let the cam arguing begin*roller*non roller*

B

blackgn1

Set on TSM Boost
Joined
Jan 2, 2007
We all always push the roller cam. More dependable. No wipped cams. Ect I know. I have two roller cams myself.:biggrin: I am begininng the process of building an engine for my wife. She has joined the Buick Family.:eek: I am starting with a bare block so going with the stock cam is out. Going less than 400hp for her safety. Sorry but she won't be rolling with a roller cam.:biggrin: I'm putting in a flat.:eek: There are so many guys on here that just can't afford the roller. I am blessed that I can but I'm not. Here's a thread to get myself and other Buick brothers in the right setup that doesn't break the bank. Remember we aren't going to the track.:biggrin:
 
So what tech info are you looking for?
 
Well I was more starting the thread to help guys that just can't go roller. We always say "save your money and buy the roller" Some guys just can't invest that kind of money in thier cars. The only option. Put the stock back in or go flat cam. I think that it would be good for guys to know some setups that are working. Brands of cams and also brands of lifters. I have seen posts from time to time but not a thread that really sums it up. If I were to wipe my cam I would pull the motor put in another and keep on trucking. All the guys here may not be able to do that. Lots of guys will refuse to go with anything but roller. Period. My engines will always have roller cams. I just can't see my wife crusing to work with a roller cam. I can't see investing in a engine that she will never use it's potential.:biggrin:
 
I'm currently running the stock cam. My car runs 12 flat in the 1/4 (pump gas, no alky). I think she'll be fine with a non-roller.
 
blackgn1 said:
Well I was more starting the thread to help guys that just can't go roller. We always say ......."save your money and buy the roller" Some guys just can't invest that kind of money in thier cars...... I think that it would be good for guys to know some setups that are working........:biggrin:
Click to expand...

At a certain level of performance a roller cam is an asset, but for a street driven GN, it is more an ego factor over a flat tappet. :biggrin:

Do you think an owner that has spent 3 times the $$$ for a roller vs. flat tappet is NOT going to give an opinion that this is the best way to go? :cool:

As far a performance, I know of many flat tappet, and stock, cams that are in consistent 10 sec. GN's.

The problem of many flat tappet cams going flat 10-15 years ago were not limited to Buicks, but many brands had the same issues due to cam core manufacturing. Later years most wiped flat tappet cams were a result of synthetic oil, improper installation and break-in.

Roller cams are not immune from problems either. There are more extreme loads due to increased spring pressure and RPM and wrong oil again caused accelerated wear on the cam lobes and the needle bearing rollers.

Anyone that has had a roller link break which takes out the cam will confirm another possibility of a failure. :eek:

Factory flat tappet cams have gone way over 100K miles without problems, and so will replacements when done and cared for properly. :)
 
LINK BARS SUCK!!!!:mad::mad::mad: Not on a Buick, but I had a link bar break during tire warm-up with the line loc on. The lifter turned 90 degrees and by the end of the run, the lobe was gone and the cam finally broke. The link bar fell to the bottom of the engine, during the run, and bounced around... It broke a 7/16 big block chevy rod, from the crank to the wristpin, and there was not a counterweight on the crank that was not totally scared with nicks and gouges. All this was in a brand new 409 chevy block with less then 5000 miles on it. 12,000 dollars to rebuild a new motor, and that was 1996!!!

Theres a story to consider...

:biggrin:
 
The drama comes from crappy oil, too much spring opressure, crappy lifters, etc.

You cant get OEM GM lifters anymore.. strike one.. cam cores for hyd cams are weak.. and the money saved going flat tappet.. its not worth it.
 
Roller because you can run more spring pressure. I like spring pressure for the cars that run higher boost.

Most importantly, on Buicks, a roller is cheaper than a new engine if the cam was to wipe.
 
Spring Pressure

Everyone talks about spring pressure on the cam lobes but what about the spring pressure on the oem valve seats? You can spend lots of cash on the best ported irons with soft valve seats.Folks have to run in the 120 psi range for "on the seat pressure" to avoid lifter bounce with a small roller yet premature seat pound out is likely.The actual Buick Engineering drawing that references maximum valve seat pressure is 82.5 psi including the upper tolerance.With respect to the iron heads only a well ported set of heads begins to see the rate of flow increase almost completely stop around 0.450" of lift.Why then the tall roller with iron heads?? Remember F=MA (force=mass x acceleration)..since this is a product then the tall cam makes "A" get large which makes "F" get large.The flat tappet does not require the high spring rates and there are little tricks to get that "roller area under the curve back while running a flat tappet cam.Also I have seen many catastrophes from an improper roller cam retention system and its lack of oiling.The OE block was never designed for a roller and neither was the valvetrain.I would love to see one of these iron headed rollers on "dyno durabilty" (a typical sawtooth schedule-peak torque to peak horsepower).It might not last very long.
 
Nick Micale said:
Do you think an owner that has spent 3 times the $$$ for a roller vs. flat tappet is NOT going to give an opinion that this is the best way to go? :cool:
Click to expand...

I only spent twice as much on a roller!

In all seriousness I think there is something to this. On the other had though I think allot of people (myself included) have gone roller to prevent a wiped lobe. Failure is always a possibility but rollers seem less prone.

As far as performance for the average road car think the performance advantage lies in the flat tappet. We have heads that suck. Someone correct me if I'm wrong but don't flat tappet cams accelerate the valve more quickly during the initial lift? Sure rollers can keep the valve open longer overall but a flat tappet will start flowing sooner.

However, after suffering a lobe failure at 8k miles on a new motor I'm sold on the roller!
 
MOST, not all.......

roller cams are more aggressive on initial lift, they can survive a steeper ramp than a flat tappet, I know of a couple stock Buick V6's that have over 150k miles, still running, still hauling buns! ( 12 sec cars) with NO cam/ lifter issues!
they have had T chain, and springs SHIMMED, not replaced! and will rev to 5200 RPM.
my never opened WE4 is as quiet as a mouse, idles so smooth, I never want to mess with it.
on a street driven car, seldom raced (if ever) flat tappet with correct oil and additives, and stock or close to stock springs, DRIVE IT FOR EVER!
 
One cam has been a Flat Tappet GN Legend IMO, Comp Cams 206.

What does 400hp and your wife driving it have to do with reliability though?

I'd consider Brad Penn oil if you're going Flat Tappet, SF oil was for the GN and that had some Zinc and PH in it that Brad Penn can come close to. ;)
 
I think alot of things effect realiability. Let take two 400hp cars. One is street driven only. The other is street driven and hits the track on the weekends. As I plan this engine 400hp may be a little more than I want. Just too much. I have to remember that this is a true street car and that I have enough sense to properly break in the cam and change the oil correctly. I want to start this thread for other guys. I have made a decision on a flat cam because I mostly want to see how it goes. I can afford a roller just not buying one. Not everyone can buy a roller and the Board always says roller cam is the only way to go. Is a roller cam the only way to go?:confused:
 
You're under the assumption that the Flat Tappet issues are from breaking in the cam, and oil changes. Sorry, this isn't the case at all.
 
cruzn57 said:
...most, not all roller cams are more aggressive on initial lift, they can survive a steeper ramp than a flat tappet....
Click to expand...

I know a roller gets more speed than a flat tappet as it goes but I think a flat tappet comes off the seat faster. Overall the roller is probably better but for a head that dies about .450 that initial lift could theoretically be of some benefit. I'm just splitting hairs.
 
I wish some of the flat tappet cam guys would chime in.:biggrin: I know all of us in this thread are using roller cams. I see why every cam thread ends with do a roller cam and forget it!;)
 
Nick Micale said:
At a certain level of performance a roller cam is an asset, but for a street driven GN, it is more an ego factor over a flat tappet. :biggrin:

Do you think an owner that has spent 3 times the $$$ for a roller vs. flat tappet is NOT going to give an opinion that this is the best way to go? :cool:

As far a performance, I know of many flat tappet, and stock, cams that are in consistent 10 sec. GN's.

The problem of many flat tappet cams going flat 10-15 years ago were not limited to Buicks, but many brands had the same issues due to cam core manufacturing. Later years most wiped flat tappet cams were a result of synthetic oil, improper installation and break-in.

Roller cams are not immune from problems either. There are more extreme loads due to increased spring pressure and RPM and wrong oil again caused accelerated wear on the cam lobes and the needle bearing rollers.

Anyone that has had a roller link break which takes out the cam will confirm another possibility of a failure. :eek:

Factory flat tappet cams have gone way over 100K miles without problems, and so will replacements when done and cared for properly. :)
Click to expand...

Can"t argue with experience and facts:rolleyes:Too many guys get caught up in the trick part of the week:eek:

Kevin

Kevin
 
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