...

Go Back   Lateral-g Forums > Technical Discussions > Engine
User Name
Password



Reply
 
Thread Tools Display Modes
  #1  
Old 04-23-2015, 11:57 AM
Decline Decline is offline
Member
 
Join Date: Mar 2014
Posts: 56
Thanks: 0
Thanked 0 Times in 0 Posts
Default 2 Bent Pushrods in 350 SBC

1969 camaro with non orignal 350 SBC with iron heads a mild edlebrock flat tappet cam, crane stamped roller rockers and mystery valves, springs, push rods all done by previous owner..But it does have all ARP hardware so thats a plus

I heard some clacking under the hood. Car had been idling funny yesterday afternoon. I thought maybe my recently changed timing was causing pinging?
Pop'd the hood..Distinct metal chatter from valve cover..Opend to find the rearmost rockers all twisted. Further inspection revealed 2 bent push rods.

Question, what else should I inspect for damage? One of the valve ends is messed up a little/flattened and put some wear marks on the roller tip. I would have to remove the head to change it obviously? Can i get away with just replacing the 2 push rods and reseting the valve lash to get back up and running?

I feel like that should be fine for now until I decide wither to change the heads out for aluminum or just swap an LH6 5.3 aluminum truck motor in there. Ive had my eye on one on craiglist for $750 with no accesories. Prbly run it carbed innitially for $ reasons
Attached Images
  
Reply With Quote
  #2  
Old 04-23-2015, 12:36 PM
Sieg's Avatar
Sieg Sieg is offline
Moderator
 
Join Date: Dec 2010
Location: Pacific Northwet
Posts: 8,034
Thanks: 33
Thanked 99 Times in 41 Posts
Default

First thing you need is compression, as in no bent valves.

I'd want to know why it happened before going any further.
Reply With Quote
  #3  
Old 04-23-2015, 01:25 PM
Decline Decline is offline
Member
 
Join Date: Mar 2014
Posts: 56
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I can do a compression test on it to see if the valve is damaged on more than just the top..
My assumption is that rockers were loose and got out of alignment with the pushrods.
Does anyone else have any theories on what causes this?
Another friend of mine recomended taking a look at the lifters as well to see if there s damage..
I really wanted to avoid taking the engine apart
Reply With Quote
  #4  
Old 04-23-2015, 02:58 PM
GregWeld's Avatar
GregWeld GregWeld is offline
Lateral-g Supporting Member
 
Join Date: Jul 2005
Location: Scottsdale, AriDzona
Posts: 20,741
Thanks: 504
Thanked 1,080 Times in 388 Posts
Default

You may be able to get away with a "lash cap" on the messed up valve. But then this push rod length would need to be adjusted due to the now "longer" valve stem.


Now then. - this didn't just bend like that as you were casually driving down the road. My guess is you experience a severe backfire or you were getting after it pretty good.

My question would be: what was the timing? Why did you decide to adjust it? And what did you adjust it to? And did you adjust and or check the TOTAL timing?? And what was that number?
Reply With Quote
  #5  
Old 04-23-2015, 05:27 PM
Decline Decline is offline
Member
 
Join Date: Mar 2014
Posts: 56
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by GregWeld View Post
You may be able to get away with a "lash cap" on the messed up valve. But then this push rod length would need to be adjusted due to the now "longer" valve stem.

Never heard of a lash cap..i will look into it. This could be a possible band aid along with an adjustable pushrood[/COLOR]

Now then. - this didn't just bend like that as you were casually driving down the road. My guess is you experience a severe backfire or you were getting after it pretty good.

It happened as i was leaving work. I went a few blocks and heard the rattleing/clanking, so i turned around and came back. I thought it was just mis firing. A couple hours prior to that my buddy and I were in the parking lot attempting to check the timing again cuz the car seemed to be running rich and smoking covering my rear bumper with a thin film of black soot. The idle wouldn't settle down enough to check base timing..I rev'd it a few times at the carburator to try and get it settle. I heard some pings or pops during that time also.

My question would be: what was the timing? Why did you decide to adjust it? And what did you adjust it to? And did you adjust and or check the TOTAL timing?? And what was that number?


My engine has never really run right since after I got my suspension installed a few months ago. I've tried various fixes.
It is an AME front clip so the motor had to come out.
My old headers were "massaged" to fit which meant the shop beat one the tubes about 2/3rds closed..So I got the AME headers to clear control arms. That seemed to work for a while..
Performance was still spotty so I got new plugs and wires.. Was better.
Then it occured to me to check the timing..Well the distributor was loose so i thought id found my culprit.. I bought a timing gun watched a few youtube videos and set my initial timing to 12degrees, then i set my total timing to 36 degrees-ish.. I say "ish" because I had no tach to reference engine rpm so i manually rev'd it to what i figured was between 2500-3000..
It was actually running pretty good like that and i did the Del Mar good guys autoX a few weeks ago. Other than my high idle and crap gas mileage(10-12 down from 15-18) I thought i was in decent shape, just thought the carb needed tuning..
Reply With Quote
  #6  
Old 04-23-2015, 09:26 PM
Che70velle's Avatar
Che70velle Che70velle is offline
Senior Member
 
Join Date: Aug 2012
Location: Dawsonville Georgia
Posts: 2,248
Thanks: 641
Thanked 175 Times in 119 Posts
Default

Solid or hydraulic cam? Do you know how to check and set valve lash?
__________________
Scott
---------------------------------------------------------------
70 velle' on custom chassis w/custom RideTech coilovers, RED sleeved 434” with Mamo 265’s, F-body Magnum, 12 bolt 3:73, wilwood 6/4's, bla, bla, bla...build. thread https://lateral-g.net/forums/showthread.php4?t=39631
New 434” engine build here https://ls1tech.com/forums/generatio...ved-block.html

Thanks Dad!!

My Chevelle is old school... It has a belt driven power steering pump.
They're 17's, but I keep em clean!
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -5. The time now is 09:14 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright Lateral-g.net