I just purchased a 65 coupe with the original 300 hp 327. It's been sitting in my cousins shop on jack stands for the past 27 years. I have the motor apart for its first ever rebuild and I am looking for advice on selecting a camshaft. I dont want anything too aggressive, just a little more power. I was thinking about the Comp cam XE262H or XE268H . Has anyone here run these cams in an otherwise stock 300hp 327? How will they compare to the factory 151 (350hp) camshaft? Any advice would be appreciated. Thanks, Byron


[Modified by nitram, 11:29 AM 8/4/2003]

 

what rear gear is in the car and if you have a tall gear the 151 advanced 4 degrees will run like a jack rabbit off the line :chevy

 

It has 3.36 gears and a 4 spd. I would really like to know how the 151 would compare to the Comp 262 & 268. I am leaning toward the 268 advanced 4 deg. with rhodes lifters. Thanks, Byron

 

People hate it when I pick cams, because I go a little toward the aggressive side. :D

But whatever you do, I would not use the Rhodes lifters or any of the other fast bleed down types. I used them once, and I can tell you that in no way does the noise compare to a solid lifter cam. They are noisy and just get worse as the oil thins out. The one thing a hyd lifter can do is keep things quiet. If that is what you insist on, then just use a good quality hyd and be done with it. The cams you are considering in no way shape or form are large enough to need any sort of bleed off device.

I've never used the 262 but I would consider it a good RV type cam even in a 327. I have used the 268 and it was pretty decent, but I only used it in 350's, no 327's. The "151" cam is a solid piece and is well proven. It is reliable, but there ARE cams out there that will outrun it easily and still maintain very decent manners on the street. The Crane 272 is a nice street runner and will hold vacuum well if you insist on hydraulic cam. I think it will be a little stonger than the 268. The 268 will have a nice lope and pull well to about 5500-5800 or so which is probably fine for your needs.

If you can be persuaded into a mild solid cam, I can tell you that the LT-1 cam that SWC Duke loves IS truly a very nice little street cam. I've used it several times and it is great. It will lug down to 1000 rpm in high gear with 3.36's and pull to 7000 rpm if you want it to. It is very easy on valvetrain and if you wanted to keep stock covers, I'd get a set of 1.6 Elgin stamped steel rockers and a set of setscrew type adjusters and forget about them after installation. In a nice sweet little 327, that thing would be great.

During your rebuild, don't get tempted to "fix" it for low octane gas. Too many folks ruin good engines by lowering compression. Watch your replacement pistons so they don't end up .045 or so down in the hole at TDC. You want them up as close as possible. No more than .020 below the deck and then you must use .015 thin headgaskets. Don't kill it by using the typical rebuilders .038-.040 thick ones unless you have it at least "0" decked.

I'm sure you are going to rebuild the original heads. *IF* the seats are worn severely, consider installing 2.02 valves. That alone won't increase performance much, but it will save the heads inexpensively. I wouldn't spend a fortune installing hardened seats on exhaust either unless you have to. The miles most of these cars get driven will never hurt those heads. I *would* spend some time on the ports in the bowl area or pay someone to to clean up the heads for better flow. You could easily approach a 400 Hp level with "double Hump" heads, a nice aluminum intake and even using rams horns 2.5" manifolds and look very stock, run on pump gas and drive great. A little goes a long way during engine rebuilds. Most end up putting out less than their original output after rebuild due to using generic parts.

Just a side note, I recently watched a relatively lo-budget 327 be dyno tested. You don't see them very often so I wanted to watch it. It was a flat top piston 327 on pump gas with a set of aluminum heads on it. I can't remember which ones,but they were a conservatively sized set and had received some port cleanup. Nothing radical. It did have a 240* something @.050 cam in it, so it was pretty stout sounding, but it was using a small single plane intake. The little sucker just screamed and the rpm kept climbing. When I left it was making right at 485 HP at like 7400 rpm! It was neat to see the little engine hanging with some that were much larger.


JIM

 

I have a Sig Erson HiFlo II cam with Rhoads lifters in my 68' Camaro........built in 1985 by me :D
It was my EDD driver at the time, so only .472 lift but it has a nice sound.
327 punched .030, flat tops with 2.02 steel double hump heads, MSD, Unilite,headers, torker II single plain intake, 4.10 gear, TH350 and 2500 stall. 13 mpg and shifts at 6700 rpms. MY motor works fine, so like any other combo take your time and do the research to match the cam to your car. By all means ask some cam makers what they recommend. When picking a cam, you must consider the cars use, other motor parts, car weight, rear gear and trans gearing.
I like my Rhoads, the bleed down below 3500 rpms works fine for my application.............. :thumbs:
Good luck :cheers:

 

The 327/350 cam was great in it's day, but the modern lobe designs give you more torque and as much power on a considerably shorter duration - which gives you much better streetability / throttle response, etc. Also, the 350 cam is quite long duration so you really have to build the rest of the motor to utilize it's hi rpm power band and it bleeds off more compression because of it, costing hp and torque. I think you'd be much happier with the Comp 268 or something similar.

 

The 151 cam has about the same effective duration as the Comp 268, but Chevrolet's duration measurements are made differently - they include a good part of the ramps but they never told us the actual lift off the base circle that they used for specifying duration.

Most modern aftermarket cams use advertised duration as currently defined by SAE as duration at .006" VALVE lift, but IMO the Comp 268 has too much overlap, which is typical of aftermarket cams. If you run the OEM manifolds use OEM cams as they were developed for manifolds, not headers. If you have headers, more overlap can be useful, but only in the upper rev range.

Not much has changed in terms of cam designs versus the sixties, except more is known about valvetrain dynamics, but GM had a pretty good handle on it back then, and their cams use standard OEM valvesprings, so the valve trains last forever. You can jack up valve spring pressure and lobe acceleration to get more area under the curve at a given duration, but durability will be affected.

The mistake most guys make with cam selection is focusing on top end power. In reality a street engine spends very little time at peak revs, so you want to cam it to get decent torque bandwidth, and if the 80 percent bandwidth doesn't start until over 2000 the engine is going to soggy and cantankerous down low.

Duke

Duke

 

I´m using XE262 in my 327. It´s a nice cruising cam, it pulls from 1300 up to 5500 RPM or so. I think that the XE268 is a bit too aggressive for the street driven 327. My car has 3.36 with WR 4 speed.

Btw, in my next engine I will definately try the LT-1 solid cam or the 151 hydraulic cam. Hope this helps.

tapio

 

"The 151 cam has about the same effective duration as the Comp 268, but Chevrolet's duration measurements are made differently - they include a good part of the ramps but they never told us the actual lift off the base circle that they used for specifying duration."

Assuming that the "151" cam you guys are referring to is the 327/350 hp cam, Crane sells the same cam in their muscle car series and markets it as such. I have it in my '64. Cam card reads:

Grind # 3863151 Hydraulic Blueprinted
57-up Chevrolet v-8 262-400 cu in

Valve setting Intake .000 Exhaust .000

Intake at cam 2981 at valve 447
Exhaust at cam 2981 at valve 447
Rocker Arm Ratio 1.5

Recommended RPM range
Min RPM 2200
Max RPM 5200
Valve float 6500

Cam timing at .050:

Intake opens 1 deg BTDC closes 41 ABDC Max lift 110 ATDC Dur 222
Exhaust opens 49 deg BBDC closes -7 BTDC Max lift 118 BTDC Dur 222

My '64 runs the quarter at over 105 mph.


[Modified by toddalin, 11:33 AM 8/6/2003]

 

Thanks for all the suggestions guys. After talking with one of the techs at Comp and a few local engine builders, I decided to go with the Comp XE262 with Comp lifters and springs.
Now for anouther question, Should I have the factory AFB carb rebuilt or go with a new Holley? Thanks again, Byron