SpeedTalk Store - Opinion Columns

Packard V8 (with 5" bore spacing) & a V-12 to follow!

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby Ratu » Mon Jul 23, 2012 1:21 am

I have been reading about the last of the Packard V8 engines. It appears that Packard designed and built a V8 with a 5" bore spacing. They left plenty of room in the engine for future expansion. They also appear to have intended to manufacture a V12 on the same tooling as that 5" V8. Does anyone know anything of this project?

Ratu
Ratu
Pro
Pro
 
Posts: 272
Joined: Sun Oct 02, 2011 6:58 pm

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby autogear » Mon Jul 23, 2012 2:24 pm

im sure Jack Vines does; if anyone.
autogear
Member
Member
 
Posts: 177
Joined: Thu Dec 08, 2011 9:03 am

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby novadude » Mon Jul 23, 2012 2:34 pm

And while we're at it, what about the rumor that Chevrolet looked at adopting a Packard design as the Mark III BBC engine.

As I understand it:

Mark I = Z11 409-based 427
Mark II = Daytona 500 splayed valve "mystery motor" based on a 409 block.
Mark III = Packard design???
Mark IV = 396 BBC introduced in 1965
novadude
Expert
Expert
 
Posts: 731
Joined: Thu Oct 11, 2007 2:24 pm
Location: Shippensburg, PA

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby PackardV8 » Mon Jul 23, 2012 3:44 pm

Yes, no, maybe to all of the above.

1. Yes, The '55-56 Packard V8 and the last big block Cadillac 472"-500" were the only US production car V8s with 5" bore spacing. The '56 Caribbean with 374", 2x4-bbls, 10.5 compression, was the largest displacement and second most powerful engine available in that year.

The Packard V8 was a mix of the GM 1949 Gen I Olds and Cad V8s, having an extended bell housing, shaft rocker arms, air-gap intake manifold and siamesed center exhaust ports. It has the head intake and exhaust surfaces at 90-degrees to the block face and unsupported lifter bores, similar to the Gen 1.5 Pontiac V8s.

2. No, Packard was out of business before their new V8 was ever de-bugged. There was never any plan or tooling for a V12 version. The V8 engine is 30" long and weighs 700# complete. That would make a V12 more than 40" long and weighing more than 1000#. Think of any modern car engine with those dimensions?

3. Yes, Chevrolet Engineering did a Mark III feasibility study of buying the tooling for their big block. They decided not to go there because:
a. Not Invented Here. Engineers usually get only one clean sheet engine design opportunity in their careers. Who'd want to give that up and de-bug an already designed engine?
b. Didn't want the brand tainted by bringing in a failed car company design.

4. Yes, the Mark II '63 Daytona Mystery motor used the same basic big block head design we have today, just installed on a square deck version of the Mark I Z11 W-motor.

5. Yes, the Packard V8s 5" bore spacing would have allowed an easy 500"; same as the big Cad. It would have needed further development, including stronger main bearing webs, reinforced lifter bores lifter bores and an improved oiling system.

6. And no, but someones sure to ask, the Rolls-Royce V8 was a clean sheet and shared no parts, dimensions or design features with the Packard V8.

jack vines
Jack Vines
Studebaker-Packard V8 Limited
PackardV8
Guru
Guru
 
Posts: 3538
Joined: Sun Jul 30, 2006 1:03 pm

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby Schurkey » Mon Jul 23, 2012 4:26 pm

Ratu wrote:I have been reading about the last of the Packard V8 engines. It appears that Packard designed and built a V8 with a 5" bore spacing. They left plenty of room in the engine for future expansion. They also appear to have intended to manufacture a V12 on the same tooling as that 5" V8. Does anyone know anything of this project?

Ratu

Karl Ludvigsen devotes about one column on one page (p. 290) to the proposed Packard V-12 variant of the OHV V-8 in his wonderful book "The V-12 Engine". The proposal lasted from May to June of 1953, at which time it was ruled out. It would have used a 12-throw crankshaft to provide even firing for the 90 degree bank angle. The original displacements intended for the V-8 and V-12 were 4.7 liters and 7 liters, both using a 95.3mm bore, and an 82.6mm stroke. (Ludvigsen appears to have converted from real measurements into metric for the book.)

The V-12 variant was originally proposed by James Nance. When he moved to Ford after Packard folded, he tried to convince Ford management to adopt/adapt the Packard engine with intentions of using a V-12 in Lincolns. That did not progress beyond informal discussion.

There's similar discussion and a few photos of the proposed and prototyped--and deeply disappointing--Cadillac "V-Future" SOHC V-12 of the early-mid '60's.

Image
http://www.amazon.com/The-V12-Engine-Te ... -12+Engine
Schurkey
Expert
Expert
 
Posts: 745
Joined: Sun Mar 01, 2009 2:42 am

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby PackardV8 » Mon Jul 23, 2012 8:23 pm

The original displacements intended for the V-8 and V-12 were 4.7 liters and 7 liters, both using a 95.3mm bore, and an 82.6
That would have been 3.75" bore and 3.25" stroke. Hard to imagine building a 4.7 liter engine which would weigh 710#. The smallest Packard V8 actually built on the 5.0" bore center was the '55 320" or 5.2 liters. Since it cost the same to build as the larger versions, it made less than no sense and was discontinued.

All the Packard V8s used a 3.5" stroke.

The 320" was 3.8125" bore
The 352" was 4.0" bore
The 374" was 4.125" bore

jack vines
Jack Vines
Studebaker-Packard V8 Limited
PackardV8
Guru
Guru
 
Posts: 3538
Joined: Sun Jul 30, 2006 1:03 pm

Re: Packard V8 (with 5" bore spacing) & a V-12 to follow!

Postby Ratu » Tue Jul 24, 2012 1:53 am

OK. Then taking the original production displacements of the Packard 5" V-8, the V-12 would come out at an impressive 480 cid (7.9 litre) or a more impressive 528 cid (8.6 litre) or a mammoth (by production car standards) 561 cid (9.2 litres). Wow! That'd likely have some torque. The engine weight might not be unacceptible in the circumstances- provided it was reasonably located in the chassis and the suspension was sorted (the Bill Allison interconnected torsion bar system would have been helpful in that regard).

What were the cylinder heads for the Packard V8 like? Were they any good?

Cheers

Ratu

PS. Jack, thanks for your point #6. I'd wondered about where the Rolls Royce/Bently engine originated. It was tempting to surmise it was an immigrant (like the Rover V-8 was). Various people had told me that the Rolls Royce/Bently V8 was sourced from Chrysler, but that has turned out to be strongly denied by everyone involved. That left the story that it was a Packard knock off. You've reported not so and also I don't think the bore spacing was anywhere near 5" in the Rolls Royce/Bently V8. So that's that legend corrected.
Ratu
Pro
Pro
 
Posts: 272
Joined: Sun Oct 02, 2011 6:58 pm


Return to Engine Tech

Who is online

Users browsing this forum: big, bill jones, carzngunz, Cubic_Cleveland, fastvette, FloydODB, gvx, hydrolastic, jay thorne, madhatter1076 and 47 guests