[69*Goat]

I am changing the cam in my 400 next week, and I need input from guys who have run one of the following cams in a 400.

First off, it has a CR of 9.3:1, 48 heads with a pocket port, TH400 trans, RAIII Ex Manifolds, 2.25 exhaust, H-pipe, 3:42 rear. Edelbrock Performer Intake, and a Cliff R Q-Jet. I am going to install a 2500 Stall converter in it at the same time as the cam swap.

Now.....

Which cam would be best?

A Crower 60916, or a Summit 2802.

I am running the 2802 in my stroked 400, but I think it may be a tad too big for my 400 build.

Any suggestions?

[69*Goat]

Here is more info.

I am replacing a 214/224 dur. 432/465 lift @.050 cam. The lobe seperation on this cam is 110 deg. Which I have been told by a couple of well known, and well respected Pontiac Guys is too small. I have been plagued by pinging, and this thing is a DOG off of the line. I cannot put more than 10-12 deg initial timing in this thing without it pinging. I am running an HEI distributor and the resistor wire has been removed. It has the standard Pontiac HEI weights and springs. I have run total timing from 33 deg to 35 degrees, all in at around 2400-2500. This thing won't even hardly spin the tires when you nail it. It has a stock stall speed converter in it, I would guess around 1300-1400 stall. The idle quality in drive Sucks!!!, as a matter of fact it feels like it is going to die sometimes, It just does not run like a 400 should. So I am searching for an answer.

[AdamIsAdam]

I'm also interested in these replies. I'm deciding on a cam too, for my upgrade from a stock 68 350 2V (265 hp, 9.2:1 CR) to a Qjet, Dave's HEI, TH350 with 2,000 stall converter, and eventually about 3.55 gears.
I'm debating between Summit 2801 or a 068 or similar.

Opinions?

[71 Ventura II]

To be honest the only guys I've seen having great success with the Summit #2802 in a 400 are running them with more compression and a 3000+ converter. Also, two of these cars are 3.73 geared 68 Firebirds. (Much lighter cars)

In regards to the lsa 110 it tends to make a narrow power-band which can also build compression in a narrow band aiding potential detonation. There have been quite a few people running in the 9.3-1 compression range posting about detonation issues. If you are having issues stay away from the modern fast ramp cams that "build" compression as this will only make it worse. If you end up calling "Bullet" make sure they know your having detonation issues!

Running a 400 in any car weighing 3600-3800lbs can be a challenge. IMHO this is the "Gray" area where you almost need a 455. But, I'd try to find a cam with an intake @0.050 of around .218-.222 and lsa 112-114. Preferably with a little extra overlap ground in to help with the detonation issue.

See my "Signature" concerning the Crower #60916. IMHO running the 1.65's, like I do, you will need a 2800-3200 converter. But, if you are running the 1.50 rockers you could get by with a 2200-2600 converter with the 3.42's. Especially with street tires.

If your car is trying to "die" with the camshaft you currently listed it sounds like a vacuum leak which would also explain the poor performance. I'd look at the bottom sealing area of the intake manifold, all vacuum lines including brake booster, and finally carb gasket. I've even seen the power brake booster have a blown diaphragm and cause a leak. Good luck, JD

[chiphead]

I've only used the XE line of comp cams, so I'll put my vote in for them.

You sure your comp ratio is 9.3? You got dished pistons or something?

I run a pretty wild 9.3:1 400 in a 67 LeMans. I run the XE274 cam. RPM, Q-jet, ported 670s, dished Ross slugs, 6.8 rods, MSD, Hooker, etc. About 10" of vac at idle, 2000 footbrake, 3200 flash stall, TH350. With 3.23 gears it ran a 8.22 in the 1/8th at 84.4 MPH. Was pretty streetable, would burn first and second from a roll. I blew the 10 bolt after 6 passes, so I went ford 9" with 3.90s. No times yet, but man it flies.

I ran the XE256 in a 60 over 350 with bone-stock 17 heads. Its best time was a 9.15 in the 1/8 with stock converter, stock TH350 and 3.23s in same car. Very streetable, nice lope, good power to 5200 RPM. It would have run better if it wasn't a cast piston clunker with lots of deck height and totally stock internals.

[PunchT37]

Between the 60916 and the 2802, i`d run the Crower.

[Formulas]

A 400 with that compression and a 214 cam that doesnt idle right and is a dog indicates there is something wrong somewhere that thing should idle smooth and have a good low end and great mid range.
And if what ever is causing the problem is just carried over after the cam swap it isnt going to get any better IMO.
A bigger cam will work good with your combo but something else needs to be addressed.

[68FireBird]

I second questioning the compression ratio. I thought the 48 heads are the 350 HO heads for the 69 motor? If thats the case and you don't have dished pistons I'll bet your over 10:1. Maybe something like the 744 cam will bleed off some compresion? I don't speak from experience, but have heard that works. I don't think the XE cams will compliment a higher compression motor. They are designed to build cylinder pressure in a lower compression motor. I'm running the XE 262 with 6x-4 heads. 8.?:1 compression and a stock converter in a 68 Firebird convertible. It's not sluggish. My time at the track was a 13.8 on street tires with a 2.20 60 ft time. Make sure of your compression ratio and pick you cam accoringly.

[sixt8bird]

Im in the mid 12s with a 226-234 on 114 lobe seperation on pump gas. It kicks ass . Heads are non ported # 16s. Killer cam!! 1.67 0-60 ft. But I am running 3:73s and a 3,000 stall. It still kicked a$$ with a 2200 stall but you could feel it needed more. Oh and this is in a 3800 lb car with me in it. 1968 Firebrd.

[68FireBird]

sixt8, I've always been impressed with your bird. How do you get it to hook so well? My chassis is stock, I'd think with more converter, I'd be slower in the 60 ft. I'm running 3.55's

[sixt8bird]

Dont know why it gets up and goes like it does. Since it rides like a brick and has WS6 rear leaf springs, KYBs, 1 1/4" front sway bar and a 7/8" rear. Poly bushings. Brick Brick Brick........ I just put on some 275 60 15 ET drags and they hook really good . Im hoping for some lower times next time at the track as when I ran the BFG DR 275 50 15s, they would spin unless I rev'd on the foot brake to about 2800-3000. Now I think I can just hammer on it off the line off idle. My nitrous runs were scary as the rev limiter hit real hard from the 1000 ft mark. So thats why the taller tires. If I didnt have so many coals on the fire, I have some Edelbrock 72s ready to bolt on to get rid of those 38 year old valves and non ported heads. Anyway, the cam I recommend really has no downside, really broad power band. On the Chassy dyno, from about 3800 to 6200 the gragh looked like an arrow-----------------
Even at 6200 it didnt fall off.Rear Wheel HP was above 310 and had a peak of 324 at about 5500 but very little peak to say the least.

[Will]

Originally Posted by Formulas

A 400 with that compression and a 214 cam that doesnt idle right and is a dog indicates there is something wrong somewhere that thing should idle smooth and have a good low end and great mid range.
And if what ever is causing the problem is just carried over after the cam swap it isnt going to get any better IMO.
A bigger cam will work good with your combo but something else needs to be addressed.

What he said.

[screamingchief]

I gotta agree with these fellas,something is'nt "right",and I also wondered about the compression numbers stated myself as well.

If possible,before doing the cam swap,check the cranking compression and report back to us.

And a vacuum gauge reading from the current combo would be a big plus as well.

A quick observation here has the stated 2 1/4" exhaust sounding a bit restrictive,especially if they're "compression bent" pipes,not a good thing with a tight LSA cam,the tight LSA cams like free breathing engines,there may indeed be some reversion happening and killing the combo's performance.

This will also affect the idle quality and driveability much like you mention.

You'll be able to tell if that's happening when you pull the intake,there will be lots of sooty looking residue up into the intake ports and such.

If that is the case,plan on a better flowing exhaust,and use a cam with a wider LSA,and a watch the overlap and valve timing events closely,dont just "add overlap" to "bleed off" cylinder pressure,it's not that simple,more overlap will often just allow reversion issues to worsen if the exhaust is retricted.

There's a lot more to picking cams than cliches or generalizations...

You'll likely want to minimize the overlap to avoid any exhaust reversion issues,and then delay the intake closing point to lower cylinder pressures and avoid detonation issues,this by it's very nature will time the exhaust events to allow the exhaust charge time to leave the cylinder while still not contaminating the intake charge.

The crower #60916 fits that description pretty well if you ask me,thus it would be my recommendation here.

If that cam does'nt run well in a 9.0:1-10.0:1 400,something else is definately amiss with the combo/tune.

JMO/FWIW.
Bret.

[ronj1977]

have you thought of the summit 2801 ( basically a 068 with more lift ) i run it in my 76 400 stock bottom end and #62 heads with headers everything else stock it has tons of torque i do have a 4-speed but it will go sideways in first and second and chirp 3rd and 4th not a lot of top end but i dont go above 5,000 r.p.m.

[69*Goat]

I have checked for vacuum leaks, and I have not found any yet. I can cover the primaries with my hand while the car is running and it will die. I have been able to adjust my mixture settings on my carb, and get a change in idle and vacuum(ie;up or down) the last time I checked vacuum at idle in park it was reading between 14"-15" of vacuum. I will check it again this morning after I drive it to work. This engine only has 20,000 miles on it. If I go to a larger exhaust, say 2.5" can I start the larger pipes after the bend from the down pipe, or do I need to start it a couple of inches after the 2.25" pipe exits the manifold?

[Larry Navarro]

Originally Posted by Formulas

A 400 with that compression and a 214 cam that doesnt idle right and is a dog indicates there is something wrong somewhere that thing should idle smooth and have a good low end and great mid range.
And if what ever is causing the problem is just carried over after the cam swap it isnt going to get any better IMO.
A bigger cam will work good with your combo but something else needs to be addressed.

My thoughts too. Even though Russell has consulted with the respected pontiac guru's, I still believe its something else. If I recall, the pistons in that motor are the typical TRW forged with the opposing valve reliefs. So I would guess that the CR is not the contributing factor......or is it?
Anyway, the cam that's in there is a speed-pro CS-1022 which Russ bought from me when he built the engine a few years ago.

[69*Goat]

I got to work and I slapped the vacuum guage on it. I have 16" of vacuum at idle in park. The needle is rock steady at 16" no flutter, no movement at all.

[AdamIsAdam]

Originally Posted by ronj1977

have you thought of the summit 2801 ( basically a 068 with more lift ) i run it in my 76 400 stock bottom end and #62 heads with headers everything else stock it has tons of torque i do have a 4-speed but it will go sideways in first and second and chirp 3rd and 4th not a lot of top end but i dont go above 5,000 r.p.m.

That's the one I'm considering for my 350 setup. You like it I take it? How long have you had it?

I'm looking for low end torque. Around town tire chirping fun. Nothing above 5,000 rpm for sure.

[Cliff R]

Russ, the wider LSA grinds with more .050" duration will be a much better choice than the small cam on a 110LSA. With medium compression ratio engines, the small/tight LSA cams are not doing much besides narrowing up the power curve and increasing dynamic compression in a narrow/early rpm range, hence the tendency to ping/detonate on pump fuel.

The lack of power off idle is simply a matter of the tight LSA cam combined with a stock torque converters stall speed. Once you increase the stall speed to at least 2500rpm's, any of the larger cams mentioned will work fine, as the engine will quickly rev into the "real" power.

As far as direct testing of tight LSA grinds in the 400 engine, we tried one, 224/230/110, with the good lobes, ported #16's, just under 10 to 1 CR. Not overly impressed at all with that combination, idled like a "stock" engine, decent power in the mid-range, DONE by 4800rpm's.

We just received some direct feedback from a customer who replaced a 230/236/110 cam with a Crower 228/235/112 cam. He couldn't say enough as to how much better the engine ran with the slightly smaller cam on a 112 LSA. He had been experiencing LOTS of detonation issues with the first cam, as the static compression ratio (400 engine) was up near 10 to 1. He now enjoys decent idle quality, strong/broad power curve, pulling to at least 5500rpm's, no pinging in the mid-range.

I'd love to see someone try the Crower 60243 cam, 228/235/112, in a medium compression ratio 400 engine with Rhoad's lifters and high ratio rockers. We only tested one of these combinations, and it made 424hp, 465tq, iron intake, unported heads, through cast iron HP manifolds (pure stock racing application)......hint, hint......Cliff

[Motor Daddy]

Put a 60310 solid, Torker II, and a good exhaust, and it will run like a raped ape! LOL