself.... But didn't know whether it would work with stock lifters.

 

Not sure about the solids but I run the std comp hr lifter.

 

IMO.....and only my opinion, people who say this, for whatever reason, just don't like rev kits.

To me, rev kits are just cheap insurance IF a push rod or rocker arm fails.......better to have and not need versus need and not have.

KW

 

I have always liked the idea of it because in theory the rev kit allows the push rod and rocker to move less spring tension; allowing the valve springs to only need to control the valve, rocker, and pushrod.
all= less rocker and pushrod load.

 

I talked to a rep for Cam motion at the LS fest this weekend. Told him what I was building and asked about the rev kit. He said years ago, especially in circle track, it was absolutly nessesary to run a rev kit. He said now a days with the quiality of springs and such being better that it wasnt nessesary. However, I still ike the idea of the rolelr staying in constant contact with the lobe. what ever the Lash is set at when the engine is hot it would be that much slop in the valve train when the valve is closed. im still undecided on this. I know these guys know there stuff but we may have been talking of diffrent reasons for using a rev kit.
He also said that for 7000ish rpm that a 5/16 chromoly pushrod would be suffecient and spring pressure should be aroun 225 closed and 650 open with a lift of 650-670ish

 

Understandable, as it's entirely a personal choice. Rev kits are not a requirement, as evidenced by the fact that most people don't use them. ("Sufficient" is a very subjective term, by the way).

Personally, I run an old AFR hydra-rev, but I do so for safety reasons as opposed to any alleged performance increase. In the event of a mechanical failure, I don't want any lifters taking a stroll in the lifter valley and inviting all of the oil pressure along with it. The rev kit could make the difference between "some" engine damage, and "a lot" of engine damage, should such an event occur. And if it helps with the longevity of the valvetrain parts and eliminating valve float at the same time, then hey, so be it.

The hydra-revs got a bad reputation years ago, because the top spring retainer plate wasn't hardened. The springs would sometimes bite into that aluminum and spit the metal shavings out into the lifter valley (-an unadvertised "feature"). Never had that issue myself, but I felt it bears repeating since we're discussing it. I don't even know if the hydra-revs are still available. Mine didn't require any grinding -- it fit out of the box -- though I'm not certain if it is LT1-specific.

Will you net 100hp? Nah. If anything, I'd expect the excess drag on the cam to negate any alleged performance increase, unless something really jacked up is happening at the valve. But that really depends on how well the rest of the valvetrain is arranged. If you're getting valve float at 5K RPM, then the selected parts are inadequate for the application, but the rev kit would theoretically help in that scenario.

If you do decide to buy a rev kit, and the heads are already installed, then I highly recommend going to harbor freight and picking up a $5 door spring installation tool. Trust me, you'll need it. (At least, mine didn't come with any installation tools).

 

I have the AFR rev kit also, and the reason I used it was to keep the valve springs from having to control the lifters. I get the pros and cons of these kits, but never been sorry I put it in there.

 

Thanks for the input. Door spring tool or Briggs Valve spring tool for the install. Motor is still in pieces now so Ive got some time to decide.