Dear Forum, I am interested in doing a cam shaft performance upgrade. I would like the car to remain streetable, but would like to feel a notable jump in power and responsiveness. I see that people tend to warn about (if not put down) Clifford, and I have also seen Comp Cams get slammed on the board, so I am wondering if anyone has any options for me. Any direction would be appreciated.

http://www.slantsix.org/forum/viewtopic.php?t=29721

Tell us more about the car and engine. Then we can provide guidance as to an appropriate profile/grind.

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Joshua

x2.... Is this your 1966 Barracuda with 225 and power steering? What transmission? Tire size? Rear Axle ratio?
Are you going to make improvements to the intake/carb, head, more compression?

We also might want to note what you consider "streetable"... some people will want to keep a fair amount of mileage, others
consider streetable to be useable on super and not so worried about mileage but want a heavy performance gain and be used
on the street or the strip...

225 ci, clifford intake, 4 barrel Edelbrock carb, headers, yes, I would like it street-able. No power steering, 15" tires, stock transmission, I am in the process of trying to find out my differential. In fact, if it has the stock differential, I may decide to target the differential instead of the engine for now. At this point, I would like the engine to be more responsive at take off. It drives nice at high RPMs, but is a bit dog 0-60 (though, weirdly, not always...every now and again it takes off great...no idea why such an inconsistency might exist).

Eugene

We got the lipstick being used but you have no information on the pig... if you are slapping
all that on a stock engine and not shaving the head/deck, doing a port job, and/or OS valves...
Then there is only 2 cams that will work for the internals of the engine... the stock 1972-1980 cam,
or the OCG 818... The OCG 818 or 819 would work if you brought the engine up to a 9:1 SCR or better...
and those would add more HP and torque if a mild port job was used even on stock valves... set either to
about 102 centerline and hope for the best.

I would bet the bog is from not getting a good acc pump shot or sloppy linkage response....
or since it's intermittent, your throttle return springs aren't seating the throttle plates at rest
and the push on the go pedal is getting more air and less fuel off the line in the transition circuit....
all in all a stock engine isn't happy with an oversized carb and intake...


If it's a stock 7 1/4" rearend I wouldn't bother, and upgrade to one of the HD rear ends...
stock and slightly stock work fine for mileage with 2.94, but are very happy with 3.23's...

If your 15" tires are bigger in diameter than say the 205/70R14, you might get away with 3.55's...as the larger tire
will artificially change your ratio compared to stock sizing...


I got to meet a kid yesterday that is driving an 11:1 SCR 225 on the street...with the A-833OD he's pulling
down 17's highway with a 4.11 rear.... it's well past the 225 HP range and "beefy"... so "streetable" depends
on how much you can tolerate...more power, more lump, or more mileage, and less noise....

Just wondering why there are no RV10 and RV 15 recommendations. Have these cam designs been superseded, or are they not suitable?

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1967 VC Valiant

Erson under went a change after our group buy a long while back, so getting one directly from them is
kind of a crap shoot. RV10 is similar to the OCG 818 or 2106 grinds in performance, the RV15 works in a
warmer than stock engine but is more for torque... if putting the effort into block mods and sporty drive train mods,
and going 4 barrel with headers, you will get better overall performance from an OCG 346 and bumping your compression
to the neighborhood of 9.7-10:1... The other reason is economical, the OCG regrind will cost less overall than
buying a cam from Erson...

I do have 15" tires. Thanks on the camshaft data. I was prepared to up the compression and do oversize valves, etc., and then my boiler died, so I am down close to 8,000 bucks, so I was just considering different cams and using a 3.55 differential.

Is the stock ‘72-‘80 cam any kind of performance upgrade from the stock cam from ’66?

Oh, and my tires are bigger than 205/70R.

Yes, later cam has higher lift and more duration. Still small, but better. Oregon cams regrind is cheapest and best way to go.

Lou

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Home of Slant6-powered fun machines since 1988

Thanks! I will look that up presently.

Eugene

So, if given a choice between upgrading from a stock '66 to a stock 1972-1980 cam versus upgrading the differential from the stock 2.93 to a 3.55, which one would provide the most bang for the buck (i.e., which would present the more noticeable boost off the line in the 0-60 or 1/8 mile arena)? Obviously, neither is a long-term goal, but if I were to choose as a for-now option? Anyone have an educated guess?

Eugene

The difference in cams is small and not worth going to all that work if you want more in the future. The rear end upgrade will be needed anyway and a jump from 2.93 to 3.55 will make a big difference.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

3.55 sure grip rear ratio will be kinder to a stock engine to get it off the line quicker, the cam will not provide
this much help until you port the head, and raise the compression ratio to help the cam, etc... but I would not
blow the money to do this gear change to a 7 1/4" rearend, and if you raise the perfomance level of the engine
eventually you will need the better rear axle to support it...

That being said, with the tire combination you describe, the engine will be turning 3000 rpm at 65 mph on the highway,
and depending on your muffler and tailpipe choices, you may get an annoying drone out of the mufflers...or go deaf
drowning it out with your stereo on long trips...

Thanks!