[Scott Roberts]

Originally Posted by Pont428

He definitely will eat that one JC. They will do push rod in first to see what power it makes. Air is Air, it doesnt know what RPM the engine is. Why dont we just wait and see? I remember when everyone said a 4.5 bore wasnt possible, and here you are JC! Lynn is doing close to 4.6 bore for me.

1) You guys are hell bent on me eatting something...weird..

2) I hope it doesnt have this kind of angularity on the push rods.. see pic below

3) Whole lot more to it then that...

4) I said that in my last post but everyone is still acting butt hurt and insisting I will be eating something still. See bold statement #1.

5) I wish both you and J.C. the best on your combos. I hope they perform as expected.

[Stan Weiss]

Originally Posted by Scott Roberts

1) You guys are hell bent on me eatting something...weird..

2) I hope it doesnt have this kind of angularity on the push rods.. see pic below

3) Whole lot more to it then that...

4) I said that in my last post but everyone is still acting butt hurt and insisting I will be eating something still. See bold statement #1.

5) I wish both you and J.C. the best on your combos. I hope they perform as expected.

Scott,
That only shows why in one of these thread I ask about how much the lifter bores could be moved and J.C. answered. But do not remember how much they were moved.

Stan

[BruceWilkie]

Originally Posted by Stan Weiss

Scott,
That only shows why in one of these thread I ask about how much the lifter bores could be moved and J.C. answered. But do not remember how much they were moved.

Stan

I'm guesstimating that intake pushrod is off center approx 1.25" .... To straighten that out means move the intake lifter bore centers the same amount... offsetting the lifter cup plays havoc on the roller and Crower told me beyond .150" is not a good idea...they dont like any offset whenever possible. The exhaust is also offset in that pic just not highlighted it isnt as severe. So your definately talking major block changes and a new cam core to run the big port at very high rpm reliably.

[J.C.you]

Originally Posted by BruceWilkie

I'm guesstimating that intake pushrod is off center approx 1.25" .... To straighten that out means move the intake lifter bore centers the same amount... offsetting the lifter cup plays havoc on the roller and Crower told me beyond .150" is not a good idea...they dont like any offset whenever possible. The exhaust is also offset in that pic just not highlighted it isnt as severe. So your definately talking major block changes and a new cam core to run the big port at very high rpm reliably.

Bruce, the port is close to 4.6 csa now with no mods to the lifter bore other than the liners. For a small cube motor such as the 445 I mentioned to achieve the target rpm of 10k before choke we would only need a port with approx. 4 csa. Definitely a smaller/narrower port and less, if any angle needed after moving the lifter bores and camshaft lobes. I believe there is enough meat in the existing IA block to get there.

[BruceWilkie]

Originally Posted by J.C.you

Bruce, the port is close to 4.6 csa now with no mods to the lifter bore other than the liners. For a small cube motor such as the 445 I mentioned to achieve the target rpm of 10k before choke we would only need a port with approx. 4 csa. Definitely a smaller/narrower port and less, if any angle needed after moving the lifter bores and camshaft lobes. I believe there is enough meat in the existing IA block to get there.

IMO it would be best to only have one arc of travel to the pushrod vs the radial arc that occurs with a fore or aft offset...

This lifter movin and such would best be accomplished with a casting revision that allowed choices in lifter bore location and angles.
Orderable un-drilled, custom drilled or standard drilled.

Custom cam cores are pricey enough let alone if you end up with a lifter position that would require welding new boss locations. A revision to the casting is a one time change and it would still be usable for standard lifter locations.

[J.C.you]

Originally Posted by BruceWilkie

IMO it would be best to only have one arc of travel to the pushrod vs the radial arc that occurs with a fore or aft offset...

This lifter movin and such would best be accomplished with a casting revision that allowed choices in lifter bore location and angles.
Orderable un-drilled, custom drilled or standard drilled.

Custom cam cores are pricey enough let alone if you end up with a lifter position that would require welding new boss locations. A revision to the casting is a one time change and it would still be usable for standard lifter locations.

Bruce, we better stay in front of the keyboard if we want to start a budget build 2.3 motor. That is as classy as I could squander.

[BruceWilkie]

Originally Posted by J.C.you

Bruce, we better stay in front of the keyboard if we want to start a budget build 2.3 motor. That is as classy as I could squander.

One works with what is available to work with... just pointin out a that a block revision that eases lifter bore location changes, opens the door in a way that allows resources to be better utilzed elsewhere. If you know goin in you have greater latitude in lifter placement than you previously had you can focus more on taking advantage of that vs trying to come up with a work-around.

In the quest to meet or beat current pro stock levels it may take another generation head design... Maybe on someones scribble pad because current blocks make it extemely difficult... impractical budget wise often sends Pontiac folks to the other brand... Not just little guy bracket racers... Make it easier for the guy with the scribblings on a notepad and that might encourage him to continue on an untried but promising path.

We WONT hit 2.7 per or anything greater without thinking forward. Bore spacing, cam tunnel placement, cam tunnel bore capability, and lifter bore spacing can lock us out of opportunities if we dont make revisions to the foundation that eases changes elsewhere.

We already seem locked to bore spacing... maybe a bit more deck width could be useful??? Room for other improvements/options in the deck??? Perhaps the cam tunnel can be revised for greater options??? Perhaps options in the mains area??? I already discussed the merit of easing lifter bore spacing and angle changes. Perhaps its time for an IA3 or MR2??? I think a lot of changes could be made to allow greater options and still be able to stay with all traditional pieces if one wants or needs to.