Chevy-powered D-type Jaguar - Joe Silnes

A friend is tracing the career of expat Norwegian Joe Silnes in the US, in particular his efforts to convert one of the D-types to Chevy power. Allegedly, this could have been one of the Jack Ensley cars, XKD521 or XKD538, or later, XKD553. Any information on the race histories for these chassis would be much appreciated, also anything on what happened to the remains of XKD021 after its major shunt in Cuba. I am aware of other V8-powered D-types, both Chevy and Buick equippped, also the fearsome XK-SS that had a big block Ford inserted but none of these appear to have a Silnes connection.

"coventryracers.com" lists XKD538 as the only one of the three that had a Chev V8 fitted. 

It was fitted in March 1959 immediately after Ensley's ownership. The conversion was featured in a Sports Car Illustrated article with photos - the white  D-type carrying number 14. The article was one that covered a number of cars converted to Chev power by Joe Silnes.

None of this is conclusive ... but maybe a reasonable lead?

Sorry, I have seen the article, but do not have a hard copy to post here.

Edited by Porsche718, 04 December 2021 - 21:56.

Even in 59 the  physically smallish and powerfull Chevrolet was  an improvement over the fairly heavy pussycat 6. People were overboring the 3 7/8 bore 283 to 4" 302ci. Even just a stock 4bbl 283 of the day would be as quick as the Jag engine.

"D"-TYPE JAGUAR. Corvette engine and transmission, Salisbury

rear, many spare body and chassis parts

GRAN TURISMO LTD.

307 Glen Cove Road, Greenvale, Long Island, New York.

Call 516-676-7272.

Autosport, 13 September 1973, Page 65

Includes front and rear photographs of a dishevelled light-coloured D-Type (with headrest but not fin).

RGDS RLT

Edited by Rupertlt1, 07 December 2021 - 15:28.

Anyone putting a Yank V8 cast iron pushrod anchor into a D-type should be taken out and given a damned good talking too.

Anyone putting a Yank V8 cast iron pushrod anchor into a D-type should be taken out and given a damned good talking too.

For someone at the time trying to make a competitive car rather than running a vintage car this was probably a good idea. 

The SBC was inserted in numerous Ferrari’s back in the day quite successfully. 

For someone at the time trying to make a competitive car rather than running a vintage car this was probably a good idea. 

Anyone putting a Yank V8 cast iron pushrod anchor into a D-type should be taken out and given a damned good talking too.

From our perspective in 2021- I wholeheartedly agree.   

However, in 1960, a D Type was just another obsolete racing car and swapping a SBC motor for the venerable 3.8L 6 was a reasonable decision.  One saved weight, lowered the mass of the engine, and gained about 50hp.  Of course when the vintage market started to take off, many of those left with D Type-Chevys were slapping their heads....

The SBC had a lot of impact in US sports car racing, and was the culmination of a long line of US V8 engines dropped into racing car chassis.  Allard comes to mind of course as a more or less production vehicle.  There was also the HWM Special, various versions of Old Yaller, Kurtis 500, the first Scarab and many others.   By the late 50's the SBC became the default choice because it was readily available, reliable, powerful, and received continuous development from Chevy. This engine allowed those with ingenuity, but without access to the latest from Europe, to construct a car that could be competitive.   As the resulting cars became more sophisticated, "Chevy Specials" began to outpace many cars with more impressive pedigrees.    A D Jag-Chevy made a lot of sense at the time.....just as a Lister-Chevy made a lot of sense in the UK at the same time.

The advantage cannot of been very big--the small block Chev V8 was still in early stages of development and the weight difference was marginal-575lbs vs 592lbs-see :

https://www.gomog.co...ineweights.html

A local (Vancouver) D Type was fitted with a big block Ford engine...The story is here on the forum somewhere

Edited by David Birchall, 08 December 2021 - 18:53.

The advantage cannot of been very big--the small block Chev V8 was still in early stages of development and the weight difference was marginal-575lbs vs 592lbs-see :

https://www.gomog.co...ineweights.html

 

A local (Vancouver) D Type was fitted with a big block Ford engine...The story is here on the forum somewhere

By 59 there was plenty of performnce parts for a SBC. Multicarb alloy intakes, a heap of cam and spring development, head development, cluch and flywheel development. I am sure some of this was being done for pussycats as well but the US Performance market was far greater than hot parts for Jags. D types were what 3.4?  Chevs were 4.7-5litre and would rev  hard if not harder. And in the US were a LOT cheaper as well.

Big block Ford probably not ideal and depends which one but they are all a lot heavier than a Chev.

Edited by Lee Nicolle, 09 December 2021 - 03:27.

By 1959 the Jaguar Six had won Le Mans 5 times, how long did it take Chevrolet to catch up?

By 1959 the small block Chevrolet had only been in production for four years. A scant two years after its introduction the little Chevy was powering Australia's fastest racing car, the mighty Tornado reaching 157.5 mph at Coonabarabran.

By 1959 the Jaguar Six had won Le Mans 5 times, how long did it take Chevrolet to catch up?

Chevrolet were selling cars, a LOT more cars than Jaguar and not racing except in the US. 

LeMans is NOT the world though Ford took on Ferrari and won 6 years later and whatever anyone says the Chevrolet is the better engine over the 289. And where was Jaguar then??

The Jags had a reasonable chassis but were underpowered and not that reliable. The Yanks [and some Aussies] utilised the simple strong reliable and more powerfull Chevs

Comparing a cooking engine designed for Mommy to drive to the store in the family station wagon with a thorough-bred like the XK is laughable.  No comparison whatsoever.  It was so underpowered and unreliable that it could only win the Le Mans 24 hours race a handful of times.  Unlike Chevrolet's dominance of the race. 

I've never been a fan of American V8s so maybe I'm missing something here. In the UK Ford engined cars, Cobra, Mustang, Falcon, GT40 etc, were rather more successful than Chevrolet engined ones, until the arrival of those nasty Can Am monsters. Maybe it is something to do with manufacturer interest. Jaguar withdrew from racing to concentrate on building road cars, they did not have the bottomless funding possessed by General Motors. Certainly they COULD have been there with the XJ13 when Ford funding overwhelmed Ferrari.

Sorry Lee, Le Mans is the world!

While the Jaguar IL6 won at LeMans, and the Chevy V8 never has, the overall legacy of both engines leads to different conclusions based upon ones native biases.

I don't think anyone is arguing that the D Type, and the 3.4 IL6 that powered it were less than wonderful creations.   However --in the context of this thread-- by 1960 a D Type was just another obsolete racing car.  Substituting a cheaper and more powerful engine was a reasonable decision.     While my preference is for the C Type over the D, I do not deny the achievements of the Chevy powered cars that left the C Type (and D Type) in the dust.    Heck, when Jaguar created what was a descendent of the D- Type...the XKE...and built lightweight versions of it...Jaguar quickly found out that it was barely competitive.  While Chevy (and Ford) powered cars continued to win more and more races.   

Comparing a cooking engine designed for Mommy to drive to the store in the family station wagon with a thorough-bred like the XK is laughable.  No comparison whatsoever.  It was so underpowered and unreliable that it could only win the Le Mans 24 hours race a handful of times.  Unlike Chevrolet's dominance of the race. 

"Underpowered and unreliable" indeed...such as the famous case of the Ecurie Ecosse Le Mans-winning D-types being taken straight to Monza after the Vingt-Quatre Heures, and finishing the Monzonapolis 500-miler, with the XK engines showing very little loss of power after running two such gruelling events, and not much wear.

Theoretically, the Chevy V8 should have had the edge: Comparable weight, much more power and torque, and a very much lower CoG. The small-block powered Scarabs were a dominant force in the US in the late Fifties, against strong opposition from Ferrari, Maserati, Aston Martin and Lister Jaguars/Chevies. The D-type was not that well suited for American circuits with its live rear axle. The whole car was, of course, designed to win Le Mans, and other races were a secondary consideration. Lister-Jaguars did well Stateside, as did the same chassis with Chevy V8s. Listers did have a fairly primitive ladder-type frame but their deDion rear suspension made for better traction on bumpy, twisty circuits, and of course the cars were lighter than the D-types.

In my book both the the XK straight-six and the small block Chevy V8 deserve classic status. The Jaguar six was conceived during those long nights of wartime fire watch, and had the disadvantage of a very long stroke. But that also meant lovely torque characteristics. And those shiny twin aluminium cam covers must have been a revelation to any enthusiast's eyes in the immediate post-WW!! years.

I've never been a fan of American V8s so maybe I'm missing something here. In the UK Ford engined cars, Cobra, Mustang, Falcon, GT40 etc, were rather more successful than Chevrolet engined ones, until the arrival of those nasty Can Am monsters. Maybe it is something to do with manufacturer interest. Jaguar withdrew from racing to concentrate on building road cars, they did not have the bottomless funding possessed by General Motors. Certainly they COULD have been there with the XJ13 when Ford funding overwhelmed Ferrari.

 

Sorry Lee, Le Mans is the world!

Lemans is a dangerous race run over 24 hours. And manufacturers build cars to win that race. Only some succeed. And organisers create rules for that race only.

Interesting but a little irrelevant more so these days.  Lemans is a footnote!!

The Ford Windsor is a tiny little thing. Too small really. Ford spent plenty getting those performance engines to actually go and stay together. Those early engines have very restrictive heads. Oiling is ok, cooling not!! and only 4 bolts per cylinder holding the heads on so hard to keep a gasket in!!  And more so 289 the cylinder skirts are too short and they used to break the skirts off the pistons. Early 302s are not much better.

More modern 302s [5 litre] have longer skirts and coupled with the modern pistons are perfectly ok.

You can make them go, that is well proven and more so these days with less ancient blocks. Mid 80s on I believe, some blocks are better material than others as well. The so called Mexican blocks.

Factory heads are still a cork however, plenty of better aftermarket heads around these days. Max stroke you can put on them is 3.4" 347 and to do that you have to check everything. Rods to cam, Rods to cylinders, grind the pan rails extensively to clear the rods, dent the pan rails after that to clear rods, You would not ever do this to an early block, the pistons would come out the bottom so far as to be scarey. The pistons to suit have the rings over the gudgeon pin which with the very short 5.4" rods. A 302 Chev you can use a 6 1/8 rods with no clearance issues. 

The larger and heavier 351 W engine looks similar but is a LOT heavier and the 3" main bearings are not good for high rpm as they are too large. And factory at least the heads are a bigger cork. Torquey, reliable for a family hack or a F100! People do race them with success but the heads are critical. Then keeping oil from frying on those humongous mains. The same as the 400M engine used in full size early 70s Fords and light commercials. Most near 100000 miles have very little oil pressure as the crank speed/ oiling has worn out the bearings. This on factory engine that eldom turn more than 3000 rpm. And yes I have done a heap of these!

Then 69 to 74 US and 83 Oz there was the Cleveland. Two versions, 2V [2bbl] heads and 4V [4bbl] heads. Humungous ports with quite poor velocity, especially the 4V with its humongous valves as well. 

Poorly oiled, average cooling but can make good horsepower. The heads too are bloody heavy. These were the heads used on Boss 302s which explains the total lack of botton end for those engines. A Boss 302 is 4V small chamber Cleveland heads on a 302W block.

Then there was the Aussie 302Clevo, same block as the 351 but with [as Ford do] the same pistons and longer 6.030 rods,, small chamber 2V heads which while are better for velocity still have  intake openings bigger than a small block Chev race port!! These heads on a 351 to me are better than 4Vs unless you are turning well over 7500 rpm which with the Clevos suspect oiling is expecting the explosion!!

I personally raced that combo for a while using 6800 max and it came to pieces still good. About 440hp at the crank. I have now gone to far better flowing alloy heads and intake. Should be closer to 500 whp  using 7200 rpm though the rest of the engine may be very suspect. I hope it lives!! I am fairly conservative in my builds however.

Edited by Lee Nicolle, 11 December 2021 - 10:45.

"Underpowered and unreliable" indeed...such as the famous case of the Ecurie Ecosse Le Mans-winning D-types being taken straight to Monza after the Vingt-Quatre Heures, and finishing the Monzonapolis 500-miler, with the XK engines showing very little loss of power after running two such gruelling events, and not much wear.

 

Theoretically, the Chevy V8 should have had the edge: Comparable weight, much more power and torque, and a very much lower CoG. The small-block powered Scarabs were a dominant force in the US in the late Fifties, against strong opposition from Ferrari, Maserati, Aston Martin and Lister Jaguars/Chevies. The D-type was not that well suited for American circuits with its live rear axle. The whole car was, of course, designed to win Le Mans, and other races were a secondary consideration. Lister-Jaguars did well Stateside, as did the same chassis with Chevy V8s. Listers did have a fairly primitive ladder-type frame but their deDion rear suspension made for better traction on bumpy, twisty circuits, and of course the cars were lighter than the D-types.

 

In my book both the the XK straight-six and the small block Chevy V8 deserve classic status. The Jaguar six was conceived during those long nights of wartime fire watch, and had the disadvantage of a very long stroke. But that also meant lovely torque characteristics. And those shiny twin aluminium cam covers must have been a revelation to any enthusiast's eyes in the immediate post-WW!! years.

If you believe they did 2 endurance races on the same engine say hello to Santa!!

It only takes a few hours to change an engine!

To me  Jag engine is ho hum. I have driven no end of Jags 50s to 90s and they are thirsty and leak oil. That is when Lucas actually allows them to run!! Many have had said engine problems fixed with a Chevy!! XJ6s and 12s especially. Those cars were good looking well mannered cars with some weird and dubious engineeering. But when mechanically good they drive nicely. Notwithstanding the electrics. What is worse? Pommy or Italian electrics at least of  late last century.

Whereas a the small block Chev has been used in near every form of motorsport with success. Very good oiling, cooling, 5 bolts per cylinder to retain the heads and if put together properly the oil stays inside!!  Downsides are too small a lifter base restricting lift on flat tappet cams though they are well out of date. Every manufacturer for the last 30+ years have used roller cams

The first instance of a Jaguar D-Type-Chevy competing (that I can find) is Jack Ensley himself at the Boca Raton races, 9 March 1958. On pole position for two events, #17 didn't show up in reports. The feature was a washout. Indianapolis car dealer Jack Ensley was no mug. He had competed extensively in an all-Jaguar D-Type before switching to the Corvette powered version. The weight distribution of the car must have been considerably altered?

The car reappears later at the Marlboro Grand Prix ( 21.9.1958) and Watkins Glen (28.9.1958). Retired with a blown diff at the latter event. The rear axle may have been the weak point on these cars?

RGDS RLT

 Lemans is a footnote!!

Congratulations!  You may be the only person who believes the world's most important and prestigious race is a footnote!  

To me  Jag engine is ho hum. 

Well, it is British, isn't it?  I would be amazed if you ever wrote even one positive word about anything from the UK.

The first instance of a Jaguar D-Type-Chevy competing (that I can find) is Jack Ensley himself at the Boca Raton races, 9 March 1958. On pole position for two events, #17 didn't show up in reports. The feature was a washout. Indianapolis car dealer Jack Ensley was no mug. He had competed extensively in an all-Jaguar D-Type before switching to the Corvette powered version. The weight distribution of the car must have been considerably altered?

The car reappears later at the Marlboro Grand Prix ( 21.9.1958) and Watkins Glen (28.9.1958). Retired with a blown diff at the latter event. The rear axle may have been the weak point on these cars?

RGDS RLT

Thanks, very valuable information.

Congratulations!  You may be the only person who believes the world's most important and prestigious race is a footnote!  

Well, it is British, isn't it?  I would be amazed if you ever wrote even one positive word about anything from the UK.

Indeed, if Le Mans is but a footnote, it is remarkable that Ford USA put in such a huge (end expensive) effort to conquer it in the Sixties. Developing the 289 Ford GT, the 427 Mk 2 and the Mark 4...all done to win at Daytona and Sebring?

In my experience (I own and have run  4 Mk 2s) the XK engine is very reliable - providing it is maintained properly. Changing oil and filters as per the book, and never ever running without proper anti-freeze coolant, ar essentials. The rope rear crankshaft oil seal was maybe not the greatest ever piece of engineering that was used on a motor car engine, but it was probably state of the art in the mid-Forties...

The closest comparison bewtween the two engines must be US sports car racing, How did the Lister-Jaguar and Lister-Chevrolet compare?  Admittedly driver ability varied significantly more than.in other series.