What are best cams

Depends what youve got and what you want. All the power with a turbo engine, is in the turbo and heads. Keep the cam small and focus on getting the heads and intake to flow, and get a turbo to match. Roughly for every 10 degrees duration you add, you will move the peak hp rpm up 300-500 rpm. If you add 10 degrees, and the powerband DIDNT move up that much, and you now have a soggy torque curve, then you have a flow bottleneck somewhere, most likely the heads. If its a street motor, keep the duration at 210 degrees or lower @ .050", and get a set of CNC ported heads and a ported intake. You may lose 30hp with the wrong cam, but you can lose 200hp with the wrong turbo and heads.
 
VadersV6 said:
Depends what youve got and what you want. All the power with a turbo engine, is in the turbo and heads. Keep the cam small and focus on getting the heads and intake to flow, and get a turbo to match. Roughly for every 10 degrees duration you add, you will move the peak hp rpm up 300-500 rpm. If you add 10 degrees, and the powerband DIDNT move up that much, and you now have a soggy torque curve, then you have a flow bottleneck somewhere, most likely the heads. If its a street motor, keep the duration at 210 degrees or lower @ .050", and get a set of CNC ported heads and a ported intake. You may lose 30hp with the wrong cam, but you can lose 200hp with the wrong turbo and heads.
Click to expand...

This is great info! Thanks for it!
Also Flat tap cams are way cheaper and a roller will only net you like 2-4 hp over it so is $750 worth that little bit????
I think not! But hay thats just me :D
 
thunderace31 said:
This is great info! Thanks for it!
Also Flat tap cams are way cheaper and a roller will only net you like 2-4 hp over it so is $750 worth that little bit????
I think not! But hay thats just me :D
Click to expand...

You do have a certain peace of mind with a roller. It wont go flat, you can run more spring pressure which will extend the powerband because the valves wont float until a higher rpm. You can only run so much spring pressure on a flat tappet before wiping lobes...on a daily driver anyway. If you get a little lazy and dont change the oil as often as you should, a flat tappet cam's lobes can go flat. You dont break it in perfect...the lobes can go flat..etc etc. The main point of a roller, is the far more aggresive lobe ramps. The valves open up much faster, which means more air in the cylinders from the time the valve opens till it closes. Say with a flat tappet cam, the piston is heading down the hole, on the intake cycle...sucking in fresh air. Say you're at 90 degrees crankshaft rotation. Lets say that with a flat tappet, you would be at ..180 valve lift. With a roller, you would be at say, .300.....you get it Im sure
 
This and I quote "If you get a little lazy and dont change the oil as often as you should, a flat tappet cam's lobes can go flat. You dont break it in perfect...the lobes can go flat..etc etc"
IS BULL SH*T!

Flat taped cams have been around for way longer than than any "Roller Cam"

More spring pressure just ate up any HP gain you could have gotten.


Next FLAT TAped cams only wipe lobes because they are not broken in properly! IF YOU KNOW WHAT YOU ARE DOING THIS WONT HAPPEN!

last with a Turbo or Blower motor you dont need super High Lift or Long lobe separations to make power!
When the Valve opens are is foreced in to the engine NOW! Donst matter how much lift or how long the valve is open you wount see that much dif.

And again Flat tapped cams will last 200,000 miles as long as they are installed and Broken in properly.

I have had many small block Chevys and Fords that I built and ran super hard Spraying N20 and revved the living crap out of them! Never 1 time did I have a lobe go flat! NEVER!
And I ran .510-.550 lift cams! With 256-305 Dur. at .50! NO ISSUES! NO ROLLERS

Also do a search on any forum rollers are big now and people think they have to have them. But you dont!

My dad for example has a 54 Ford P/U with a 302 and a powerdyne blower on it. He lives in Brighton and Drives the truck to work in canton 5 days a week in the summer rain or shine never has this eng. (I built it with him) wipped a cam! Just another example.

BREAK IN IS THE KEY TO LIFE WITH A FLAT TAPPED CAM!

Afet break in the cam is hard and unless you run it dry will not wipe a cam.
Or you have a line bore problem with the lifter bore and the cam tapped where the cam dosnt ride on the lobe right.


I know there are eng. builders on here that will agree with me :)
 
One more thing here

On a N/A engine Roller cams do make a lot more power but in a Blower or Turbo motor you just dont need one!

Another example

My buddie has a 9.50 drag car very old school with a Roots blower on it. Guess what he uses for a cam lol FLAT not ROLLER its a big one and he dose drive it on the street a LOT! Woodward cruiese telegraph cruise and to work 3 days a week if he feels like it!

Sorry just another example.
 
thunderace31 said:
One more thing here

On a N/A engine Roller cams do make a lot more power but in a Blower or Turbo motor you just dont need one!

Another example

My buddie has a 9.50 drag car very old school with a Roots blower on it. Guess what he uses for a cam lol FLAT not ROLLER its a big one and he dose drive it on the street a LOT! Woodward cruiese telegraph cruise and to work 3 days a week if he feels like it!

Sorry just another example.
Click to expand...

Havent been hooked up by the fairer sex in a few years? Whats with the hostility? Things have changed my friend. The oil formulations have changed, and yes, if you dont change the oil as often, you WILL lose lobes. If you dont break it in properly, you WILL lose lobes. I dont know what school of engine building you came from, but your theories arent in line with this plane of reality. Chalk it up to the engines I was building on my own since I was 12, or the hundreds of engines/thousands of heads from all makes and types, stock to NASCAR and just about every other class you can think of, that I machined and built during my years at JMS racing engines...the guys who build most of the engines for engine masters, hot rod, car craft, popular hot rodding, street rodder, etc...Ive got a couple hours of engine building time under my belt. When it comes to many aspects of cars, I dont know it all, but my experience with engine building isnt something I consider "shadetree".
Rollers make more power. The lobe ramp designs that can be achieved with rollers, can never be done with a flat tappet. The 1920's are long gone, and flat tappets are likely never going to be a mainstay in engine manufacturing ever again. This is like "a turbo buick CAN run 10's with stock heads"..yeah...so? How much boost do you have to cram into it and heat the crap out of to do it?
I guess pro stock and top fuel need to go back to flat tappet, since its so awesome.
"Flat taped cams have been around for way longer than than any "Roller Cam""
Is that Flat taped or flat tappet? Maybe you should learn how to spell it before waving the "flat taped" flag. I also like how you threw up roller cam in quotes, like saying "Yall dont need dem new fangled "fuel injectors". After all, carbs have been around alot longer than any high falootin' fuel injectormobobbers" While you're at it, why not just convert your car back to a steam engine powered turbo buick. After all, they've been around alot longer than "internal combustion engines".
Most of our cars run flat tappet cams, including mine. But to say roller cams arent superior is ridiculous.
And to think an engine ceases to benefit from a roller cam because its got forced induction, is also ridiculous.
Do a search on wiped cam lobes, right here on this site, and tell me it hasnt been a problem.
 
thunderace31 said:
This and I quote "If you get a little lazy and dont change the oil as often as you should, a flat tappet cam's lobes can go flat. You dont break it in perfect...the lobes can go flat..etc etc"
IS BULL SH*T!

Flat taped cams have been around for way longer than than any "Roller Cam"

Well, my friend, you are VERY much uninformed. Roller cams have been around since Henry Ford was just a twitch in his daddy's pants. The Hicks engine had over head valves and roller followers in 1910!!Steam & Engine of Australia - Hicks Marine Engine Just about EVERY aircraft radial engine built, has a roller lifter. Some engines built in the 1920's and 30's even have four valve per cylinder, roller cams, roller rockers, superchargers/turbochargers, and fuel injection and even Nitrous oxide injection. Nothing new here. Roller cams are the cam of choice for ALL the new cars of today. WHY? Because they make better power through the reduction of friction. The oils available today do NOT have the needed levels of Zinc (and other additives) to keep a flat tappet alive. PERIOD! The auto manufacturers, demanded that the oil companies reduce the zinc and other metals to improve cat converter life. They DID. Now, cars with flat tappet cams will suffer. New cars all have roller cams, so they don't need the additives.
Will a flat tappet cam work in a turbo Buick? YES!!!! "IF" you take the proper precautions. Read up on the oiling issues posted elsewhere on this site. For me..........I'll use a hydraulic roller, thank you very much. Like Vader, experience dictates proceedural changes. How many Buick V6 cams have you installed (and had LIVE) in the last 10 years? There are only a few (very few) cam companies that know how to grind a flat tappet cam for a Buick V6. Here is a picture of an old radial engine with a roller lifter. Look close and you can see one. Note: Cams are not "shafts" on a radial engine, but rather rings, with the lobes on them. http://www.rotaryeng.net/turbo-comp-bill-f.jpg This picture also shows the turbo-compound devise, where they use a turbine to drive a shaft linked to the crankshaft through gears. They add about 150 HP each. Allison V-12's also have roller cam shafts, but the Rolls Royce Merlins/Griffons, did not. Here's a picture of the OLD Allison V-12 with roller cams. (look at the bottom of the page to see a drawing of the valve train) http://www.oldengine.org/members/diesel/Duxford/allison.htm
Click to expand...
 
Too stiff of valve springs robbing horsepower is a bit of a myth, since the springs also push the lobes back up while the valve is closing. There is a fair amount of loss in flat tappet valvetrains due to the increased friction, but the loss in a roller-rocker/lifter setup is almost immeasurable.

There's nothing wrong with a flat tappet cam, as long as its broken in correctly, but in a Buick engine with the all the problems with the number 3 lifter bore, you're really rolling the dice with today's crappy oil.
 
Just curious what is the correct way to break in a flat tappet cam? The machine shop I intend to use on my rebuild does recommend the rollers, but still how do you break in the flat tappet cam?
 
Not miss informed very very informed on things in this area!

Roller cams are not needed for big HP

All you talk about is the life of the cam, Life of a cam is not going to change just because its flat tappet or Roller!

I have even reused flat cams!

And I have put 2 Turbo Buick V6 engines together for friends both flat cams! No issues one is 4 years old and runs in the 9's! No issues!

drive on the street and is no in Az. still going strong and getting driven more now than ever.

Im not going to argue with anyone over this. I just think people need to know the facts before they spend $750 on something they really dont need.

And for the change in how things are made if anything they have gotten better not worse over the years in the Flat cam dept. More hardning options and better lifters better break in lubes and synthetic oils to help an engine live longer and make more power!

My last comment on this guys do what you do as they say. Lots of miss informed folks out there in the buick world it seems. AND ITS NOT ME!

Plus I think vendors just want you to spend Huge $$$ on things because they make more $$$ Sad really sad :rolleyes:

Dont get me wrong not knocking anyone here, I have delt with many vendors and all have been great! and there are many new products that work great and are way better than factory parts.

Me personally I will put the $$$ I could spend on a roller cam set up and make my Block stronger (IE Better rods, cranck, Girdle Pistons, and Heads) so I can make more HP And put you on the trailer! :D

I could also care less about TSO or this at o race class's If you want to run lets do it! Im a street racer for life! (Best have some $$$ lol)

Oh and by the way the 9 sec motor I put in the buddies car cost a total of $4800 to build! that was with GN1 heads new valve covers a Girdel new rods and Pistons and many other little things I have leared over the years! How many can do that and see it live!

An engine is an engine treat them with care and you will get great resaults every time. No dif. its a Buick V6 Or a flat head flipping V8!
Oh and how many on here are Master ASE Certified mechanics?? not many Im sure! But I am! :eek: :biggrin:
 
chadly said:
Just curious what is the correct way to break in a flat tappet cam? The machine shop I intend to use on my rebuild does recommend the rollers, but still how do you break in the flat tappet cam?
Click to expand...

Use a good break in lube such as Crane Cams or Lucus oil cam lube, put a lot on the lobes and when you install your lifters put more in the lifter boars and on the bottom of the lifter.
Run the engine at 3000 RPM for 20 - 25min (Most will say on the cam card or there web site what they recomend for the cam you purchase) Turn the Motor off
drain the oil and filter (You have to change the filter!) put in new oil and let it cool all the way down (Best is over night or 8 hours)
YOUR DONE and will never have an issue if your machine work was done right!
 
First you say this:
"You dont break it in perfect...the lobes can go flat..etc etc"
IS BULL SH*T!"
Then you proceed to give that guy the proper break in procedure.
Also, whats the point of a break in procedure if you're going to re-use the cam?
Re-using a flat tappet cam is a pretty ****ty thing to do to your friend. Quite a gamble to take, using someone else's money. You have to be pretty arrogant to let your friend cover the bill for what will most likely go wrong.
With the 231, the #3 exhaust lifter bore isnt as offset as the others, causing it to not spin as fast as the others. This has lead to a flat lobe on MANY TR's, if you dont break in with weak springs, do the proper break in procedure, use good OEM lifters, and periodically use a good treatment fortified with ZDDP.
I never said that a roller cam is "necessary", or "needed" either.
But if you want peace of mind, and more power with the same lift and duration as a flat tappet cam with the same specs, go roller. A roller can actually be re-used!
As for the 9 second buick motor you built for your friend with no mention of block prep...lets see pics and timeslips! Whats with the "new valve covers" part? Is that as important as the GN1's?
 
1st off you need to reread I reused a cam in one my engines that was all of 10 pass's old because I spun a rod bear that was not good out the damn box!

My eng not a friends as you state! And that cam was fine for 10,000 miles street racing and the track for 2 years!

I also never said the cam break in was BULL SH*T As you state.

What was stated is that ROLLER CAMS Are not needed and Flat cam's work fine if installed right or maybe that makes things a little clearer for you hard a$$ HEAD!

I have only used break in springs on HUGE Cams ones like are in Turbo Buicks with low lift Dur. dont need them! Again never been an issue for me and so many others I know that are local to me!

4HP for $750 joke! Put your money some place else is all I am saying.

Reason people have issues with a Flat cam is they have no Business being in an eng anyway and should have let a shop to the work for them!

Call comp cams call Lunati call Edelbrock they will tell you the same thing. ITS EASY! and it save's $$$ lots of $$$$

When I get my new engine in the car this winter next year Ill be at some Buick only events you guys can all see for your self that it works and works well!

Humm lets see how many have been 10's with unopend ALL STOCK INCLUDING The cam motors???? A TON!

Not needed :)

Learn to read also sorry this so blunt I just hope it helps some people on here save some $$

Old people are set in there ways and think they know it all! THEY DONT!
20 year I have played with cars! (Im only 36 years old) I have learened from my mistakes and plan to continue to learn as I grow old! But this issue with the roller vs. Flat cams is dumb!

Also I have put some 40 engines of all makes together with and without roller cams they all maid big power! I have one on the stand right now thats going in a 9 sec LS1 camaro! No spray no blower no turbo! ALL MOTOR!
and yes it has a roller cam lol Why because they came with them and 2 its N/A ! and its huge! 780/820 lift and tons of duration again N/A! Need the valves open longer to do that same work!
 
VadersV6 said:
First you say this:
"You dont break it in perfect...the lobes can go flat..etc etc"
IS BULL SH*T!"
Then you proceed to give that guy the proper break in procedure.
Also, whats the point of a break in procedure if you're going to re-use the cam?
Re-using a flat tappet cam is a pretty ****ty thing to do to your friend. Quite a gamble to take, using someone else's money. You have to be pretty arrogant to let your friend cover the bill for what will most likely go wrong.
With the 231, the #3 exhaust lifter bore isnt as offset as the others, causing it to not spin as fast as the others. This has lead to a flat lobe on MANY TR's, if you dont break in with weak springs, do the proper break in procedure, use good OEM lifters, and periodically use a good treatment fortified with ZDDP.
I never said that a roller cam is "necessary", or "needed" either.
But if you want peace of mind, and more power with the same lift and duration as a flat tappet cam with the same specs, go roller. A roller can actually be re-used!
As for the 9 second buick motor you built for your friend with no mention of block prep...lets see pics and timeslips! Whats with the "new valve covers" part? Is that as important as the GN1's?
Click to expand...

Whats with the "new valve covers" part? Is that as important as the GN1's?[/QUOTE]
Need to clear roller rockers
I dont have time slips ITS NOT MY CAR!
Block was done by a reputable Machine shop local and I cleaned and preped it from there! Hell I know how to do this stuff folks its reall not that hard take your time and work sloooooooooooow
You #3 lifter bore issue can be fixed also with a good sho they can line bore them and brass sleeve if need to make it set just perfect!
Had it done on the 2nd eng I did :)
No issues again :)
dont argue with someone like me you cant win LMAO!
Flat works has worked and will work again!
 
thunderace31 said:
Use a good break in lube such as Crane Cams or Lucus oil cam lube, put a lot on the lobes and when you install your lifters put more in the lifter boars and on the bottom of the lifter.
Run the engine at 3000 RPM for 20 - 25min (Most will say on the cam card or there web site what they recomend for the cam you purchase) Turn the Motor off
drain the oil and filter (You have to change the filter!) put in new oil and let it cool all the way down (Best is over night or 8 hours)
YOUR DONE and will never have an issue if your machine work was done right!
Click to expand...


So, if you've broken in a cam like this, and it runs fine for 8000 miles would you say you're safe? Cause' I did and then it wiped a lobe. Now I know there are things that can cause this other than the oil/zinc issue, but I couldn't rule it out so I went roller.

I see what you're saying about the roller "panic" but IMO you're taking it too far. Will a flat tappet live in a properly built engine? Yes. I think if we looked at how many engines (turbo 6's) that are built using flat tappet cams the stats would confirm that. (that's speculation) However, there is no denying that oil is changing without consideration to flat tappet cams and that the buick 6 is prone to cam failure. With that in mind it seems ludicris to say that there is NO reason to run a roller. The power gains are there, and it's more than 2 hp. Also, I would guess that the percentage of "unexplained failures" with rollers is lower with rollers than it is with flat tappets. That's a guess and it would probably take some vendors/builders to support, but I think it's probably fairly accurate.

I guess my point is there is something to be said about not "freaking out" and jumping on a band wagon. But there is also something to be said about not holding on to the past too long. The debate isn't "dumb". Both sides have some good points and the bottom line for most is that if you can, why not? What are the downsides to the roller other than price?

HTH. Just trying to stay cool. james
 
So Im old? Im 35. Ive machined and built hundreds and hundreds of stock to full tilt race motors in the 7 years I was at JMS. By the time I was 18, I had owned a 63 Nova/SBC, a 64 Nova/SBC, 72 Vega/SBC, 70 Cougar/4V 351C...mini tub, 4.56's in a 9", 8200rpm shift point, and a 67 Cougar/stock 302. I did the engines on all of them. And I was just getting started. My grandfather was a mechanic for 60 years. My dad was a mechanic before working for IBM. Every guy in the family was a gearhead. I may have an old timer resume, but Im by no means old. Did I say flat "taped" cams dont work? No. I said if you dont do it right, you WILL lose lobes on these engines. Hot Rod magazine did an article a couple years back on the major problem with flattening cam lobes. This was happening to many THOUSANDS of engines around the world and no one knew why. It was happening to every aftermarket cam manufacturer as well. It was a lifter shortage and the change in oil additives that was causing it. Using an offset bushing isnt something the average guy can do in his driveway during a cam swap. Get real. Some people like to use worn out stock springs for cam break in on these engines. I dont think its necessary, although some have had a repetetive issue of wiping lobes until they broke it in with old springs. A good coat of moly, new OEM lifters, new cam and a proper break in with straight weight dino oil is all thats needed, and as long as you dont go crazy with the spring pressure, it will last. Do you have any idea how much faster a lobe wipes out when that 1 lifter is spinning at 1/3 the normal speed? This isnt a SBC or anything else. This is a specific problem with a specific engine. Some have reverse tapered the lobe for #3 and it seems to have worked well, although it would make more sense to have cam blanks made with the #3 exhaust lobe offset to accomodate the misaligned #3 lifter bore...but everyone gets their blanks from a couple people who arent about to retool their foundries.
Block was done by a reputable Machine shop local and I cleaned and preped it from there!
It was cleaned after it was machined? Nice.
Nowadays, engine manufacturers are trying to extract the most hp out of the smallest displacements possible, while still producing almost zero emissions. So why have they ALL gone roller?
1. Reduced friction.
2. More aggressive lobe ramps which equal more hp from the same lifts and duration. ALOT more than 4hp.
3. Allows a drastic reduction in zinc and phosphorous content in oils, (pollutants) which are absolutely necessary to keep a flat tappet cam alive.
I wish more of the people who have lost lobes would get in here and shut this rude A hole up.
 
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