Broke a pushrod, looking for advice

[7t500]

Was cruising the other day and broke a pushrod. Noticed the engine felt like it was running on 7 cylinders, lost oil pressure, and then it came back up to normal. When I got home I pulled the valve cover and found a pushrod was thrown.

Initial inspection shows wear marks on the pushrod and I'm willing to bet that the pushrod deflected and was thrown. Now I'm trying to figure out what's next... I'm absolutely ordering new pushrods but am tempted to do cam/lifters to rule out the lifter variable.

Engine specs:
470 stroker (440 source kit)
906 heads - done years ago
-hardened seats
-new valves/springs/retainers
Comp xe268h cam w/ hyd flst tippet lifters
Aluminum 1.6 roller rockers
Edelbrock RPM intake

727 trans
Hughes 2500 stall converter

8 3/4 rear with 2.94 SG.

Honestly, I love the cars highway manners but wouldn't mind more fun around town. My initial plan was to do heads/cam/converter/3.23 gears... however, the daycare expenses are eating into the car fund.

So, do I just do the pushrods? Swing for a cam? Is it even worth doing a cam with the unported 906 heads?

Sorry this got long winded but got a lot to figure out... thanks in advance!

 

[BSB67]

Initial inspection shows wear marks on the pushrod and I'm willing to bet that the pushrod deflected and was thrown.

Throwing a rod usually means a connecting rod.

I doubt the pushrod is at fault. Probably lifter.

 

[slimt]

Or is it a solid lifter ? And did the adjuster back off on the rocker arm? Then the push rod escaped the pocket. Did the push rod bend? Just one, or?

 

[BSB67]

Or is it a solid lifter ? And did the adjuster back off on the rocker arm? Then the push rod escaped the pocket. Did the push rod bend? Just one, or?

This too.

 

[1 Wild R/T]

Threw a rod looks like this....

You had a pushrod pop out.... Big difference..

What sort of rocker arms are you running?

 

[eldubb440]

(20) Blues brothers we've thrown a rod - YouTube

 

[Ironbuilt]

(20) Blues brothers we've thrown a rod - YouTube

 

[67charger383]

Solid Roller!

 

[DGE330/NC]

Threw a rod looks like this....

View attachment 1149988

You had a pushrod pop out.... Big difference..

What sort of rocker arms are you running?

that there is professional grade Throwing a rod !

 

[7t500]

Throwing a rod usually means a connecting rod.

I doubt the pushrod is at fault. Probably lifter.

Good point, ill update the title. I doubt the pushrod itself is at fault either but it is a 3/8 rod and atock 906 heads, which have been known to have clearance issues and I checked it but may not have accounted for enough deflection.

 

[7t500]

Or is it a solid lifter ? And did the adjuster back off on the rocker arm? Then the push rod escaped the pocket. Did the push rod bend? Just one, or?

Hydraulic flat tappet lifters. Adjuster dod not back off. No bend but it snapped the cup off the rocker side of the pushrod.

 

[7t500]

Threw a rod looks like this....

View attachment 1149988

You had a pushrod pop out.... Big difference..

What sort of rocker arms are you running?

I was going to title it lost a pushrod but it wasn't lost per se...

Rockers are adjustable aluminum roller rockers.

 

[7t500]

Solid Roller!
View attachment 1150008

I've contemplated thus but so far have been leaning hyd flat tappet for street use

 

[67charger383]

I've contemplated thus but so far have been leaning hyd flat tappet for street use

QC on new flat tappet lifters just isn't there anymore. They keep failing/breaking. If you do go flat tappet buy NOS lifters from eBay

 

[BSB67]

Hydraulic flat tappet lifters. Adjuster dod not back off. No bend but it snapped the cup off the rocker side of the pushrod.

Wait. Do I understand you correctly; the cup broke off the pushrod? Hmmmmm.

Post pictures of the pushrod, the broken cup, the rocker adjuster and the rocker arm. On which valve and cylinder did this happen?

 

[Photon440]

Back in the day when I used to crank my old 383 to the moon, I'd sometimes experience a sudden misfire. Pop off the valve covers and find a bent pushrod. I'd pull it out, hammer it flat (roll it on something flat to see how straight I could get it) and keep driving it.

 

[1 Wild R/T]

Take a look at the bottom of the rocker arms near the adjuster, see if theres any evidence of the pushrod cup contacting the rocker body instead of just the adjuster... If the pushrod is a little long you'll see the damage you have....

 

[4mulas]

Everyone else will tell you what to do about the valvetrain. My input is that if you’re looking for more. Cam and a street brawler type of deal I’d use minimum 3.5 ish or even 3.7 ish gears. Going from 2.94 to 3.23 is kind of a negligible jump. 3.55 would still allow reasonable highway cruising. 3.73 and above the revs get high at 60 mph…

 

[7t500]

Wait. Do I understand you correctly; the cup broke off the pushrod? Hmmmmm.

Post pictures of the pushrod, the broken cup, the rocker adjuster and the rocker arm. On which valve and cylinder did this happen?

Pics below. This was on the intake of cylinder 5.

 

[7t500]

Take a look at the bottom of the rocker arms near the adjuster, see if theres any evidence of the pushrod cup contacting the rocker body instead of just the adjuster... If the pushrod is a little long you'll see the damage you have....

I dont see any damage near the adjuster on the rocker... it looks like the rocker may have gotten nicked when the pushrod got displaced.