Hot Rods Torque cam for low compression 350

Hello all if you have seen any of my other posts in building a 350 crate engine for my a body tempest its a stock 260hp unit with 882 style heads and damn near a flat cam I have stock highway gears 2400 stall on th400 and I'm looking for more low end punch to start this ones life itll have 1 5/8 shorty headers 2 1/4 duals turbo mufflers aftermarket new HEI with no power steering no a.c. I highly doubt this engine will ever see north of 5000 rpm so I want low end grunt to off set the high rear gear ratio and to enjoy my power but I refuse to sacrifice any reliability as this is a daily driver. I also want to get what I can from the 2400 stall(chose this because it was the lowest offering form the trans company....sbc grunt cam for smog heads 8.5:1 compression....school me on torque cams that can be used with my set up....thanks guys!

 

Towing, Rv or truck / 4x4 designated cam.

The 2400 converter is the odd ball part but I think you've heard that already

 

Yes I've been schooled lol so is there a converter that would suit this style of cam I'm looking for? I'm in serious send it back mode for a lower stall but this now brings me back to the drawing board for researching converter companies ...many people use tci but would I want an economy style converter or a mild performance (slightly more stall than stock)???

 

also what would my max duration and lift need to be with 8.5 to 8.1 compression??? Want to make torque not high rpm power to make up for my current sub 3.0 rear end gear ratio...thanks

 

If you want more torque across the board,I would have a bit of material milled off those heads,and run the thinnest head gasket you can.
On real low budget,making something outta nothing builds,I have had lots of luck with the old Cam Dynamics/Crane 270 degree advertised flat tappet hydraulic on 289/302 Fords,but never done a 350 Chevy for that type of setup.
I think the Comp Cams 268 would probably be a decent one,or this one from Isky:
http://iskycams.com/cart/index.php?main_page=product_info&products_id=368
If you run a steel shim head gasket,and mill the heads a touch,you can get up around 9:1 compression and take advantage of what an aftermarket cam has to offer.

Scott



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Look for an 1800rpm converter, no higher.

Drop the exhaust diameter to 2". You want proper cylinder scavenging at the steady-state cruise RPM, not necessarily the peak power point.

Run a carburetor no bigger than 500cfm. The electric choke Edelbrock one will do nicely. You want a carburetor that properly meters fuel at the steady-state cruise RPM, not necessarily the peak power point.

I would not go over 260º (advertised) on the cam, maybe less. Get the highest lift that can be had, at that duration. Install it with an adjustable timing set, at 3º advance. Make sure that you get, and use the valve springs that go with the cam. Look for a narrow LSA, rather than a wide one. Think more 108º (or less), rather than 112º.

 

I had a large journal 327 in an impala and used a compcam 268 adv duration high energy but if you go that much u need to change your valve springs. (What gimpy recommends would be better). I ran a 2-2400 converter and stock rear end. Maybe u should use a 1800-2000 depending on the cam you choose. I would change the rear end gears maybe to a 3:55 , 3:73 I felt like that's what was missing from my set up. It ran 15.8 in the 1/4 mile on street tires. Go to the camshaft sights they have recommendations for the cam profile your looking for. TCI converters are expensive. I've bought 2 recently 1 auction sight believe Oregon brand or made there the other from jegs both work the way they suppose to at half the price.

 

The engine will be temporarily be running a holley 500 cfm 4412 and most rv cams I saw are 112 love Sep what are the benefits to a close lsa?

 

I

Was looking at this one

Hydraulic Flat Tappet. Smooth idle. Great for daily driver or towing applications. Works with TBI fuel injection.

• Advertised Duration (Int/Exh): 270/280
• Duration @ .050 (Int/Exh): 204/214
• Gross Valve Lift (Int/Exh): .420/.443
• LSA/ICL: 112/107
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1000-5000
• Includes: Cam & Lifters (#71817PR-16)

Part Number: 10120100LK
This too much for my compression and heads I'm hunting a sub 2000 stall converter to match

 

Looking at 204/214 would 2000 stall be okay??

 

The wider the LSA (Lobe Separation Angle) the more overall torque the cam will make. While that might sound good, it will make that torque at an RPM much higher than your projected cruise RPM.

Most RV's are crankin' high RPM, all-the-time. Not exactly low end grunt.

A tighter LSA will make better torque at a lower RPM. It will fall off as you get towards where the wider one made peak torque, but how often will you be at 4500-5500?

If you put sub 3.00:1 gears in an RV, you would probably smoke the transmission before you got off the line, and certainly climbing the first grade.

 

A narrower LSA will close the intake valve sooner (given same duration) and increase dynamic compression at lower speed. So will advancing the cam.

Do I have that right Gimpy?

 

Crane had a cam that they used to call Compucam. I think it is called Powermax now.

If I recall correctly, they had a 104º LSA, would work with your stock springs, and make excellent low end torque.

 

Yup. So do both. It is a "free" compression upgrade.

 

Okay so what came profile would be recommended given my current setup to increase low end torque? With my highway gears and low compression engine?

 

Let me look at some.

 

Probably something like this:
Crane Cams 114102
"BRUTE LOW END TORQUE"
or
Crane Cams 114112, but that would give up a little low end.

 

Sounds like a good one ill do some hunting

 

Would these work okay with my highway gears as posted before?? Thanks

 

Also guys could I use my chevy lifters that came with the engine if I install it prior to first firing it? Would save me a few bucks

 

It should be good. I forget, did you post an exact gear ratio and tire size?

 

That engine was test cranked at the factory. Not 100% sure that would have a negative effect. I don't like re-using lifters, but I am not sure that yours qualify as used.

 

No idea what the rear gear is for certain its 2.73-2.93 somewhere tire size 225/75/r15

 

I hope they'd still be new haha

 

Probably get away with it with mucho break-in lube (paste) and stock valve springs , and of course ,instant firing and break-in with zinc additive..(I know, famous last words)

 

BTW, as stated, cam advanced 3-4 deg. .Not theoretical ,but actual degree-ing in .

 

I think your lifters are probably OK to use, make sure to put a lot of the moly disulfide lube on the cam and lifter face with the new cam if you do. But seriously, SBC lifters are cheap. Buy a kit that has the matched parts with springs, cam and lifters.

I would tend to go a bit bigger around 260-270 total duration for what you want, since the engine is a 350. A bigger engine tends to mellow the cam a bit. Or put another way, you can run a bit more cam with bigger engine vs smaller engine. Concur on installing it advanced 3-4 degrees to help boost lower rpm torque.

 

If they are 2.73's you will be a little over 2130(converter loss raises RPM some), at 65. At ~3276 you are at 100.


If they are 2.93's you will be a little over 2285(converter loss raises RPM some), at 65.
At ~3516 you are at 100.

You do not want a converter that is above that, in-fact, well below. Otherwise, an unreasonable quantity of fuel will not be used for pushing the vehicle forward, but instead be used to heat transmission fluid.

Heat is the #1 killer of transmissions on the street.

Look at those two RPM numbers at 100. There is absolutely no responsible reason to go that fast on the street. Ergo, there is absolutely no reason to chose a cam profile with a designed RPM range at, or much above that.

So many people miss this.

 

Install what ever you pick with 4 to 6 degrees advance and it will give you the grunt your looking for. Make sure you contact the manufacturer to see if there is ground in. My last Comp Cam had 4 degrees ground in.

 

Thanks for that info lol yeah I've heard bad stories about not using low detergent high zinc for brake in I'm using comp cams brake in 10-30 oil ill use the springs until I swap heads next year to something a little more performance friendly... Can someone give me the lowdown of the degreeing of the cam??? I'm looking at the comp cams 260H and 252H has anyone had any experience with these cams??