[loup]

Hello,

I'm considering the XE274/1.65 combo for my Firebird '67. The car has a 406, 9.5 CR, 16 mildly ported heads, 3.23 gears,
700r4, Performer intake, headers. The car is mainly street driven but I want a strong motor that will be
fun to drive.

Is there a better cam/rockers combo that will serve me better or should this one work perfect ?

Thanks.

[loup]

Hello,

I'm considering the XE274/1.65 combo for my Firebird '67. The car has a 406, 9.5 CR, 16 mildly ported heads, 3.23 gears,
700r4, Performer intake, headers. The car is mainly street driven but I want a strong motor that will be
fun to drive.

Is there a better cam/rockers combo that will serve me better or should this one work perfect ?

Thanks.

[Bud Lyons]

Loup, I put an XE274 into my 462. I was warned that they are noisey. This cam really annoys me with the sound it maks. I wish now would have gone with a Lunati hyd. cam.

[rand68]

Hi,

I'm planning on building something very similar to your setup. I'm using a TH400 tranny, and my gears are 3.08, but other than that pretty comparable.

I had Rocky Rotella run about 15 engine simulations for me with a variety of different cams. I highly recommend finding someone with some engine simulation software as that will give you a very good guess of what it will actually do.

I'm going with the Crower 60918. This was just discussed in another thread. Here's a link to it
http://performanceyears.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=10&t=002336& p=
There's a pic of a simulation run for the 60916 in that thread.

[ August 26, 2002, 05:23 PM: Message edited by: rand68 ]

[Cliff R]

The comment "mainly street driven" carries a lot of weight with camshaft selection. The XE274 is too much cam for a 9.5 to 1 406 for daily operation (in my opinion). The 60919 Crower cam with HS 1.65 rockers is a great choice for 400 engines. This cam (with 1.71 rockers) produced 417hp/453 torque in a 406 with unported #16 heads. We have a couple in service powering basically stock GTO's. One daily driven 66 runs 13.0's in street trim spinning most of the way thru first gear, a solid 12 second car with slicks.

Idle quality with the 60916 cam in a 406 at 10 to 1 compression is decent, about 9-10" of vacuum at 750rpm, noticable lope. I couldn't imagine using a 230 degree cam on a 110LCA in a 9.5 to 1 street driven 406cid engine.....Cliff

[loup]

Cliff,

Are you talking about the 60916 or 60919 for 417 HP ?

[ASCAVO1]

I HAVE A XE274 THAT WAS CUT WITH A 112 LSA AND 240 ON THE EXHAUST DURATION IN A 406 STREET DRIVEN 67 GTO WITH PORTED 670 HEADS. THE CAM IS NOISY!!!!! TRIED FULL ROLLER AND ROLLER TIP ROCKERS, 951R LIFTERS AND STD 951 LIFTERS. NICE MID RANGE AND TOP END BUT I RATHER A LITTLE MORE ON THE BOTTOM END TO MOVE 3800LBS. GO WITH THE CROWER 60916. ART

[Cliff R]

The 60916 (221/229, .450/.470, 112LCA). Have reserved the 60919 for 10 to 1 455's. Have made as high as 505hp/551 tq with the 60919 cam in 462's. In a 10 to 1 468 cid (engine in my car) the vacuum at idle is 6-7" at 700rpm with the timing set at 10 deg initial. Not the right choice for a mostly street driven 406 even with Rhoad's lifters. The 60916 cam idles with noticable lope, strong power from just off idle right to the shift point of 5500rpm. The 60919 cam offers nearly identical performance in a 455 engine at 10 to 1 CR, just more of it!

[slowbird]

the 274 works great for use the car ran 11.88 and it is now driven every day to work. The only noise i have noticed is the lopey idle.

[ponchopete]

"Noisy" cams? I'd like to know what folks are doing wrong to have a Comp XE274 produce valvetrain noise! There are definite problems in the engine if this cam is producing valvetrain noise, and I seriously doubt it's the fault of the cam. Forget about the XE274, I have several customers running the XE294 in their engines, one for almost two years, and have yet to report valvetrain noise. Granted, these aren't daily drivers, but all are driven frequently and see track time. ??????

[KS circutguy]

Ponchopete,
Probably valve train problems,ie; worn guides, valves.Wrong length push rods.etc.

I'm running a UltraDyn solid in my street-strip 80 Firebird and have yet to hear a noise from the valve train and thats after 2yrs. of heavy use on the street.

And I've only adjusted the things 3-times in that amount of time. [img]tongue.gif[/img]

http://photo.starblvd.net/zanko20

[ August 27, 2002, 05:40 PM: Message edited by: KS circutguy ]

[Bud Lyons]

I just had the heads rebuilt. New guides were installed. The valve train geometry is correct. The roller tip rides on the center of the valve all thru the lift cycle. I have 70 thousands clearance between the rocker arm and the retainer. I put each lifter on the base circle of the cam and then gave the Kool Nut a half of a turn. What is wrong with that?

[Tom Vaught]

KS circutguy,
Apples and oranges, guy.

Hydrallic cams use the lifter to take up clearance, no ramps to speak of. Solid cams have
ramps to take up clearance to reduce noise. My
Comp solid wasn't noisy either. Bud's Hydrallic
may be noisy due to the lifter not keeping pace with the ramp design. Try a different set of lifters, springs, or a different profile. I like the high lift 744 copy myself. Tom V.
What is the spring pressures on your set-up Bud?

[Skip Fix]

I think I'll agree with what Tom said about cam ramps being the cause. I think almost every aftermarket cam I have used with agressive ramps(Comp, UD etc) have more valve train noise than factory cams even with hydraulics. Some sound almost like solids and if your solid makes no noise where's the lash? Some noise is "normal" for solids as they take up the lash but what's normal for some folks is too much for others.

I too have been unimpressed with my Comp XE and its a milder cam 262/270.

[Craig Berkheimer]

I used the Ultradyne's 288/296 soild cam with #16 heads and a Torker 2 on my old 406. That motor went a best of 11.18 @ 118mph. No power adders. Gasoline only! 68 Firebird 3400lbs 10in tire.

[Bud Lyons]

Tom, we put in Comp 998-16 springs installed at 1.75. I think the seat pressure was 195#. I'm at work and all the paper work is at home. I know we did everything by Comps specs.

[Half-Inch Stud]

see signature for 11.00/123MPH result. Car combo was good for mid 10's if I bothered to dial-in. Only made 6 runs before selling the racecar.

was a Lunati SPC1-320 HYD, with Crane Hi-Intensity lifters. Idle and 60foot were excellent.

Valvetrain had some noise . Made me think the rod bearings had something to show. Rod bearings were fine.

My 2 aggressive Ultradyne flat-HYD cams also has some valvetrain noise.

H.I. Stud

[Half-Inch Stud]

valvetrain noises were always loudest at idle. Motor power noise overtook any mechanical noises after 2500RPM. So, I only assume the valvetrain gets quieter, while approaching highway cruise and beyond.