917 Question

[daepp]

Anyone know the approximate weight of a 917 engine? Just curious how it compared to a GT40 motor of its time.

[Dave Colangelo]

I dont know the specifics but my guess is much heavier. It was a flat 12 as apposed to the v-8 the GT40 was running. It also had the MFI system on it which would have been heavier than the 4 barrel holly carb the GT40 was running.

According to Wikipedia the curb weight of the GT40 was 2002LBS and the curb weight of the 917/30 (Can-Am Car) was 1800 LBS. It also says the 917 space frame chassis was only 93 lbs. The 917/30 was the open cockpit car not the one raced at le mans in 1970. Keep in mind there were multiple iterations of both the 917 and the GT40. It seems from these articles that both cars weight in right around 2K Lbs.

Both cars were running engines right around the 4.5 - 5 liter mark as well so im sure they were similar in weight. If im not mistaken the 917 was simply putting down more power and lead to its eventual win. One of the coolest things I have always found about these cars is they were good up to 250MPH+ and only had a 4 speed transmission!

Regards
Dave

[Dantilla]

Next time I pull the engine out of my 917, I'll weigh it for you.

[daepp]

I am surprised that 15 minutes of googling produced no answer. I know they are of limited production and there were a few different models but I just would have guessed someone would have that info.

Am I correct that they were Mg cases, Al heads and Ti rods?

[yellowperil]

260 KG or 575 lbs

[wayner]

I am going to guess that the GT40 engine was lighter based on knowing that a production Ford 5.0 v8 was lighter than a Datsun straight 6.

Just a guess though. Materials on the 917 12 motor are probably lighter than the Datsun 6 motor, but that big long crankshaft on the 12 had to add up two something.

On the other hand, the GT40 had a 7.0 litre and not a 5.0 litre, so I'm not sure that my comparison means anything at all...

[bcoats]

Not sure but going to see Seinfeld tonight, maybe I'll ask him!

[Dantilla]

Did the GT40 use an iron block?

Also need to account for the Ford's liquid cooling system vs. air-cooled 917.

[Quicksilver]

I know that 2 people can pick one up (without exhaust).

[Bill Verburg]

Originally Posted by daepp

Anyone know the approximate weight of a 917 engine? Just curious how it compared to a GT40 motor of its time.

the 4.5 liter 912 engine used in the original 917 was 542#

[fbarrett]

Yebbut...GT40s were notoriously heavy, especially the Mark II (427) version, which was closing in on 3,000 lb.

[daepp]

Thanks guys. Looks like the winning-est GT40 with the 427 weighed in around 500 with only 385 HP.

[Bill Verburg]

the 917 4.5L 12 used a mg crankcase and covers, 160#

the aluminum chassis frame and brackets weighed 104# and were designed to be in tension or compression and doubled as oil conduits to get the oil from the engine to the front mounted coolers. There was some later experimentation,917 052 was the first race chassis) w/ mg chassis tubes which weighed 93#, the whole car as it appeared at LeMans in 6/71 weighed 1690#, the 3rd mg frame 917 was the winner at Le Mans 6/71(917 053)

the whole car weighed

[Bob Kontak]

Originally Posted by daepp

Thanks guys. Looks like the winning-est GT40 with the 427 weighed in around 500 with only 385 HP.

Well, if you look at first place finishes, the 302 is tied with the 427.

The 302 had to have been lighter.

From Wiki:

The GT40 was originally produced to win long-distance sports car races against Ferrari (who won at Le Mans six times in a row from 1960 to 1965). Chassis # P-1075, which won in 1968 and 1969, is the first car in Le Mans history to win the race more than once with the same chassis, using a Ford engine originally of 4.7-litre displacement capacity, enlarged to 4.9-litre (also known as a 5.0) with special alloy Gurney-Weslake cylinder head.

Surprised me that Ford allowed the 1,2,3 sweep in 66, given his well publicized bromance with Enzo.

http://en.wikipedia.org/wiki/Ford_GT40#Le_Mans_24_Hour_victories

[rusnak]

I think two people can carry the frame, but doubful about the motor.

Porsche used a hoist to move it. Here's an interesting series of pics showing the 917 engine being installed into the frame:Gunnar Racing

[kundensport]

4.5 liter was270kg
5.0 liter is 280kg and the 5.4 liter is 285 kg

regards, Hans

[Charles Freeborn]

Here are all the specs:

https://www.dropbox.com/s/v92fmsvh2xtywst/Type_917_Specs.pdf

-C

[Igofastr]

For those not immersed in the GT40:

The first cars (Mark I, iron small block Ford 289) were developed in 1964-1965, and failed at their first run at LeMans. The Mark II (iron block 427) was an evolution of the Mark I, bigger engine, more cooling with some minor areo changes. It won LeMans in 1966. The Mark III was really an entirely different car, still powered by the 427, and still called a GT40 even though it really had little to do with the original Mark I. It won in 1967.

Due to newly adopted limitations in displacement, the big block motors were outlawed in 1968. Ford, having humiliated Enzo, pulled out of sponsorship. A number of privateers went it alone, returning to Mark I cars with the 289/302 motors. The Gulf-sponsored team was the most successful, winning in 1968 and 1969 (improbably) with a somewhat heavy, outdated race car. Rules changed again, effectively banning any variation of the Ford small block and the GT40.

Interestingly, perhaps the ultimate version of the GT40 was produced by Gulf in 1967...powered by the Ford 351. Rules had changed (or at least the interpretation thereof) making it possilbe to narrow the frontal area of the car by chopping and narrowing the windscreen...resulting in the Mirage. There were only 3? produced, all made effectively by mutilating a standard GT40. Most (all but 1?) were eventually converted back to normal Mark I specs.

For its time, the Ford small block motors were quite light (at least the blocks). Ford had developed a new thin-wall casting method used on the entire small block range 260, 289, 302, 351. With aluminum heads, water pumps etc, its still a pretty light motor.