[John Milner]

I'm considering a hydraulic roller camshaft for my 428 that I am building. My current engine combination is as follows:

.030 428, TRW forged pistons with 13cc dish, forged SD455 rods and un ported 1968 16 heads. I will be using roller rockers and likely an Edelbrock Performer RPM intake. I estimate my compression to be about 10:1.

I have only used hydraulic flat tappet camshafts in my Pontiacs in the past so I don't have experience with roller camshafts. What would be a good hydraulic roller camshaft and lifter to use in this engine? This is a street car that I want to run and sound good. I would prefer to have a quiet valvetrain. 400-425 horse would be the goal. I would like to have plenty of low end torque.

My car is a 1971 GTO with a 4 speed and 3:23 rear gears. It has a good 2 1/2" exhaust system and ram air exhaust manifolds currently. I doubt I change to headers but it is a thought.

[tom s]

I have the Stump puller in 2 of my 428s.You will like it.Tom

[mikebaronehouston]

Stumpy.

[25stevem]

Are these the original #16 heads that came with the motor and have screw in rocker studs?

[John Milner]

Thanks for the replies. I will look at the stump puller cam.

The heads do have screw in studs and 2.11 1.77 valves. I may need to go in and install longer valves and springs if I use the stump puller but that’s perfectly fine.

[mikebaronehouston]

Might need to do a bit of headwork.

SD Performance designed the cam around 240 CFM, I believe. Dave will confirm.

[tom s]

I have one in a stock 48 headed engine,I think that one is a 455.The build was on this site at one time.Tom

[77 TRASHCAN]

Tom, that means it’s still here......somewhere. Someone will find it for us!!!

[tom s]

there was actually 2 builds,the second one was to convert the engine to a track roval car.Intake,cam and oil pan change.Went to a little more cam to kill some bottom end.When I get home I can post it.I have it saved on my home computer.Tom

[Steve C.]

Which 'Stump Puller" ?

SD Performance revised Stump Puller:

Part number 51-000-11
Grind number: P8 3194B / 3196B HR112+5

281 / 287
230 / 236
.3890 / .3910
112.0 LSA / 107 ICL

His old Stump Puller used lobes 311B and 3122B / note it has less valve lift

.

[Cliff R]

It would EASILY make 1hp/CID and probably a bit more than that with pretty much stock #16 heads and 230/236 cam.

I did a 428 a few years back with unported KRE aluminum "D" ports. 236/242 @ .050" HR cam, iron intake, Q-jet. It cranked out 497hp/540 torque on the dyno and idled with 12" vacuum at 800rpm's. I used Comp XFI lobes on that cam, pretty sure they were .361".

That engine allowed us the opportunity to test intakes, the Edelbrock RPM and Pontiac 455 HO (re-pop). The RPM made 491hp/535tq and the power dropped to 487hp with the HO intake...........Cliff

[Steve C.]

Here is the original "Stump Puller". I got the intake lobe number wrong above post.

Before the revised stump puller it used Comp lobes 3111B & 3122B

Grind # P8 3111B / 3122B HR112#5

286 / 290
230 236
.3770 / .3800

Note the revised stump puller has shorter seat timing and more valve lift.

[tom s]

I actually like the original better.Tom

[Mike Davis]

IMHO unless you are dead set on a Hyd Roller, your HP goals of 400-425 can be done with a flat tappet for a lot less money and less possible headaches.
Just my personal opinion.
With unported heads and exhaust manifolds I do not see an advantage.

[John Milner]

Thanks for the replies everyone. I do have a couple of new flat tappet hydraulic camshafts on the shelf, an Isky Tomahawk TC01 (224/232 .480/.485 112) and a Crower 60243 (228/235 .479/.494 112).

I wouldn't say that I'm dead set on a roller but with the uncertainty of the quality of new hydraulic flat tappet camshafts and lifters, I have just been considering going the roller cam/lifter route.

[redhawk44]

Hey John, I tend to like the Lunatti Hyd Roller cams. Nothing against any of the others but I went with this one and I am very satisfied. 239 243 @.50 with a 112 lobe separation. I got advice on it from Paul Carter here and I am very happy with the results. I am running a 461 with 72 cc Edelbrock heads , 10.5-1 CR, and a 308 rear gears. I have not dyno'd it but a big gain from the previous choice that was running about 475 hp.

[tom s]

That cam would be a little rough in a 428 and stock iron heads on the street,that is closer to the Old Faithful cam.JMO,Tom

[Jay S]

Stock D ports generally don’t gain any flow after .5” lift. Most of the flow is even in by .4”. It isn’t all that difficult to find a HFT cam that max’s out the stock head flows lift capabilities. But, I think what your looking for would be something more like this, with less lift, and a wide 114 LSA for the compression and RA manifolds.

https://butlerperformance.com/i-2936...tegory:1272239

Personally I prefer Bullet’s profiles over that Butler Compcams extreme energy grind with a little less acceleration on the ramps. Would cost more and likely have to wait quite a while to get it, but worth it IMHO. Generally you don’t have to spend as much money on lifters to get a quiet valve train with one of Bullets grinds, especially if you express that up front when they design it and pick the profiles. Even though that Bulter cam doesn’t have a lot of lift, it has a lot acceleration off the seat and usually needs high end lifters, like Johnson PR’s to operate quietly.

You could go with a bigger HFT and make as much or more power as theses 230* @.050” hyd roller cams. But the HR that 230* size is going out perform the cams on hand (Crower 60243 and the Isky) pretty easily. Mostly more average power.

[Stan Weiss]

Unless the head backs up or goes turbulent after peak flow I like to go with more lift. Lets say the cam is installed at 106 ICL. Then peak lift will be at 106 ATDC. But peak piston speed / max piston generated depression is around 75 ATDC (Note intake and exhaust tuning also needed to be looked at) so I try to get as close to max lift / flow is I can there.

Stan

[Cliff R]

Below is a dyno pull from a 455 Pontiac engine using one of the "low" lift HR cams. This is a pretty "basic" engine with factory #16 heads, dished pistons, good rods and pistons. It's using the 236/242 @ .050" HR cams on a wide LSA. Note that the engine makes over 500ft lbs torque from 2600rpms to 5000rpms. This is what I look for in engines built here, plus the wide LSA produces good vacuum at idle, right off idle and excellent street manners.

Butler sells this cam, pretty sure it around .520/.540" lift with 1.5 rockers.

It would work fine in a 428 built with iron heads provided you had at least 10 to 1 compression, closer to 10.5 would be even better........

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