327 power questions - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 09-01-2012, 09:48 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,052
Wiki Edits: 0

Thanks: 321
Thanked 783 Times in 749 Posts
Malibusurfer
back in the 70s we ran a sig ersom high flow 2 solid cam in 327s.There are better cams available now. All we had then were 11:1 pistons(dont recommend that now) 750 holleys, 4779, torker manifolds,long slot stamped steel rockers,194s with screw in studs or 202s same castings. I worked at a gas station that had 7 ,,57 chevy belairs.I had a 65 acadian.

All the 57s that had solid cams revved to 7200 and the hydraulic cams all went 6500. All the cars were street driven and bracket raced. We all had problems with points.not cams. WE used dual point mallories or GM off road points. we changed the points about every 6 weeks to 2 months.
You are not asking much from your engine,good ignition,moderate cam,decent carb and intake and try not to shift at 7k and try not to grin every time,,,,

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 09-01-2012, 09:57 PM
Registered User
 
Last photo:
Join Date: Aug 2012
Posts: 50
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
I just want something that gives me a smile when I stomp on the gas and I won't hurt the motor... 400hp would be plenty I would think... At .60 over, motor is on borrowed time anyways, and I don't want to speed it up..
Dizzy I'm thinking just simple HEI with Davis unit in it or similar to gets a few more rev's out of a stock deal....
Would a magnum cam 268, 270, or 280 be in the ballpark?? Not stuck on Magnum cams, but am I thinking right???
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 09-01-2012, 09:59 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,052
Wiki Edits: 0

Thanks: 321
Thanked 783 Times in 749 Posts
if its a hydraulic flat tappet cam,expect 6500 rpm.For HEI,you need to have a much better than stock coil to support over 5500 rpm.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 09-02-2012, 01:58 AM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: Hopewell, Va
Age: 62
Posts: 1,203
Wiki Edits: 0

Thanks: 0
Thanked 117 Times in 113 Posts
327 power questions

Your engine will make more usable power over a wider RPM range with a XE268H. That's because the larger cams will be hindered by those 461 heads at higher RPMs where it's designed to shine. So all you'll be doing is giving up low-mid RPM torque for nothing more at high RPM. Now, if you had some modern heads with 180-200cc intake runners, that would be different. Just comment from a guy who used a few "too big" cams over the years. You could call Comp Cams and get a custom ground XE268H on a 108 Lsa for a more lopey idle. One more thing as the duration increases you will need larger converters also. For instance a 12-243-3 X4270H 1800-6000 .480/.498 lift 226/234 duration, 397 hp @6000 torque 402 @ 4000. XE268H .447/.480 lift and 224/230 duration @ .050 396 hp @ 6000 torque 401 @ 4000. Your compression ratio compliments the XE268H also. You got to remember you are using stock rods too.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 09-02-2012, 07:22 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,077
Wiki Edits: 0

Thanks: 17
Thanked 332 Times in 312 Posts
You can spin that engine as high as you like, you're just wearing out parts though. 400hp at 5500 RPM is NOT any better than 400hp at 7500 rpm. The XE268h cam would work okay for that combo but a smaller cam would be a little better. While still a little too big if you really want to be able to spin it and have an old school solid cam sound the Lunati 60140 would work, it's critical to use the proper springs though.

FWIW, those heads really don't ever need more valve than 1.94/1.6, the valve size is NOT the restriction, you can get 250cfm+ around a 1.94 valve. Going to a larger valve will actually hurt power, but it's one of those "bigger is better" old wives tales that just won't die.


Instead of pretending you have a race engine build according to what you really have and your results will be much better.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 09-02-2012, 09:14 AM
Registered User
 
Last photo:
Join Date: Aug 2012
Posts: 50
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
I have stated at least 3 times I don't want to race this motor, just have fun and get as optimum power I can for the parts I have... That's not pretending to be anything else than what I have stated repeatedly.... I do appreciate all the help.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 09-02-2012, 10:30 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,077
Wiki Edits: 0

Thanks: 17
Thanked 332 Times in 312 Posts
"love to rev" and "6000-6500" are not words normally associated with street engines.

stock 327's don't "love to rev" more than a stock 350. and if you plan on driving it above 6000 rpm then you should get a well built short block that can take some abuse.

Since you realize this is a street application and big cams are counter productive I would go with the VooDoo 262 cam or one very similar. With an RPM intake, a 750 carb, shorty headers, 9.5:1 compression and that cam I would expect peak power to be around 5700 rpm at about 375hp. A hair more compression and better headers and the 268 cam would put you at 400ish.

Remember you need "optimum power" where you will be using it, NOT at the peak RPM.

The previously mentioned XE268 or the solid cam I mentioned will both also work fairly well but give up some low end torque and mileage- if you want more of a hotrod sound it may be something to consider though.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 09-02-2012, 10:54 AM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,052
Wiki Edits: 0

Thanks: 321
Thanked 783 Times in 749 Posts
Malibusurfer
fyi 6000 rpm is not really that high of rpm.
The limiting factors to rpms(for dependability) is piston speed and valve train stability,at least at 8000 rpm and lower.So a 350 with a 1/4 inch longer stroke than a 327 will not love to rev as much.
Look back to the mark 1 big blocks,the valve train was not reliable past 5000 rpm,the mark 4 was much better and revved freely to 6k in some factory applications. The 283 would rev 7,000 no problem with not much more than cam,manifold,carb and headers,3 inch stroke,piston speed not as high as a 327,its all math.
forged pistons will last longer than cast in high rpm situations,we all know this. New valve spring technology(last 20 years) allows higher rpms without spring failures and last longer than what we had in the 70s. factory forged GM cranks are very good items,no worries there.Ive seen 1 rod failure in a 283 back in the 70s.street guy (Doug Hall,predator rep in western Canada back then) had a street car that rarely was under 5,000 rpm. That engine was from a full size car with unknown history that had a cam ,manifold ,carb and headers put into a chevy2 with 4.11 gears,and it lasted 2 years of daily abuse.

what ap says is partially true,most cars are not operated at high rpm for long periods of time,but if you do decide to run 7,000 rpm with modern cam springs and good valve train it will last and not likely come apart. Any engine can come apart and its usually the faster guys that lose an engine,,,
list a few cars that rev past 7,000 now,,,BMW/Honda both make power through rpm,anything over head cam(valve train stability)
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
The hidden power of 327's olk9cop Introduce Yourself 1 12-15-2008 06:41 PM
327 power! backyard71nova Engine 5 03-13-2008 09:55 PM
327 questions 67ssguy Engine 2 11-06-2007 09:17 AM
327 questions 1 Day Engine 9 12-28-2006 09:10 AM
ok i got a 327 as u know i have a few questions please. Eric327 Engine 6 06-25-2005 09:32 PM


All times are GMT -6. The time now is 11:59 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.