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View Full Version : newbie cam question, dont beat me! ;)



shaun
02-27-2004, 02:57 AM
I see a lot on these boards about cams and everybody is always refering to a solid, hydrolic, or roller cam. What is the diffrence between these types? What advantages/disadvantages does one have over the other? Pictures always help if ya got them!

Craig
02-27-2004, 04:11 AM
solid and hydraulic flat tappet cams look like have a flat bottom that rides on the cam lobe.
http://www.jegs.com/photos/817rhlifters.gif
Hydraulic lifters require no periodic adjustment to the valvetrain. They have an internal adjustment if you will, that compensates for valve lash. Set 'em once and you're done.
Solids have to have a clearance set between the rocker arms tip and the valve stem. This has to be done periodically. These rev higher than a hydraulic cam.
Rollers, as the name implies have a small wheel that rides on the cam surface.
http://www.jegs.com/images/products/2701053016_small.gif
These also come in hydraulic and solid with the same advantage/disadvantage as a flat tapett cam.
With the roller tip you have less friction at the cam/lifter interface. The roller also allows for a more aggressive cam lobe profile. In other words the ramp that opens the valve can be steeper and get the valve open faster because of the roller.

shaun
02-27-2004, 11:20 AM
So when people are talking about solid, hydrolic, and roller cams they are talking about the lifters? why dont they just say that in the first place :)

Hotcrusader76
02-27-2004, 11:24 AM
IMHO...
Stay with hydraulic for a reliable lake boat
Go solid to impress your friends with power:D
Go roller if you have money to spend....and again....impress your friends with power:D
As far as the finer details? Stay tuned...I am sure you're going to be in for a ride with that question from many of the heavy hitters here.
Good luck...
Note--I've run Hyd versions just fine....very reliable. My next motor is going to have a solid roller...but then again it's not an everyday lakeboat.

Hotcrusader76
02-27-2004, 11:25 AM
Originally posted by Shaun
So when people are talking about solid, hydrolic, and roller cams they are talking about the lifters? why dont they just say that in the first place :)
Yes, lifers and the camshaft the compliments them...or is the other way around:D

shaun
02-27-2004, 01:52 PM
Are ceritan cams designed to be used with a certian type of lifter? This would make sense then.

victorfb
02-27-2004, 02:05 PM
yes. a cam that uses roller lifters is not compatable with a flat tappet. also a roller cam that used solid lifters cannot be interchanged with hydrolic lifters. all cams are designed for that application. so im told. :p
sorry for steeling your avatar shaun

Moneypitt
02-29-2004, 07:43 AM
Be aware that roller cams are a different heat treat due to the fact that they don't have to match hardness with the lifters.(no friction by comparision to flat design) So, you will need a bronze distributor gear to prevent damage to the dist. gear teeth on the cam.....The main advantage to "roller" lifters is they allow extreme valve spring pressures that slam the valves shut at the higher RPMs. These same pressures with flat lifters WILL flatten the cam lobes very quickly. The advice about using Hyd. lifters in a mild river/lake boat is true..There are several quite "hot" grinds available from just about every cam grinder, and they are just about maintaince free. Any solid set up will need some maintaince now and then.........If in doubt, use HYD.....Moneypitt

shaun
02-29-2004, 11:35 AM
Thanks for all the great info. Sounds like for my setup hydrolic lifters would be the way to go, unless i am able to find a good set of rollers for cheap.

Foggerjet
03-01-2004, 05:43 AM
Not only do roller cams allow higher spring pressures, they require it. Roller lifters are much heavier than say a solid flat, so to keep from "throwing" the lifter off the cam lobe, a double or triple spring is req'd. I've seen race motors with 350+# of seat pressure, WOW.
fog

cstraub
03-02-2004, 06:36 AM
Just be sure if you use the flat tappet profile you use:
cam lube on cam and lifters
Use GM's engine break in lube, available at GM dealer
Use a light 10-30 oil and over fill the crank case with 4 more qts.
Don't let the engine drop below 2000 rpm for 30 minutes.
We lost 2 lifter mfg. a couple of years ago and these things have been giving us fits.

1BIGJIM
03-02-2004, 07:46 AM
Ok, I will bite :D Overfill the crankcase with an additional 4 quarts of oil? I have never heard of anything like that before. Never to old to learn a new trick:rolleyes:

Fiat48
03-02-2004, 11:26 AM
I think it's a good trick. 4 more quarts would be a pretty good "splash" oiling system to get that camshaft through break in. And the GM lube. Been doing that for years. You ought to hear the Ford guys cry when I tell them to use it. On the big cams, we used to do weak springs to get throught the break in period.
But personally, I would never do a flat tappet cam anymore. Just too many advantages to a roller.

cstraub
03-02-2004, 11:36 AM
Yeah, it's common practice for circle engines during break in. Puts the crank and rods in the oil and throws it on the cam. This is just fine during camshaft breakin and you won't hurt anything. Do not run the engine on a load like this. . . just break in.
Just had a customer loose a cam this weekend. . .he told the guy take the heavy springs off and use a set of break in rockers. . .didn't do it. . .now the cam has 10 lobes and 6 round circles.
Chris

shaun
03-02-2004, 01:26 PM
30Min! Oh my neighbors are going to f'ing love me! I dont plan on use a flat tapped it sounds like to much of a pain in the ass for my application.

Fiat48
03-02-2004, 03:00 PM
Reason #98 why to go roller. If you cheat that cam on break in..it will go flat. Trust me.