[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.

[Stan Weiss]

Originally Posted by BruceWilkie

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.

Bruce,
What has the Pontiac bore spacing got to do with producing 2.7 HP per ci? It has been done with smaller bore spacing, just look at Australian Pro Stock.

Stan

[BruceWilkie]

Originally Posted by Stan Weiss

Bruce,
What has the Pontiac bore spacing got to do with producing 2.7 HP per ci? It has been done with smaller bore spacing, just look at Australian Pro Stock.

Stan

Ask any of them if they would like to give up bore space for stroke at whatever ci limit they run...

Bore space dictates bore size, which dictates valve size, which = potential flow capability, which = HP potential.