after reading a bunch of posts on cams it seems that the hot set up is a roller cam with a 260/270 dual profile.where can one find this cam?is it a custom grind?also what machine work needs to be done in order to run a roller set up thanks

 

I've got the Crane Cams small one and there was no machine work as such. You do have to pay close attention to push rod length and springs. I would work with a competent machine shop if possible to make sure the geometry is correct.

 

I am using a Predator Custom 284/284 hydraulic roller cam in my 400. There is no question that a 260/270 will give better low RPM torque. My custom cam cost less than many off-the-shelf cams.

I used a Comp Cam 31-1000 Ford Retro-fit Hydraulic Roller Cam Kit, and 5.0 Liter Ford Replacement Roller Lifters. This was much cheaper, than the aftermarket Roller Lifters with the bar link. I did have some minor block machining to do, however.

My heads take 3/8" rocker studs and guide plates, so I used adjustable roller rockers and 8.8" hardened pushrods. I determined the length of the pushrods after assembling the valvetrain and using a Pushrod Length Checker.

My cam requires 145 lb closed, double valve springs, so the springs seats had to be milled so the springs wouldn't bind at 0.595 lift.

I was able to do all the work, except for the springs and spring seats which was done by a local machine shop. He was doing the valves as well.

 

The last time I talked to Comp cams they would grind a custom cam for about the same price as a std grind but you had to wait 6 weeks for delivery and of course the cam was not returnable.

I plan on using a 260/268 HR cam in my 400 truck engine.

 

what are the specs on the 260/268 cam,if you dont mind me asking.that sounds like the hot set up.im going to use an edelbrock performer intake with a q-jet,badger pistons (hope to end up around 9.2:1),and some work on the exhaust ports any idea how much power this set up will produce with that custom cam?also,are roller rockers nesasary with a roller cam set up thanks

 

260/268HR seat to seat
IVO 24
IVC 56
EVO 68
EVC 20
Lobe centers 110
Lift at valve:
Intake 0.510
Exhaust 0.555

I think Danlee has run the figures thru his dyno setup for this cam.

 

With ported 2V heads, 9.2:1 CR, 600 CFM carb, dual plane intake, headers, and a 260/268HR cam (using solid lifter ramp rates), I get Torque = 472 ft-lbs peak @2500 (flat to 3500 RPM), and horsepower = 362@4500 RPM.

I don't know how you will put a q-jet carb on a square bore performer intake. If you can do it provide the CFM and I'll plug it in.

 

You can get a bit more if you pay close attention to your heads.

 

Pocket Porting and a 2.15" Intake Valve have been shown to make improvements in head flow.

 

After the cam itself the most important part of the engine is the heads. I have seen many people put lots of trick parts into an engine build and leave the heads in an "as cast" condition without even a minimum amount of cleanup, -very sad...

 

thanks for all your help!ive been running the q-jet for about a year now i bought the kit from bcbroncos and used a kick down from lokar.the carb is a 750 cfm.ill bet going from a spread to a square knocks a little off of that but i dont think it matters on such a low reving engine.if if i can keep my foot out of it,it also gets better milage than the stock 2 barrel.The biggest benifit though is off road,its like poor mans fuel injection.

 

In case anyone is interested in my cam.

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Main > Vehicle_Type - Auto > Cylinders - 8 > Engine_Make - FORD-MERCURY > Year - 1977 > Engine_Size - 351M-400 C.I.
Camshaft Specification Card BACK TO LIST
Part Number: 529541 Grind Number: HR-216/325-2S-12
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1970 1982 FORD-MERCURY 8 GOOD IDLE, DAILY USAGE, PERFORMANCE AND FUEL EFFICIENCY, OFF ROAD, TOWING, 2400-3200 CRUISE RPM, 8.75 TO 10.0 COMPRESSION RATIO ADVISED.BASIC RPM 2000-5500
Engine Size Configuration
351-351C C.I. V

Valve Setting: Intake .000 Exhaust .000 HOT

Lift: Intake @Cam 325 @Valve 562 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 339 @Valve 586
Rocker Arm Ratio 1.73

Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 28.0 BTDC 70.0 ABDC 278.0 °
Exhaust 76.0 BBDC 30.0 ATDC 286.0 °

Spring Requirements: Triple Dual Outer Inner
Part Number 99890
Loads Closed 132 LBS @ 1.875 or 1 7/8
Open 364 LBS @ 1.315
Recommended RPM range with matching components
Minimum RPM 2500
Maximum RPM 6000
Valve Float 6500

Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 1.0 BTDC 35.0 ABDC 107 216.0 °
Exhaust 49.0 BBDC (5.0) BTDC 117 224.0 °

Remarks:
FOR ENGINES NOT ORIGINALLY EQUIPPED WITH HYD. ROLLER CAMSHAFTS. REQUIRES 36532-16 HYD. ROLLER LIFTERS AND SPECIAL LENGTH PUSHRODS. USE A CRANE BRONZE OR STEEL DISTRIBUTOR GEAR TO PREVENT WEAR.