39 replies to this topic

[Racers Edge]

1967 Cosworth Lotus 49...new car, new engine, new era, does anyone have any reference to the DFV engine numbers that Cosworth used in the first race by Hill & Clark?

[Gary C]

ha!! 001, 002 & 003 ???

[Henk Vasmel]

According to Such Sweet Thunder (Blunsden & Phipps), Jim Clark used engine 703. Engine 701 was written off during initial testing. Engine 704 was delivered at 2/6/67, so the thursday before Zandvoort (race on Saturday ?). Graham Hill had driven his car before, so I would guess engine 702 then. I cannot find any positive proof now.

Henk Vasmel

[Barry Boor]

ha!! 001, 002 & 003 ???

I always thought that the first digit in DFV numbering signified the year of manufacture, in which case 701, 702, 703 and 704 would seem more likely.

[Don Capps]

Originally posted by Barry Boor
I always thought that the first digit in DFV numbering signified the year of manufacture, in which case 701, 702, 703 and 704 would seem more likely.

It did until the numbering system was almost overwhelmed in the early/mid-70's.

The 700 blocks were renumbered as 800's for 1968. So, 705 and 805 are really the same block.

I remember seeing the numbers for Zandvoort being 702 and 703, Hill and Clark respectively, but I can't recall the source, darn it.

[Gary C]

I remember when my friend Simon Bull was getting the Tyrrell 005 restored that he managed to trace the block all the way back to Jochen's win at Monaco in 1970!!

[Dennis Hockenbury]

Originally posted by Henk Vasmel
Jim Clark used engine 703. Graham Hill had driven his car before, so I would guess engine 702 then. I cannot find any positive proof now.

According to Michael Oliver's excellent 'Lotus 49' (page 40), Clark did use engine 703 and Hill used engine 702.

Both engines suffered timing gear damage resulting from the torque reversal problems present in the early DFV's that would damage the gear train. Hill retired from this event on lap 11 due to a timing gear losing two adjacent teeth disabling the cam drive. Clark also suffered the loss of two gear teeth but as they were not adjacent, his 703 was able to continue running thus winning the first time out.

Luck or acute mechanical sensitivity on Clark's part? Both I would think.

[Gary C]

.....................and yes, wouldn't we all like to know where 703 is now????

[bschenker]

You min this one?


or is this realy DFV 803

[bschenker]

You min this one?


or is this realy DFV 803

[Gary C]

................sowhere is it??

[Peter Morley]

DFV703 was converted to DFW703 (e.g. 2.5 litre) for the Tasman series.
The photo isn't sharp enough to show the 3rd letter, is it a W or a V?

There seems to be some scoring around the number, and the lettering seems to be larger than on other engines, is that definitely the original number?

What happened after the Tasman races, was DFW703 converted back to a 3 litre?
Given that 803 was a 2.5 litre engine it seems likely that DFW803 was DFW703 re-numbered?
If so what happened to 803??

[Don Capps]

I was never certain if the blocks were physically re-numbered after any rebuild to become an 800-series block/engine or simply had the log books changed to denote the redesignation. I have always assumed it was the latter. Apparently, only the 700's were affected by a redesignation, the 900's being used for quite awhile after being modified to latter specs -- DFV 919 being an example.

[Don Capps]

Originally posted by Peter Morley
DFV703 was converted to DFW703 (e.g. 2.5 litre) for the Tasman series.
The photo isn't sharp enough to show the 3rd letter, is it a W or a V?

It looks like a "W" when I enlarged it.

[Peter Morley]

Originally posted by Don Capps
I was never certain if the blocks were physically re-numbered after any rebuild to become an 800-series block/engine or simply had the log books changed to denote the redesignation. I have always assumed it was the latter. Apparently, only the 700's were affected by a redesignation, the 900's being used for quite awhile after being modified to latter specs -- DFV 919 being an example.

We've got DFV 910, that started out as DFV 810, and it was re-numbered.

[Don Capps]

Originally posted by Peter Morley
We've got DFV 910, that started out as DFV 810, and it was re-numbered.

I am learning more everyday.

Or, perhaps another sign of "Ah yes! I remember it well!" Syndrone on my part when I check my notes....

[bschenker]

Is this clear enough?



Not functional engine fitted in the Bellasi when hi was back at Lugano in 1994 - 96

[Racers Edge]

Cosworth DFV vs DFW.... what are the differences of these 2 engines:



Clark in the DFW Cosworth powered Lotus 49....

[bschenker]

I have My Owen theories about the renumbering of the Cosworth engines.
Cosworth have produced a series of engine cases in 1967 and may by also numbered a higher number of blocks then engine produced on this year, this mouldings were for 1968 renumbered. But 801, 802, 803 was first, second, third engine of 1968. The same was repeated on 1969.
Cosworth always rebuilt my DFV802 but I have always used documents for DFV802 from 1969 since 1972 when the Bellasi with this engine was sold to Mr. Wheatcroft. The Swiss Custom have always checked this and especially by Airfreight from Zurich Kloten.

[Bernd]

Originally posted by Racers Edge
Cosworth DFV vs DFW.... what are the differences of these 2 engines:



Clark in the DFW Cosworth powered Lotus 49....

Levin.

DFW was the destroked 2.5L Tasman version of the DFV. The designation DFW is seldom used in regard to this engine and from memory was used later by Cosworth for another derivative.

Duckworth was very unhappy with the engine in 2.5L form. He never got it to work quite right.

[Peter Morley]

Originally posted by bschenker
I have My Owen theories about the renumbering of the Cosworth engines.
Cosworth have produced a series of engine cases in 1967 and may by also numbered a higher number of blocks then engine produced on this year, this mouldings were for 1968 renumbered. But 801, 802, 803 was first, second, third engine of 1968. The same was repeated on 1969.
Cosworth always rebuilt my DFV802 but I have always used documents for DFV802 from 1969 since 1972 when the Bellasi with this engine was sold to Mr. Wheatcroft. The Swiss Custom have always checked this and especially by Airfreight from Zurich Kloten.

So when they rebuilt 802 as a 9 series engine (e.g. it became 902) you asked them to keep the 'old' number on the engine? That makes sense!

I suspect the main reason for re-numbering the engines would be to convince the customers that they have the latest specification engine, teams (& Mansell) always complained that everyone elses engine was better than theirs, so giving them the latest numbers should re-assure them that it isn't an old engine.

[Peter Morley]

Originally posted by Racers Edge
Cosworth DFV vs DFW.... what are the differences of these 2 engines:

Clark in the DFW Cosworth powered Lotus 49....

DFW was 2.5 litres, e.g. shorter stroke, so different crank & rods at least (& metering unit).
Seemingly the same bore so pistons & liners unchanged.
Of course they should have reduced the port sizes etc., but presumably didn't which might explain why Duckworth was unhappy with it.

Reports at the time said that all they did was change the rods, I can't work out how someone thought that would change the stroke, it's amazing what qualifies people as authors!

[bschenker]

the 802 was never rebuilt to 9xx stats so also make no sense a number change. But I was never asked to change the number or hold the old one. The story about 802 has becomme 902 make no sense.

[SEdward]

"Well it's certainly got some poke".

A wonderful quote from Graham Hill after testing the Lotus 49 with the DFV at Snetterton just before the 67 Dutch GP.

Source is the "Nine days in summer" video.

Edward.

[Peter Morley]

Originally posted by bschenker
the 802 was never rebuilt to 9xx stats so also make no sense a number change. But I was never asked to change the number or hold the old one. The story about 802 has becomme 902 make no sense.

Are there any external differences between 8 & 9 series engines, I thought all the differences were internal (e.g. timing gears etc.)?

[Racers Edge]

Great shot of Clark and DFV 703 engine...[ June 1967 Zandvoort race day], the first win for Cosworth and Lotus 49....

[bschenker]

Originally posted by Peter Morley
Are there any external differences between 8 & 9 series engines, I thought all the differences were internal (e.g. timing gears etc.)?

The Silvio Moser Racing Team bought the Brabham Ford BT24-3 with a Cosworth DFV 802 engine from Frank Williams at Slough GB.

The engine was from Ken Tyrell and the winner on the GP of Spain on 4th may 1969 Jackie Stewart and it was indicated as a 1968 engine, just rebuilt at the factory a few days before I picked it up and with partial 1969 specifications.

Regarding the internal differences, I remember from the bill made by Cosworth they always mentioned on their invoice, that it was a “replacement kit with a part number”, I can’t tell whether it was always the same number. I think it is clear that Cosworth used the last specifications parts, the only thing I cannot understand is the reason to change the engine number after one year with partial 1969 specifications, without making a full change.

The 1969 specifications were not only inside, otherwise how could I fit a 67 or 68 engine without problems, There were no problems changing a 67 or 68 engine, in the BT24-3 chassis, however a 69 or newer engine could not be mounted easily since it needed a modification of the frame.

[Peter Morley]

Originally posted by bschenker

The 1969 specifications were not only inside, otherwise how could I fit a 67 or 68 engine without problems, There were no problems changing a 67 or 68 engine, in the BT24-3 chassis, however a 69 or newer engine could not be mounted easily since it needed a modification of the frame.

That is very strange - the DFV from a McLaren M23 fits a Lotus 49 without any problem, and the 49 is earlier than the Brabham and the M23 engine much later.

Cosworth did not make any major changes to the dimensions of the DFV until very late on (1980s?) when they introduced the low sump version (which I think was the F3000 specification). And there is no big problem adapting a low sump engine to a tall sump car (many people in TGP have done that).
The only difference is to the sump all the dimension above the sump are the same.

Different pumps have been used - later on they went to narrow pumps, but that was in the ground effect days when they tried to make the engine as narrow as possible, so that the ground effect ducts could be as wide as possible.
It is easy enough to change pumps - assuming you can find the right ones for your installation.
But it is unlikely that they changed significantly in 69, Cosworth only made detail changes until the engines were very well established (e.g. into the 70's).

I vaguely remember that there is one mounting lug that was not used later on (it was used to mount the 'Christmas Trees' - rear suspension mounting frame on the 49, so it was redundant by the time Lotus ran 49Bs), but it is still cast into the block (they didn't change the pattern) and can be drilled & tapped if required.

[PeterElleray]

Peter - I've had a look at the original Cosworth drawings from the period - the only difference i can see in the pre 1970 engines is in the engine oil deairiation system, towards the rear of the right side pump assembly . I wonder if it was a union related to this that caused the fouling problems in the BT24 chassis?

[Peter Morley]

Originally posted by PeterElleray
Peter - I've had a look at the original Cosworth drawings from the period - the only difference i can see in the pre 1970 engines is in the engine oil deairiation system, towards the rear of the right side pump assembly . I wonder if it was a union related to this that caused the fouling problems in the BT24 chassis?

That is about the limit of the type of external changes I thought there was.

They should be able to fit their early pump to a later engine and all should be well in the Brabham.

In the 70's they moved onto a twin water pump, but that was much later than 9 series.

[PeterElleray]

Hi Peter - i have the drawings infront of me, here's the story (although there are a few other details not in this).

The first change recorded is what is referred to as the post '70 engine. This one has the deaeriation system on it. Then at some stage after jan '71 an inlet is added to the left hand water pump. The original inlet is a 90 degree bend facing forwards from the right hand pump, lining up with a typical radiator pipe running down the side of the chassis from a front radiator layout (Lotus 49). The extra inlet was obviously to accomodate the breed of twin side radiator designs of the early 70's. All of the pictures i have seen 'in period' show the teams either fitting tortuous right angle pipes to the original right hand forward facing intake (the M23?) or welding a similar fitting to the LH pump onto the right hand pump.

In 1978 the right hand pump is tidied up and now faces out at 90 degrees to the crank axis like on the rhs. Its also narrower.

The ground effect setup dates from 1981 (Cosworths own version). Now the oil out and air out are at the front of the left hand pump, whilst there is a new water in on the top of the left hand pump. This is the most common spec in use today (i think). We were using this setup in the late 80's on 3.5 litre DFV's. The mechanical pump drive gearbox from the rear of the lh camshaft also originates at this time.

The shallow sump first appeared - i think! - on the DFX in 1988. I did an installation for one at Lola that year. Then we get the definative shallow sump, with shear plate replacing the machined bracket on the forward face of the sump. By this stage we are looking at DFR/DFZ. The drawings i have are f3000. Infact this was the engine spec that we fitted to the prototype Bentley GTP as recently as 2000.

One thing that was always impressive when fitting Cossies was the quality of the installation drawings and information that you got with them. Not every engine manufacturer does this! John Judd is another one who gives you exactly what you need if you are fitting one of his Sports Car engines. It always gives you confidence when you get this sort of thing.

[Peter Morley]

Originally posted by PeterElleray

One thing that was always impressive when fitting Cossies was the quality of the installation drawings and information that you got with them. Not every engine manufacturer does this! John Judd is another one who gives you exactly what you need if you are fitting one of his Sports Car engines. It always gives you confidence when you get this sort of thing.

I agree totally - Cosworth are a class act, but there is apparently an exception.
When a friend was fitting the DFV in his Penske, it didn't make any sense - until he checked with an engine builder who said "you don't want to use that installation drawing it's wrong"!!

Your information confirms what I thought - fitting a 69 engine in the Brabham shouldn't be a problem, it should have the same pumps etc.
And it is quite easy to modify the later pump to fit - but I do undertsand that the space frame might get in the way.

[PeterElleray]

Hi Peter - Any idea what the problem was on the drawing ?

[Peter Morley]

Originally posted by PeterElleray
Hi Peter - Any idea what the problem was on the drawing ?

Something to do with the oil outlet from the sump.
Either the inlet & the outlet were reversed, or it was in a different position - I wasn't around when they found the solution.

[Macca]

Dragging this one up to save starting another thread.........Pete Lovely's Lotus 49 seems to be for sale and seems to have been converted back to original R2-spec from R11-'49B'-spec......

(sorry for the long link, haven't yet found out how to shorten them)

http://www.classicdr...&lCarID=1759906

Paul M

[Bill Wagenblatt]

I'm pretty sure Lovely sold the car in late 2006 or early 2007. If he did this would be the 2nd time it's been sold in 2 years.

Bill

[David M. Kane]

Bob Baker now owns the Lovely car.

[Bill Wagenblatt]

Has he sold it - the link above is for a Belgian location

[Peter Morley]

That's our car.

The components removed from R2 when they converted the chassis to a B-type.
That is suspension, brakes, wheels, steering, ZF gearbox, nose etc.
Fitted on a new chassis, with a very early DFV.

R11 is still in the States, but I understand that Pete Lovely sold it fairly recently, and is still a B-type as it always was.

[Red Socks]

Oh so its a replica then.