***Buick 350 Alum Heads Update***

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Compression ratio would be almost identical. They are only a few cc smaller. The 10:1 engines are actually only about 9.5:1 if you measure them. Stock rockers or rollers?

 

Question:
The "loaded heads" ... how are they configured? is that the standard shaft and factory rockers? or the HD shaft and roller rockers?

 

The complete ready to run heads would not include any rockers. I can’t see many people using stock style rockers on these heads, rollers would be the way to go. Spending all that money and not being able to adjust the lifter pre load? Adjustable pushrods are a bandaid I guess.

 

i would. purely so i could recover from the cost of the heads, if need be.

 

I have always run the adjustable pushrods with no issues with stock rockers.

 

I think stock rockers are an affordable option on a less aggressive build. Since the valve is moved out slightly, contact of roller rockers need to be corrected .

 

It will be interesting to see if piston valve reliefs are needed.

 

Actually correcting the contact of the rocker is up to the end user. We put 50 dyno pulls on the pictured rockers. The exhaust rockers on the wagon have been that way since the early 1990's, 750lbs open, 900 today, same set of rockers . It really doesn't present a problem, looks worse than it is. They work because there shaft mounted, everything stays square to each other. Contact with 3/4 of valve diameter, ok, only half, I'd would move it. The stock rockers fit nicely, the rocker pad is wide enough, there good for up to .550" lift. After that you may experience wear.

 

My pistons were notched for the iron heads, but with the aluminum as far as we can tell they didn't need to be notched or it would be very minimal.

 

A lot of it depends on the camshaft too. A cam like this would need reliefs for sure.

 

.700 + lift cam...…… what are ya going to do with that.....catch flies.
"oh, I got a big cam in my engine....but no....I don't race it. it's just there to say I got a big cam in it."

you know you can go 9.00 in the 1/4 with 400 h/p and you can go 9.00 with 600 h/p. how you get there matters.
i'm not a keyboard racer...……...

 

Great to know stock rockers work. What about pushrods? Stock? Or different?

 

Also... Stock rockers good to .550 lift? .550 lobe lift or after the ratio is figured in? I assume after.

 

Nice. Was thinking a crower 4, or a ta near its specs once I get my short block together. Nice to know i can use stock rockers.

 

I would warrant aftermarket rockers if.... using high valve spring pressures and high RPM

 

My cam is bigger than yours

 

But I am the only one that ran a 576 lift and a 255-265 duration @50 cam in a street car.