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  #1  
Old 08-24-2005, 09:36 AM
odilon odilon is offline
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Question Mechanical cam, hidraulic lifter

Hi guys,

This may sound a little stupid but... why can´t I use an mechanical cam profile with hidraulic lifters
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Old 08-24-2005, 09:58 AM
j_cizzo j_cizzo is offline
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Definitely (depending on the profile of the cam). solid lifter cams can afford to be more radical than hydraulic cams b/c they don't rely on oil to keep the valve train in tune, simplistically speaking. if you were to put a hydraulic lifter on a very radical high-lift and high-duration solid-lifter cam with heavy springs, the lifter could collapse, pump-up, whatever, it just won't function properly, but if the cam is fairly mild you shouldn't have a problem. you could probably go to the cam manufactures website and compare, if you see the solid cam you have and a hydraulic cam with either the same or more radical specs than you can definitely pick up a set of lifters that would coincide with that cam and it will work perfectly.

hope this helps!
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Old 08-24-2005, 03:05 PM
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perfmachst perfmachst is offline
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hello, the solid lifter cam lobe has clearance ramps on them to take up lash.
a hydraulic cam doesn't have clearance ramps. If you put hyd lifters on solid lobe, it might wipe lobes off, at worst, have valve train noise. don't mix and match. as for hyd. lifters not working on radical cams is not true. a cheater cam for stock eliminator, has a very aggresive lobe, almost like a roller, and have to use a hyd. lifter. most will turn 7000 rpm.and they have very large durations also.just food for thought. use the correct lifters for the cam.
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Old 08-26-2005, 07:53 AM
odilon odilon is offline
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Default UHm........ What are these ramps ?

Hi Guys, thanks all

What are these clearance ramps ? I have adjustable rocker arms, may I correct these ?

Ok, my problem.... : 292 mopar purple cam mechanical, but I really need lower duration at idle, so I wan´t ot use rhoads variable lifters.... Is this possible
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Old 08-26-2005, 08:46 AM
DartGT66 DartGT66 is offline
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The 292 purple cam should be hydraulic. Rhoads lifters shouldn't be a problem with them and they help, but how about switching the cam to the correct one?
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Old 08-26-2005, 12:17 PM
odilon odilon is offline
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cry2 Chaging cam

I really prefer changing the cam but, I am in Brazil and a U$ 150,oo cam will cost... + U$ 100 shipping + U$ 125 coustoms.... almost 400 bucks

Some day I will find an on-line store tha can ship the parts to me with a lower invoice (under U$ 50,00 we pay no coustoms taxes) and I will have a lot of parts.... a dream
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Old 08-26-2005, 03:37 PM
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pishta pishta is offline
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if in fact it is a 292 mechanical, you can loosen the rockers a bit to a larger lash, say .022 and that will give you a little less duration across the board. It will give you more noise though. The ramps ease the valves down so they dont bounce. Running a hydro on these may never allow the valves to seat properly and may cause you to burn up the exhaust valves because they use the seats to transfer their heat and you are reducing their seat time when the cam is using the clearance ramps to actually act upon the cam.
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Old 08-26-2005, 07:41 PM
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IMHO rhoads lifters are just a band-aide for a over camed engine, if you sell your cam & lifters you can buy a cam to fit your engine set-up and be happier and faster only down side more labor
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Old 09-04-2005, 02:41 PM
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pishta pishta is offline
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It is never advisable to run mechanical lifters on a hydraulic camshaft. Although certain racing applications could benefit from the additional RPM potential of the mechanical lifters (and some racers do so), the ramp design of the hydraulic lobes is not designed for use with valve lash. The harshness (evidenced by the valve train noise) will shorten the life of the camshaft and lifters, and also the rest of the valve train. Never run hydraulic lifters on a mechanical camshaft, as immediate lifter pump-up will occur, leading to a lack of performance, and probable catastrophic engine failure.
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Old 09-04-2005, 08:03 PM
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dave571 dave571 is offline
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Quote:
Originally Posted by odilon
I really prefer changing the cam but, I am in Brazil and a U$ 150,oo cam will cost... + U$ 100 shipping + U$ 125 coustoms.... almost 400 bucks

Some day I will find an on-line store tha can ship the parts to me with a lower invoice (under U$ 50,00 we pay no coustoms taxes) and I will have a lot of parts.... a dream

It is not advisable to change the lifters on a cam, at ANY time. The lobe is ground to make a wear pattern with a new lifter. Once that is done (the cam run in) the two are mated for life.

If you change one you run a very high chance of ruining both.

Pull the solid cam, and number the lifters. Then sell it off, and buy what you need.

If you can't swing the cash, then save until you can. It's a much better way to go then to have a oil pump full of lifter/lobe shavings.

Try Don at FBO. www.4secondsflat.com He ships a lot of stuff internationally, and may be able to help with your customs woes.
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