Roller Cams
 

In doing some research on roller cams it looks like a 327 with flat top pistons can easily make close to 375 hp at the crank. By adding newer aluminum heads you can see another 25 hp. There are a few of you guys on this forum who have gone with roller cams in the larger small blocks but I don’t recall anyone, except 65 tripleblack, who has installed a roller in a 327. So I was looking for some feedback on your results. Is the power gain worth the money? Any issues with cam creep? My thought is to go with a roller that has similar idle and vacumn characteristics as the L79 cam and the new TF heads.

These changes will not change the stock appearance and should offer a real seat of the pants performance improvement.

My personal approach to a really satisfactory level of performance was top down. A well sorted out carb, reworked set of orig heads, headers and a well tuned ignition. What you are considering I did give it some thought, but I can't justify $800-1000 for heads and another $700-$800 for a cam that I already have spec wise. With the above, I have more than enough power and great MPG. :cheers: Dennis

You can buy a lot of Corvette jewelry and souvenir clothing for that kind of cash.

I wouldn't go the roller cam unless you changed to the new heads.

If you add up all the HP claims by aftermarket products you will easily have about 800 or 900 hp

Look back to 1965. They were making 375 hp with all stock components. Today you can change the Carb, intake, cam (without going roller) and the aluminum heads and easily be over 400 hp with the 327 and 2 1/2 inch manifolds and more if you add headers. You can also do it without the aluminum heads but she will probably spend as much modifying the originals as you will buying the new aluminum heads.

I appreciate the feedback, I am going with the TF heads but it will be better to do it all at one time. The heads are set up for either a roller cam or a flat tippet so I don’t want to do the heads and latter change the cam. I know Hitch and Sky 65 are running a roller in a 350 but I am not aware of anyone else except 65 tripleblack. His set up is more extreme than what I am talking about.

I am without question, one, if not, the last of the die hard flat tappet cam believers. NOT ANY MORE!!!
We just recently built a SB400 (NO, it's not a 327) with a roller cam for my son's 73 Vette. Oh my God, night and day difference! We used the bone stock 73 400 heads and had about $1000 worth of work done to them, including bigger stainless valves and beehive springs, screw-in studs and guide plates. The pistons are flat top with a pin hole for 5.7 rods. We went with a 69 Z28 manifold (same as 70-72 LT1) that I had in the attic and a Holley from a 66 425hp engine lying around, We converted it from 2in to 2 1/2in manifolds and a complete off road ex system from Corvette Central. Of course, the entire assembly was balanced.
It's going to put the hurt on some BB cars!

Yes, yes, yes, the money spent to upgrade the iron heads would have bought some alum heads and yes, the cam kit (cam, lifters, push rods, button, roller tip rockers, bee hive springs) from comp Cams, was about $1000.
It's the old saying, "how fast do you want to go? How much money do you want to spend?".
I'll be installing roller cams from now on instead of flat tapped cams. Oh ya, don't have to worry about oils with zinc and phosphate now.

IMHO the 327 needs to breathe and rev high to make good power. That means solid lifters. A Roller Hydraulic would be a second option. Lacking torque, you want a 327 to spin. I think the al heads and roller cam is a great idea, even if you are not going to stroke it.

Hydraulic roller cams typically have a valve train limiting speed of about 6000 maybe 6500 at best, and that's with some pretty stout valve springs - much higher rate than OE. With massaged OE heads that flow about the same as the new TF double hump heads and LT-1 cam/OE valve springs peak power arrives at 6500 on a 327 with a little rolloff to 7200 and incipient valve float at 7250, so a hydraulic roller may be leaving some of the top end power bandwidth on the table on a 327. The 327's mean piston speed at 7200 is 3927 fpm. With a 3.75" stroke piston speed is the same at 6240, so a hydraulic roller makes more sense on a long stroke configuration.

Mechanical roller cams are generally not advised for road engines due to life limitations - about 20K miles before the lifters begin to disintegrate.

Duke

I already have a 69 Z/28 intake, ported 2 1/2 exhaust manifolds, Vette Packs and an AED 650 dp. I am not interested in an LT1 cam but I think the roller will help out on the torque. I don’t plan on reving it past 6000 because of my bottom end. Btw, I also have a TKO 600 and 3.70 rear gears.

I appreciate the opinions.

Mark,

I'm also running a roller w/modified original heads (spring pockets machined for larger springs) for 3 years now. been trying to talk Bluestripe into one,....


https://cimg1.ibsrv.net/gimg/www.cor...279073bcd2.jpg

Tell me more, what cam, displacement and power is it making?

I don't know why anyone needs all that razz a ma taz about revving to 7000+ rpm in s street engine. Even if you're not speeding or drivng recklees, the racket your engine makes at that speed will bee noticed my the cops and you might go to jail for doing nothing, like what happened to me many, many years ago.

Besides, all the tales about the poor, poor pitiful me comments about the "weak" 327 rods will make you think about all those revs.

The smart thing to do on a street engine is to keep the power band 6000 or less and avoid all the extra costs related to building reliablity past that rpm level.

Lot's of guys like to build up for high rpm and then they use the 3.00/1 rear drive ratios. You now have a mismatched power train combination.

I don't care if anyone wants to argue about it. I won't.

I have what amounts to a '71 LT-1 in my '69 Camaro. It has ported 492 heads with single trough valve relief pistons. 10:1 give or take? It has headers and a Victor Jr with a 750 dp on it. I put it in the car in the summer of '87 along with the Comp solid street roller. It has 236 @ .050 and .565 lift before the lash.

Best. Part. Ever. I love the WIDE powerband, smooth idle and general driveability. It pulls hard to 6500 in 1st and I shift about 6400 out of second and 6300 in third. Car ran 12.71 at 110 mph on street tires with 2.0 short time in the early 90's when there were few cars that made the 100 mile trek each way on their own power. I would do it again. It probably doesn't have 20,000 miles on the setup but all is still tight. Figure 375 whp or so back when that was something.

I have a couple of big blocks more recently assembled that both got hydraulic rollers. Especially with how the large block seems to like to flatten cams, for a street car it seemed that it will be cost effective over time.

I’ve ridden in Mark’s car and he absolutely revs it right up there...Awesome car with spectacular side pipe racket!

:D

Mark, I vote for aluminum heads...I’m a fan of ditching weight. I saved at least 60 lbs when I ditched the old iron junk for the alum heads and water pump on my GMPP crate motor last year...

Just sayin...


https://cimg4.ibsrv.net/gimg/www.cor...860b1caced.gif

I think the TF heads will give you lot of horsepower-per-dollar. The horsepower-per-dollar is probably much lower for the roller cam.

I put a roller cam in my recent 383 build because I was trying to match the power of a GM ZZ383 crate motor that used a roller cam. And, I simply wanted to stuff as much technology as possible into a stock looking engine. So, it was sort of a "science project" that was not based on horsepower-per-dollar.

My guess is that at most, the roller cam was worth maybe 25 HP over a good flat tappet cam, and that would be at 6000 rpm, with lower gains at lower rpm. And, I had 383 CID to work with. On a 327, the improvement might be 20 HP.

That being said, I'd probably do the same thing again, but I can understand the arguments in favor of flat tappet cams, especially in vintage blocks that are rather expensive to convert to roller cams.

If you are on the fence about this, keep in mind that the only difference between the flat tappet TF heads and the roller TF heads is the springs they install. That's not a big expense to change later if you decide to change to a roller cam. The spring swap can be done without removing the heads.

So, you could drop on a set of flat tappet TF heads and run them with your existing flat tappet cam. Then you could change to a roller cam later if you want to squeeze out every bit of power you can.

I’m in the process of assembling mine right now. It’s a 327 with 350 SJ crank, 10:7, TF DHC heads w/1.6 rockers, 6” rods and etc. I went the Howard’s 110885-10. It’s a HR 225/.560” w/1.6 rockers.

Haven’t run it yet, but It’s built to have decent low end torque and power through 6000rpm. I’m shooting for 1.1-1.2 hp/cu with the setup. I am also running 3.70s and a TKO 600. The Lunati Voodoo and Comp HR 276 were also in the running.

I am using that Howards cam in my 355 but an LSA of 108. I ran it for a couple years with 1.5 rockers and it ran great. But....I can't leave anything alone so I am in the process of changing to 1.6 rockers right now. Not to hijack the thread but rockers are you using?

Thanks
Tom

I went with the Comp Ultra Pro Magnums.

Thanks. Please let me now how they set up. I am having problems with my Scorpions.

Thanks
Tom