Somebody was thinking outside the box.CamKing wrote:................ and even twin fire(firing 2 cylinders at the same time, every 240 degrees).
Ken
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Somebody was thinking outside the box.CamKing wrote:................ and even twin fire(firing 2 cylinders at the same time, every 240 degrees).
Holey torque spikes, CamMan! With what, maybe 900 lb-ft. peak torque spread over only three power strokes every two revolution?CamKing wrote:.. even twin fire(firing 2 cylinders at the same time, every 240 degrees).
It didn't.
They're a bad idea for any racing application.
did they move the cam bearing locations for better support of the cam like the GM BB pro stock block.???CamKing wrote: ↑Wed Sep 27, 2017 11:56 amYep. I ground 100's of those cams.MTENGINES wrote:That is the Stage 2 INDY head and block.
The first Indy Buick Turbo V6's(1984ish), were the standard Stg-2 lifter layout. The blocks would crack in the lifter valley.
In the late 80's they switched to the layout in the photo. Over the years, we made even fire versions, odd fire, and even twin fire(firing 2 cylinders at the same time, every 240 degrees).
They changed the lifter locations, to allow bigger intake ports. I think they also made the block lighter.Ratu wrote: ↑Fri Sep 29, 2017 2:35 pm CamKing writes, "The first Indy Buick Turbo V6's(1984ish), were the standard Stg-2 lifter layout. The blocks would crack in the lifter valley. In the late 80's they switched to the layout in the photo."
So it is a Stage 2 Buick after all, albeit a heavily revised one.
It is interesting because to stop cracking in the valley one could merely add some ribs or a little extra material (or a lot, if you are "conservative" with your analysis and designing), so a fix is known and not super-difficult to do. On the other hand, this is a significant design alteration and represents major change (needs changes to patterns, needs different cam blank, needs different valve-gear, causes a need for re-doing the heads- likely new patterns there, leads on to re-doing manifolds etc. etc. etc.). It's a biggie this. Was it a design change driven by the demands of getting a better breathing cylinder head design or some other reason or reasons?
Can you tell us more about what happened and the story about why they made this alteration? Who were the designers involved?
Nope. Only the lobe locations changed. They did go to needle bearings, and that helped a lot with cam flex.pamotorman wrote: ↑Fri Sep 29, 2017 3:04 pmdid they move the cam bearing locations for better support of the cam like the GM BB pro stock block.???CamKing wrote: ↑Wed Sep 27, 2017 11:56 amYep. I ground 100's of those cams.MTENGINES wrote:That is the Stage 2 INDY head and block.
The first Indy Buick Turbo V6's(1984ish), were the standard Stg-2 lifter layout. The blocks would crack in the lifter valley.
In the late 80's they switched to the layout in the photo. Over the years, we made even fire versions, odd fire, and even twin fire(firing 2 cylinders at the same time, every 240 degrees).
Is ductile iron an option for a casting that large and complex?