[John Milner]

What is everyone's favorite cam for a low compression 400? I'm mainly just looking for something with good low end power and good drivability. My engine is a '71 YS 400 with 96 heads. I'm guessing my compression to be in the 8.25:1 range. I'll be running log manifolds, stock intake and stock 71 quadrajet. I have been looking at the Pontiac 068 camshaft or something along the lines of a Summit 2801 cam. I don't want to run a higher stall torque converter than stock and my rear gears are 3:23's.

[PunchT37]

Crower 60240 with stock springs. One of the smaller voodoo cams with a spring change. Course, all cams should have new springs. It’s just the lower lift and gentle lobes on the crower make it so you can use it on stock heads with no guide clearance problems.

[F ROCK]

I had the same engine in my 71 GTO: YS 400 8.2:1 comp., #96 heads, 7041264 carb,
Those came with the 067.
I put RA manifolds on mine w/ a pypes 2.5"; over the years I had tried multiple rear end ratios, but i think my favorite with that setup was 3.23. (Maybe it was 3.21?) 27"tires. With a t400 before i converted to 4 speed m20.
Stock, low comp engine but it ran great and lasted 22 years for me.
It was still running when i sold it; and it has been installed "as is" in a 70 Catalina.

I was told that the 8.2:1 compression was too low for the 068 in a 400.
I was happy with the 067 in there; it was my DD.

[ponyakr]

"...just looking for something with good low end power and good drivability..."

Voodoo 256.

https://www.lunatipower.com/voodoo-h...8-256-262.html

Here's a Howards that's not quite as steep.

https://www.summitracing.com/parts/h...w/make/pontiac

Small Crane.

https://www.summitracing.com/parts/c...1/make/pontiac

Obviously, a Summit 2800 is one of the cheapest low rpm choices.

https://www.summitracing.com/parts/sum-2800

[tjs72lemans]

My 72 has a basically stock rebuild except Howards springs with a Lunati voodoo 256 cam. The dyno said the 8.2 compression ratio whistled at 7.8. It made 308 H.P. and 400 ft. lbs. torque. It idles great, has good vacuum and starts well. If that's what you're after.
I haven't actually driven it yet, but it should be very street friendly with good gas mileage and pump gas.

[PontiacJim1959]

I rebuilt a 72 400. 7K3 heads I gasket matched the ports and did a clean-up of the ports. Cast 8 valve relief pistons that were part of the rebuild kit, so maybe 8.2 or even less. Q-jet and Offenhouser 360 intake because I had it. Stock exhaust manifolds I smoothed up a little on the insides, 3" dual pipes I custom made.

I used the Comp Cams XE274/lifters and recommended springs and it was a really strong pulling cam. All done at about 5,500 RPM's and the power dropped off, but it would spin higher and didn't gain anything. 3-speed Dearborn manual trans, 3.23 single legger and 27" tall tires.

No problem spinning tires when I dumped the clutch. About 16MPG on the highway @ 70 MPH - less if I was toying with it.

I never checked valve spring coil bind or spring retainer-to-valve guide clearance and I probably should have, but I did not have any issues and I may have just been lucky. Had BB 7/16" rocker arm studs, poly locks, Comp Cams 1.5 stamped rocker arms.

[pastry_chef]

Originally Posted by tjs72lemans

It made 308 H.P. and 400 ft. lbs. torque

RPM for peaks? Any idea what type of dyno?

Thanks

[steve25]

Plain & simple, it's far better with your needs for your motor and cars rear gearing to error on the small side of Cam duration, so in light of keeping with that I say the 068 Cam is too big for a 7.9 to 8.2 comp 400 motor.

After the low comp motors came to be the factory never again used the 068 Cam but in the 455 motors, so that tells you a lot!

Apples to apples a 455 will make pretty much 13% more torque then a 400, so it stands to reason that in terms of low comp motors a 455 with the 068 Cam would still have the needed drivability of a 400 with the 066 or 067 Cam, and that pretty much stuffing a 068 Cam in a low comp 400 will reduce Torque by 13 Percent!

If you want to continue with valvetrain up grades then it would not be a bad idea to step up to 7/16" rocker studs and Poly locks if you do go with 1.65 rockers.

If it where my car I would run a 067 replacement Cam with 1.65 rockers and be sure to stuff on a fresh set of valve springs if the current ones have more then 30K on them and replace the O ring stem seals while your at it.

With the 067 Cam you will not have any issues with push rod guide hole interference and since the Cam also still has a stock base circle dimension you will not have loose noisy rockers when using the stock rocker nut and the 20 lb setting!

[steve25]

PS, it would not be a bad idea with the higher lift rockers to step up to 7/16" rocker studs and Poly locks since the stock studs with valve lifts above .430" have been know to snap off at the transition point where the factory rocker nut seats.

[abefromen]

Originally Posted by steve25

If it where my car I would run a 067 replacement Cam

Nobody makes an 067 clone, 066 is as close as you can get.

[77 TRASHCAN]

Originally Posted by abefromen

Nobody makes an 067 clone, 066 is as close as you can get.

Butler offers one now. THey have a line of cams, labeled Ram Air cams. THe 067, 068, 744, 041. THey ALL come in hydraulic flat tappet or.........hydraulic roller. Sounds crazy someone provided a link in another thread, here recently...

[abefromen]

Originally Posted by 77 TRASHCAN

Butler offers one now. THey have a line of cams, labeled Ram Air cams. THe 067, 068, 744, 041. THey ALL come in hydraulic flat tappet or.........hydraulic roller. Sounds crazy someone provided a link in another thread, here recently...

You're right they do they sell the Melling brand HFT but the specs shown at rockauto are exactly the same for the Melling 067 which is the SPC5 and the 066 which is the SPC4.

I'd have to check as I don't remember but I think the specs shown are 066.

[John Milner]

Thanks for the replies everyone. I will be upgrading to the big block chevy rocker studs and nuts for an adjustable valve train but everything else will be stock. I'll run a good new stock replacement valve spring or whatever the camshaft calls for. I mainly just don't want an engine that is a complete dog. Sounds like I may need to rethink going with a 2801/068 camshaft. This is my first low compression Pontiac engine to build. I'm used to higher compression 400, 428 and 455 engines. I don't want to over-cam it.

[Cliff R]

John, the Crower 60240 is an excellent replacement cam and the biggest cam I would use in a pretty much stock late model low compression 400 build.

It will make apprx 12" vacuum at 750rpm with around 10-12 degrees initial timing. Excellent throttle response, just a hint of "lope" or attitude, very strong mid-range, and pull really hard to about 4800-5000rpm's.

It works well with a stock converter and not a lot of gear.

I ran a low compression 400 in the Ventura for a few years back in the 1980's. With a stock converter, TH400 and 2.73 gears the car went 14.0's at 99-100mph and a best ever 13.82 @ 101mph.

It will work with stock springs, but I use and prefer the Crower 68404's set at 1.600" installed height.........

[Sirrotica]

The High Energy C/C used to come in 240,252,260,and 268 advertised durations flavors. I've used all but the 240 in Pontiacs and they've all worked well. The series was designed for low compression engines and have fairly quick ramps, but still set the valves down gently. Slight lope in the 268, maybe choose the 260 for a 400, if it's still available. They can be used with a stock type spring too, as the lift is around 450.

Due to the quick lobes they do sometime have slight valve noise, if that is a concern.

[track73]

Intake Duration at 050 inch Lift:204
Exhaust Duration at 050 inch Lift:214
Duration at 050 inch Lift:204 int./214 exh.
Advertised Intake Duration:278
Advertised Exhaust Duration:288
Advertised Duration:278 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.421 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.444 in.
Valve Lift with Factory Rocker Arm Ratio:0.421 int./0.444 exh.
Lobe Separation (degrees):112

This is the cam I ran in my low compression 400. Great low end .

["QUICK-SILVER"]

Butler's 067 cam has too much advertised duration for the lobe sep.
It has 66.5° overlap. That's more than factory 068 with 63° OL.
And way more than 066 and 067 that had 55° and 54° OL respectively.

Pretty much make ram air exhaust and some stall converter mandatory with a low compression 400.

No idea what their thought train was to call it an 067
Clay

Link to Butler cam and two good pages for comparing cam specs

https://butlerperformance.com/i-3164...tegory:1234841

http://www.wallaceracing.com/camcode1.htm

http://www.classicalpontiac.com/cgi-...rface/cams.cgi

[Scarebird]

One thing to note is if you are using a flat tappet cam, make sure to use the oil additive. I did not with a 2801 and wear was evident upon removal.

That said, the 2801 worked fine in my 71 YS 96 headed 400.

[geeteeohguy]

Helped a friend with an 8.5 CR 389 and he picked a Comp 268XE and the thing has ran like a scalded cat for the past 10-ish years. And does it on 87-89 octane. Car is a '65 Lemans with an M-20 and 3.36 rear gear with HO exhaust manifolds, PYPES X flow exhaust, and a Holley 750 carb. Strong running engine, but not rough or nasty.

[tjs72lemans]

M for peaks? Any idea what type of dyno?

My data shows it peaks around 3500. I watched him dyno it, but I have no idea of difference between one from another.