Well, i've been thinking about going to solid roller within a year or so, a Comp 280SR, 280/286, .608/.614 in particular. But with my springs i can only get about 140# of seat pressure with my 1.46 springs, and i dont really feel like buying new springs, and having the pockets machined to 1.55. Also if i get rid of these heads, chances are, the next person wont want to use huge high pressure springs. Ya think a rev-kit would add enough pressure to rev to 7k. How much do rev kits usually add?

 

In short... if you need new springs, the rev kit isn't going to change that.

Springs are relatively cheap... (cheaper than a rebuild anyway), don't skimp. As far as selling stuff, heck, it'll probably need new springs by then anyway

 

Well, by the time i swap cams, my springs will have MAYBE 1000 mi on then and the motor 3000mi, since i have the corolla now and its pretty just a strip truck. And this is already the 2nd set of springs i had to buy, cause the 1st set, were way too short, and i ended up getting valve float @ 5500 rpm (75lbs on the seat).

The current cam is a 230/244 .519 .534 hyd flat tappet cam, so there will be very very little wear on these springs. Cost of new springs/retainers, machining wil probably come close to $400. Rev kit is $130, and has the added protection if i kill a lifter or pushrod, and wont put exessive wear on my rockers or valve seats.

If i can get an extra 20-30lbs from a rev kit, then i think i would be totally happy. Do you think it will add enough pressure to do that?

 

you are confused on how the rev kit works. it will NOT help control the valve, only the lifter.


Springs, $100, retainers.. oh $35 for steel, machineing is about $50.


?

 

Jordan,
I think I understand how the rev kit works. And i still have a question. Won't the fact that the lifter is controlled reduced the required spring pressure at the valve because not as much of its spring force is required to keep the lifter on the cam lobe? Isn't the seat pressure is related to the open pressure and thats really what your interested in.

I'm not trying to say that it will work, Phil and yourself are probably completely correct. I'm just asking for a little more in depth explanation because I see where this guy is coming from. If his lifters are controlled by somethign other than his valve springs then he doesn't have to run as much valve spring pressure open or on the seat. He just needs enough spring pressure to control the valve, pushrod, rocker and not (as much of) the mass of the lifter .

Thanks

 

actually, i noticed that comp recommends 155lbs on the seat with that cam, and the same springs are suggested for a solid roller up to 7200 rpm. I would definetly think that 140 on the seat and say 20-30 with a kit would hold it down.

 

here is how it works

1) springs control the lifter on the valve

2) when the valve begins to "float" and the lifter cannot stay on the lobe of the cam a "rev kit" is installed to put extra pressure onto the lobe of the cam to give you some more rpm outta the motor before it floats again

so if you are going to bandaid your situation with a rev kit it might work "sorta" but dont expect it to work fully

 

if comp only says you need 155 for that cam, 145 may cut it.. the rev kit would be a good idea, but is for sure a band aide.


Setting the valve down on the seat is the job of the springs, and the rev kit wont help this.

Yes, it does take the weight of the lifter out of the equation, but I still would reccomend the correct springs