350 vs 400 - 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> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-05-2004, 03:37 PM
slu slu is offline
Registered User
 
Join Date: Jan 2004
Location: TN
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Question 350 vs 400

I have looked but haven't found a direct answer to this question and I hope I am not cluttering the board with something that has been discussed over and over.

I have an F1 running a 350 4-bolt with 881 heads w/ roller tip lifters and a "268" Comp Cam, 650 Holley Carb and behind it is a 350 Turbo trans and a 12 bolt GM rear end with the biggest (tallest) radials I could find. Sorry I don't have the rear end ratio or exact tire size.

I am currently going through the truck from the frame up. It will be a "daily driver" 10 miles round trip in town, 5 days a week. Weekend trips on the interstate. I am not interested in performance other than I want to be able to get on the interstate w/o getting run over and then cruise at 75-80 all day. MPG is of interest but being a realist, I know it's like wanting your cake and eat it too. The motor wasn't much on the low end, but I could cruise all day w/o a strain.

The motor is going to have to be rebuilt. Would I be better off with the CI's of a 400 set up the same way or would there not be that much difference? Someone has told me that I might get better performance and gas mileage by going with the torqueier 400.

Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-06-2004, 12:19 AM
lluciano77's Avatar
Short changed on common sense
 
Last photo:
Join Date: Jun 2003
Location: california
Age: 37
Posts: 3,548
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I think a 350 has the best gas mileage potential. For some reason 350 is a magic number. It is a good compromise between power and mileage. The 400 will get you more torque, but at some expense.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-06-2004, 11:24 AM
slu slu is offline
Registered User
 
Join Date: Jan 2004
Location: TN
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally posted by lluciano77
I think a 350 has the best gas mileage potential. For some reason 350 is a magic number. It is a good compromise between power and mileage. The 400 will get you more torque, but at some expense.
Thanks, lluciano77, I appreciate your response. If I don't go with a rebuilt 400, I'll go with a crate 350. Around here it's cheaper to go with a crate than with a re-build on the 350.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-06-2004, 12:24 PM
bullheimer's Avatar
NEVER use credit cards!
 

Last journal entry: car with tt2's, (stockers going back on)
Last photo:
Join Date: Jan 2002
Location: North of Seattle
Posts: 2,529
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 4 Posts
more cubic inches means worse milage. how in the world could a crate engine be less than a rebuild? at least you get a new crank, rods pistons etc. not like a crate is a bad idea tho.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-06-2004, 04:06 PM
slu slu is offline
Registered User
 
Join Date: Jan 2004
Location: TN
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally posted by bullheimer
more cubic inches means worse milage. how in the world could a crate engine be less than a rebuild? at least you get a new crank, rods pistons etc. not like a crate is a bad idea tho.
I'm not exactly comparing apples to apples. Out of Nashville, I can get a new, not rebuilt 350, long block for about $1500. The machine shop that most swear by around here has quoted me a price of $2500 for rebuilding my 350. That price includes balancing and any work necessary such as head work, line boring, etc. That is just plain machine shop work, stock rebuild, no performance parts or blue-printing. 30 day warranty.

Most likely, the motor could get by with just a boring and new pistons, rods, but you know how that goes. When I bought it, the guy had had a crank kit put in and head work done . The motor should have been bored when he put in the kit, but hadn't. It ran good, didn't use excessive oil, but would develop a slight miss and foul a plug after a couple days of running. The motor probably has 10,000 miles on it.

In a discussion, a fellow told me with the 400, even with more CI, the added torque could keep the foot out of the carb increasing mpg and that was the only reason I considered it.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-08-2004, 03:47 PM
STUPID is as STUPID does...
 
Last wiki edit: Crankshaft Coalition Wiki Last photo:
Join Date: Nov 2003
Location: Stupidville, USA
Posts: 1,693
Wiki Edits: 1

Thanks: 11
Thanked 80 Times in 74 Posts
I would go through the 350. If you aren't looking strictly for performance it is more cost effective. You can do a good rebuild with a kit from Nortern Auto Parts... http://www.northernautoparts.com/Pro...uctModelId=380
I doubt you would have to replace the rods so this kit will work for you. They have other more expensive kits so look around on their site.
What I would replace is the TH350 trans. Lose it. Put in a 700R4 rebuilt to Corvette specs and will you see a major increase in mileage, more response off the line and less engine wear at highway speeds. Look here... http://www.smokemup.com/tech/700r4.php
Lots of good info. Run through the RPM calculaters to see the benefits of the O.D. swap... Best thing you can do.
Mark
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-08-2004, 09:06 PM
Ghetto Jet's Avatar
current hot rod: CTS-V
 

Last journal entry: Lets Get Started With the Improvements
Last photo:
Join Date: Nov 2003
Location: Pennsylvania
Age: 28
Posts: 1,726
Wiki Edits: 0

Thanks: 10
Thanked 5 Times in 5 Posts
Here's a brand new 350 with 4 bolt mains $1200.00 made by GM, has a 3 year 50,000 mile warranty and makes 260 horses with a extremely tame cam, 8.5:1 compression, will give you great gas mileage. Great motor, I bought one. Heres the link, I only paid about $100 for shipping. http://www.paceparts.com/product.asp?0=0&1=0&3=3169
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-09-2004, 07:58 AM
slu slu is offline
Registered User
 
Join Date: Jan 2004
Location: TN
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Many Thanks

Thanks for the comments and suggestions. Another machine shop, recommended to me, quoted $2500 for a rebuilt 400, 4-bolt.

I don't think, that with what I'm looking for in a motor, I'm going to go wrong with the 350 crate. Thanks, Ghetto Jet, for the link.

Astroracer, thanks for the link, too. I have thought about this off and on and now would be the time. This probably is the best answer to the mpg. issue.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics 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



All times are GMT -6. The time now is 07:30 PM.


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.