I'm calling bs..... - Page 4 - 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
lost password?   |   register now

LinkBack Thread Tools
  #46 (permalink)  
Old 10-23-2012, 11:26 PM
painted jester's Avatar

Last journal entry: Wifes 79 comeing together!
Last photo:
Join Date: Jan 2011
Location: Central Michigan
Age: 70
Posts: 2,430
Wiki Edits: 0

Thanks: 182
Thanked 627 Times in 485 Posts
Originally Posted by hcompton View Post
American's use long stroke big piston low rpm v8s. ferrari and other high rpm engine use shorter stokes and higher piston speed to make more power. 1.5 covers higher output v8 like bmw, merc but 1.2 is very fair for road use.

You cant make more power without higher piston speed, more displacement or boost. Nothing else makes any difference at all sep where things were built with a restriction of some type.

looked at another way 2 hp per ci would mean a stock 5.0 litre ford mustang from 1989 would make 604hp. or a 350 would be 700 hp.

A short stroke engine has a slower piston speed moving up and down the cylinder then a long stroke engine running at the same rpm is what I think you meant to say! the formula is: Piston speed ft. per min.= (stroke in inches x rpm)/6



Last edited by painted jester; 10-23-2012 at 11:47 PM.
Reply With Quote Quick reply to this message
Sponsored Links
  #47 (permalink)  
Old 10-24-2012, 10:23 AM
Registered User
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 8,885
Wiki Edits: 0

Thanks: 10
Thanked 1,068 Times in 885 Posts
Originally Posted by zildjian4life218 View Post
Okay so I consider myself still a newbie when it comes to the hotrodding world we all love so I am coming to you for input. My buddy has a foxbody that he road races and is looking for more power. His dad told him that he can get a 331ci $700 eagle rotating assembly and put it in a "boss" 302 block with some certain head and it will make 450hp (which I could understand) but he then said and spin it 9-10k rpm all day long with no problems.... I feel as though this is..... well seems like rather out of reach assuming its probably a cast crank with steel i beam rods and hypereutectic pistons but hey I could be wrong... it has happened before and im sure its not the last. Can someone with more experience as me chime in on this? I just wanna know how far off the road I am or am not.
You are right! It takes a lot of rocket science by the time an engine starts getting into the mid 6000 RPM catagory. This just goes crazy about 7000 RPM and CRAIZER above that point.

Structural strength of the block, crankshaft, rods and pistons becomes a huge issue not so much from the 450 hp thought that drives you to a lot of stuff made from 4340 steel like the crank and rods, high quality forged pistons with lightened tool steel floating pins, internal balance, very expensive dampers like the Rattler or Fluid Damper (cannot use the latter on NASCAR tracks because of imbalance issues after hot soaking). This would take ported aftermarket heads to feed the CFM requirements with a pretty exotic valve train to track the cam at those RPMs. Basically from 7000 RPM up you've got to dry sump the engine as the windage gets to be such a power limiter, you've got to put the crankcase under a continious vacuum and you've got to remove the oil that isn't in the galleys. Removal gives the oil time to rest and degass inside the crankcase it gets mixed with the air and gasses in there which actally makes a stiff brown mousse that is several times more viscus than the pure oil, this will cavitate in the pump and within the bearing clearances quickly destroying both pump and bearings followed by a massive engine failure as the bottom end comes out. All 4-bolt mains and crank girdles are not only necessay to keep the bottom end ridged enough that wandering dimension changes won't cause enough distortion to blow the engine, but another unadvertised purpose they serve is to bust up the rotating assembly is a failure does happen to soak up some of the energy to where the crank assembly isn't sailing about the track till its energy is used up. So dry sumping is used to extra capacity with storage away from the rotating mass to give the oil time to vent off before going back into the engine among other things.

So yes you can build a cheap high RPM engine by just buying a radical cam, stuff springs and some top end and exhaust goodies, but without the rocket science everywhere else it won't be together for long.

Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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
Calling all C-10 owners oldsmobilekindofguy Suspension - Brakes - Steering 6 02-24-2008 08:18 PM
Calling all 59'ers ApacheAngel Hotrodders' Lounge 0 05-30-2007 12:18 PM
calling old timers dickl Hotrodders' Lounge 1 04-26-2007 07:00 AM
Calling all Cars sandidande Introduce Yourself 3 01-16-2007 08:38 PM

All times are GMT -6. The time now is 10:11 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.