400 cam selection

I'm building a 400 with aussie heads and TMI pistons for my 4x4 F250. The cam that came with my rebuild kit is a Comp Cam 255DEH. For what its worth, I ran the numbers through the desktop dyno. I get 464 ft/lbs at 2000 and 300 hp at 4000. Sounds like it is going to be a stump puller, but I'm afraid it will fall on its face after it gets wound up. I'm thinking about swapping to another cam to extend and flatten out the torque. I've been looking at the Comp Cam XE262H. This one should also give a good lope at idle.

Any suggestions/experiences with a 335 series engine like this?

only thing i would be worried about is compression ratio with those heads on a 400 sends it through the roof unless you have dished pistons from what ive read and heard about from other guys maybe someone else can chime in

depends on which TMI pistons he's got, tim sells two different versions of his special zero deck pistons, both are rated at 9.5:1, only difference is one is dished teh other is a more flat top for stock open chamber head, which are the ones i bought, i'm wishing now that i had gone with the dished ones and a set of aussie or cleveland 4v closed chamber heads, as far as a cam for these motors go, well, the possibilities are endless, but i will tell you what cam research told, me, they said for what i wanted to do with mine is pretty much teh same as what you are prollly gonna do with yours, lookin for torque and driveability, they said i needed a 520 544 lift and a 224 and 234 @ .050 duration, they said thatd get me what i wanted out of it with the stock 2v head

Originally Posted by fordmonsta

520 544 lift and a 224 and 234 @ .050 duration, they said thatd get me what i wanted out of it with the stock 2v head

yeah and it's smooth as glass idle when it warms up. NO lope at all! Sounds like a stocker.

Originally Posted by BUCKETOBOLTS

I'm building a 400 with aussie heads and TMI pistons for my 4x4 F250. The cam that came with my rebuild kit is a Comp Cam 255DEH. For what its worth, I ran the numbers through the desktop dyno. I get 464 ft/lbs at 2000 and 300 hp at 4000. Sounds like it is going to be a stump puller, but I'm afraid it will fall on its face after it gets wound up. I'm thinking about swapping to another cam to extend and flatten out the torque. I've been looking at the Comp Cam XE262H. This one should also give a good lope at idle.

Any suggestions/experiences with a 335 series engine like this?

Best bet is to talk to Tim as he has experimented with a lot of cams and he is well versed in using Aussie CC heads on the 400. Also, you may want to talk to danlee on the FTE site as he has worked with Tim and he has spec'd cams for other 400 builders. I think danlee posts over here sometimes so you may be able to PM him. I believe the 400 that was used in the FordMuscle article was danlees motor. Hope that helps.

--J

also another thing to look for in a cam for a 400 is just keep in mind that most cams are rated as a cleveland which is 49 cubes smaller, so if it says it'll chug like hell at idle in a 351 it'll prolly idle pretty good in a 400,

"also another thing to look for in a cam for a 400 is just keep in mind that most cams are rated as a cleveland which is 49 cubes smaller"

Definately. I see a lot of 400s and stroker Clevelands that are undercammed.

What's the compression and what rpm do you want for the power peak from this engine?
What's the rest of the combo such as the carb, intake and exhaust details?

My pistons are the 30cc "0" deck that should give me 9.5:1 with the aussie heads. Other pieces are an Edelbrock Performer 400, Holley 670 Street Avenger, and 1 3/4 headers. The truck is a 78 F250 4x4 regular cab long bed, 33x12.50 tires, and 3.50 gears.

For instance, I built a 393W for my Bronco. I run 9.5:1 dished pistons, stock D5TE heads, Performer, 600 Holley, and 1 1/2 Headers. I picked out the FRPP M50 ('95 Cobra "R") cam. Specs out at .453" lift, 210/220 @ .050, with a 114 LCA. Looks like a boat cam, idles like a stock cam, and pulls my 4200 lbs rig very well, but seems to fall on its face above 4000 rpm. I know the heads may contribute to the choking of this engine. But it doesn't see 4000 under a load very often.

The F250 will probably never leave the pavement. Though I may try to use it to tow the Bronco to and from the trail.

Like I said before, I have been looking at the Comp XE262. Comparing apples to oranges, I have seen a similar cam used in SBC's. Has a very street rod/muscle car idle with good vacuum. It clears up just off idle and makes plenty of torque. My friend swears by it and has used it in everything from Cameros to 1/2 ton 4x4's.

It just depends what you're looking for as the power range. I don't go by the rpm range listed by the cam company or how the cams perform in a Chevy...but as far as the XE262 in a 400 with the other parts mentioned, I'd say you're looking at around 350HP @ 4700-5000rpm.

If you want it to pull past 5K and be making power closer to 400HP you'll need something more aggressive. Something in the mid 220 range at .050 like a Comp XE268, the "520 544 lift and a 224 and 234 @ .050" cam suggested, or like a Lunati Bracket Master II (224 int./234 exh. 536/562 lift).
http://store.summitracing.com/partdetail.asp?part=LUN%2D00093LK&autoview=sku

With the factory 3.50's and 33" tires my cruising RPM's should be around 1600 @ 45mph and 2200 @ 60mph.