rebuilt top end - compression too much for battery
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
Let us know how this turns out.
I had this same problem with my new motor.
I immediately thought of a bad battery and went and got a new one.
My starter was new and it didn't seem like that should be the issue. But it wouldn't turn over right even with the new battery.
Turned out it was timing.
I actually ended up moving the distro a gear notch before I got it right.
Your cam could very well change your timing that much.
I had this same problem with my new motor.
I immediately thought of a bad battery and went and got a new one.
My starter was new and it didn't seem like that should be the issue. But it wouldn't turn over right even with the new battery.
Turned out it was timing.
I actually ended up moving the distro a gear notch before I got it right.
Your cam could very well change your timing that much.
Thread Starter
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
Let us know how this turns out.
I had this same problem with my new motor.
I immediately thought of a bad battery and went and got a new one.
My starter was new and it didn't seem like that should be the issue. But it wouldn't turn over right even with the new battery.
Turned out it was timing.
I actually ended up moving the distro a gear notch before I got it right.
Your cam could very well change your timing that much.
I had this same problem with my new motor.
I immediately thought of a bad battery and went and got a new one.
My starter was new and it didn't seem like that should be the issue. But it wouldn't turn over right even with the new battery.
Turned out it was timing.
I actually ended up moving the distro a gear notch before I got it right.
Your cam could very well change your timing that much.
I plan on buying the mini starter since is cheap and lifetime warranty
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
oops!
Thread Starter
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
Le Mans Master
Joined: Aug 2008
Posts: 5,578
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From: Austin TX
Racer
Joined: Mar 2013
Posts: 423
Likes: 25
From: Boca Raton Florida
If it was all working fine before the upgrade then it should to be something you changed or touched. Assuming the starter and wiring was not removed then it all should be ok still.
That slight of a compression rise is not even close to being able to cause a hard start. It would be different with a new tight engine with say 12.5-1 or higher compression and lots of timing. Start with the basics….take off the coil wire and see if it still turns over slow….if so then it is NOT timing. Make sure your carb is not bleeding fuel down in the cylinder while sitting after running….it should be dry inside. If no fuel or timing issues then it is electrical for sure…either wiring, starter, or battery.
That slight of a compression rise is not even close to being able to cause a hard start. It would be different with a new tight engine with say 12.5-1 or higher compression and lots of timing. Start with the basics….take off the coil wire and see if it still turns over slow….if so then it is NOT timing. Make sure your carb is not bleeding fuel down in the cylinder while sitting after running….it should be dry inside. If no fuel or timing issues then it is electrical for sure…either wiring, starter, or battery.
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Joe Kucinski
Senior Member since 1492
Joined: Aug 2000
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
just put in a new cam, lifters, timing chain, heads, pushrods, rockers, and headers. Rotating assembly left in tact (pistons, crank, etc.)
Car is a 1981, CCC fully functional and operating the new motor.
From a cold start engine fires up...if engine is warm (say from 30 min of driving)...I shut it off...come back 5 min later...she can barely crank...I had to get the battery charge on it in start mode so i could get it running.
My original compression was 8.5:1...based on my rough math with new iron GM heads, Com cams extreme cam ( CCA-CL12-238-2), and the head gasket....my new compression, I'm around 9.6:1.
I know the battery in my 81 is not the correct one....so what should i get for a battery that can handle the needed "umph" to turn the motor over?
Car is a 1981, CCC fully functional and operating the new motor.
From a cold start engine fires up...if engine is warm (say from 30 min of driving)...I shut it off...come back 5 min later...she can barely crank...I had to get the battery charge on it in start mode so i could get it running.
My original compression was 8.5:1...based on my rough math with new iron GM heads, Com cams extreme cam ( CCA-CL12-238-2), and the head gasket....my new compression, I'm around 9.6:1.
I know the battery in my 81 is not the correct one....so what should i get for a battery that can handle the needed "umph" to turn the motor over?
I have the same problem on my BB
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
just put in a new cam, lifters, timing chain, heads, pushrods, rockers, and headers. Rotating assembly left in tact (pistons, crank, etc.)
Car is a 1981, CCC fully functional and operating the new motor.
From a cold start engine fires up...if engine is warm (say from 30 min of driving)...I shut it off...come back 5 min later...she can barely crank...I had to get the battery charge on it in start mode so i could get it running.
My original compression was 8.5:1...based on my rough math with new iron GM heads, Com cams extreme cam ( CCA-CL12-238-2), and the head gasket....my new compression, I'm around 9.6:1.
I know the battery in my 81 is not the correct one....so what should i get for a battery that can handle the needed "umph" to turn the motor over?
Car is a 1981, CCC fully functional and operating the new motor.
From a cold start engine fires up...if engine is warm (say from 30 min of driving)...I shut it off...come back 5 min later...she can barely crank...I had to get the battery charge on it in start mode so i could get it running.
My original compression was 8.5:1...based on my rough math with new iron GM heads, Com cams extreme cam ( CCA-CL12-238-2), and the head gasket....my new compression, I'm around 9.6:1.
I know the battery in my 81 is not the correct one....so what should i get for a battery that can handle the needed "umph" to turn the motor over?
Very interesting...I have a 78 with AFR heads, the same cam and same compression (9.6:1) and I have the exact same problem as you. Starts fine cold, but barely turns over (if it even will) after it heats up. Originally, I thought it was heat soak on the starter and bought a shield. Unfortunately, it still suffers from it.
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
Very interesting...I have a 78 with AFR heads, the same cam and same compression (9.6:1) and I have the exact same problem as you. Starts fine cold, but barely turns over (if it even will) after it heats up. Originally, I thought it was heat soak on the starter and bought a shield. Unfortunately, it still suffers from it.
oops!
Racer
Joined: May 2013
Posts: 421
Likes: 6
From: Chicago IL
I am wondering more about the cam and compression since those are both the same. Anyone else running the XE262H cam with higher compression and have a starting problem after warming up?
Thread Starter
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
My starter has to be at least 15 years old, its possibly the original...and the Patriot headers actually touch the end of the starter so heat is def transferring to it. My Mini starter arrives today...I may try and tackle it tonight, may not...worst case its going on over the weekend as I am taking to a buddys house with a lift so we can do the front end bushings/springs/shocks, and a new 1 piece oil pan felpro gasket to stop my timing chain cover leak.
I am still going to replace the battery and alternator but AFTER i do the mini starter swap, this way I can keep track of the root cause and fix. Ill post a pic tonight when I get home of what the starter looks like, etc.
I am still going to replace the battery and alternator but AFTER i do the mini starter swap, this way I can keep track of the root cause and fix. Ill post a pic tonight when I get home of what the starter looks like, etc.
Last edited by Brians1; Sep 17, 2014 at 09:16 AM.
Burning Brakes
Joined: Nov 2012
Posts: 788
Likes: 100
From: Indianapolis IN
It definitely sounds like more of a "ground" issue to me than anything else, been there - had that !
While you're at it clean your ground contact points and make sure you have many points included.
Battery to frame , engine to frame, battery to engine, frame and battery to body,engine to body, etc... (before anyone feels the need to correct me -of course not the fiberglass. body/interior - ie. dash)
It makes a difference of an OK flow to an excellent flow, and this shows up during a "hot start" - especially with good compression and a good amount of ignition advance.
While you're at it clean your ground contact points and make sure you have many points included.
Battery to frame , engine to frame, battery to engine, frame and battery to body,engine to body, etc... (before anyone feels the need to correct me -of course not the fiberglass. body/interior - ie. dash)
It makes a difference of an OK flow to an excellent flow, and this shows up during a "hot start" - especially with good compression and a good amount of ignition advance.
Last edited by 68post; Sep 17, 2014 at 10:17 AM. Reason: no ..not really
Thread Starter
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
It definitely sounds like more of a "ground" issue to me than anything else, been there - had that !
While you're at it clean your ground contact points and make sure you have many points included.
Battery to frame , engine to frame, battery to engine, frame and battery to body,engine to body, etc... (before anyone feels the need to correct me -of course not the fiberglass. body/interior - ie. dash)
It makes a difference of an OK flow to an excellent flow, and this shows up during a "hot start" - especially with good compression and a good amount of ignition advance.
While you're at it clean your ground contact points and make sure you have many points included.
Battery to frame , engine to frame, battery to engine, frame and battery to body,engine to body, etc... (before anyone feels the need to correct me -of course not the fiberglass. body/interior - ie. dash)
It makes a difference of an OK flow to an excellent flow, and this shows up during a "hot start" - especially with good compression and a good amount of ignition advance.
Safety Car
Joined: Jan 2009
Posts: 3,736
Likes: 56
From: anchorage ak
My starter has to be at least 15 years old, its possibly the original...and the Patriot headers actually touch the end of the starter so heat is def transferring to it. My Mini starter arrives today...I may try and tackle it tonight, may not...worst case its going on over the weekend as I am taking to a buddys house with a lift so we can do the front end bushings/springs/shocks, and a new 1 piece oil pan felpro gasket to stop my timing chain cover leak.
I am still going to replace the battery and alternator but AFTER i do the mini starter swap, this way I can keep track of the root cause and fix. Ill post a pic tonight when I get home of what the starter looks like, etc.
I am still going to replace the battery and alternator but AFTER i do the mini starter swap, this way I can keep track of the root cause and fix. Ill post a pic tonight when I get home of what the starter looks like, etc.
oops!
Thread Starter
Burning Brakes
Joined: Nov 2013
Posts: 889
Likes: 13
From: Jax/St. Augustine FL
Hey guys - The started got delivered yesterday, and I also took the Vette to my buddies house as well last night, so when I got there I took a few quick shots of the starter. Looks to be of good quality, def smaller, and yes the solenoid was included - not bad for 7- bucks and lifetime warranty.
