|
Re: Will solid rollers live in a street vehicle?
[Re: MR_P_BODY]
#946371
03/09/11 09:35 PM
03/09/11 09:35 PM
|
Joined: Nov 2003
Posts: 6,293
Rock Springs
Bob_Coomer
master
|
master
Joined: Nov 2003
Posts: 6,293
Rock Springs
|
Rev kit is a band-aid Forget those things. Run the correct springs for the application and forget those Dinosaurs. How can they help with a poor design or cheap made lifter that the pin falls out of the wheel etc. I dont understand the idle thing either. How can a engine at idle be hard on the lifters? Again another compromise and band-aid for a engine with oiling issue. Keep away from cheap lifters, and keep spring pressure reasonable, get a valve spring that will control the valve's and run it. In the end no one is going to know if it will survive or not, about as accurate as playing the lottery and expecting to win  Choose good parts, good assembly technique, along with correct part selection will go a long way. I dont know about you but I like to make educated guess's off research and past experiance more so than "he said so" 
[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: MR_P_BODY]
#946372
03/09/11 09:41 PM
03/09/11 09:41 PM
|
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
Stanton
Don't question me!
|
Don't question me!
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
|
Quote:
I dont think I have ever seen a rev kit for a Mopar
There's a pic of a BB Isky setup in Andy's book.
The purpose of the valvespring is to get all the components back to their static or closed position after a valve event. This includes the valve, locks, retainer, rocker, pushrod and lifter. Furthermore, it has to do this without leaving any gap between the components which would result in damage.
Any spring would do the job except that as the ramp rate, lift and speed increases, so does the momentum of all the components. It takes a lot of pressure to stop all those things dead in their tracks and then push them the other way!
A rev kit has springs between the heads and the lifters and the purpose is to keep the lifters in contact with the cam. As a result, the valvesprings no longer have to deal with lifter weight so the valvespring pressures can be decreased. How much would be determined by the pressure of the rev kit springs.
Still, quality valvetrain components will yield good results without having to go the rev kit route. I'd bet that less than 1% of the Mopar roller setups out there are using rev kits.
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: Stanton]
#946374
03/09/11 10:50 PM
03/09/11 10:50 PM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Quote:
Quote:
I dont think I have ever seen a rev kit for a Mopar
There's a pic of a BB Isky setup in Andy's book.
The purpose of the valvespring is to get all the components back to their static or closed position after a valve event. This includes the valve, locks, retainer, rocker, pushrod and lifter. Furthermore, it has to do this without leaving any gap between the components which would result in damage.
Any spring would do the job except that as the ramp rate, lift and speed increases, so does the momentum of all the components. It takes a lot of pressure to stop all those things dead in their tracks and then push them the other way!
A rev kit has springs between the heads and the lifters and the purpose is to keep the lifters in contact with the cam. As a result, the valvesprings no longer have to deal with lifter weight so the valvespring pressures can be decreased. How much would be determined by the pressure of the rev kit springs.
Still, quality valvetrain components will yield good results without having to go the rev kit route. I'd bet that less than 1% of the Mopar roller setups out there are using rev kits.
I know what they are but never even knew they made
them for a Mopar.... I really doubt they would even
make one for the SB with the angle on the PR... I
never planned on using one, I just never seen one
for a Mopar... my springs have 250 seat and about
640 open... its a little less than I'm use to running
but the engine I'm building now will only run to
like 7200 rpm... real low for me
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: Bob_Coomer]
#946375
03/10/11 01:01 AM
03/10/11 01:01 AM
|
Joined: Oct 2007
Posts: 4,213
New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,213
New York
|
There are 2 methods of removing lash, which is what destroys rollers:
1. hydraulic lifters
2. rev kit
Boffin Emeritus
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: polyspheric]
#946378
03/10/11 12:37 PM
03/10/11 12:37 PM
|
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
Stanton
Don't question me!
|
Don't question me!
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
|
Quote:
wouldnt the total pressure on the lifter/cam be the same with a revkit as with harder springs
No. Because of valve lash there would be no pressure from the valvespring on the lifter at all, only the pressure of the revkit spring.
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: Stanton]
#946380
03/10/11 04:14 PM
03/10/11 04:14 PM
|
Joined: Aug 2004
Posts: 2,128
sweden
sshemi
top fuel
|
top fuel
Joined: Aug 2004
Posts: 2,128
sweden
|
Quote:
Quote:
wouldnt the total pressure on the lifter/cam be the same with a revkit as with harder springs
No. Because of valve lash there would be no pressure from the valvespring on the lifter at all, only the pressure of the revkit spring.
You mean that there is pressure on the lifter without revkit?
Am i a stupid mother &¤#"&???
Could someone please explain how it works.
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: sshemi]
#946383
03/10/11 04:41 PM
03/10/11 04:41 PM
|
Joined: Jan 2003
Posts: 17,914
S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,914
S.E. Michigan
|
The rev kit forces the lifter to follow the cam profile at all times, and any lash that is used in the system is upstairs from the lifter. From someone who is a big proponent of street rollers here's my advice: If you don't want to run any given part for any given reason, then don't do it Do whatever you deem the best plan for you and whatever gives you a decent amount of confidence. However....keep in mind some people run around on the street with 15:1 compression and aluminum rods....yet they won't use a roller because of perceived reliability issues. As if what they already have is going to last forever  Everything we do to make more power has some sort of potential reliability sacrifice. It may not always be enough to notice, but it's always there. To think otherwise is kidding oneself. It's all good, build your car/engine any way you want, the important thing is to have fun with it.
Rich H.
Esse Quam Videri
|
|
|
Re: Will solid rollers live in a street vehicle?
[Re: maximum entropy]
#946387
03/10/11 09:47 PM
03/10/11 09:47 PM
|
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
Stanton
Don't question me!
|
Don't question me!
Joined: Oct 2005
Posts: 8,911
Ontario, Canada
|
 1) It keeps the lifter in contact with the cam - at all times 2) It reduces the required valvespring pressures 3) It ensures that regardless of any top end breakage, there will be no loss of oil pressure due to a lifter flying out of its bore or damage to the cam or lifter from an unloaded lifter bouncing off it. Its kind of a shame that there aren't more manufacturers producing these things !
|
|
|
|
|
