Hot Rod Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
506 Posts
Discussion Starter #1
For a small block 355 or 383.What does everyone think of this cam?Idle quality,Brake vacuum,Mileage,power,driveabilty,Would you drive with it everyday?
I have a early chevy truck(1970) with a
355 9.25:1
256H xe cam
gear drive
8" balancer
Camel bump heads 2.02/1.60
1.52 magnum roller rockers
Performer rpm intake
Performer #1406 carb 600cfm
TH700-R4 with 2000 stall
3.73 rears
I like the power the combo has.For an everyday driver.But the cam does'nt sound alot more than a stock cam.So im thinking of stepping up.A little.I have a set of L31 vortec's I had screw in studs installed and .500 lift springs.I was thinking of installing a bigger 268xe cam also.Does anybody think its worth the time/money?
 

·
Registered
Joined
·
506 Posts
Discussion Starter #3
I only installed the camel bumps at the time because thats all I had.Thats why I got the vortecs.I also got an edelbrock rpm intake to with it.I was thinking of swapping the camel bumps out for the vortecs and 268XE cam.
 

·
Registered
Joined
·
17,612 Posts
With the reasonable cams you are using (the one you have and the one you're thinking about getting), you don't need an rpm intake. I can't for the life of me figure out why you guys want to use them on a good, low-rpm street motor. The 268 cam will never allow you to see the potential of the rpm manifold on the top end anyway and you'll be giving up cylinder filling on the bottom end. Also dump the gear drive. You'll make more horsepower with a good double roller chain like a Cloyes and besides, the noise from the gears will make you nuts in just a short time. Seriously, you'll hate yourself for putting that crap in the motor.

If rump-rump is what you want to hear from the motor, have Comp grind the cam on 106 degree lobe centers instead of 110. They'll do it, just call 'em up and tell 'em what you want. You'll have to live with less manifold vacuum, but hey, you have to give up something to get something, right?
 

·
Banned
Joined
·
9,993 Posts
I think the RPM manifold is a perfect match for the 268 cam- the rpm is a highflow dual plane intake and is exactly what that 268 needs. Also I ran a gear drive for quite a ****e adn liked it- not everyone likes a quite enginer, in factmost hotrodders love to hear the noises their car makes (assuming they're not rattles and parts falling off).
 

·
Registered
Joined
·
506 Posts
Discussion Starter #6
I have over 10k miles on this truck with that motor.And the gear drive, does'nt bother me.I've never had any trouble with running gear drives on previous motors.I was interested in the 268XE because I dont think I'd lose much mileage,and maybe gain more sound(or at least not sound stock)
 

·
Registered
Joined
·
17,612 Posts
ap72 said:
I think the RPM manifold is a perfect match for the 268 cam- the rpm is a highflow dual plane intake and is exactly what that 268 needs. Also I ran a gear drive for quite a ****e adn liked it- not everyone likes a quite enginer, in factmost hotrodders love to hear the noises their car makes (assuming they're not rattles and parts falling off).
OK, you have your opinion and I have mine. The RPM simply has too much volume for a short cam and stock converter. It will hurt an otherwise strong motor in my opinion. As far as the gear drive, yeah it'll impress the geeks down at the drive-in, but the old guys who have built a motor or two will just laugh at you.
 

·
Registered
Joined
·
366 Posts
techinspector1 said:
OK, you have your opinion and I have mine. The RPM simply has too much volume for a short cam and stock converter. It will hurt an otherwise strong motor in my opinion. As far as the gear drive, yeah it'll impress the geeks down at the drive-in, but the old guys who have built a motor or two will just laugh at you.
Are you saying that the RPM intake is not right for my set up?

If so, what do you recommend?

383 with TF 23* heads, 10.3 CR, full length headers, XE274 hydraulic flat tappet cam, 4 speed ST-10 with 3.36 axle and 27 1/2" tires. Vehicle curb weight is 3300#.


Thanks,
 

·
Bowtie or Die!
Joined
·
636 Posts
Ive built and ran many different engines. I installed a P/Jackson "quiet" drive in my last build. I really cant tell any performance improvements. But I do love the slight whine and knowing my chain isn't stretched or about to break. The last 327 I built I put a cloyes chain in it. Ran it for a couple years (HARD RUNNING). That chain was so stretched I could have used it for a jump rope.
 

·
Registered
Joined
·
17,612 Posts
glen242 said:
Are you saying that the RPM intake is not right for my set up?

If so, what do you recommend?

383 with TF 23* heads, 10.3 CR, full length headers, XE274 hydraulic flat tappet cam, 4 speed ST-10 with 3.36 axle and 27 1/2" tires. Vehicle curb weight is 3300#.


Thanks,
No, I didn't say it was not right for your setup. I said it was not right for a short cam and stock converter on a 9.25:1 355 like bonzipenguins has. You'll be moving enough air to support an RPM, he will not.

I think I know where this all started. The magazine dyno tests. In almost every case, the RPM manifold will show making more horsepower than the Performer. Of course it will, because upstairs is where horsepower is made. And of course, everybody wants to use the parts that make the most horsepower. But it is not horsepower that pulls your daily driver from stoplight to stoplight, it is TORQUE. If you'll look at these dyno tests, you'll see that the Performer makes more torque in an rpm range that is useful to the daily driver. In other words, it will make more torque "under curve" than the RPM manifold and is a far better choice for a 350 motor that will use a short cam (rpm limited) and a stock converter.
 

·
Registered
Joined
·
1,441 Posts
While it is true that vortec heads are better than humps,the camel humps will make plenty of power.Before HotRod and others told the camels they were junk they would make well over 400 horsepower.Now however they are in therapy feeling totally inadequate due to all the magazine articles.I have heard after these heads read the magazine articles they won't go over 200 horse for fear of disputing the advertisers in these rags and being sued.In fact it has come to light recently that the infamous 302 z28 could only flow enough air to make 125 horsepower according to recent magazine tests.Of course this explains the 20 minute e.t the 1970 LT-1 ran. Or could it be that although I admit time marches on and new design heads are better, Magazines get paid to use and promote certain products as totally obsoleting older "we can't make no money on these"parts.
 

·
Registered
Joined
·
25 Posts
you gotta be dead in the head to think that double humps wont make some serious power for a small block chevy. plus intakes to match are cheaper along with more parts to choose from for old heads. Cars would do wheelies long before vortec heads came out.
 

·
Race it, Don't rice it!
Joined
·
7,734 Posts
barnym17 said:
While it is true that vortec heads are better than humps,the camel humps will make plenty of power.Before HotRod and others told the camels they were junk they would make well over 400 horsepower.Now however they are in therapy feeling totally inadequate due to all the magazine articles.I have heard after these heads read the magazine articles they won't go over 200 horse for fear of disputing the advertisers in these rags and being sued.In fact it has come to light recently that the infamous 302 z28 could only flow enough air to make 125 horsepower according to recent magazine tests.Of course this explains the 20 minute e.t the 1970 LT-1 ran. Or could it be that although I admit time marches on and new design heads are better, Magazines get paid to use and promote certain products as totally obsoleting older "we can't make no money on these"parts.

Had that same thing all typed out in my head already. Mags are advertisement's in disguise.
 

·
Save a horse, Ride a Cowboy.
Joined
·
5,122 Posts
bonzipenguins said:
I only installed the camel bumps at the time because thats all I had.Thats why I got the vortecs.I also got an edelbrock rpm intake to with it.I was thinking of swapping the camel bumps out for the vortecs and 268XE cam.
Check out the last month's magazine that has the 350 EQ Vortec head buildup. (Sorry, I'll go find the specific issue for you and repost). 440+ hp with the XE268H cam and AirGap.
 

·
Save a horse, Ride a Cowboy.
Joined
·
5,122 Posts
camaroking383 said:
you gotta be dead in the head to think that double humps wont make some serious power for a small block chevy. plus intakes to match are cheaper along with more parts to choose from for old heads. Cars would do wheelies long before vortec heads came out.

You're right. But they are ancient technology. Fully professionally ported they are barely equal to the latest "as-cast" offerings.

Don't forget horsepower is a function of RPM. You can make 800 hp by spinning a 327 over 10,000 rpm.

Better heads make the same power at lower rpms and better torque across the board.
 

·
Hotrodders.com Moderator
Joined
·
1,642 Posts
You mention you want a racier idle. That racier idle equates to increased overlap, which also equates to diminished low speed torque.

You can't have your cake and eat it too. You have a 4500 pound pickup, and tight converter.

You can use more cam, but you better increase the stall speed of the converter.

I would suggest at least 2600 RPM if you step up to let's say a Comp 280 Magnum, etc.

When it comes to cams, it's all about power ranges, and with a big truck and a tight converter, you need peak torque to come on as soon as possible.

The more duration and overlap you dial into it, the later that is going to happen.



nairb
 

·
Banned
Joined
·
1,533 Posts
Go to Comp website and look at the different power curves for the EX cams.
The cam you want for a daily driver is the XE 262. Less HP (about 10) but more power down low. Have that cam in my Camaro and love it! :cool:
 

·
Registered
Joined
·
506 Posts
Discussion Starter #19
I have all the stuff to swap to vortec heads.I was considering the swap because I had got a great deal and got screw in studs,and better springs installed.I only payed $250.00 to get these heads from a friend.It's just somebody else said that the head swap would be a waste of time.And I would'nt see any noticeable improvement in power,or mileage.I was thinking of a cam swap.Not really just for the power.This cam does'nt sound much different than a stock one.It made enough power to smoke the little mustangs and honda's.But I'd like a little more sound out of the cam.I was thinking of a 268XE and 270H Lazer cam.
270/275 adv. dur.
220/225 [email protected]
465/460 lift
108 LSA
104 intake centerline
I have a Breakaway Sitting around the garage.That should be o.k with the new cam.Right?
Also I've run timing chains on previous projects.And they were o.k.Everybody has there own opinion.But I like the gear drives a lot better.I've never had any problems running gear drives.And I beat my engines to death.Plus I have a noisy one in my engine and with the super 40 flows I cant even hardly hear it past 1800rpm.Cruising its barely noticeable.
 

·
Banned
Joined
·
9,993 Posts
I'm going with a VooDoo 262 ground with a 106 LSA. the tighter lobe seperation will give you amore noticeable idel, but the shorter duration will help keep low end torque up. It will have a peakier TQ curve because of the narrower LSA, but its close. Also I like the Voodoo cams for their ramps, Asemetrical just makes sense, not to mention they're a little steeper than most hyd. cams which allows more area under the curve. You want maximal lift with minimal duration for a truck. I feel the 262 is a good compromise- even better with a set of high ratio roller rockers.
 
1 - 20 of 23 Posts
Top