F1 V6 90 degree vibration questions

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Piscine
Piscine
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Joined: Tue Sep 27, 2022 6:11 pm

Re: F1 V6 90 degree vibration questions

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This is timely as I recently completed a non-stock rebuild of a 90 degree V6 Maserati engine as was placed in the SM and Merak. Mine is a late Merak SS variant I stroked by offset grinding the crankshaft, custom (lighter) rods, altering the piston pin location and compression with more custom pistons resulting in a displacement of 3.3L. Lots of weight removed from all rotating components yet still they are rough at lower rpm, but are fabulous in peak operating ranges. With the cams and compression this engine prefers to live at 4000-8000. No vibration once it’s revved out. It hates idling, this is the nature of these. My only gripe is, compared to say a twin plug 2.8L 911 engine, the 90 degree v6, until it’s revved high, does not rev as quickly nor with that same urgency as the 911 engine twin plug race motor does pretty much everywhere. Likely due to the Maserati crankshaft weighing a good bit more? It weighed some 40lbs even after lightening while the 911 crank was about 31lbs.

Note Maserati’s new MC20 engine is 90 degree and 3 pin odd fire crank as well I believe. There have been several successful variants of the 90 degree v6 on racing in the past as well.

This same Maserati 3L engine was run at Lemans in 73-75 by the Ligier team, who won its class and placed 8th overall in 74. A 4v variant was made as well which, in final iteration, made some 420bhp at 10,500rpm. The 2v variants in race trim made about 100bhp less and obviously did not rev as high. The most well-known 90 degree racing v6 might be the Cosworth 6r4 engine which has identical bore and stroke and crankshaft pin and main journal sizes as the Maserati engine and crank. In group B, the Cosworth dominated and earned its legendary status.


More on the origins of the Maser engine for those who might be interested. The Maserati engine is also a 3 pin throw with odd fire like the Buick. Buick indeed made later modifications such as splitting the pins and adding a counter balance shaft at the center just above the crankshaft. The later Buick engines with counter shaft and split pins are indestructible.

Maserati actually built their v6 in this configuration entirely on purpose. Some have conjectured it was due to Maserati needing to cut costs this just knocking 2 cylinders off their v8. Nothing can be further from the truth as the block casting and central Jack shaft design driving the camshafts via inboard timing chains was every bit as involved and expensive to develop as would a 60 degree v6 have been. Maserati needed the low profile yet short engine design a 90 degree benefits from to fit the SM hoodline, which a 60 degree would not have accomplished.

Tommy Cookers
Tommy Cookers
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Joined: Fri Feb 17, 2012 3:55 pm

Re: F1 V6 90 degree vibration questions

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Piscine wrote:
Tue Sep 27, 2022 6:46 pm
This is timely as I recently completed a non-stock rebuild of a 90 degree V6 Maserati engine as was placed in the SM and Merak...
Maserati actually built their v6 in this configuration entirely on purpose. Some have conjectured it was due to Maserati needing to cut costs this just knocking 2 cylinders off their v8. Nothing can be further from the truth as the block casting and central Jack shaft design driving the camshafts via inboard timing chains was every bit as involved and expensive to develop as would a 60 degree v6 have been. Maserati needed the low profile yet short engine design a 90 degree benefits from to fit the SM hoodline, which a 60 degree would not have accomplished.
I believe their underemployed '90 deg V8' transfer machinery was a factor in choosing the 90 deg V6 ....
much better for delivery and for cost .....
if the bore centres of the 2 engines are the same that could be seen as confirmation


... eg as soon as Buick saw how poor was the producability and serviceability of their 215 all-aluminium V8 ....
they designed in 90 days the all-iron 198 V6 ....
it was in quantity production 8 months later - sharing at no cost the (215 V8) transfer line and tooling
for 3 years
because the 198 was designed to have the same bore centres as the 215 (and a lot else)

the Pontiac Tempest also used the 215 - and Pontiac didn't like it
similarly they introduced a successful 'cheap-and-cheerful' iron engine on their 389 V8 transfer line & tooling .....
the 195 slant-4 - 'half-a-V8'
(the Tempest notoriously had a 'skipping rope' constrained propshaft for its united engine and rear transaxle assembly)

Ford Germany and Ford UK made many 60 deg V4s using their 60 deg V6 tooling etc
why else would a 60 deg V4 have been chosen ?

simply - the defence of the 90 deg (3 throw) V6 is that a 60 deg 3 throw V6 is all-round worse

Honda Porsche fan
Honda Porsche fan
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Joined: Fri Sep 16, 2022 4:44 am

Re: F1 V6 90 degree vibration questions

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Piscine wrote:
Tue Sep 27, 2022 6:46 pm
This is timely as I recently completed a non-stock rebuild of a 90 degree V6 Maserati engine as was placed in the SM and Merak. Mine is a late Merak SS variant I stroked by offset grinding the crankshaft, custom (lighter) rods, altering the piston pin location and compression with more custom pistons resulting in a displacement of 3.3L. Lots of weight removed from all rotating components yet still they are rough at lower rpm, but are fabulous in peak operating ranges. With the cams and compression this engine prefers to live at 4000-8000. No vibration once it’s revved out. It hates idling, this is the nature of these. My only gripe is, compared to say a twin plug 2.8L 911 engine, the 90 degree v6, until it’s revved high, does not rev as quickly nor with that same urgency as the 911 engine twin plug race motor does pretty much everywhere. Likely due to the Maserati crankshaft weighing a good bit more? It weighed some 40lbs even after lightening while the 911 crank was about 31lbs.

Note Maserati’s new MC20 engine is 90 degree and 3 pin odd fire crank as well I believe. There have been several successful variants of the 90 degree v6 on racing in the past as well.

This same Maserati 3L engine was run at Lemans in 73-75 by the Ligier team, who won its class and placed 8th overall in 74. A 4v variant was made as well which, in final iteration, made some 420bhp at 10,500rpm. The 2v variants in race trim made about 100bhp less and obviously did not rev as high. The most well-known 90 degree racing v6 might be the Cosworth 6r4 engine which has identical bore and stroke and crankshaft pin and main journal sizes as the Maserati engine and crank. In group B, the Cosworth dominated and earned its legendary status.


More on the origins of the Maser engine for those who might be interested. The Maserati engine is also a 3 pin throw with odd fire like the Buick. Buick indeed made later modifications such as splitting the pins and adding a counter balance shaft at the center just above the crankshaft. The later Buick engines with counter shaft and split pins are indestructible.

Maserati actually built their v6 in this configuration entirely on purpose. Some have conjectured it was due to Maserati needing to cut costs this just knocking 2 cylinders off their v8. Nothing can be further from the truth as the block casting and central Jack shaft design driving the camshafts via inboard timing chains was every bit as involved and expensive to develop as would a 60 degree v6 have been. Maserati needed the low profile yet short engine design a 90 degree benefits from to fit the SM hoodline, which a 60 degree would not have accomplished.
Are 90 degree V6 engines acceptable for road car use in economy cars that are not performance cars?

Greg Locock
Greg Locock
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Joined: Fri Jun 29, 2012 11:48 pm

Re: F1 V6 90 degree vibration questions

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I've seen 2 vehicle programs where the disgusting creatures were responsible for such appalling lack of refinement that the management killed the programs. Now it has to be said that with a great deal of care the 90 degree Buick V6 3.8 litre can be made to work in a vehicle, if the bodyshell and transmission is designed around it.With 50 years of development behind it perhaps that isn't surprising.

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BassVirolla
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Joined: Fri Jul 20, 2018 10:55 pm

Re: F1 V6 90 degree vibration questions

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Piscine wrote:
Tue Sep 27, 2022 6:46 pm
This is timely as I recently completed a non-stock rebuild of a 90 degree V6 Maserati engine as was placed in the SM and Merak. Mine is a late Merak SS variant I stroked by offset grinding the crankshaft, custom (lighter) rods, altering the piston pin location and compression with more custom pistons resulting in a displacement of 3.3L. Lots of weight removed from all rotating components yet still they are rough at lower rpm, but are fabulous in peak operating ranges. With the cams and compression this engine prefers to live at 4000-8000. No vibration once it’s revved out. It hates idling, this is the nature of these.
If you care, i would like to see some pics of this engine, as some of the Merak. I'm a big Citroën fan. Nowadays I'm rebuilding a stock M25 turbo diesel engine. 😁

Tommy Cookers
Tommy Cookers
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Joined: Fri Feb 17, 2012 3:55 pm

Re: F1 V6 90 degree vibration questions

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I think that I still think that I think that (considering the V6 as 3 V twins joined) .....

only cylinders at 90 deg can have 'all' primary force cancelled by crankshaft counterweights (of the right mass)
(strictly we would also need coplanar rods)

this is consistent with the view that the 120 deg engine(s) current have some primary imbalance
120 deg is best for F1 engine performance without structural performance eg the 1961-dominant Ferrari

all V6s will have some secondary imbalance (except the 120 deg ???)


and having suggested that 1966 McLaren F1 should have used 6 pistons in their US Ford Indy V8 .....
I notice that Jaguar have in modern times been selling a car that has such an engine format