Hi everyone,
Have been following TC for sometime now and I know that most cam selections are for street/strip vehicles so I know my request is a little out of the ordinary. I would like to use a hyd flat tappet Lunati cam for this engine. It will hardly ever see 4500rpm but will need to pull as hard as it can from 1800 to 3500rpm. Cruise rpm is 2300rpm. I would like 500lbft. Engine will sport vortec heads, performer manifold, 6 inch rods with appropriate pistons to achieve 9.5 to 1 compression, 1 5/8 long tube headers. It is really nothing fancy or exotic but your replies will be very much appreciated. There are just to many cams out there for me to make the right decision and not second guess myself.

Thanks, Brian

This is the smallest Lunati I could find, still too large in my opinion.

06103 HYDRAULIC, Noticeable idle. Good all around cam for everyday driver. Power range 900-4800, 270°/280° adv dur, 204°/214° duration @.050", .420"/.442" lift, .280"/.295" lobe lift, 112° Sep/108° Int C/L, timing events: 06°ATC 30°ABC / 43°BBC 09°BTC, 06103 cam, 06103LK cam and lifters

EA3.0 shows a significant gain in the torque below 3000 rpm using a cam about 10 degrees smaller at .050", like the Wolverine WG-1128. 9.5:1 is a lot of compression for this engine.

Chevy hi-peformance mag. did a 406 useing the same heads and compression and the used a lunati cam with 230*@.05 and .480 lift cam. I don`t know the grind number but they did a couple different stories and it made more than 500ftlbs of torque. maybe someone here could find a like for you.

The engine is called The Impersonator, linked here:

http://chevyhiperformance.com/techarticles/148_0401_imp/index2.html

If you notice the dyno graph, they start the test at 2500 rpm's and go to 5500 rpm's, well out of the range this truck will be using.

I have been "mentally designing" an engine for my daily driver 84 Suburban that sounds very similar to what you want. Max RPM about 4500, maximum torque at around 2000.

It will be a 400 SB. I want a small FT hydrualic cam, SR Torquer heads(I need the heat cross-over for the winter), 9:1 SCR, Performer & Q-Jet.

I talked to Ron Iskendarian At Isky and the cam that he recommended was there 256/262 Supercam. Looks like it would make killer torque, especially in a 400. graemlins/thumbsup.gif

http://www.iskycams.com/productdisplay.php?productnumber=201256/262&sku=3810&hdwt=31101&loc=101&dealer=no

I have been withholding a little info here to see what sort of a response I would get and sometimes these low rpm torque engines are just as hard to choose cams for as are high performance engines.I picked up the manual How to Build Big-Inch Chevy Small Blocks and they have a 406 in there using a Lunati 230/230 @ 0.050, .455/.455-inch, 114* lobe separation cam. Their dyno results gave them 472lbft @ 2400, 525lbft @ 3500 and a peak of 427hp @ 5100. 9.5/1 comp ratio, 35* ignition timing, vortec heads, RPM air gap, HP 750cfm Holley carb and 1 5/8 headers. I guess I am a little scepticle, this cam seems a little long on duration to make these kind of numbers. What do you guys think? I am no means an expert nor have I built a 400, yet. [ Had one in 1977 in a 3/4 ton, what a gutless pig.]

Thanks, Brian

Imho, if you go with big valves and a Lunati 275/225 cam on 108/104 centers, (PN 07101), you are looking at very close to a 392hp at 5000 and 455t at 3500 rpm motor...

And if you go with a CC 260HE cam, you are about a 351hp/4500 and 470t at 2000rpm motor..

And this one will have almost a dead flat torque curve up to 3500rpm, (470 to 462t!!)..

Find a solid equivalent cam to the 260HE and you jump to 372hp and 489t at the same rpms!!!!

Perfect, imho, for your truck if that is what you want??

pdq67

I thought my 405 would be a big stump puller. But it comes on hard at around 3500 rpm and the cam is 224/230@.50. I am not sure your smaller heads(my are afr190s) or headers(mine is a 1-3/4inch, would make a big difference, but I would pick a smaller cam if I was you.

Many years ago there was a mag article by Vizzard on a 350. He ended up with a crane H-272-2 cam and roades lifter. He said for more torque below 2500 go with the H-266-2 and a stock 69 Qjet intake.
I didn't see a huge diff with the roades lifters in the curve and thought the cam was a little small to even consider them. But I was a teenager...
What I got from it was that a 216/22x 112 lsa crane cam was about the biggest you can go w/o starting to loose torque below 2500. I think Vizzard said something to that effect and along the lines of you make more everywhere in the usable range up to a 216 @050.
Now this is a 400, not a 350 like the test.
I recall reading other things along the lines of trucks pulling better at speed with a similar sized cam like a 266 or 272. You trade a little at 1500 for more at 25-2800.
With a 9.5 CR, I'd lean to the 272.
Look at some of UDH's Hyd cams. He has comments about towing and such in the description.

W/o an OD trans, it's real hard to spend a lot of time @1800 rpm.

oh, and the qjet intake was better below 2500 compared to the then new performer intake.

68chevelle533, check comps site for dyno tests on the xe cams. The 268xe has a relatively large exhaust lobe which screws with the torgue curve/output.
With 195's, You would probably do better with a HE268 or 270Magnum. Or UDH's 272/272 solid....