MARKUS_P

I was impressed of the difference in power output between hydr. lifters and hydr. roller lifters.
I wasnīt aware that thereīs such a great difference in power output due to reducing internal friction. Well, now I know better and plan to use a roller type lifter.
What modifications are needed to run them in a non roller block?
There are retro fit roller lifters available, if I use them do I still have to modify the block?

PatsLs1vette

im using competition cams retro roller lifters in my older block,ive been seeing alot of guys using them but have seen some of the locking bars come apart and do some damage.And no mods to the block they slide right in,youll need shorter pushrods too,i used comp cams hardened.
one other thing you cant use oem lifters in a non roler block cause the lifter will sit too high out of the lifter bore.Ive already tried.

[Modified by patsnitrovette, 7:55 AM 12/16/2002] :mad


[Modified by patsnitrovette, 7:56 AM 12/16/2002]


[Modified by patsnitrovette, 7:57 AM 12/16/2002]

Twin_Turbo

What I like about rollers is that you don't have to break in the cam.

Also, if you can get the rollers with the spring loaded horiz. bar. If you back off the rockers the springs will push the rollers up and you can pull the cam without removing the intake. Especially usefull if you have a 2pc timing cover.

Rollers are expensive though, one of the main manufacturers went out of business.

Marck

MARKUS_P

Thanks for all this info Pat and Marck!
I can remember a forum member who had problems with lifters coming apart :eek:
There are different types of "rotation blockings" available. Which one are the best one?
I plan on using comp cams extreme energy roller camshaft.
I think Iīll try to get all the stuff from them in a set.
Cam, lifters, pushrods, springs,....donīt know what else they offer....?

That means I donīt need to modify the block if I use retro fit roller lifters.
Thatīs some good news :yesnod:
Thanks for the info guys :chevy

Fevre

I really like my retro roller cam, it idles just a little lumpy and pulls from about 2000 to 6500 rpm's in my current 350ci. I plan on putting it in a 383 with higher comp and FI so I think I will get better low end with only a slight loss in rpm potential. I was lucky and got a deal on a set of rollers and a cam for under $500.

Twin_Turbo

I have these:
Crane horiz bars, lunati has the same ones.



One thing about the cam, the flat tappet cam is held in the engine by the force the lifters put on it (the cam is angled in the angine a little, the rear sits lower than the front so that the force pushes it back)
The rollers don't do that so you need a theust button in front of the cam. Make sure you use a stiff timing cover or a button between the cover and waterpump to keep the cover from flexing.

Marck



[Modified by Twin_Turbo, 7:27 AM 12/16/2002]

mrvette

IF you want to go roller, I would strongly recommend getting an old truck block from say '88 up... they should be allready machined for and come with all the parts you need for a factory setup.....any aftermarket stuff I have seen by it's very nature of design....'toggle' set up comes to mind'.....is unreliable for a street machine.....race cars run short while then torn down again.....soo you have a chance to see defective parts/bad wear.....
the factory uses a double D ...two flatsides, and a plate over each lifter pair...
held down by a spyder looking spring with 2-3? bolts in the lifter valley drilled into special casting spots......older blocks have no such spots.....
HOWEVER, maybe they can be added, or something modified to use the factory rollers.....NOW, I THINK the blocks are identical in other respects near the lifter area.....of course they have a 1 piece rear main seal...which appeared in '86 .....

GENE

MARKUS_P

Iīve already heared about these so called cam buttons.
They are made out of PTFE to reduce friction.
I have three books about engine building at home and plan to do a very slow engine build up.
One part after the other - right now Iīm just planning.
When my engine combo is defined Iīll start buying parts starting with a 4 bolt SBC.

zwede

There are 2 types of roller buttons; Nylon and roller bearing. I would recommend the roller bearing.

As for the aftermarket retro lifters not being reliable, my experience is the opposite. I installed one lifter pair wrong with the result being the lifter rollers rotated 30 degrees to the cam. I drove it like that for 2 years before I took the intake off for some porting. The cam lobes were deeply grooved, and most of the roller wheels were worn away. The heat and stress on those lifters must have been tremendous. The lifter body actually hit the lobe towards the end. Yet the lifters were still in one piece. Nothing broke off or otherwise damaged the motor. I had to replace the cam and that lifter pair. I think this is proof (atleast to me) that the comp cams lifters are very sturdy.

dman535

Here is my experience with these units. I had a comp cams unit that cam apart after 5,000 miles of use. Comp ended up taking the cam and lifter set back. If I ever go roller again, I will do solid lifter and will do a horizontal tie bar or factory style set up. No more horizontal tie bars for this guy !


http://mywebpages.comcast.net/derek.atkin/Images/cam_5.jpg

MARKUS_P

You mean no more vertical bars for you donīt you? :confused:
:rolleyes: Maybe you had bad luck..... zwedes' experience shows that they are quite sturdy.

mrvette

From what I have seen, I can't understand how you could possibly 'install wrong' a lifter pair.....they only go one way.....especially that toggle type aftermarket crap.....
and like you said....one way or another....you had troubles...and so have others'.....that'sy why I recommend using the factory type setup....
double D lifters with the appropriate retaining clips, and the large spyder spring holding the clips down....and that requires a factory roller block....

for STREET use, I would NOT go any other way....period.....

cams and work are just too damn EXPENSIVE to take chances with....

obtaining the correct block from the git go is the only way to do it right....

GENE

zwede

Gene: It's only possible on big-blocks due to the offeset lifters. The bar has astep on it. If the bar is upside down, the lifters will be rotated approx 30 degrees compared to the cam.

I'm very happy with the aftermarket roller lifters. Besides this problem which was caused 100% by myself, they have worked great.

BeaterShark

Just hit 15K miles with my Comp Cams street solid roller cam and Endure-X lifters. No complaints here.

Metal Wulf

how much tq & hp increase do you get by going to a roller setup? is it worth the 4-5 times the cost? :crazy:

Lohkay

Actually the increase in power comes from the fact that you can run steeper ramps with a roller than with flat. In most cases u can notice a 5-10% increase.

mrvette

zwede, I never owned a BB, I was thinking SB....so I know not of what you speak....sorry 'bout that....

GENE

BeaterShark

What a mod is "worth" is relative. When I bought it, an extra $400 was nothing to me. If I were doing it now, I would go with a solid flat tappet setup.

I'm not sure of the HP and TQ differences between flat vs. roller and I really don't think anybody can truely measure them. The big advantage of the roller setup is less friction and the ability to run more aggressive ramps. So, you will not see a roller cam with the same duration vs. lift that a flat tappet cam will have.

My cam is a "street" solid roller with 236/242 duration @ .050 and I get 14" of vacuum at 700 RPM and total lift in the .560 range with 1.5 rockers.

72rdstr

If you're using an older flat tappet block;
have your machinist check to ensure the lifter bores are square to the camshaft. With flat tappets it is not a problem if they are slightly off as this just makes the lifter rotae slightly (which it'd designed to do anyway). If it's off enough it can cause the roller lifter to rotate. As you can see by the previous pictures, this is a BAD thing.
Call Comp Cams and they'll give you the scoop.

MARKUS_P

Itīs the profile of the lobe itself. the ramp is steeper, which means max. valve lift is achieved faster than normal, more time the valve is open means more gas into the cylinder which results in more power.
Duration can be measured at 0.050" but donīt think two cams with same duration and lift have to perform equal. Again, itīs the profile of the lobes. Therefore valve lift over crankshaft degree diagrams are available to help choosing the right cam if you have enough knowledge.
One more thing, due to pysical limits the camprofiles are often nearly similar from two different cam manufacturers - natural limits nobody can ignore :yesnod:

Iīd like to know which cam type has the steepest ramp except the roller type. I guess solid cams, but not sure why a hydraulic shouldnīt be as steep...