305 mess - 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 12-12-2012, 08:39 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
305 mess

i have a 305 that a guy built for a street stock and the only thing i did to it was put new valve seats and springs and retainers on it .it has a 460 lift solid lifter cam ,not sure about duration and ,im having trouble with popping out carb around 3000 rpms, i had the valve covers off and checked rockers ,i adjusted intake to .018 and the exhaust at .020 and still have popping ,sounds like she is running on about 6 cyls just before it gets to 300 she wants to go,and then it breaks down .it has a new holley 600 on it and was running great. i got a 305 harmonic balancer for it and when i tried to time it ,the marks are no where even close.any help would be nice ,ty ,bud

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-12-2012, 08:56 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by stroker385 View Post
i have a 305 that a guy built for a street stock and the only thing i did to it was put new valve seats and springs and retainers on it .it has a 460 lift solid lifter cam ,not sure about duration and ,im having trouble with popping out carb around 3000 rpms, i had the valve covers off and checked rockers ,i adjusted intake to .018 and the exhaust at .020 and still have popping ,sounds like she is running on about 6 cyls just before it gets to 300 she wants to go,and then it breaks down .it has a new holley 600 on it and was running great. i got a 305 harmonic balancer for it and when i tried to time it ,the marks are no where even close.any help would be nice ,ty ,bud
Check the firing order. Pat particular attention to the wires for #5 and #7- they're next to each other at the cap and at the spark plugs so it's very easy to swap the wires.

There are three commonly encountered timing tab/damper line combos. If the parts are mixed up the timing as seen w/a timing light will be wrong. More here.

Was the cam broken in correctly?

If you have a HEI distributor, it needs a full 12 V-plus to the coil. No ballast resistor or resistor wire like the factory used on points ignitions. What about the ignition advance?

Vacuum leak? Fuel filter? Fuel pressure? Fuel old or stale?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-12-2012, 09:32 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
you might find this a bit weird ,i bought this motor after it won 4 championship races ,she has some milage on her,he ran a 500 holley 2 bbl.anyways this engine is in a 73 chevy half ton step side with 6 inch lift and 35 in all terrains on it ,might be too much for this truck,im also thinking that the torque converter might be the issue.it has a b&m stall speed 2200 to 2400 hole shot the truck is idleing at 900 rpms and when i shift it it feels like the tranny is gonna come out of it or a universal is gonna drop out and the rpms drop 2 between 200 and 400 rpms all but dies.if i turn idle down it will not run in gear
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-12-2012, 09:36 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
the wires ive gone over a dozen times ,the 5 and 7 are confusing to me and could see me putting them on wrong ,but they r ok
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-12-2012, 09:46 PM
painted jester's Avatar
TAKE A KID TO A CAR SHOW
 

Last journal entry: Take a kid to a car show
Last photo:
Join Date: Jan 2011
Location: Central Michigan
Age: 68
Posts: 1,789
Wiki Edits: 0

Thanks: 100
Thanked 274 Times in 223 Posts
Quote:
Originally Posted by stroker385 View Post
you might find this a bit weird ,i bought this motor after it won 4 championship races ,she has some milage on her,he ran a 500 holley 2 bbl.anyways this engine is in a 73 chevy half ton step side with 6 inch lift and 35 in all terrains on it ,might be too much for this truck,im also thinking that the torque converter might be the issue.it has a b&m stall speed 2200 to 2400 hole shot the truck is idleing at 900 rpms and when i shift it it feels like the tranny is gonna come out of it or a universal is gonna drop out and the rpms drop 2 between 200 and 400 rpms all but dies.if i turn idle down it will not run in gear
The Idle issue may be timing and vacuum advance! If you are even running vacuum advance? At 900 rpm the vacuum to the advance canister is advancing the timing and when put in gear the idle drops, vacuum drops off, and it retards the timing and the engine wants to stall ! unplug the vacuum line at the dist. and plug it off and then set the timing and Idle ! when you have it idling good try putting it in gear with the vacuum line still plugged and see if it still try's to stall.

Jester
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-12-2012, 09:50 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
ty jester and cobalt ,i have some things to check out ,thanks again and i will let you know if i find anything
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-12-2012, 09:54 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by stroker385 View Post
you might find this a bit weird ,i bought this motor after it won 4 championship races ,she has some milage on her,he ran a 500 holley 2 bbl.anyways this engine is in a 73 chevy half ton step side with 6 inch lift and 35 in all terrains on it ,might be too much for this truck,im also thinking that the torque converter might be the issue.it has a b&m stall speed 2200 to 2400 hole shot the truck is idleing at 900 rpms and when i shift it it feels like the tranny is gonna come out of it or a universal is gonna drop out and the rpms drop 2 between 200 and 400 rpms all but dies.if i turn idle down it will not run in gear
If there's not enough initial timing, the carb primary butterflies have to be opened so far the carb is now trying to idle on the transition circuit between the idle and main circuits. It does not like to do that and the result is a poor idle that will almost cause the engine to stall when going from Park/Neutral to Drive.

One way to tell if this is happening is if the idle mixture screws do not have much or any effect on the idle.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-12-2012, 10:11 PM
painted jester's Avatar
TAKE A KID TO A CAR SHOW
 

Last journal entry: Take a kid to a car show
Last photo:
Join Date: Jan 2011
Location: Central Michigan
Age: 68
Posts: 1,789
Wiki Edits: 0

Thanks: 100
Thanked 274 Times in 223 Posts
Quote:
Originally Posted by cobalt327 View Post
If there's not enough initial timing, the carb primary butterflies have to be opened so far the carb is now trying to idle on the transition circuit between the idle and main circuits. It does not like to do that and the result is a poor idle that will almost cause the engine to stall when going from Park/Neutral to Drive.

One way to tell if this is happening is if the idle mixture screws do not have much or any effect on the idle.
What Cobalt says is true theirs another cause for no change when the mixture screws are screwed in all the way and the engine doesn't stall at idle, I would like to add and that's a blown power valve. That's at Idle! not at 900 rpm into the transition or main circuits.

Jester
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-12-2012, 10:14 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by stroker385 View Post
i have a 305 that a guy built for a street stock and the only thing i did to it was put new valve seats and springs and retainers on it .it has a 460 lift solid lifter cam ,not sure about duration and ,im having trouble with popping out carb around 3000 rpms, i had the valve covers off and checked rockers ,i adjusted intake to .018 and the exhaust at .020 and still have popping ,sounds like she is running on about 6 cyls just before it gets to 300 she wants to go,and then it breaks down .it has a new holley 600 on it and was running great. i got a 305 harmonic balancer for it and when i tried to time it ,the marks are no where even close.any help would be nice ,ty ,bud
You meant seals, not seats, right?

These new springs- do they have enough installed height? Not coil binding? Check the valve lash hot to be sure the valves aren't too tight or even being held off the seat once warmed up.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-12-2012, 10:25 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 7,803
Wiki Edits: 0

Thanks: 312
Thanked 749 Times in 720 Posts
check for broken springs too.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-13-2012, 07:28 AM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: Hopewell, Va
Age: 62
Posts: 1,191
Wiki Edits: 0

Thanks: 0
Thanked 117 Times in 113 Posts
305 mess

I would start from scratch. Use a piston stop in the #1 spark plug hole to find TDC. Remove all the spark plugs. Rotate the crank past TDC to install the piston stop. Continue to rotate the crank with a breaker bar and socket on the damper bolt clockwise until you feel it gently touch the piston stop. Make a mark on the balancer and rotate the crank counter-clockwise until you feel it gently touch the piston stop again. Mark the balancer again. Split the difference between the lines and you have TDC. I hope TDC is on the original balancer line. The 305 engines timing cover scale is at the 12:00 position. If the scale is at the 2:00 position it has a 350 timing chain cover installed. Check the casting numbers on the block behind the alternator to make sure it is a 305 engine. Once you have found TDC pull the drivers side valve cover and turn the crank 2 revolutions watching #1 exhaust and intake valves. When both valves have opened and closed the balancer line should be back at TDC. Pop the distributor cap to see if the rotor is pointing to #1 spark plug wire.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 12-13-2012, 01:45 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
thanks for the input on the harmonic balancer , i will definately try that.the timing cover has the tube like thing for timing at 12:00 but it also has a dial on right side 2:00 and none hit at all,so ty i appreciate the tip.i will do that im a back yard mechanic and i mean back yard its cold out there .i did adjust the air on metering blocks ,i turned them out another 1/4 each and the engin picked up and smoothened out .im about to road test and see what happens. i also pulled the vac adv from dist and plugged it and then shifted it and same thing ,hard shift,could this converter be locked up? it is 7 yrs old
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 12-13-2012, 01:49 PM
Registered User
 
Join Date: Dec 2012
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
i also didnt find any broken or binding springs the guy that built the motor told me what to get for springs for that cam and thats what i got ,i dont remember what they were now but they seem fine
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 12-13-2012, 02:02 PM
Registered User
 
Join Date: Jul 2009
Location: Atl
Posts: 43
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sounds like you're having a detonation issue.....it is quite possible that this engine has a very high compression ratio & if you're running low octane gas it will cause it blow back thru the carb. Unfortunately, there is no easy way for you to figure out the compression ratio w/o breaking the engine down or asking the person you purchased it from

One other common issue w/ 305's is when the 305 HO heads are used w/ flat top pistons & big cams they tend to top out around 3000 rpms.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 12-13-2012, 03:27 PM
painted jester's Avatar
TAKE A KID TO A CAR SHOW
 

Last journal entry: Take a kid to a car show
Last photo:
Join Date: Jan 2011
Location: Central Michigan
Age: 68
Posts: 1,789
Wiki Edits: 0

Thanks: 100
Thanked 274 Times in 223 Posts
What intake are you running and where is you pcv routed to?

Jester
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
Yet another mess st3gamefarm General Rodding Tech 5 05-12-2012 04:04 PM
did i mess up?? 2112jb Engine 32 03-15-2007 09:50 AM
Uh what a mess!!!! Jag Daddy Electrical 1 04-11-2004 01:25 PM
Please help. Did I mess up??!! 1967stang Transmission - Rearend 3 01-05-2004 08:47 PM
no mess liquid_larry Engine 2 12-05-2001 06:41 PM


All times are GMT -6. The time now is 04:51 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.