Cam for fuelie

[Rob M.]

I'm currently in the process of building up a L84 setup for the '63 coupe and I've got the following cam delivered (see pictures). I can't make up from the specifics if this is the right cam for a solid lifter fuelie setup. Could some of the experts here make the call and explaining me if I got what I need?

thanks,
Rob.

[Duke W.]

Re: Cam for fuelie

CS-113R is the Federal Mogul number for the '57-up 3736097 "Duntov" cam.

The gross lobe lifts are rounded to three decimal places from the .26250/.26650" on the drawing.

The "SAE J604 duration" of 270 degrees is based on .006" valve lift at 1.5:1 rocker ratio (which is .004" lobe rise above the tops of the .008/.012" clearance ramps) with .012/.018" clearance at the valve.

SAE J604 did not exist when this cam was designed in 1956. GM specs of the era listed the "lash point duration", which would be the duration measured between the tops of the clearance ramps - 287 degrees.

Other than the .004" higher clearance ramp on the exhaust side the lobes are identical. At any point measured from maximum lift to the tops of the clearance ramps, the exhaust lobe lift specified on the drawing is exactly .00400" greater than the inlet lobe lift, and the CS-113R should fully comply with drawing number 3736098, which is the drawing for the finished camshaft, not the "casting number".

3736097 is the camshaft and pin assembly part number.

Duke

[Ray C.]

Re: Cam for fuelie

Hi! Rob

The Federal Mogul Seal-Pro CS-113R has been machined to the same specifications as the Duntov "097" cam. I have used this cam in a 1963 340-HP SWC that I sold, a 1961 270-HP and it is currently being installed in a 1961 315-HP Fuel Injected Corvette project.

Ray

[Joe L.]

Re: Cam for fuelie

I'm currently in the process of building up a L84 setup for the '63 coupe and I've got the following cam delivered (see pictures). I can't make up from the specifics if this is the right cam for a solid lifter fuelie setup. Could some of the experts here make the call and explaining me if I got what I need?

thanks,
Rob.

Rob-----


The CS-113R is the correct part number for Speed-Pro/Federal Mogul's reproduction of the GM #3736097, which was the GM part number of the cam originally installed for your stated application.

The specs I see on the box look very close to the specs for the 3736097. The very slight differences I note may be due to measuring differences used by Federal Mogul as opposed to GM or actual slight manufacturing differences. In any event, I don't think you'll find any camshaft closer to the original specs than what you have here. In fact, you might not come any closer even if you were to find an NOS piece.

[Rob M.]

Re: Cam for fuelie

All thanks for your feedback. I'm feeling very confortable now building the engine using this cam!!!

regards,
Rob.

[Timothy B.]

Re: Cam for fuelie

Just for my own information, does this camshaft look like it's parkerized and what is this treatment?

Also, intake centerline at 108 is ATDC and exhaust centerline at 112 is BTDC correct??

[Joe L.]

Re: Cam for fuelie

Just for my own information, does this camshaft look like it's parkerized and what is this treatment?

Also, intake centerline at 108 is ATDC and exhaust centerline at 112 is BTDC correct??

Timothy----


From the picture of a section of the cam in the original post, the lobes appear to be parkerized.

[Gary C.]

Re: Cam for fuelie

Rob, always like to use lifters from the same manufacturer as the cam and/or their recommended part number to use with that cam. Gary....

[Larry M.]

Re: Cam for fuelie

Just for my own information, does this camshaft look like it's parkerized and what is this treatment?

Also, intake centerline at 108 is ATDC and exhaust centerline at 112 is BTDC correct??

Parkerizing is a method of protecting a steel surface from corrosion, and increasing its resistance to wear, through the application of an electrochemical phosphate conversion coating. Google the term for additional info.

Most, or all, cams years ago were parkerized. No sure anymore. It costs more. May also be one of the reasons we now have more cam lobe failures.

Larry

[Duke W.]

Re: Cam for fuelie

Just for my own information, does this camshaft look like it's parkerized and what is this treatment?

Also, intake centerline at 108 is ATDC and exhaust centerline at 112 is BTDC correct??

Points of maximum lift are 108.5 deg. ATDC and 112.5 deg. BTDC. You figure out the "centerlines". I just deal with POMLs.

Parkerizing aids the breakin process. AFAIK it was used for all OE cams and is used by FM and Crane that are the only two vendors I know of that manufacture cams to the original print dimensions and specifications.

The dark mottled gray surface indicates this cam is Parkerized, however, it should be polished off the journals.

Duke

[John D.]

Re: Cam for fuelie

Duke, I never knew that the 6098 number on the cam was not a casting number but the number on the finished drawing. That's very interesting.
There is a lot of history to how that CS113R evolved.
In the 70's it was sold by TRW and was known as TP113. Then Sealed power took over and called it CS113R. Then you know the rest. Sealed Power was taken over by FM and now it's in their box and but still known as CS113R.
I think anyone who plans on rebuilding the 57 to 63 engines would be wise to stock up on this cam as it's quite affordable and God only knows when it will be discontinued. I have been pushing this cam for many years for the 57 to 63 FI owners. My 63 the LWC has this cam. But the scary part is most anything I really like anymore seems to disappear or be discontinued. In fact the local aftermarket auto stores seem to have a hard time getting this cam. Makes me nervous. John D.

[Duke W.]

Re: Cam for fuelie

I've stated many times before that the number on the cam is the number for the finished camshaft - NOT THE "casting number" that everyone calls it. For example drawing number 3736098 has the detailed lobe data. Drawing number 3736097 is a small (A-size) drawing that just shows the pin and the front of the camshaft.

The same applies to all other OE camshafts.

The piece we buy is an "assembly" of cam and indexing pin. There is no "casting number" per se as none was needed to differentiate castings. The finished drawings also have dimensions for the "as cast" lobe geometry.

Each OE cam had a unique casting to minimize the amount of required grinding in high production. AFAIK there is only one aftermarket blank made by CWC Textron from which all currently available OE replacement and aftermarket cams are ground.

I doubt if the Duntov cam will ever become "unavailable". I don't think Crane lists it as a standard product, but I know they have lobe masters and can at least grind it as a custom product.

Notwithstanding the above, I still recommend the LT-1 cam to replace the Duntov and 30-30 in all mechanical lifter 327s, but not necessarily 283s, and I still recommend that someone with a 283 with small port heads have the Duntov ground at 110/118 POMLs, which will broaden the torque bandwidth, but slightly tame the idle characteristic.

Duke

[Michael H.]

Re: Cam for fuelie

Notwithstanding the above, I still recommend the LT-1 cam to replace the Duntov and 30-30 in all mechanical lifter 327s, but not necessarily 283s, and I still recommend that someone with a 283 with small port heads have the Duntov ground at 110/118 POMLs, which will broaden the torque bandwidth, but slightly tame the idle characteristic.

Duke

Incredible !

[Timothy B.]

Re: Cam for fuelie

In my thinking the J604 SAE specs for a cam would be good figures to determine intake valve closing to establish compression ratio. I have never understood why .050 timing points are listed.

I like these cam conversations, I also remember the LT1 cam from my youth and it IS sweet. I think the engine would just rev forever and the power does start low in the RPM range. Would I install it in my restored correct motor? Probably not, but only because I have this NCRS thing.

[Duke W.]

Re: Cam for fuelie

The inlet closing point for computing the DCR is arbitrary. Some use the SAE J604 closing point. The KB piston web site uses the .050" closing point plus 15 degrees. Most calculators don't even tell you what they use relative to what input is required.

That's why DCR is nothing more than a loose guideline, but most guys seem to hang their hat on it like it's the holy grail.

Just goes to show you...

Duke