ATR 212-206 Roller Cam

[Ed Valvo]

Anyone using one? I'd like to see a dyno graph of one or some timeslips. I have one in a shortblock sitting on the engine stand and was wondering how it works for people. TIA.

 

[Dominic]

Anyone using one? I'd like to see a dyno graph of one or some timeslips. I have one in a shortblock sitting on the engine stand and was wondering how it works for people. TIA.

I have used that cam, it works just like all the rest of them do. If you're wondering if it will do the job, then i would have to say yes it will do the job just fine.

You won't see anything more than MAYBE a tenth or two and MAYBE 1 or 2 mph from one hydro roller cam to another. I have built well over 15 stock block/stock ported head combos in the past few years and have used almost every cam imaginable (all are hydraulic rollers). Only thing i noticed is the billet gold cores from Crane are stronger and Comp's grinds are very accurate.

I have heard of people going in the 9's with a 206 flat tappet and a 218 hydraulic roller, with the same combo, and i belive it. The smaller cams get the turbo on the pipe quicker and build torque quicker, and the bigger cams just raise the rpm range of the torque and horsepower peaks, they make a lil more peak HP too.

If you want an example here's one for you.

This is one of my customers cars

212-206 roller in a stock block with bowl blended stock heads and stock valve size, lightly cleaned up stock intake, stock headers, Hooker exhaust, stock computer with turbo link and a Joe Lubrant street chip @ 20 degrees, 3" downpipe, Precision front mount, GT 67 Q trim, 3500 converter, 60# injectors, stock susp with 275 drag radial and 3.42's, just the average bolt on's nothing exotic.

On pump gas leaving at 8#'s boost i think it was a 1.74 60', I saw 13#'s boost 1st gear 14# 2nd and it creeped to 15 at the top of third. It went 12.40 @ 110. The car is a T-Top car and it weighed 3610 with me in it.

Next pass i cranked up the boost. i saw 17#'s in second and before i let off in third i saw about 18#'s and it went 12.00 @ 116. I will be taking to car to the track soon to test with higher boost levels and a better set of tires.

Hope this helps.

 

[Ormand]

That was a good answer, Dominic. In "theory" a turbo engine would run better with more intake duration, like the ATR cams, and the "turbo" grind from Crane, Isky, etc. But there are a lot of people running the opposite, with more exhaust duration, like a small block uses, and they swear by those cams. Same thing is true of "even" cams, like 206/206. My take on this is that the Buick engine is just real insensitive to cam selection. Turn up the boost, give it plenty of fuel, and it will go fast!

 

[Dominic]

That was a good answer, Dominic. In "theory" a turbo engine would run better with more intake duration, like the ATR cams, and the "turbo" grind from Crane, Isky, etc. But there are a lot of people running the opposite, with more exhaust duration, like a small block uses, and they swear by those cams. Same thing is true of "even" cams, like 206/206. My take on this is that the Buick engine is just real insensitive to cam selection. Turn up the boost, give it plenty of fuel, and it will go fast!

Yes!,

I love the straight up and more exh duration cams too! I actually run one in my 86 T-Type. Now i am in process of building 2 with the new Full Throttle&speed Rollers with the new design duration figures. Mike Licht has a good thing going over there, you should check them out!

 

[norbs]

I will not go back to a small cam again, due to higher prone to detonation. Lost 3 mph also. The smaller cam was way more prone to pinging. Somthing to think about.

 

[Dominic]

I will not go back to a small cam again, due to higher prone to detonation. Lost 3 mph also. The smaller cam was way more prone to pinging. Somthing to think about.

Maybe you lost 3 mph because you were detonating? Think about it? Detonation is caused by more than likely wrong amount of timing or lack of fuel/octane. And yes a smaller cam will more than likely have less overlap wich will cause less cylinder blow down between valve cycles and therefore raise cylinder pressure. But maybe you didint' have enough fuel? or octane? maybe the cam wanted less total timing? The increased cylinder pressure will bring on detonation because most small cams have less overlap. So yes small cams are more prone to detonation. The big cam is exhausting some of your inlet charge and allowing you to have less cylinder pressure spikes in the rpm band A small cam has to do all the work in a shorter rpm band with more cylinder pressure compared to a big cam.

 

[John Wilde]

Norbs,

Is your 210 considered a small cam?
I have used 218* Flat Tappet, 224* Flat Tappet, 224* HR, These were from Dan at DLS
-230-232*HR Designed by Tim Cole at CC
-234*HR from Duttweiler.

These were with max ported M&As and Champion Aluminums on a 234 CI TSM Type Motor

 

[John Wilde]

We went 135MPH with 230-232* and 131MPH with lower boost and 100 more lbs in the car with the 234*. The 131 pass also had a bad intake leak, we are not sure how much better it will run but I would expect in the 135-137 Range on kill.

 

[norbs]

Well i had a 224 in the car and on the street and now i went to a 210/10 HR, and with the same program it really detontates with the same fuel 94 octane alot more even on part throttle. The car does feel like it has more torque on the bottom, but it has 100% lost power over the 224, i also ported the heads to flow 180 cfm+ on the exhaust and when i ran the 134 mph i was only flowing 157 cfm on the exhaust. Right now i think i am going to put the other cam back and see what happens. All my runs have zero knock, recorded but last pass out i broke a spark plug and it ate the valve and turbo. Hard to tune for knock when you don't pick it up!

 

[6APPEAL]

John,
I'm putting together a TSM type motor with a 224 flat tappet. How did you car run with that cam? I'm planning on 83 # inj, P/P, big valve iron heads, maxed out P/P intake, FAST programming by Cal, PTE 70TSM turbo and assorted other goodies. I'm hoping for kill (9.9x) on the strip and still be able to do the cruise-in scene.
Thanks,
John

 

[John Wilde]

John,
I'm putting together a TSM type motor with a 224 flat tappet. How did you car run with that cam? I'm planning on 83 # inj, P/P, big valve iron heads, maxed out P/P intake, FAST programming by Cal, PTE 70TSM turbo and assorted other goodies. I'm hoping for kill (9.9x) on the strip and still be able to do the cruise-in scene.
Thanks,
John

We never got the car to the track with that cam.
I can tell you that the car would get sideways at 65MPH
when we tuned it on the freeway. This was with 28.5 X 10.5 Firestone Slicks.
I had an Art Carr 9inch and a Fast and the car drove very well.
Considering Jason Cramer has gone 9.8s with this cams baby sister the 218, I don't think it should be a limiting factor.

 

[norbs]

i had 2 224 flat tappets,they drive well, but don't last , always a lobe here or there failing. Go roller, save your bearings and crank...

 

[John Wilde]

i had 2 224 flat tappets,they drive well, but don't last , always a lobe here or there failing. Go roller, save your bearings and crank...

Ok so it was not just me!
I think I am lost 2.
I think my block was junk anyway and needed to be bushed.
Maybe the 218* is the biggest you should go with a flat tappet???

 

[Ed Valvo]

Dominic, Mizzi??????????

 

[John Wilde]

Dominic, Mizzi??????????

You are a quick one!!!!

Please send me the dyno information!!! :biggrin:

 

[6APPEAL]

Too much spring pressure???? Any other ideas on why 224's seem to wipe lobes? I don't want to wipe a cam, so if I need to I'll back down to a 212 or 218. Just means I have to go back into the motor.
John

 

[norbs]

Only way to prevent wiping 100% is to go billet roller. You can pay for it now or pay for it later in a dead set of bearings and crank over the next 10-20k miles.

 

[Dominic]

Dominic, Mizzi??????????

Yes,

Hello Ed. :smile:

 

[Mike Licht]

Only way to prevent wiping 100% is to go billet roller. You can pay for it now or pay for it later in a dead set of bearings and crank over the next 10-20k miles.

I have seen billets wipe too. If a roller lifter fails any cam will fail.
Mike

 

[John Wilde]

I have seen billets wipe too. If a roller lifter fails any cam will fail.
Mike

I have to agree with Mike, we lost a billet roller in our 109 Motor.
I think that motor was cursed.

-Lost a Set up Champion Irons
-Lost a Set of M&As
-Lost 3 flat tappet cams
-Lost a billet HR cam