jb78L-82

I am looking for some feedback from C3 owners of 74-1980 L-82 engine equipped cars that are basically stock and the original L-82 cam was replaced with the comp cams 268 camshaft. Is it worth making the change from a horsepower point in an internally stock L-82 4 speed (3.70 gears) with 65,000 miles that runs fine. I am concerned about the stock timing chain with the nylon gears that can be problematic and if I am going to change the timing chain and gears, I am considering the cam as well. The engine has roller rockers, no pollution control, a Holley 650 Qjet replacement, and 2.5 inch true duals with shorty headers. any thoughts?

bobs77vet

i have that camshaft in a built motor and i like it....it definitely has that lopy idle and shake to it....not too much but definitely not stock......so if the lopyness and shake bothers you you may want to go one step lower.....i also had to go to a lower vacuum threshold vacuum advance mechanism on the carb for the auto transmission since the idle dropped down too low. i have fuelie heads and the same exhaust i did run an H pipe and it gave some additional low end torque and mellowed it out some......i would think you would want to change the heads for maximum benefit

jb78L-82

Thanx. Appreciate the comments but still looking for someone who may have swapped it into a mostly stock L-82 and the difference if any. I have a feeling that I may not get much of a response on this one.

bobs77vet

you never know some body may have done that, good luck bob

outlawkinser

I have the XE268H in mine along with a few other "goodies". Check my signature for a full list. I really like this cam. I like the lopey idle, but it is a dream to drive in town. You can lug it down in 3rd gear and it will still pull nicely. My engine started out as an L82 motor.

jb78L-82

What is your Compression ratio, 9:1 or higher? Stock heads or aftermarket? Any problems with the XE268 versus the 268HE since the XE has a faster ramp up profile? Some folks claim that there have been problems with the XE 268 versus the more traditional 268HE. Thoughts?

427Hotrod

The 268H is a good solid and reliable cam that would do fine in your L-82. I've used it in a lot of motors and it always works out well.

The first time I used it was in my '64 Vette that had a flat top piston 350in it. I ran it with stock heads and later with the old 292 *Turbo* heads using headers, a Holley Street Dominator intake and a 750 DP. It replaced a 30/30 Duntov that I pulled out.

Overall it idled a lot nicer and pulled harder in the lower ranges. Top end was very similar to the 30/30 using 3.36 gears and a close ratio M-22. When all was done it ran high 12's in pure street trim and was dead reliable with stock rockers on it.

The XE268 is an improved version but does run the risk of being a little noiser. If you are leaving everything else the same I'd use the 268H and forget about it.

JIM

jb78L-82

Terrific! That's exactly what I was looking for!

The Money Pit

I ran one in my 355 for 6-7 years, and 120,000 or so miles. Not a bad cam for a near stock 350, but I have also run Edelbrock Performer cams in 350's and I give the nod to the Edelbrocks. The duration is slightly less so lowend off the line is better. I did not notice much difference on the top comparing the two,...but definately noticed the lowend grunt. This is seat of the pants off the line pull.....you will notice it everytime you take off from a standstill.

The Comp cam is decent though.

jb78L-82

Thanx for the tip about the Edelbrock Performer cams!! Did you use the Performer Plus or RPM? My L-82 has a 4 speed and 3.70 gears so I would assume that I would want the Performer RPM since my car typically operates between 2,500-5,600 RPM's, more mid to high RPM and the Performer plus is for low to mid range torque. Yes?

The Money Pit

Performer cam,...duration @ .050 something like 204 degrees.... It'll turn 5500-6000 easy enough, but the real grunt would be off idle to about 5000. Perfect for a stock 350.

For what it's worth, I ran my Comp 268 with 3.70's and a th350,...

outlawkinser

My Compression ratio is 9:1. Stock L82 heads, but they have been ported and polished. I haven't had any problems with the XE. It's been in the car since 1997. Bear in mind that I installed the complete Comp Cam valve train. I also installed a Comp Cam Magnum Double Roller Timing Chain. And yes, it is a bit noisier than the HE.

Mike

jb78L-82

So would you run the 268H now or would you go with the Edelbrock Performer if you had to make a choice today?

jb78L-82

Did you notice a big improvement in HP with the 268XE versus the stock L-82 cam and did the porting and polishing of the stock heads help much? When you say that the XE is noisy, do you mean that there is a lot of valve train noise? My Stock L-82 with comp cams roller rockers 1.5, which I have had on the valves for 15 years, are noisy now! Thoughts and Thanx.

gkull

The CC 268 is made for about a point more compression than you have. The Crane 272 power max is made to trap pressure. It is listed with a low valve float number because of the springs. I run them with 120- 130# seat.

I've put this cam in 3 different 350's and they increase the power and mileage

Part Number: 113941 Grind Number: H-272-2 (REPLACES HMV-272-2)
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 GOOD IDLE, FOR 350+ CU. IN. MODIFIED ENGINES WITH FREE-FLOWING ABOVE WATER EXHAUST SYSTEMS FOR PERFORMANCE APPLICATIONS IN LIGHT PLEASURE AND SKI BOATS, INCLUDING JET BOATS, 8.75 TO 10.75 COMPRESSION RATIO ADVISED (C.A.R.B. E.O. D-225-18). BASIC RPM 2000-5000
Engine Size Configuration
262-400 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 3027 @Valve 454 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3200 @Valve 480
Rocker Arm Ratio 1.50
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 25 BTDC 67 ABDC 272 °
Exhaust 75 BBDC 29 ATDC 284 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99848
Loads Closed 114 LBS @ 1.700 or 1 45/64
Open 318 LBS @ 1.240

Recommended RPM range with matching components
Minimum RPM 1800
Maximum RPM 5600
Valve Float 6200
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 1 BTDC 35 ABDC 107 216 °
Exhaust 51 BBDC (3) BTDC 117 228 °

jb78L-82

Thanx, gkull for this other option!

Hotrodrobert

I like Isky 201256262 in a near stock engine better than even the Crane and have better luck with the CC260 than the CC268

Ganey

The 268H is a great cam, I have rec. it many times.
218/218 110LS

The cam GKull rec. is another good one.

The Performer "350" cam is 204/214 112LS
If you want the Performer cam, get the "400" cam for stock heads.
214/214 112LS

Ganey

260H is 212/212 110LS & Comp says gets better gas mileage than stock cam, meaning L-48 cam. I have not run it, not enough for me.
Good choice for many depending on the setup. I have rec. it & many are happy w/ it.

jb78L-82

Thanx, again, for all the comments!