engine vacuum with comp 270 magnum - Third Generation F-Body Message Boards


Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

engine vacuum with comp 270 magnum

Reply
 
Thread Tools Search this Thread
Old 07-21-2002, 11:04 AM   #1
Junior Member
Thread Starter
 
Join Date: Dec 2000
Location: Chattanooga, TN
Posts: 92
engine vacuum with comp 270 magnum

I've been looking at many websites and magzines for a future build-up for my car. I ran across a 355 on the AFR website that looks sweet. Basic rundown of the engine:
AFR 190 heads
RPM type manifold
9.5:1 compression
comp 270 magnum cam (224* int/exh @ .050 .470" lift 110*LSA)
1 5/8" headers
etc.
My question is about the cam. It's a bit bigger and has a tighter LSA than I'd like for idle/vacuum. I currently have an L-82 cam (yeah, i know it sucks) i my 350 with similar duration numbers and it doesn't give me enough vacuum at idle to run my power brakes very well. I was also looking at an XE 262 cam also from comp that has slightly less intake duration to help that out. Surely several people use these cams, what kind of vacuum numbers do they put up?
Black 84 Z is offline   Reply With Quote
Old 07-21-2002, 11:25 AM   #2
Senior Member
 
Join Date: Mar 2002
Location: Coushatta LA
Posts: 266
I have put together two 355 chevys using stock vortec heads,the XE262H cam and a rpm intake. I love this combo for the street, slight lope at idle, good vacuum, excellent drivability. I personally saw this combo run 14.20's in a 4000lbs trk with 3.42's and slicks and a stock converter. The AFR 190 heads you mentioned are hard to beat.

Lonnie
boogie is offline   Reply With Quote
Old 07-21-2002, 01:57 PM   #3
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 661
I have a comp 280H in mine and I pull 14 inches at idle and my brakes work fine
84 Z-28 350 is offline   Reply With Quote
Old 07-21-2002, 02:35 PM   #4
SSC
Supreme Member
 
SSC's Avatar
 
Join Date: Jul 2001
Location: Pueblo Co
Posts: 3,974
I used the 270H's in 3 of my 350's the last couple of years, there great for power but economy will suffer. The highest vacuum I could pull at idle was 10/11in with a conservative timing setting. Down the road in cruise it will pull around 17/18in of vacuum, not too bad but that equals around 12-14 MPG more 12 then 14. Power brakes work fine but under a fair amount of heavy accelration then braking they get touchy.
SSC is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Trans am V.S Rx8! TreDeClaw Theoretical and Street Racing 8 02-27-2017 12:58 AM
[PA] 1985 Trans am 90% restored Reddeath210 Firebirds for Sale 14 10-06-2015 08:20 AM
2500 stall, needs trans cooler? TreDeClaw Transmissions and Drivetrain 15 08-14-2015 06:58 PM
Bogging at 40mph need help!! Infested Tech / General Engine 2 08-14-2015 05:25 PM
Code 12 Distributor not sending to ECM bradleydeanuhl DFI and ECM 4 08-12-2015 11:48 AM


Go Back   Third Generation F-Body Message Boards >

Tags
270, 270h, 288, 350, 355, 383, 84z, brakes, cam, cams, comp, edelbrock, idle, magnum, magumn, power, run, xe

Thread Tools Search this Thread
Search this Thread:

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


Advertising
Featured Sponsors
Vendor Directory

1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92


All times are GMT -5. The time now is 11:39 PM.


All content copyright 1997 - 2014 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: