[HWYSTR455]

Butler recommended the BBC rockers?

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[64speed]

No they provided the pushrod length necessary. I was overloaded with information I didn’t understand yesterday but basically this is my 2nd go round with this. My Pontiac rockers just never made the grade with these heads but the BBC make the grade perfectly

[HWYSTR455]

Originally Posted by 64speed

No they provided the pushrod length necessary. I was overloaded with information I didn’t understand yesterday but basically this is my 2nd go round with this. My Pontiac rockers just never made the grade with these heads but the BBC make the grade perfectly

So you gave Butler the length your builder provided and they shipped you the pushrods requested.

You should ask them about using BBC rockers, see what they say.

Bookmark this thread for future reference.

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[NeighborsComplaint]

Originally Posted by HWYSTR455

So you gave Butler the length your builder provided and they shipped you the pushrods requested.

You should ask them about using BBC rockers, see what they say.

Bookmark this thread for future reference.

.

Already called it after the first motor broke. It's the rockers.

Interesting tidbit ... assume for the moment the OP was running the Lunati 712 cam in the ill-fated motor. With 1.7 ratio rockers his lifts were .606"/.623" (I/E). If the rockers were 1.8 ratio, .642"/.660" (I/E). If the cam was the 713 , then .634"/.640" (I/E) w. 1.7 rockers and .671".678" (I/E) w. 1.8 rockers.

[1968GTO421]

Originally Posted by NeighborsComplaint

Already called it after the first motor broke. It's the rockers.

Interesting tidbit ... assume for the moment the OP was running the Lunati 712 cam in the ill-fated motor. With 1.7 ratio rockers his lifts were .606"/.623" (I/E). If the rockers were 1.8 ratio, .642"/.660" (I/E). If the cam was the 713 , then .634"/.640" (I/E) w. 1.7 rockers and .671".678" (I/E) w. 1.8 rockers.

Good point, however I believe this time 64speed is using the 041 cam with .470" lift (with 1.5 rockers). With 1.7 rockers lift would be around .533". Many cams have that lift with 1.5 rockers so I think this time he might be OK with those rockers. But I would not go that route. I would investigate the problem Gach mentions in post #1491. I believe Pontiac engineeers knew the limits of their block and didn't exceed the 1.65 ratio rockers. FWIW

[grivera]

Dave - did the builder have Pontic Crower SS on hand as well or just the BB SS Crowers?

[64speed]

Yes he had a few different brands. Caster1 had the same problem with his engine

[Gach]

The only thing that I can think of there’s a distinct possibility The stud placement on those heads are a little off compared to standard placement. Enough so the BBC rocker work perfectly.

I’ve kind of run into this situation before.

[64speed]

They work and I have good geometry, no problems on the test stand

[Gach]

Originally Posted by 64speed

They work and I have good geometry, no problems on the test stand

I believe it, and don’t think it had anything to do with the original failure. Like I said I’ve run into this situation before.

[64speed]

Originally Posted by Gach

I believe it, and don’t think it had anything to do with the original failure. Like I said I’ve run into this situation before.

Wayne said that it had happened on mine and Tommys engage but obviously he had never experienced it with factory parts.

[tom s]

FYI,in 1963 pontiac offered 1.75 rockers for it 421 SD heads!I have a half set of NOS ones.Tom

[Gach]

If the geometry is correct, lift not going to matter. As long as the duration doesn’t exceed 200 at .200 lift thats when the issue manifests itself. I doubt his hydraulic roller was.

Here’s what I did fine to be a issue, I’ve found 2 blocks that the lifter bores had hair line crack. Remember certain lifter bore are attached to the block like a cup handle. 2 and #6. I think #2 let go on his block.

[64speed]

Yes it was #2

[64speed]

Back on the road. For some reason the hydroboost seems a little spongier than it was before but maybe it’s just my mind playing tricks on me

[400 Lemans]

Good job.

[64speed]

The filter adapter got dropped in the install and now its cracked. I am gonna have to get another so I am not gonna make the car show

[NeighborsComplaint]

Originally Posted by 64speed

The filter adapter got dropped in the install and now its cracked. I am gonna have to get another so I am not gonna make the car show

JB Weld. Don't worry about how it looks,

[JSchmitz]

Originally Posted by NeighborsComplaint

JB Weld. Don't worry about how it looks,

No and no.

[Gach]

Here’s a crazy story about J&B Weld don’t laugh…LOL you know how the stock blocks have that loop casted in the back you know were bell housing bolts up. By The distributor. You can hook up a motor puller, to yank the motor out. on Opposite side of the distributor.

Well he dropped the block and it broke off, so for aesthetic reasons only I took J&B Weld and put it back on, so when I got motor done I told him twice DON’T hook the motor puller to that loop. Absolutely DON’T even made a note and taped it to the block.

Later I stop over to see the progress and guess what the chain and hook was hooked up the loop…he had just set the motor in car. I’m like holy CHIT !

I had run the motor and broke it in on my engine stand. Oh it gets even better, later that day he calls flipping out and says this motor is knocking!! So I go there fire it up and sure enough it’s rattling !! I ended up pulling intake and head off on passenger side, guess what I found ? A broken intake bolt, his buddy standing there and says, oh that’s were the missing intake bolt went.

This is really weird I only found a partial bolt, the head was missing, so just a precaution I pulled driver side head off, there was the head of the bolt. LOL luckily it did not damage to the head of valves. I’m guessing that it broke and sucked it from one side to the other. Still puzzled me to this day, but the motor been in Service for like 5 years with no issues. Crazy !