8-71 wieland 350 sbc build questions - 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
  #1 (permalink)  
Old 11-11-2009, 09:18 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
8-71 wieland 350 sbc build questions

Ok so I have an '79 camaro that I want to build a 383 stroker with an 8-71 to top it off...besides the block work where do I start..ive rebuilt small blocks befor with success but never a stroker or supercharger so I need some help...it says the charger needs a 7.5:1 - 8:1 CR and not sure how close you have to stick to that? Any answers?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 11-11-2009, 09:35 PM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls/Suncrest, WA
Posts: 5,287
Wiki Edits: 9

Thanks: 115
Thanked 139 Times in 130 Posts
The c.r. you build to depends on how much boost you want to run. I'm running 10 - 12 pounds with an 8-71 383, street driven car, I'm using JE forged -31 dish pistons, putting me right at 8.4:1 c.r. with no issues, but I also run a BTM. I ran at the strip in July with a straight 6AL, aggressive timing and yep, detonation took it's toll, in a big way

For obvious reasons, I installed an alcohol/methanol injection system to compliment the rebuild, call it insurance on steroids.

I overbuilt my motor with splayed billet mains. If you're not a savage (yeah right, he he, with a blower motor...) you could get by on 2-bolts and cast parts I suppose. I'd never build a blower motor on the light side myself.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 11-11-2009, 09:40 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ok so can this build be done and still run on pump gas? and Im just not sure where to start on parts I need. I looked at the stroker kits on jegs and summit and they have some with 9.somethin CR...what would that do?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 11-11-2009, 09:48 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I would also like to know about what heads to run and if you have to do any milling to them?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 11-11-2009, 09:55 PM
camaroman7d's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 47
Posts: 2,245
Wiki Edits: 0

Thanks: 3
Thanked 9 Times in 9 Posts
Your first purchase should be a book called "Street Supercharging". Bone up a little on the subject before you start buying parts. It's not rocket science, but having a decent foundation will prevent problems down the road.

With that said, What is your goal? do you want the blower for the look and sound or do you want to make power? If you want to make power, keep the compression as close to 8:1 as you can. No more than 8.5:1.

You are not going to find a "kit" that will give you what you want. A rotating kit can't accurately list what the compression ratio will be, because that all depends on your heads, deck height, head gasket, etc...

Do you already have your heads? If so you have to build around them.

If you are trying to make power you want all forged parts (crank, pistons, and aftermarket rods, I prefer H-beams).

Do you have a budget in mind?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 11-11-2009, 10:03 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well I have been told that going forged is better so prolly go that route. Oh and Im going for the hp and ft. lbs and the looks and sound will just come with I guess. I will look into that book you told me and read up.

Im actually in college at wyotech in laramie wy. now and as soon as I get done Im gonna start with a 4 bolt main 350 and figured that would be a good start. The money Im not to worried about because this project is going to take a while I figured so I can just save up.

The heads I was thinking about starting with some 202s cuz my buddy has a pair he will sell but what would you recomend?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 11-11-2009, 11:00 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
So your saying a 350 w/ an 8-71 will produce as much as a 383 w/ a 8-71?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 11-11-2009, 11:19 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
alright well im gonna look into it more and see what I can do...if I stick to 7.5:1 CR what kind of boost do you like I could run
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 11-11-2009, 11:34 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ive always been told that the greater the boost the greater the PSI of air being forced into an engine? is that what your saying or is that not it? Ive never really been around turbos, chargers, boost, etc. so Im sorry if im asking alot of questions.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 11-11-2009, 11:48 PM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ok so where do I go or who do I ask to find the "right" combos? If im gonna spend the money I want it to last!

so I got this info now:
forged parts, stay close to 7.5:1 CR, 200 to 220cc high flow heads, roller cam, two boost 750cfm holley carbs.

any other advice. whats the best thing to do about fuel and air?
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 11-12-2009, 12:11 AM
Registered User
 
Join Date: Nov 2009
Location: Iowa
Age: 23
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
on how stuff works.com it says that the "procharger" or centrifugal supercharger is the most efficient as opposed to the types that mount on top the engine, roots, and twin-screw. What you agree with that?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 11-12-2009, 06:55 AM
345 desoto's Avatar
Registered User
 
Last photo:
Join Date: Sep 2006
Location: Skaneateles, NY Summer/Port St.Lucie, FL Winter
Age: 71
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What CAMAROMAN7D, and F-BIRD'88 both said. The first thing you need to do is to become an armchair expert on supercharging, by reading and comprehending everything you can on it. Pick KNOWLEDGABLE people's brains and visit all the Web Site's available on the subject...THEN you can make informed decisions about what is the best choice for the parts you're going to need for your build. Make your parts decisions on what you're REALLY looking for out of the engine. F-BIRD'88 seems to be the man to listen too, along with a few others on this board. PERSONALLY (my opinion only), I think an 8-71 on a 350/383 is a bit much for the street. As for the compression ratio, I built my Hemi (for the street) with 7.5:1 CR and run 5 lbs of boost, to run reliably on pump gas. If I had built it for Street/Strip, I would have built it to different specs...Strip only, the 8-71, more boost, etc., etc. Before I started accumulating parts for the build, I did what you need to do...read, pick others brains, etc. You'll be AMAZED at the $$$ you'll save buy not buying stuff you really don't need, or breaking parts you spent your hard earned on. It doesn't take a whole lot of blower to set you back in your seat. BTW, the car in the picture is the one I built the blower engine for...
Attached Thumbnails
Click image for larger version

Name:	67 Corvette Yellow.jpg
Views:	74
Size:	71.2 KB
ID:	41896  

Last edited by 345 desoto; 11-12-2009 at 11:48 AM.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 11-12-2009, 09:48 AM
camaroman7d's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Vacaville, California
Age: 47
Posts: 2,245
Wiki Edits: 0

Thanks: 3
Thanked 9 Times in 9 Posts
If you go the 350 route you really don't need an 8-71. I don't agree that the 350 at 7.5:1 compression is going to out perform a 383 at 8:1 compression. I do agree that you will ba able to run more boost, but you're also going to need that boost to try to even out the odds. In the end you will just have less torque and the power will be close. It really is no cheaper to build a 350 over a 383 these days. Since you will need all new parts why give up the extra torque and HP.

There is no reason you can run 12lbs of boost with good flowing heads on a pump gas 383. You have to pay attention to the details and make sure your tune up is right. My 383 is 8.47:1 and I run 12lbs of boost on 91 octane pump gas. With that said I had a lot of parts on hand when I started the build otherwise I would have wanted my compression at 8:1.

Keep in mind flow is more important than boost, flow makes power.

You need to have a goal in mind or you will be all over the place and not know what parts you need. You can't just start buying parts or taking advice blindly and hope for the best. Figure out a goal wether ET or HP and then you can make a plan to get you there.

Often in cases like this the budget decides the goal for you. Do you have any idea how much this is going to cost? Don't just look at the $2500 blower kit and think that's it. That is just the begining.

Get out a pad and paper and list the parts you think you want or will need and look up the prices. Don't forget things like linkage, air cleaners/scoop, fuel lines, etc..
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 11-12-2009, 10:07 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,484
Wiki Edits: 0

Thanks: 20
Thanked 388 Times in 364 Posts
going to a 350 instead of a 383 at this stage is a BAD idea IMO. with a 383 you have about 10% more displacement, which means that instead of having to run 15 pounds of boost you could run only 12 pounds and have the same volume of air, with that you could also have a slightly higher static compression than you would with a 350, meaning you would make more power from the same volume of air.

The cost comes into play, except when you have to replace the crank, rods, pistons, flex plate and balancer anyway, there is NO cost difference to run a 383. You're air speed through the ports will be better with a 383 too so you can run 215cc runners instead of 200cc (on a 350) which again alows you to run less boost and make the same power...

to choose a 350 over a 383 would be like choosing a 327 over a 350, if you're just building a street machine there is NO REASON to go smaller in this case.


BTW, if you're really trying to push the limit you may want to look at getting an aftermarket block too (a good idea over 500hp), in which case you're now looking at 400+ ci engines.

When all else is equal always go for more displacement on a street engine.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 11-12-2009, 12:19 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,484
Wiki Edits: 0

Thanks: 20
Thanked 388 Times in 364 Posts
a good forged crank for a 383 costs nearly the exact same as one does for a 350, shipping included.

I'm not really sure where you were going with most of your post...

As far as proven power MANY people have proved that displacement wins on street engines and given the same power level a 383 is more durable than a 350, until you get to racing conditions in which case at the upper RPM range a short stroke can be advantageous.
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:
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
Wanna build a SBC 302. Need Help!!! Super Chevy Hotrodding Basics 9 03-12-2011 08:16 AM
SBC 350 superiority rebuttle...was:POWERED BY CHEVY, WRITTEN ON A FORD, (from 'Engine Oldsmolac911 Hotrodders' Lounge 50 01-12-2011 11:00 PM
this is a saver.... GM build codes TooMany2count General Rodding Tech 24 11-23-2009 10:36 AM
What to consider when choosing your first SBC build? CandiMan Engine 16 05-25-2009 08:50 PM
79 CJ 5: SBC or Stock Build Up? mav79 Engine 7 08-20-2003 11:28 PM


All times are GMT -6. The time now is 08:46 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.