Solid lifter camshaft

[David H.]

I see an ad in the latest Driveline (page 46) for a "097 Duntov Camshaft 1957-1963.
"An absolute correct reproduction of the dual pattern camshaft part # 3736097 originally designed for all solid lifter Corvette engines from 1957-1963. Same specifications, exact sound, manifold vacuum, valve adjustment".
Does anyone have any experience with this camshaft as a replacement for my 327/340hp 1962 car?
Can someone confirm that this part number 3736097 is the original camshaft for this engine?
Or should I just use the NAPA one that Duke recommended?

Thanks

[Joe L.]

Re: Solid lifter camshaft

I see an ad in the latest Driveline (page 46) for a "097 Duntov Camshaft 1957-1963.
"An absolute correct reproduction of the dual pattern camshaft part # 3736097 originally designed for all solid lifter Corvette engines from 1957-1963. Same specifications, exact sound, manifold vacuum, valve adjustment".
Does anyone have any experience with this camshaft as a replacement for my 327/340hp 1962 car?
Can someone confirm that this part number 3736097 is the original camshaft for this engine?
Or should I just use the NAPA one that Duke recommended?

Thanks

David-----


GM #3736097 is the correct original part number for the camshaft for your application.

[Duke W.]

Re: Solid lifter camshaft

Calling the Duntov cam "dual pattern" is somewhat of a stretch. The 228/231 .050" lifter durations occur because the .012" high exhaust clearance ramp is .004" taller than the .008" high inlet clearance ramp. Other than this, the inlet and exhaust lobes (and therefore the inlet and exhaust valve motions) are the same.

If you study the GM drawing you will see that at any point above above the tops of the clearance ramps, the exhaust lobe lift is exactly .004" more than the inlet lobe, which is due solely to the .004" higher clearance ramp. Take out the clearance and only look at the opening and closing flanks, and both lobes are identical.

Since the .050" lifter rise durations of mechanical lifter cams include the clearance ramps, they cannot be directly compared to hydraulic lifter camshafts because the valve doesn't even begin to move until lash at the valve is taken up, which is clearance ramp height time rocker arm ratio (actual, not "advertised").

For example, the Duntov cam durations at .058"/.062", which factors out the clearance ramps are 220/220, which is what you should use to compare to a hydraulic lifter cam. So duration is very close to the L-79 cam, but the L-79 cam has more lift (good) and less overlap (good). Also, the Duntov has some pretty harsh dynamics (bad) that Chevrolet learned about and eliminated in cam designs from the early sixties on.

Likewise the durations of the other OE mechanical lifter cams can be "converted" to approximate hydraulic lifter equivalents when factoring out the clearance ramp heights, which are listed first.

30-30 - .017/.017, 239 239
L-72 - .012/.012, 231/231
LT-1 - .012/.017, 231/239

If some of the above data seems to repeat, it's because the LT-1 cam uses the L-72 lobe (with a smaller base circle) on the inlet side and the 30-30 lobe on the exhaust side.

As far as the world knows, the Sealed Power/Speed Pro CS-113R from Federal Mogul meets all the specs of GM drawing 3736098, which is the finished "Duntov" camshaft drawing with all the lobe details and manufacturing notes.

3736097 is the assembly of cam and indexing pin, which is what GM sold over the counter. They did not sell finished camshafts without the indexing pin.

Duke

[John D.]

Re: Solid lifter camshaft

David, Jeff Reed's replacement 097 cam in "The Driveline". Several of my customers were/are quite pleased with the cam.
Call Jeff up and ask for the spill on the cam. You will be impressed.

Now I am not saying Dukes info on nice LT1 cam is not correct though. Been around here tooooo long to say that.

[Joel F.]

Re: Solid lifter camshaft

Anyone know what Jeff is charging for his cam? Does he include lifters or do you need to get them at Jegs?

[Bill B.]

Re: Solid lifter camshaft

This camshaft was considered a cheater cam back in the early 60's. Many believe it's the answer to what the 096 Duntov was ailing. Others believe it’s too hard on the valve train. Either way it’s a real screamer.

Schneider Racing Cams

Grind Number 274/76F
Gross Duration Int 274 Exh 276
.050 Duration Int 230 Exh 234
Lobe Lift Int .320 Exh .330
Valve Lift Int .480 Exh .495
.050 Valve Intake Opens 7 BTDC Closes 43 ABDC
Exh Opens 49 BBDC Closes 5 ATDC
Lobe Sep 110 Degree Int 108
55 deg's Overlap
Lash set Int & Exh @ .014"

Bill

[Michael R.]

Re: Solid lifter camshaft

i belive crane cams are back . they made a 097 cam i have used them in the past. and always use the breakin oil.