Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Sign in using an external account
Register Forgot Password?
Register Search Today's Posts Mark Forums Read FAQ Vendor Directory
Search
C3 Tech/Performance
V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette Sponsored by
VBP

Welcome to Corvetteforum.com!
Welcome to Corvetteforum.com.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Corvetteforum.com today!


Corvette Store
 
 
C7 Parts & Accessories
C6 Parts & Accessories
C5 Parts & Accessories
C4 Parts & Accessories
C3 Parts & Accessories
C2 Parts & Accessories
C1 Parts & Accessories
Wheels & Tires
Sponsored Ads
 
 
Vendor Directory
  
Reply
 
 
 
 
Thread Tools Search this Thread
Old 03-25-2003, 05:43 PM   #1
Chris@VetteFinders
Platinum Supporting Vendor
 
Chris@VetteFinders's Avatar
 
Member Since: Dec 1999
Default Those with a 268H comp cam or similar specs....

What heads are you running and what rwhp are you making?

Please include any info on other significant mods. I need to buy new heads!

Thanks
Chris@VetteFinders is offline   Reply With Quote
Old 03-25-2003, 06:08 PM   #2
Draginslayer
Junior Member
 
Draginslayer's Avatar
 
Member Since: Mar 2003
Location: Glendale AZ
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I bought the ProTopline 200cc runner 64cc chamber - 23 degree Pro Aluminum Lightning Cylinder Headswww.procylinderheads.com. I got them for $1350 fully assembled with springs to match my cam. I've been told these heads are a little too big for my cam but I plan on upgrading to a XE cam eventually and thought these couldnt hurt with my 268HE. Over the stock heads they were probably one of the best things I have done to my engine. It idles better, gets better throttle response, and added some power. I've heard good things about AFR 195cc heads also which may be a better choice but my engine mechanic recommended these heads to me and I trust him on his decisions.
Unfortunatly I can't tell you RWHP with my combination because I haven't had a chance to visit a local dyno because I've been busy with my new tranny but if I get around to it any time soon I'll leave a post on the forum.
I'm hopeing to hit High 13's maybe low 14's in the quarter if everything gets back together anytime soon if that helps.
Draginslayer is offline   Reply With Quote
Old 03-25-2003, 10:56 PM   #3
no_radio
CF Senior Member
 
Member Since: Jun 2000
Default Re: Those with a 268H comp cam or similar specs.... (Draginslayer)

I have the 268H in my '74. Over the weekend I swapped in AFR 195 heads, 1.6 Pro Magnum roller rockers, and an Edelbrock RPM Air Gap. Also have Hooker Super Comp headers, MSD billet distributor with 6AL, chambered exhaust, with a speed demon 650 mechanical secondary.
What's your compression ratio? Comp told me the XE cams may detonate with higher compression ratios, even with aluminum heads. They recommended the Magnum 270H, which isn't much bigger than my 268H.
I was hitting high 13s with my Chevy 882 heads and Edelbrock Performer, you should have not trouble hitting mid 13s with your combo once dialed in. Don't forget the tuning, I picked up .5 seconds on 0-60 in my 454 suburban with a simple vacuum spring change.
if running auto you'll need a higher stall converter, though.
Jeff
no_radio is offline   Reply With Quote
Old 03-25-2003, 11:24 PM   #4
Glensgages
CF Senior Member
 
Glensgages's Avatar
 
Member Since: Jan 2003
Send a message via AIM to Glensgages
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

While NOT a Chevy, I can offer this story. 20 years ago, a buddy had a 268H in a Pontiac 400/auto/3.73 T/A. Iron intake, Q-Jet, 'on-sale' headers, etc. It idled like a race car, but ran low 14s @ 96-98 MPH. He eventually ran mid-13s, I think, with that same cam. I liked it so much, when I built my next motor, I used Comp Cams, altho the 292H in my Z28.
Glensgages is offline   Reply With Quote
Old 03-25-2003, 11:29 PM   #5
Shark Racer
CF Senior Member
Support Corvetteforum!
 
Shark Racer's Avatar
 
Member Since: Jan 2000
Location: San Jose CA
Send a message via ICQ to Shark Racer Send a message via AIM to Shark Racer
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

Chris- you might want to specify which cam you're running.

From what I recall, you're running the XE268H cam, which is split duration.

Glensgage is talking about the CS268H, single-profile.

As far as heads, I would think AFR190 would be a closer match for your setup than AFR195. A larger cam and performer RPM intake would be better for the 195s.

Take this as you will.

-Steve
Shark Racer is online now   Reply With Quote
Old 03-26-2003, 09:00 AM   #6
Chris@VetteFinders
Platinum Supporting Vendor
 
Chris@VetteFinders's Avatar
 
Member Since: Dec 1999
Default Re: Those with a 268H comp cam or similar specs.... (no_radio)

Quote:
I have the 268H in my '74. Over the weekend I swapped in AFR 195 heads, 1.6 Pro Magnum roller rockers, and an Edelbrock RPM Air Gap. Also have Hooker Super Comp headers, MSD billet distributor with 6AL, chambered exhaust, with a speed demon 650 mechanical secondary.
What's your compression ratio? Comp told me the XE cams may detonate with higher compression ratios, even with aluminum heads. They recommended the Magnum 270H, which isn't much bigger than my 268H.
I was hitting high 13s with my Chevy 882 heads and Edelbrock Performer, you should have not trouble hitting mid 13s with your combo once dialed in. Don't forget the tuning, I picked up .5 seconds on 0-60 in my 454 suburban with a simple vacuum spring change.
if running auto you'll need a higher stall converter, though.
Jeff
I'd really love to see a dyno sheet (or time slip) on your setup. Almost exactly what I have minus the heads.


[Modified by Chris@VetteFinders, 9:02 AM 3/26/2003]
Chris@VetteFinders is offline   Reply With Quote
Old 03-27-2003, 10:42 PM   #7
Chris@VetteFinders
Platinum Supporting Vendor
 
Chris@VetteFinders's Avatar
 
Member Since: Dec 1999
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I thought this was a fairly popular cam? Anyone else?
Chris@VetteFinders is offline   Reply With Quote
Old 03-27-2003, 11:43 PM   #8
VETDRMS
CF Senior Member
 
VETDRMS's Avatar
 
Member Since: Dec 2001
Location: Billings MT
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

This is a great site for dyno combinations.

http://www.ryanscarpage.50megs.com/combos1.html

I'm sure you should be able to find something similar to your setup,
as they list a bunch of combos with stock heads and mild cams.

:cheers:
VETDRMS is offline   Reply With Quote
Old 03-28-2003, 10:50 AM   #9
no_radio
CF Senior Member
 
Member Since: Jun 2000
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

Quote:
I'd really love to see a dyno sheet (or time slip) on your setup. Almost exactly what I have minus the heads.
[Modified by Chris@VetteFinders, 9:02 AM 3/26/2003]
If I get to dyno it I will definitely publish the results here. I just installed the heads last weekend, haven't even had a chance to tune it, but pulled a 4.8 second 0-60 already (per GTech).
Jeff
no_radio is offline   Reply With Quote
Old 03-28-2003, 12:01 PM   #10
The_Dude
CF Senior Member
St. Jude Donor '11
 
The_Dude's Avatar
 
Member Since: Jul 2001
Location: abiding
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I have the same cam, but still have stock heads and no dyno runs. I'm watching this thread with interest though, as new heads will be my next mod. :cheers:
The_Dude is online now   Reply With Quote
Old 03-28-2003, 12:13 PM   #11
terryrudy
CF Senior Member
 
terryrudy's Avatar
 
Member Since: Jun 2000
Send a message via MSN to terryrudy
Default Re: Those with a 268H comp cam or similar specs.... (The_Dude)

I got the comp cams 268h with edelbrock aluminum egr intake, trick flow 23 degree aluminum heads, hedman headers, and true 2.5" duals. Stock carb. No complaints when I am pounding the pedal to the metal. Ide and off-idle is another story. Not as smooth as I like. In any case, my next project is TPI.
-terry
terryrudy is offline   Reply With Quote
Old 03-28-2003, 12:38 PM   #12
MotorHead
CF Senior Member
 
MotorHead's Avatar
 
Member Since: Apr 2000
Location: Never argue with Morons. If you do, you'll lower yourself to their standards, and they'll win, based on experience !!!
Default Re: Those with a 268H comp cam or similar specs.... (terryrudy)

I got 285 RWHP and 327 RWT from a 270H cam with Sportsman II heads, shut down a 5 grand because of lousy ignition I had at the time :D
MotorHead is offline   Reply With Quote
Old 03-28-2003, 07:44 PM   #13
loose nut
CF Member
 
Member Since: Aug 2002
Location: High Ridge MO
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I am using the 268h cam and have excellent throttle response . The car
quits pulling at 5600rpm's but Im using stock heads and a quadrajet.
Overall I am very pleased with the cam. The only thing that keeps my car
from being a dog though is the 370 gears and 4-speed.
loose nut is offline   Reply With Quote
Old 03-28-2003, 09:15 PM   #14
Nomad78SA
CF Senior Member
 
Nomad78SA's Avatar
 
Member Since: Feb 2000
Location: Clarksville,Tn,USA
Default Re: Those with a 268H comp cam or similar specs.... (79L82hatch)

Terryrudy,
No complaints when I am pounding the pedal to the metal. Ide and off-idle is another story. Not as smooth as I like
Explain your dislike a little more, not as smooth. Do you mean the car wants to get up and take off or what?
What gears and tranny are you running also?
I am also running a 268H cam in my 388ci and it has a nice lope and the throttle response is instant and crisp. I have not had mine on the road yet but I really am looking forward to it...my built 700R4 and 3:55 gears ought to move the vette along just fine
Neil in Tenn



[Modified by Nomad78SA, 8:16 PM 3/28/2003]
Nomad78SA is offline   Reply With Quote
Old 03-28-2003, 09:45 PM   #15
Chris@VetteFinders
Platinum Supporting Vendor
 
Chris@VetteFinders's Avatar
 
Member Since: Dec 1999
Default Re: Those with a 268H comp cam or similar specs.... (Nomad78SA)

How long til you get it on the dyno neil?

I am anxious to dump these heads!
Chris@VetteFinders is offline   Reply With Quote
Old 03-29-2003, 12:21 AM   #16
Bullyj
CF Senior Member
 
Bullyj's Avatar
 
Member Since: Oct 2002
Location: Rockwood TN
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I just installed a XE268H cam, Edelbrock performer aluminum heads (60899), Edelbrock airgap intake, and Edelbrock performer 600Cfm carb. I do have some clearence problems I'm going to have to work out. It runs like a different car though. I personally would not go with a bigger cam unless you get a stall converter.
Bullyj is offline   Reply With Quote
Old 03-29-2003, 01:49 AM   #17
71coupe
CF Senior Member
 
71coupe's Avatar
 
Member Since: Jun 2001
Default Re: Those with a 268H comp cam or similar specs.... (Nomad78SA)

I agree with Nomad78SA, that 268 should give you crisp throttle. I am running the XE268 & 200cc Dart heads (see sig). When cold, it has a very rough idle. I baby it for the first 15 min or so (no heat passages in heads & no choke)
After it is warm, it has a smoother idle and launches hard. I am making way more top end power with this setup than I ever did with my old 383 that had stock chev heads.
(9.6 CR & no pinging unless I advance it really far)


[Modified by 71coupe, 10:52 PM 3/28/2003]
71coupe is offline   Reply With Quote
Old 03-29-2003, 06:20 AM   #18
Nomad78SA
CF Senior Member
 
Nomad78SA's Avatar
 
Member Since: Feb 2000
Location: Clarksville,Tn,USA
Default Re: Those with a 268H comp cam or similar specs.... (71coupe)

Chris,
Dyno is still a ways off...We had hope to paint the Silver this weekend but the weather here in Tenn has a cold front in this weekend so it may have to wait until next weekend. Here is a pic of where I am at.

Once I get the car home I still have a ton of work to do. A lot of the Vette Brakes performance plus suspension stuff has rusted and I will have to remove those items to address it. I am very disappointed with the quality of some of their stuff. I even had to repaint the calipers they sent to me but this is info for another thread. :mad

Some of my freinds here run the 268H and are very pleased with it, most of them running a warmed over 350ci cars. Ask at one of the local cruise in one evening what they are running and their thoughts.

I personally like the dyno numbers I get using this cam for a street car. My heads are TFS aluminum 23 degree with 195cc intake port volume,64cc combustion Chamber Volume and 2.02/1.60 valves. On the dyno I should be over 400 torque/400 hp..not rear wheel dyno
I have hear a lot of good stuff on the AFR heads if price is not a concern. I would not go over 195cc if you are going to keep your motor trimmed to a 350/355ci. Your exhaust plays havic on what dyno numbers you can achieve,stock vrs headers.

Mountainmotor often gave awesome advice in this area and would be a good person to contact if he is still around as well as some others here. I also have enjoyed Ganey's thoughts on performance related items as well as many others.
Neil in Tenn
Click the image to open in full size.


[Modified by Nomad78SA, 5:36 AM 3/29/2003]
Nomad78SA is offline   Reply With Quote
Old 03-29-2003, 07:35 PM   #19
Nomad78SA
CF Senior Member
 
Nomad78SA's Avatar
 
Member Since: Feb 2000
Location: Clarksville,Tn,USA
Default Re: Those with a 268H comp cam or similar specs.... (Nomad78SA)

TTT,
for Chris
Neil in Tenn
Nomad78SA is offline   Reply With Quote
Old 03-29-2003, 11:08 PM   #20
glen242
CF Senior Member
 
Member Since: Apr 1999
Location: Moon Twp. PA USA
Default Re: Those with a 268H comp cam or similar specs.... (Chris@VetteFinders)

I am running a HE268H with 64cc TFS 23* heads. I will try and get it on a dyno this summer. DD shows 337 HP @ 5500 rpm, and 399 ft/lbs torque @ 3500 rpm.

My mods are in my signature.
glen242 is offline   Reply With Quote
Old 03-29-2003, 11:08 PM
 
Go Back   Corvette Forum > C3 Corvettes, 1968 - 1982 > C3 Tech/Performance
Reload this Page Those with a 268H comp cam or similar specs....
 
 
 
Reply

Tags
195cc, 268h, 383, 400, afr, cam, chevy, comp, crisp, pontiac, quality, specs, throttle, vacuum, xe268h


Thread Tools Search this Thread
Search this Thread:

Click for Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ZR1 Heads, results? BIGWILYT C6 Corvette ZR1 15 02-04-2014 11:54 PM
Patriot heads xzo124 C5 Tech 1 05-07-2013 02:32 PM
AFR Heads bucketlist1957 C5 Tech 9 12-07-2010 11:53 AM
2461 & 2461-X Heads, whats the difference oldsarge C1 & C2 Corvettes 8 05-07-2010 02:28 PM
LS3 VS LS7 Heads mitchell c C6 Tech/Performance 7 02-19-2010 09:50 PM


All times are GMT -4. The time now is 08:35 PM.


Emails & Password Backup