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Buick V-6 with weird lifter spacing

Posted: Sun Sep 24, 2017 5:31 pm
by Ratu
Here is a picture of the valley of a V-6 engine. I understand this is a Buick V-6 Stage 2 engine and has 90-degrees between the cylinder banks. I am unsure of a particular detail. If you look at the lifter bores, they are paired and do not alternate as in a conventional US push-rod engine. What I mean by this is that normally the lifter bores alternate Left/Right/Left/Right etc along the cam. These ones do not do that. They go Left/Left/Right/Right etc all the way along the cam instead. I can see that would allow room for big inlet ports, although it would require off-set rockers to run. I assumed this picture is of a Buick Stage 2 V-6 until I saw some other pictures of the Buick V-6, also labelled as Stage 2, which all featured the conventional lifter bore layout. Now I am confused. What is the story here? Was this a development of the Buick and if so where does it fit in the scheme of things Buick V-6?

Thanks

Ratu

P.S. And just to make things even a bit more interesting still, it appears the 60-degree V-6 engine of GM has the lifter bores laid out in the unconventional manner (L/L/R/R etc). That one has an interesting looking cylinder head! But it is not the same engine as the one in the picture I've attached, so far as I can tell. I am certain the cylinder bank angles are different.

Re: Buick V-6 with weird lifter spacing

Posted: Sun Sep 24, 2017 6:15 pm
by peejay
The Stage 2 is a racing engine development of the 231 V6. Toughest Buick block ever, too.

Odd thing: The pictures I have of Stage 2 blocks have the normal Buick cam layout. Given that those heads look like nothing I've ever seen before in the turbo Buick world, I am wondering if that isn't a Busch Grand National engine. Pushing the lobes together like that makes a lot of room for a big straight intake port, doesn't it?

Re: Buick V-6 with weird lifter spacing

Posted: Sun Sep 24, 2017 7:07 pm
by ijames
All of the stage I and II block pictures at www.gnttpe.org show the stock alternating lifter layout. The original stage II heads used rectangular intake ports but they developed a head for the Indy cars with big square intake ports (I think to make the head a little shorter for better aerodynamics; I've read that they don't flow any better and maybe worse) so that could be an Indy head but I don't know what the block is. Oh, it's not a TA Performance block because it doesn't have the lifter valley braces that that block has.

Re: Buick V-6 with weird lifter spacing

Posted: Sun Sep 24, 2017 8:51 pm
by The Radius Kid
That could be after market.It doesn't look like any BMS Stage 2 block I ever saw....and I own an on center Stage 2 bock.Can you get some pics of either side and the faces around where the bell housing bolts up?That might help a bit.

Re: Buick V-6 with weird lifter spacing

Posted: Sun Sep 24, 2017 10:15 pm
by peejay
Does it have a deep skirt like practically all Buicks, or are the oil pan rails up at the crank centerline?

Once, I saw a Buick V6 block that had the oil pan rails up high, like no other Buick that I'd ever seen. I couldn't tell you what the cam lobe order was because I was fixated on how weird the skirts looked and this was many years ago. My assumption was that it was an Indy block and was designed for a dry sump and some sort of funky structural oil pan arrangement.

More telltale that is probably not a NASCAR unit: Those appear to be roller lifters...

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 4:37 am
by grandsport51

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 5:59 am
by grandsport51

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 9:01 am
by Walter R. Malik
The photo sure looks like a competition GM 3.4L 60 degree V6 engine to me.

Maybe not though.

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 10:41 am
by DaveMcLain
That's interesting. It looks like it was done to get more room for the intake ports. I bet that makes the cam core expensive.

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 1:49 pm
by Ratu
I don't have any other pictures of this engine at the moment. I'll go look.

Meanwhile, it does look to be at 90-degrees, but if it was a 60-degrees engine (assume it was for a moment), if that is the case what heads are we seeing here?

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 2:41 pm
by user-17438
That is the Stage 2 INDY head and block.

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 4:35 pm
by The Radius Kid
MTENGINES wrote:That is the Stage 2 INDY head and block.
That being the case,it looks like Buick made some changes to the block for higher rpm longevity.
I do remember they had a one inch lower deck height than the standard Buick V6 for "packaging reasons".

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 5:13 pm
by Walter R. Malik
Ratu wrote:I don't have any other pictures of this engine at the moment. I'll go look.

Meanwhile, it does look to be at 90-degrees, but if it was a 60-degrees engine (assume it was for a moment), if that is the case what heads are we seeing here?
I guess I should have explained myself better ... It LOOKS like a 60 degree V6 GM engine does but, judging by the lifter angle it IS probably in the 90 degree engine family... (or even the special 80 degree bank angle that some Indy engines were).

Re: Buick V-6 with weird lifter spacing

Posted: Mon Sep 25, 2017 9:14 pm
by peejay
Walter R. Malik wrote:
Ratu wrote:I don't have any other pictures of this engine at the moment. I'll go look.

Meanwhile, it does look to be at 90-degrees, but if it was a 60-degrees engine (assume it was for a moment), if that is the case what heads are we seeing here?
I guess I should have explained myself better ... It LOOKS like a 60 degree V6 GM engine does but, judging by the lifter angle it IS probably in the 90 degree engine family... (or even the special 80 degree bank angle that some Indy engines were).
Looks nothing at all like the 60 degree engine!

Besides the bank angle being far too wide (there is maybe 2-3" between the heads in a 60deg), the pushrods are on the far side of the intake manifold flange. You can remove the intakes without removing the pushrods but you have to remove the pushrods to get the gasket out and in.

Re: Buick V-6 with weird lifter spacing

Posted: Wed Sep 27, 2017 11:56 am
by CamKing
MTENGINES wrote:That is the Stage 2 INDY head and block.
Yep. I ground 100's of those cams.
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).