GT350 R question

fourspeed · April 22, 2009 at 5:56 AM

Can any Shelby experts tell me who ground the camshafts for the 65 GT 350 R model B Production racers? Can you post the specs? I was curious as to how much of a difference there was between the 65 R models camshaft and the stock K code camshaft. I also wonder if perhaps different cams were used for different track layouts?

camp upshur · April 22, 2009 at 10:05 AM

Numerous period magazine articles on Shelby American engine build-ups circa 1963-1965 cite Engle camshafts, some specifically mention Engle roller camshafts. Most articles as I recall were for Cobra Weber equipped 289s or just generic S-A 289 build-ups. The snap-shots into the S-A engine building operation are illuminative but I don't recall per se an R-Model engine build-up article. As years passed many assumed it was the C7FE flat tappet, but that obviuosly didn't come around to after S-A stopped campaigning the cars. Archival research into Hot Rod, Popular Hot Rodding, Cars and Sports Car Graphic recommended. Good luck.

rr64_old · April 22, 2009 at 4:17 PM

Your answer (maybe Mark Hovander knows?) may also depend on time frame as it did for Cobras. Cobras, even with Webers, started off with the stock HP289 camshaft design and evolved from there. The specifications I have collected don't show a whole lot of lift (back then stock rocker arms were used) but they did play with event timing and where legal roller lifters. The "factory" specifications for camshafts is real confusing to me because they gave specifications at different lifts at different times as procedures changed. That makes comparing information in a 1966 parts catlog and a 1970 one not straight forward.

RPM_old · April 22, 2009 at 5:26 PM

There were lots of differences in the R model motors as Shelby did alot of good tech work at the time.Four unique power plants that varied but 3 used his aftermarket or contracted camshafts.Haven't found the info on lift and duration I'm looking for but maybe at a later date I can update this thread.

HipoCV · April 22, 2009 at 6:03 PM

The one 'R' engine I am familiar with had the C7FE cam. Dan (rr64)has the oil pickup from that engine. The backup engine had the regular C3OZ HP cam in it.

C6ZZKGT · April 23, 2009 at 11:12 AM Official Post

I have an original Shelby American performance equipment parts book from that era. The latest price list with the book is March 1, 1966 so I feel that it should be somewhat correct. It lists three different engine assemblies. The 289 Cobra High Rev Racing engine is an S1CR-6003-6. It had Webers and a roller cam. It sold for a whopping $3,195 with a dealer cost of $2,445. The next one down is listed as a 289 Cobra Racing engine and it had Webers and a flat tappet cam and is an S1CR-6003-4 and it sold for $2,995 with a dealer cost of $2,295. The lowest one was a Competition GT 350 Road Race engine that used the 715 4V with a flat tappet cam and is an S1CR-6003-3. It sold for $2,645 with a dealer cost of $1,995. None of the above engines used the C3OZ cam based on the cam specs given for the engines. The book also has all of the cam specs for all of Shelbys camshafts so it makes it easy to compare to see which one went with what engine. These engines all came complete with carburetion and the only things that you needed was a starter, alternator, fuel pump, fan and pulleys.

-Fred-

camp upshur · April 23, 2009 at 11:55 AM

Thank you for posting Fred.

If ever you have any extra time, would sure be interested in those cam specs.

Do the engine descriptions make any mention of combustion chamber relieving? In the 45 year old articles S-A really played that up.

Best

round2K_old · April 23, 2009 at 3:50 PM

Fred - did the list rated BHP?

C6ZZKGT · April 23, 2009 at 4:06 PM Official Post

Dave, The Hi Rev Racing engine is rated at 395 HP @ 7000 with a torque of 330 @ 4100 RPM. The Cobra Racing engine is rated at 390 HP @ 6750 RPM with a torque of 341 @ 4000 RPM. The Road Race engine is rated at 350 HP @ 6750 RPM with torque of 312 @ 3800 RPM.

-Fred-

C6ZZKGT · April 23, 2009 at 4:19 PM Official Post

Steve, All of the engines listed have a 10.8 to one compression ratio. The book does list full competition heads as being milled .050 and combustion chambers polished and sized to 47 CC. You might want to call Larry at Valley Head Service in Northridge, California. He was one of the original contractors to Shelby at that time and that is when I first met him. He was working out of a chicken coop on Sherman Way in Reseda doing heads for a chicken farmer from Texas. I will post the cam specs when I have more time as there is a lot to post.

-Fred-

camp upshur · April 23, 2009 at 7:35 PM

Fred,

Yes very familiar with Larry Ofria and he was indeed a key player for S-A back in the day. Thanks.

Steve

C6ZZKGT · April 23, 2009 at 9:45 PM Official Post

Steve, The following is right out of the Shelby American Performance Equipment book under engine specifications for the valve system:

289 Cobra High-Rev Racing Engine

Camshaft type: Roller tappet

(All specifications taken at 0.001" valve lift for all three camshafts listed below)

Valve lift: 0.485"

Intake valve opens: 40 degrees BTDC

Intake valve closes: 78 degrees ABDC

Intake valve duration: 298 degrees

Exhaust valve opens: 84 degrees BBDC

Exhaust valve closes: 25 degrees ATDC

Exhaust valve duration: 289 degrees

Intake tappet clearance (hot) .012"

Exhaust tappet clearance (hot) .014"

289 Cobra Racing Engine # S1CR-6003-4

Camshaft type: Flat tappet

Valve lift: 0.500"

Intake valve opens: 37 degrees BTDC

Intake valve closes: 72 degrees ABDC

Intake valve duration: 289 degrees

Exhaust valve opens: 76 degrees BBDC

Exhaust valve closes: 33 degrees ATDC

Exhaust valve duration: 289 degrees

Intake tappet clearance (hot): .025"

Exhaust tappet clearance (hot): .025"

289 Cobra Road Racing Engine # S1CR-6003-3

Camshaft type: Flat tappet

Valve lift: 0.445"

Intake valve opens: 29 degrees BTDC

Intake valve closes: 75 degrees ABDC

Intake valve duration: 284 degrees

Exhaust valve opens: 75 degrees BBDC

Exhaust valve closes: 29 degrees ATDC

Exhaust valve duration: 284 degrees

Intake tappet clearance (hot): .018"

Exhaust tappet clearance (hot): .018"

-Fred-

camp upshur · April 24, 2009 at 9:37 AM

Fred,

Thanks alot for posting all of these specs.I'm a little surprised how low lift the roller flanked profile is. I guess it just shows the limitation of valve springs at the time.

Steve

RPM_old · April 24, 2009 at 6:01 PM

Fred,does your book provide the camshaft manufacturer names?I read somewhere that he had 4 different camshaft manufacturers at that time 64-65 like he did with all his spec stuff for the cars?

C6ZZKGT · April 25, 2009 at 1:48 AM Official Post

There is nothing in the book that indicates a munufacturer on the camshafts. Any parts that are Ford manufactured have Ford part numbers. Everything else is Cobra car or Shelby part numbers. I would think that Larry at Valley Head Service would most likely know. You could call him and let him know that I referred you.

-Fred-

J_Speegle_old · April 25, 2009 at 2:07 AM

I know that Sullivan produced some of the race cams used on some of the R models and Trans Am engines

rr64_old · October 31, 2010 at 12:44 PM

<BLOCKQUOTE id=quote><font size=1 face="Verdana" id=quote>quote:<hr height=1 noshade id=quote>

I know that Sullivan produced some of the race cams used on some of the R models and Trans Am engines

From what I remember the Sullivan associated with Cobra engine pieces is also this Sullivan. "Sully cams" were not ones he made maybe but ones he designed.

[http://thehotrodsofdearborn.com/sully.html]

Edited by - rr64 on 10/31/2010 12:46:55

GT350 R question

Participate now!

Users Viewing This Thread