'76 sbc build , need more head advice - 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 03-17-2008, 09:59 PM
RippinRon's Avatar
Member
 
Last photo:
Join Date: Jun 2004
Location: Thornbury, Ontario
Age: 34
Posts: 948
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by TheCiscoKid
Crap, just got it together before winter.I'll do a leak down test, I think it's probably valves as motor doesn't smoke.Motor had 70,000 on it.
BTW ....Picton is in Ontario,Canada.I work in the town Avril Lavinge comes from.If it gets much warmer my 30 x 40 igloo garage will melt soon. :oP
Cisco
Napanee! My Aunt and Uncle live there!

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 03-17-2008, 10:04 PM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

I can't get the car out because there's 2 feet of solid ice in front of the garage.What happened to global warming? I've had stuff growing this time most years. Cisco
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 03-17-2008, 10:06 PM
RippinRon's Avatar
Member
 
Last photo:
Join Date: Jun 2004
Location: Thornbury, Ontario
Age: 34
Posts: 948
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
At least the ice fishing is good!
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 03-17-2008, 10:54 PM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

Are your Aunt and Uncle related to Avril? LOL The fish moved to deeper water after the Zebra mussels cleaned the water, not as much ice fishing now.Used to be lots on the ice in front of the house, haven't seen anyone in years now.Besides who likes frozen fish?I don't even feed my cats fish and I have 13 ,oops 16 of them.have to include the German breeding stock
too. Cisco
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 03-18-2008, 10:50 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 66
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Cisco,
those numbers are fine and the good news is you very likely can burn "elcheapo" brand 87octane with maxed timing...

nah, leave it together..... rule of thumb is if all cylinders do test within 10%....keep on driving....135 X 1.10% =148= close enough

when you "can" test drive and downshift with the vac guage...the vac guage is likely to read 24Hg+ and steady...when it does read <23Hg after alot more miles tear it down (and likely you will be adding a qt of oil every 1,000 miles at that point)

on any motor "some" cylinders live a much harder life (do more work with a less than best A/F mix) so the do wear faster

if this is a fresh build.....ignore the comp test results and vac readings till you get 500+ road miles on the motor (and re-torque and re-tune the whole motor)
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 03-18-2008, 11:30 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 66
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Cisco,
the "catch 22" of building a street (low) rpms performance motor is that there is not a hell of alot of power (TQ) there to begin with to add onto....

the rv 204/214 cam will make almost as much TQ at 2k as the stock 190/202(?) cam for good normal acceleration....and a bit quicker "wind up" for passing a truck (with your relatively tall 2.73 gears good for mpg)

any cam much bigger kills that 2k street rpms number.... DD example from another thread on a 8.5CR motor:

222/222 vette cam=72ft/lbs @1k, 243ft/lbs@2k
same motor with a oem 190/209= 160ft/lbs @ 1k, 309ft/lbs @ 2k

243ft/lbs vette cam x2.73 gears=663ft/lbs at the tires
309ft/lbs stock cam x 2.73= 843 ft/lbs at the tires= roughly 30% more actual force twisting the hides at 2k rpms

bottem line is the "stock" motor build (250hp?) is the most and soonest maxTQ possible in the street rpms range...stock small 2V, stock intake, stock cam, etc....takes alot of careful planning and tweeking to actually get more TQ at street rpms than a plain vanilla 8.5CR 87octane 350

a year of planning and 2 years worth of tweeking my 208/214 cam 302 motor and I do know it would perform better driving normal with a stock 289 cam...but I don't want to give up 0-60mph in just a tad over 5 seconds with 3.55 gears and chirping the tires on the 1-2 shift with a automatic

Last edited by red65mustang; 03-18-2008 at 11:44 AM.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 03-18-2008, 03:03 PM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

The engine that is in my car is 70,000 mile 1976 4 bolt sbc out of a truck,487 heads.I put a new RV cam, oil pump,stock timing set,Edelbrock manifold & carb.It is the one with 2 cylinders down.My 74 Vet had 3:08 and it was way quicker and had nothing done to it.3:08 vs 2:73 aren't that far apart are they?I just don't think this motor has the balls it should.
My friends motor that I'm thinking of using is the 10:1 sbc with the big cam.I'm wondering weither to use my RV cam or something else in it.I want mpg not tire burning torque.
I guess what I have to decide now is if to change the motor or not.I'm keeping my th350. How much of a lower gear can I use without hurting mpg?Using a axle calculator ,car doing 2000rpm ,car is 60 mph.
Cisco.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 03-18-2008, 05:28 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 66
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
re-curve the dist will help it grow some gonads...

sorry my post wasn't clear...for a really responsive motor on the street you do want to have way more than the minumum needed TQ available...so that just a little pedal the rpms jump very quickly when accelerating normal (hard for me to keep my car steady at 2k=40mph=320ft/lbs x 3.55 gears=1136ft/lbs in a 3400lb car=1ft/lb per 3lbs of car weight)...touch the gas and it jumps to 60mph!
(and when the grand kids are in the car you can light'em up)

each additional full compression point added only adds "up to" 4% to the power...your at roughly 9/1 and say 260hp....put a rv cam in a 10/1 motor would be only 10hp more "possible" AND require 92-94 octane likely

I am chuckling because you started out asking for a 90% hwy cruiser "only" and 87 octane and mpg (=9/1CR 87 octane rv cam) ....now yer askin' fer "vette' performance (and 87 octane and mpg!).... that's a oxymoron... or.... go buy a $71,000 ZO6...505hp and 25(?)mpg hwy on 94 octane

ya gotta choose your priorities...or get out your wallet and buy a OD tranny and much lower gears....or just stick a simple NOS kit on it.... (and have 87octane and mpg and "vette" performance)

Last edited by red65mustang; 03-18-2008 at 05:39 PM.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 03-19-2008, 04:31 AM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

EXCUSE me if I expect more from what I have or for trying to build on a budget. Cisco
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 03-19-2008, 07:55 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 66
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Cisco,
apology!
I was chuckling because you "clearly" stated your "priorities" in your post #15...
and repeatedly asked for "best mpg possible"...
then you compared the performance of this "truck motor" designed for low end TQ to a "vette" motor designed for high rpms performance (apples to oranges)

a car only uses around 40-60hp to maintain hwy speed depending on the car wt...so motor rpms @ hwy speed does pretty much determine mpg....go any deeper than about 3.08 gears and mpg will be less and that's not nearly enough to to give it some balls

best solution for best performance and best mpg on the "truck" motor is a OD tranny to keep it at 2k=60mph with much deeper gears to give it some gonads when it downshifts WOT
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 03-19-2008, 10:32 PM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

Thanks, Red.
74 Vette L48 ,2 bolt,piece of crap low CR, but burned out, chirps when shifts, doesn't glue you to the seat when accelerating,gets 25mpg.I drove it until everything went,then I sold it for almost what I paid new.
76 4 bolt truck motor ,487 heads, low CR,with my cam ,intake,headers,I'm saying it should run stronger,A 3:08 isn't that much dif than a 2:73 is it?
The truck motor doesn't pull, doubt it will burn and gets 15mpg and it should be the better motor.
The way it is here,I can't find a SBC in a wrecker.I found a camaros LS motor and trany for $6500 at a wrecker last week.If my motors dying ,it's gotta go.My cheapest opition is my friends motor,but with 10:1, I don't think I want it.A fresh build will be $5000 for a sbc.I'd like a cheaper solution.(dreamer)
My car sat at a hot rod shop for 2 1/2 years.I dragged it home,stripped it back to frame,re-did almost all the shops work in 4 months.I have some body issues and glass to replace,then I'll paint it myself.Once that's done I will not want to take it apart.The other issue is what do I paint on it.I raise pedigree cats(truth,see below).Do you think I'd get thumbs up for flaming cats on the fenders? LOL
Cisco
Kerakterkatz ( character cats )
Maine Coon cats with character
http://kerakterkatz.tubazaar.com
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 03-20-2008, 08:10 AM
Member
 
Last photo:
Join Date: Dec 2004
Location: San Antonio, Texas
Age: 50
Posts: 4,023
Wiki Edits: 0

Thanks: 0
Thanked 24 Times in 24 Posts
5000 seem very expensive. I rebuild my sbc or bbc for about 1000.00. That is with new pistons and all the machine work (block and head) and with bearings and gaskets. I do my own assembly but that would only be another 200 to put it together at the machine shop.
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 03-20-2008, 08:48 AM
Member
 

Last journal entry: dash mods
Last photo:
Join Date: Aug 2004
Location: Picton,Ont,Canada
Age: 64
Posts: 189
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
'76 sbc build , need more head advice

hey 454 Buddie!!!! Build me a 383 please. LOL
I'm in Canada, we get reamed.Maybe I should post ,looking for a motor.
I spent this morning looking at crate motors on line,again way cheaper in the USA. Cisco
Reply With Quote Quick reply to this message
  #29 (permalink)  
Old 03-20-2008, 09:07 AM
Member
 
Last photo:
Join Date: Dec 2004
Location: San Antonio, Texas
Age: 50
Posts: 4,023
Wiki Edits: 0

Thanks: 0
Thanked 24 Times in 24 Posts
you already have a motor, right? so buying pistons and getting the machine work should be the same price, right?

how much to clean and bore a block? 130.00
install cam bearings and freeze plugs? 40.00
turn a crank? about 125.00
a basic valve job? about 150.00 for a V8
resize 8 rods? 60.00
engine bearings, pistons, oil pump, gaskets, 310.00 from summit racing
summit cam and lifters, 80.00
assembly, 200 to 300.
Reply With Quote Quick reply to this message
  #30 (permalink)  
Old 03-21-2008, 09:38 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 66
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Cisco,,,
you are to funny...post #15 says my tire burning days are done (like mine)....and now you want to burn rubber....AND chirp the hides on a shift!

1974 L82 is to far back for me to recall details but it was only a 8.5CR? 250HP motor same as the 8.5CR=150psi 250HP you have now....
if you were chirping the hides with 3.08 gears it was very like due to "ALL the parts "tuned" and designed to work together" for peak performance as F-bird posted

On the 74' vette, the tranny shift vacuum and rpm's modulator valves rpm's shift points were tuned to the cam shaft (which was a WOT "mid range power" 222/222 cam) and dist curved to work with that camshaft and CR (correct spark timing can be 30HP gained over the whole rpm's range) ....

crummy mpg and a dog can be from many things (read your plugs) but
'fair chance" your tranny does need some attention...maybe just the bands adjusted for better shifts or a correct $15 vac modulator tuned to the rv cam...tranny's do need a tune up....(I do not believe in "a fix in a can" at all but I've have seen good improvements in shift quality with the $9 Lucas Tranny conditioner/cleaner many times)

can you tune the tranny and motor to chirp the tires with truck heads/2.73 gears/rv cam/and tall(?) tires.....IF this car does weigh about 300-400lbs+ less than the vette did....probably-maybe-yes with maybe a shift kit also needed

re: gear swaps
this is the best (basics) article I've found for explaining all about gears

http://www.pontiacpower.org/reargear.htm

Re: rebuild
you can buy a "brand new" GM complete 250HP long block for $1500 (which will also comp test at 8.5CR= 150-160psi!!!!) ....basic re-machine a block and heads is about $1300 around here (454 left out balancing and cleaning) plus $300 for the parts...assembled and tested is $1800/3 year warentee....you can buy a 290HP (on open tube headers) brand new GM long block for $2000 for a better chance of "chirping" the hides (270hp with exhaust pipes)

re:mpg
just mount your vac guage on the dash so you can read it while driving to know how hard the motor is actually working.... and re-train you right foot to keep it above about 12Hg accelerating.... and tune the motor for max Hg at hwy cruise speed will gain you atleast 2-3mpg+ combo intown/hwy
I'm guessing that your car weigh's 3,000lbs...with the rv cam the guage should be reading 18Hg+ at 60mph on a level road (really tweeked it may read 20Hg)
hard to read in the pic' attached but it does say "poor gas mileage" in the yellow/brown band below the "best economy" green band"
Hg reads low=carb is rich
hg read high=carb is lean

edit: LOL...thought about it...can the rv cam "chirp" the tires???....kinda depends on how much weight is in the rear and no posi allowed....might only be a "cheeeeep" on a "open rear"....which is likely what you had on the vette to chirp them

ps: which model Edelbrock did you buy
Attached Thumbnails
Click image for larger version

Name:	Tach and Vac.jpg
Views:	98
Size:	114.3 KB
ID:	28707  

Last edited by red65mustang; 03-21-2008 at 10:09 AM.
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
SBC 350 superiority rebuttle...was:POWERED BY CHEVY, WRITTEN ON A FORD, (from 'Engine Oldsmolac911 Hotrodders' Lounge 50 01-12-2011 11:00 PM
SBC HEAD QUESTION: Need Help Picking A Head Mustangsaly Engine 10 11-30-2007 02:48 PM
SBC 400 cylinder head question JohnyR17 Engine 9 02-28-2007 05:12 PM
Need aluminum head help for sbc 350 batman09 Engine 3 09-03-2004 10:35 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 06:59 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.