Please lord, give me the ambition to start fabricating my fuel system this week...


Stay tuned - 412 inches, XR288HR cam, afr 195s, 1,000 cfm 4bbl, holley singleplane and of course a '730 ECM w/ wideband.


-- Joe

 

subscribed..interested to see how those heads do with a cam that size on a 412" motor. My buddy has an oddball 408 (350 block with alot of stroke) and the next size up 294hr cam with AFR195's and he runs mid 11's, and made 530-ish whp with a 150 shot i think? Seems to run pretty good but I think it could use more head

 

Good question. A typical AFR combo is the 195s on a 383 with the same cam, but less compression. That build made around 500hp. I'm at just under 11:1. Curious to see how much spark advance I can get away with on 93 octane.

This will be an open loop only setup. Will tune the fuel map with a wideband, and may run a knock sensor just for safety but no closed loop. I'm not even going to try with this cam.

I have a 250 shot under my workbench, but I think I'm already at the limitations of a 2 bolt 400 block... Plus I have a manual trans and without a window switch nitrous = scary.

-- Joe

 

I'd be more scared of those rods than the block. I know a lot of machinists who won't use them. The big end doesn't like to stay round.

 

You could probably get it to run closed loop with some effort but open loop is much better for stuff like this That cam and 195's on a 383 makes for a good combination of parts. This 412 should be no different but I am starting to think all 400 motors running over 6000 rpm should be using minimum of 210cc heads Even 5500+ probably wouldnt hurt. 6500+ 220cc heads or larger depending on cam type and compression. big bore motors need air flow and make plenty of torque to deal with any low speed air issues in the larger heads.

I've known a few racing buddies spraying 150 shots on their 11 second or quicker 400 blocks and done fine for a few years. One cracked the block finally but its been 9.8's doing so. they can hold up sometimes.

 

This combo, according to EE pro, should be done by 5800 or so, so probably shift around 6,000. The cubes take a lot out of the cam. If it was a solid roller (7k motor) probably a 210cc would be the ideal application.

I wanted something that could make enough power down low to use an overdrive gear (which I don't have yet, but still) so I could drive it to work without waking up the neighborhood.

We shall see how it goes. I'm also building a 700sq foot addition on my house so I'm juggling multiple things.

-- Joe

 

If all goes well I'll start the plumbing next week.

We're going to go with a Vortec/LSx style fuel pump sender (has built in baffled bucket) with a 255lph walbro pump. GM to -6AN adapters and braided -6AN fuel hose for the supply. May use a combination of -6AN braided hose and 3/8" steel line for the return.

I won't use the built in regulator on the pump, but instead use a rail mounted regulator for adjustability.

-- Joe