Re: Buick V-6 with weird lifter spacing
Posted: Thu Sep 28, 2017 9:49 pm
Somebody was thinking outside the box.CamKing wrote:................ and even twin fire(firing 2 cylinders at the same time, every 240 degrees).
Ken
Ken
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Buick V-6 with weird lifter spacing
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Ken
Re: Buick V-6 with weird lifter spacing
Posted: Thu Sep 28, 2017 9:56 pm
I am curious about how well that worked... Making a V6 run like that is absolutely trivial with an overhead cam engine, and I wonder how well that would work for those of us who run with heavy traction-limited situations.
Re: Buick V-6 with weird lifter spacing
Posted: Thu Sep 28, 2017 11:16 pm
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).
As I understand it, the concept emerged from the decades-long dominance from the fifties on by Harley-Davidson V twins over the competitor's even-firing parallel twins in Flat Track racing. It later spread to Moto GP in the form of various 'Big Bang' arrangements in 4 cylinder bikes. There are several theories as to exactly how it works, but it seems to be something to do with improved control due to the tire ceasing to side-slip between the torque pulses that overcome the lateral traction at the limit.
I always wondered what twin fire would do in a WoO Sprint car... (probably rip the crank out of the block in one lap!)
Re: Buick V-6 with weird lifter spacing
Posted: Fri Sep 29, 2017 11:42 am
It didn't.
I told them it wouldn't work, but they wanted to waste their money, so I took it.
they figured it would make the same power, but at a lower RPM, but that's not how engines work.
Even though it was firing 2 cylinders at once, it still took 2 revolutions to fire all 6 cylinders, so the mass passing thru the engine would be the same at each RPM.
All it did was run extremely rough, and and make the plenum chamber act twice as small.
Re: Buick V-6 with weird lifter spacing
Posted: Fri Sep 29, 2017 11:46 am
They're a bad idea for any racing application.
A twin fire WoO engine would turn the engine into a 410", 4-valve, 4-cylinder. I'll take the V-8.
Re: Buick V-6 with weird lifter spacing
Posted: Fri Sep 29, 2017 1:45 pm
twin fire ,they were called "twingles" was done way back in the ford flat head days. gary balough ran a 427 chevy at the 1 mile dirt modified race in NY but the vibration kept cracking the welds in the oil pan.
Re: Buick V-6 with weird lifter spacing
Posted: 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?
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?
Re: Buick V-6 with weird lifter spacing
Posted: Fri Sep 29, 2017 3:04 pm
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).
Re: Buick V-6 with weird lifter spacing
Posted: Sat Sep 30, 2017 12:44 pm
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?
The changes were done by Buick Racing. Buick poured a krap load of money into the project. The main 2 engine builders working on the Buicks back then, were Fisher Engineering, and McLaren Engineering. Later on, you had Brayton Engineering and Menard.
Re: Buick V-6 with weird lifter spacing
Posted: Sat Sep 30, 2017 12:46 pm
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).
Re: Buick V-6 with weird lifter spacing
Posted: Mon Oct 02, 2017 1:03 am
Thanks CamKing.
I think I may have found another cylinder block with a similar lifter bore arrangement. This is a NASCAR cylinder block for Chevrolet, cast in the United Kingdom...
I think I may have found another cylinder block with a similar lifter bore arrangement. This is a NASCAR cylinder block for Chevrolet, cast in the United Kingdom...
Re: Buick V-6 with weird lifter spacing
Posted: Mon Sep 14, 2020 1:30 am
Another old thread...............
Was the English cast block made out of CGI or was it ductile iron?
pdq67
Was the English cast block made out of CGI or was it ductile iron?
pdq67
Re: Buick V-6 with weird lifter spacing
Posted: Tue Sep 15, 2020 2:58 pm
Is ductile iron an option for a casting that large and complex?
I thought we got CGI blocks because that's as good as it gets with today's metallurgy when the casting is big and detailed. It's not as good as "ductile" but it's actually possible to cast a block with CGI.