[64speed]

Originally Posted by grivera

What was your oil pressure prior to this issue?

25-30 hot at idle

[64speed]

I would think if the lifter jumped the bore and turned sideways on the cam isn’t there shavings? What about fishing the vanished pushrods out of there?

[64speed]

I will pull the intake and valley pan ASAP and report back

[Holeshot71]

Are the poly locks loose on that cylinder?? If they are it could be the cause of some of the noise you were hearing and the push rods to get tossed.

[GTOLou]

Originally Posted by 64speed

That’s not who I used. Wayne Sless built my engine

Came close to having Wayne do a BBC for a 78 Z28 a year ago. Just worried about part backlogs, etc...went w/ a stroked crate sbc, an outfit out of Kearney NB. Blueprint Engines - I think Frieberger loves them. Was on sale from Summit - my door in like 3-4 days. lol.

Wayne has a nice reputation and even did that video series on poncho motors. Wayne is in Anderson, SC now....I have not used, but would..

[NeighborsComplaint]

OK, you have my head spinning. Back on Page 60 you said "Wayne (your builder) has it ... and you hope to have it back in 3 months." which I assumed meant you pulled the motor already and ran it to his shop. Now you are talking about inspecting and repairing it yourself indicating the motor is still in the car?

Do you know for a fact a pushrod failure caused the damage or what damage has even occurred? You don't know what caused the problem other than than 2 pushrods came out of their cups in the rocker arm body and lifter due to misalignment and the resulting loss of spring tension. You don't know if the rocker arms were simply mis-adjusted causing the pushrods to be launched or if the lifter also came up out of its bores cleanly and simultaneously due to the over-rev and loose rockers. If only one came up and out, the adjacent lifter paired by the link bar typically rotates and can destroy a cam lobe along with the attendant damage to the lifter in pretty short order. Only a partial top end tear-down will verify the outcome and point to the possible cause. Lots of things could have happened from minor to major.

This is just a thought, but fitting BBC rockers on a Pontiac may have shortened the usable length of the slot in the trunnion and limited the travel of the rocker arm. The rockers could wind up being installed in a nose down attitude with standard length Pontiac pushrods in an effort to centerline the tip to valve contact on a Pontiac. This would reduce the valve lift limit similar to running a standard Chevy Small block with "short slot" (low lift) rockers and a high lift cam. The result would be a bent pushrod which typically displaces itself and witness marks on the underside of the trunnion slot from the rocker stud. Your builder in all likelihood checked those clearances but it's something to consider in your investigation.

[NeighborsComplaint]

OK, you have my head spinning. Back on Page 60 you said "Wayne (your builder) has it ... and you hope to have it back in 3 months." which I assumed meant you pulled the motor already and ran it to his shop. Now you are talking about inspecting and repairing it yourself indicating the motor is still in the car?

Do you know for a fact a pushrod failure caused the damage or what damage has even occurred? You don't know what caused the problem other than than 2 pushrods came out of their cups in the rocker arm body and lifter due to misalignment and the resulting loss of spring tension. You don't know if the rocker arms were simply mis-adjusted causing the pushrods to be launched or if lifters came up out of their bores cleanly and simultaneously due to the over-rev and loose rockers or if only one came up and out which typically turns the lifter 90 degrees and destroys a cam lobe along with the attendant damage to the lifter. Only a partial top end tear-down will verify the outcome and point to the possible cause. Lots of things could have happened from minor to major.

This is just a wag on my part but, fitting BBC rockers on a Pontiac may have shortened the usable length of the slot in the trunnion and limited the travel of the rocker arm. The rockers could wind up being installed in a nose down attitude with standard length Pontiac pushrods in an effort to centerline the tip to valve contact on a Pontiac. This would reduce the valve lift limit similar to running a standard Chevy Small block "short slot" (low lift) rocker with a high lift cam. The result would be a bent pushrod which typically displaces itself and witness marks on the underside of the trunnion slot from the rocker stud. Your builder in all likelihood checked those clearances but it's something to consider in your investigation.

[ZeGermanHam]

Originally Posted by NeighborsComplaint

OK, you have my head spinning. Back on Page 60 you said "Wayne (your builder) has it ... and you hope to have it back in 3 months." which I assumed meant you pulled the motor already and ran it to his shop. Now you are talking about inspecting and repairing it yourself indicating the motor is still in the car?

Reading the comments on page 60 in context, when he said "Wayne has it", it was in reference to the previous comment about the engine build sheet, not the engine itself. I agree with your other comments, and am very curious to learn what caused it. Time will tell!

[64speed]

Wayne has the build sheet and pushrod specs. Not the engine. I will post pics when I open it up for the big reveal.

[P@blo]

Just curious but should you not have a copy of the build sheet when you paid him?

[64speed]

Originally Posted by P@blo

Just curious but should you not have a copy of the build sheet when you paid him?

Wayne is my go to and my filing cabinet

[64speed]

Well it is with great sadness that I report the block is junk. Here’s you some pics

[tom s]

WOW,catastrophic!

[ZeGermanHam]

Ugh, I'm really sorry to see this news, David.

What are you holding in the first photo? Curious to hear what people thing might have caused it.

[gtospieg]

first pic looks like a busted pushrod....

[64speed]

Busted pushrod, broke totally in half

[64speed]

To be honest I think I’m less upset than my wife. I set myself behind a long time and honestly I am out of money so it will be a LONG time but I am not Joe Biden. I will Build Back Better ��

[grivera]

Damn Dave - sorry to see this. Hopefully you can source a block and get back in the game by spring. Also curious if the BB Chevy rockers contributed to the pushrods coming loose.

[64speed]

I wish my rotating assembly wasn’t based on big journal cause I know where a 400 is but no 455s here

[Skip Fix]

In looking for a higher ratio rocker years ago(1.75-1.8) I checked about every other engine family . A BBC rocker is roughly 0.120 longer stud to roller tip center than ANY Pontiac rocker. Comp's SS BBF are their BBC with a 0.045 offset trunnion to shorten the distance. Crower has a BBC with a 0.090 offset I used WITH a lash cap and a 0.200 shorter pushrod. It took that to get a decent pattern.