Need help with valves

Let me know if you got this taken care of.Total Performance is right down the street from me and should have these.You must have talked to some one who does not know what they are talking about,those are the size valves that I used in my small bolck heads,many years ago.
Greg

 

Don't have any books handy but you might want to check Chevy valves as replacements. Old hot rodder trick was to machine the heads for their use to pick up some size.

Just a though

 

The talk of the Chevy valves is the size of a small block ,big valve.That is what we used in the old days.I will talk to Dave today and see what is going on for you and get back with you.
Greg

 

Hi there,

I'll start off by saying that I'm definitely not an expert on Shelby's. I don't own one (although I am determined to at some point), but I've been passionate about them for well over 20 years. I have owned Mustangs for 20 years, so I know something about the engines. It is my understanding that the 1966 Shelby's had a stock K-code (Hipo) motor with only the carb, manifold and headers being changed. Changing valve size would not lend itself to the type of operation that CS had going. The K-code heads (and all other 289 heads for that matter) had 1.785/1.447 valves (factory tolerances were 1.773 - 1.788 and 1.442 - 1.457). All 1966 GT350's should have left Shelby American with those valves. 1.880 and 1.625 are definitely Chevy valve sizes (I don't know of a 1.63, so I'm assuming the shop rounded off the 1.625... think 1 7/8 and 1 5/8). I would imagine the article you referenced in a Branda magazine was about a vintage racer. Motors prepped for vintage racing back in the day would have definitely made use of such tricks as using larger Chevy valves. Can you give any further particulars on the car being restored? Is it a vintage racer, or was it? Is it a concours resto? Is it being restored to race? If it's a vintage racer, I would get in contact with Cobra Automotive (cobraautomotive.com).

Again, I don't claim to be an expert, because I'm not. There are a LOT of individuals on this site with a lot more knowledge about these cars than me, and I'm sure they'll correct me if I'm wrong.

Hope this helps,
Josh

P.S. You should be able to buy the appropriately sized Chevy valves at just about any speed shops, i.e. Jegs, Summit, etc.

 

Nehemie511,

I did some research and came up with the fact that original GT40 style valves in the old Muscle Parts catalog (from 1969) were the size that were described to you. Intake valve P/N C9OZ 6507-AA was 1.875 inches in diameter and exhaust valve P/N C9OZ6505-AA was 1.625 inches in diameter. They were supposed to be used with intake C9OZ 9424-D, and 351 Windsor heads in the Controller Kit (Stage 5) which would add up to 125 hp over stock or add camshaft C7FE 6250-A on top of that to get the Dominator Kit (Stage 5) to increase output to 155 hp. All this from a 289. The same tricks applied to a 351W for even more power. Good luck finding a set of these valves. I can't recall the last time I saw a set.

Hope this helps.

 

What you need are very easy obtained items from virtually every valve manufacturer and hi-performance parts purveyor.

You need standard NON RAIL dimensions: 11/32 (.3415) stem dia; 4.911 overall length, single groove, .250 tip length valves. These dimensions are shared by both early Ford and Chevrolet small blocks.

The head diameter is your discretion. Very early publications showed mostly 1.94 Chevrolet intake valves turned down to 1 7/8", and stock 1.60 Chevrolet exhaust valves. However for the past 40 years most Ford engine builders, using iron FoMoCo castings settled on 1.90 intakes and 1.60 exhaust (some went larger on the intake but it led to shrouding and relieving issues and loss of combustion chamber efficiency).

An inexpensive recommendation may be something akin to a Manley 10548-8 intake (1.90) and a Manley 10549-8 exhaust (1.60) commonly available widely. From your vantage in Europe try Summitt Racing or Jegs, I have colleagues in Germany who've bought from them, in fact E-Bay may be usable, I've purchased many automotive parts for my other vehicles from Europe via E-Bay and found it quite satisfactory administatively (paypal and shipping).

Regarding the 1965 GT-350 S models: the owner's manual and ancillary blueprinting specifications produced by Shelby American circa 1965 list the oversized valves. However such was not he case internally in the 306 HP variants fitted (1.78-1.45 in actuality).

Good Luck

 

Very well explained! This was a no brainier back in the day! We did this all of the time,when you could not get a stock performance valve for Ford!
Greg

 

See... I told you there were a LOT of people who know a lot more than me. Oh well, I looked smart for a few hours. :blush:

Keep us up to date on the restoration progress that your aquaintence's make. I love to see restoration photos and hear stories. There's something to be learned from every car as far as I'm concerned.

Josh

 

Hay
if you need any bits or parts for your shelby and you are in europe
there is a place called stateside auto parts the owner has worked on american cars for years and has a parts shop and carries everything in stock very he doesnt have anything in stock.
good luck on your restoration
Dave