R Model Heads, Cam and Intake

[g.ride.garage]

I was wondering what the correct heads and cam were for the 1965 R model engine? Also were there any modifications to the intake manifold (porting)? I get conflicting information when I search the internet.

Thanks.

[gt350hr]

 The heads were production C5OE hipo heads with the banana water ports welded by HydroHead out here in California. Pallets of these modified heads were sent to both Mondello and Valley Head Service for full portind and combustion chamber work along with the "chevy valves".
The intakes were ported ( as the small letter Cobra intakes were small ) and the last runs built in '66 used large letter intakes also ported. The camshafts were ground by Engle ( a California grinder) and often their HL56 profile. One way we used to tell original heads was by the stamp noting how much they were milled and blue anodized aluminum retainers for the valves. I still have one set of original heads and one cam.
   Randy

[g.ride.garage]

The heads were production C5OE hipo heads with the banana water ports welded by HydroHead out here in California. Pallets of these modified heads were sent to both Mondello and Valley Head Service for full portind and combustion chamber work along with the "chevy valves".
The intakes were ported ( as the small letter Cobra intakes were small ) and the last runs built in '66 used large letter intakes also ported. The camshafts were ground by Engle ( a California grinder) and often their HL56 profile. One way we used to tell original heads was by the stamp noting how much they were milled and blue anodized aluminum retainers for the valves. I still have one set of original heads and one cam.
   Randy

Would you happen to know the specs on the camshaft? Also do you know how much the heads were milled?

[mygt350]

Randy, would you happen to know specs of the R-model cam?

[68countrysedan]

According to the 1966 Shelby American Performance Equipment parts catalog, the competition  GT350 road racing engine (PN S1CR-6003-3) had the following cam installed:

Valve lift: 0.445 in
Intake Opens: 29 deg BTDC
   "       Closes: 75 "    ABDC
   "        Duration: 284 deg

Exhaust  Opens: 75 deg BBDC
    "        Closes:  29  "   ATDC
    "         Duration:  284 deg

Intake /Exhaust tappet clearance (hot): 0.018 in

Specifications taken at 0.001 in valve lift

The cam and lifter set was PN S1CR-6250-2

Unknown if this is the identical cam installed in 1965 GT350 R, but it's a start.


As for full competition cylinder heads, the catalog lists PN S1CR-6049

Ports are enlarged and polished.

-Intake: 2 1/16 in x 1 1/16 in
-Exhaust: 1 1/2 in x 1 1/16 in
-I/E Valves: 1.875 in / 1.600 in
-Heads are milled 0.050 in and water ports are welded prior to milling
-Combustion chambers are polished and volume is 47cc.

Hope this helps.

     

[6s2020]

The heads were production C5OE hipo heads with the banana water ports welded by HydroHead out here in California. Pallets of these modified heads were sent to both Mondello and Valley Head Service for full portind and combustion chamber work along with the "chevy valves".
The intakes were ported ( as the small letter Cobra intakes were small ) and the last runs built in '66 used large letter intakes also ported. The camshafts were ground by Engle ( a California grinder) and often their HL56 profile. One way we used to tell original heads was by the stamp noting how much they were milled and blue anodized aluminum retainers for the valves. I still have one set of original heads and one cam.
   Randy

Rogers Porting Service, North Hollywood were also used by SAI to modify heads.

[gt350hr]

  SAI also used Lockerman porting service on occasion as well as Slover's. The majority were done by Mondello or Valley. The amount of "deck milling" varied by the "net" combustion chamber volume needed.
     I don't have a cam card for my HL56 IIRC it was similar to the ''not yet made" LeMans cam but a little smaller.

[shelbydoug]

  SAI also used Lockerman porting service on occasion as well as Slover's. The majority were done by Mondello or Valley. The amount of "deck milling" varied by the "net" combustion chamber volume needed.
     I don't have a cam card for my HL56 IIRC it was similar to the ''not yet made" LeMans cam but a little smaller.

There wasn't a lot of lift in any of those period cams and a 500+ is very common today.

Was there a tech reason why or is 500 just a waist of time?

[SFM5S000]

Here's a sample of the welded "banana ports"  also note the milling of the head surface essentially took away or removed the "thumb pads" indicating how much of the head surface was removed. In this case these chambers cc measure 47cc's as noted by the "47" stamped on the end of the heads. As others have mentioned SAI had other vendors doing port work, though Valley Head and Mondello did the majority. These particle set were done by Louis Unser having the HU head stamp which Randy G help me identify. These heads I run on my car.

As for the "R" model manifold mods, in addition to the port matching this was another detail which was typically done. (See pic). I got this manifold from Jim Cowles RIP. Even though I still prefer my 48 IDA Weber's.

And lastly, though not THE "R" Model cam but what it became; the C7FE aka LeMans Cam. Later rendition.

Noting Shelby Doug's cam lift  question. As I recall. Longer duration with shorter lifts in or around .500+- profiles provided better scavenging and breathing at sustained higher RPM's versus high lift short duration were better suited to drag applications. This is what I remember. I'm sure Randy will correct me, but again as I recall that was the mind set. Anyway...

Cheers,
~Earl J

[gt350hr]

   The "around" .500 lift "was" due to stock rocker arm capability , camshaft technology ( at the time .500 was allot) and valve spring materials. The LeMans cam was known at Ford as SK 27337 before being SK 882 ( the H&M version), C6FE-B and eventually C7FE-A. the basic lobe configuration didn't change. This cam was "created" by Don "Pop" Sullivan (rip) a noted camshaft expert at Ford. SAI experimented with cams from Isky , Potvin, and Crane , as well as Ford and Engle "in the day". It is important to remember R model engines were CAST flat top ( reworked valve pocket) pistons with "pressed" pins and "stock" hipo rods for the first year.
   Randy

[paul]

Earl J,
   what type of piston and what compression ratio is your motor with those 47cc heads?
Thank you, Paul.

[SFM5S000]

Hi Paul,
As I mentioned these heads are on the car. Randy Gillis had a custom set with a -17cc "dished" pistons netting a hair over 10:1 CR (compression ratio) I went with them. A flat top piston with just eye brows would have pushed the CR over 11:1 - 11.5:1 somewhere in that vicinity.
A little too much to run on today's pump gas. I'm good with the performance for what it is for the most part, but every now and then do I wish it were higher? And deal with needing a better grade of fuel? eh? Sometimes
As mentioned before, just about ANY of today's aftermarket aluminum heads will out perform these. Again, it's okay by me. (You know my car).
Cheers
~Earl J

[Helmantel]

According to the 1966 Shelby American Performance Equipment parts catalog, the competition  GT350 road racing engine (PN S1CR-6003-3) had the following cam installed:

Valve lift: 0.445 in
Intake Opens: 29 deg BTDC
   "       Closes: 75 "    ABDC
   "        Duration: 284 deg

Exhaust  Opens: 75 deg BBDC
    "        Closes:  29  "   ATDC
    "         Duration:  284 deg

Intake /Exhaust tappet clearance (hot): 0.018 in

Specifications taken at 0.001 in valve lift

That cam has rather wide lobe separation angles at 113/113. The LeMans cam had much narrower angles at 107/109 while the Hipo cam had both narrower (intake) and wider (exhaust) angles at 109/119.

[shelbydoug]

Why was it necessary to weld up the 'banana ports'?

[Dan Case]

I think I read a long time ago it was part of making the decks more rigid to resist head gasket failure. The ports in the heads were welded up and the steam holes in the block were often drilled and tapped for threaded plugs.  They sometimes used metal  wire or metal o-rings pressed (hammered into) grooves around chambers.  The ex-Le Mans GT40 heads (the GT40 owner traded me for a set of modern aluminum heads and some cash) we are using in our red car got metal o-rings around the chambers in them. When Joe Mondello and I worked on my project he and an engineer at Felpro® determined what modern head gasket to use along with the rings. Mr. Mondello freshened the heads for my project.

I gave away all my GT350 related magazines a long time ago but circa 1965 there was a comprehensive article with lots of pictures of how Cobra / GT350 racing long blocks were being prepared at the time.  Maybe some reader here has a copy and can quote why "banana ports" were welded up.