408 hp????

[bermblaster41]

Just ordered parts for my 408. I went with scat rotating assembly non forged- AFR fully cnc 205 heads -Solid custom ground roller cam Specs[.600 lift intake and exhuast- duration a .050 252 intake and 255 exhuast. lobe seperation 104 - custom carb 750 hp from cam builder- compression 10.5 victor jr intake -msd ignition with 6al. I will have rev limiter a 6400 rpm Any one having experience with this combo??? Just curious on aprrox torque### and HP ### at the fly wheel. Bermblaster

[392cobra]

I would guess in the 550-575 HP range.

Very healthy!

[JustOne]

With that cam, you may be closer to 600, and will not make peak power until 65-6800. A 104 lobe seperation is going to give you a VERY nasty idle, and may not run under 1500 rpm. Is this a tight lash street roller, or is the ramp rate designed for drag racing?
Depending on your driving habbits you may want to rethink the cam. There is nothing wrong with a solid street roller, but make sure that the profile is not so wild that the car can't be driven on the street.
My cam as is hydraulic with a 242/250 dur ation and 612 lift, but a 112 center lobe to help calm down the idle.

Justin

[bermblaster41]

thanks for the replies. My machinist designed the cam with the cam designer for street use and what the car is. I will be sure to check with my machinist on monday. Thanks again. Berm

[Shiloh4065]

The lobe separation MIGHT BE 114 rather than 104.

[bermblaster41]

lobe seperation is 104

[385Fox86]

If this is for a street car then those heads and that cam are way to much there is a mustange here in town that runs a 408 with a set of 180 cfm 60cc chamber heads 2.02 int 1.64 exh. 224 234@.50 512 524 lift cam 780cfm holley msd igntion T-5 trans and 3:73 and the thing is wild on 10.5 slicks but is tame enough to tool around in and doesn't need to tow a gas station
runs 11.0s on motor and 10's on reasonable spray

[DAVID GAGNARD]

Being your rotating assembly is non-forged, I'd keep the rpm limit at 6,000...........
I would think the AFR 205 heads would be a little too much for the street, you may be better off with the 185s if all your planning to do is street use with the car......

David

[hound dog]

Bermblaster41,
Just ran the rough numbers through my Dyno 2000 and came up with 527 HP at 7,000 and 451 tq. at 5500. By going to the same cam I used (Lunati 51012 hyd. roller) the numbers changed to 526 HP at 5,500 and 6,000 with torque of 538 at 4,500. I think you may be a bit overcamed. Heads are OK though. You may have a small block engine but it is making big block cubic inches and you have to have the heads flow accordingly.
h dog

[wannabebuilder]

if its over 500hp i would say thats a nice little ride you got there chappy.

[jmarsey]

bermblaster,

If you plan on driving that thing on the street, you are going to hate it. Your cam specs, duration @ .050 and LSA, if correct (the 104 is nuts), would be in the range of your typical circle track cam with a power band in the 4000 rpm to 7500 rpm range. The cam specs don't make sense for your combination and your motor would perform so much better with a cam that was properly matched.

It's interesting, if you look at hound dog's post and his desk top figures, shows the difference between the two cams with the Lunati cam having much more realistic figures, although you would probably see a bit higher hp number from the Lunati. And that's a Hyd roller. No big deal.

I'm just saying it like it is. You may want to talk to some other engine builders and get opinions from guys that drive these things, have actual seat time experience, and have a clue about cam specs.

Good luck with your project,
John

[Rick Parker]

Your duration @ .050 should be no more that about 248 intake & 242 exhaust for a reasonable street engine. With a LSA near 110. It will pull hard to about 6800 RPM and idle at about 1000 RPM. What you are proposing will not be drivable.

[scottj]

Lunati has a line of street solid rollers that have less aggressive lobes; Keith Craft used one in his "Hulk 408" street engine project. Specs were 264/268 @ .050, .668 lift, and 106 LSA. The engine had Brodix CNC Track 1s, 10.2:1 compression, and a Victor jr. The engine made 647hp/596tq on pump gas.

My engine builder built a very similar 408 and used AFR 205s- made 650 hp on pump gas. That particular engine went into a Superformance owned by one of the engine guys on Jimmy Johnson's Nextel Cup team.
My "street" engine is a 434 with AFRs and a Lunati solid roller- 266/272 @ .050, .688/.667 lift, and 106 LSA.

The 106 LSA on these "street" cams is actually 2 degrees tighter than the 108 LSA on my circle track engines. The reason they tighten the LSA on these big street rollers is to bring the torque curve down on the RPM scale.

Regarding street drivability; my engine definitely has a rough idle and it likes a minimum of 2200 rpm for part throttle cruise. In my opinion, the key to getting good street manners with these engines is in having a custom carb built for the engine; and your engine builder appears to have included this in your build. But, I would ask about pressure fed oiling for the lifters and how long the valve springs are expected to last with your lobe and rpm range.

Are these the type of engines that everyone can consider a good street engine? obviously not. But, I have no drivability issues in 5 years of using mine on the street. I think people do tend to underestimate what having this much power means on the street. For one, it is definitely not a high rpm power curve; in fact from a roll on in 2nd gear it will rip the tires loose (Hoosier 335/17s) at 2500 and at 3500 on a 3rd gear roll on. I tend to lug my engine and use the torque, that way I can actually use some of the throttle. Because of the power available, 3rd and 4th gear are the only gears you can really "get in to it". A leisurely drive on the back roads, using about 1/2 throttle in 3rd and 4th gear between 3500 & 5500rpm, equates to 70-120 mph. It is very similar to riding a high HP sport bike. Hmmm...come to think of it, it's not a good street engine at all. But, not because of drivability issues, it's because it makes too much power... build it and have fun
Scott

[WildBill3]

we are in that 600+ range also on lift comstom ground mechanical roller wow what fun its a beast and i love it these are racers on tha steet MORE POWER HAHAHAHA!!!!

[WildBill3]

we are in that 600+ range also on lift comstom ground mechanical roller wow what fun its a beast and i love it these are racers on tha steet MORE POWER HAHAHAHA!!!! sorry didnt meen to post twice

[WildBill3]

Hey guys Have fun

[bermblaster41]

I got my 408 up and running. It idles at about 850 and has the radical idle I wanted. Took it for a small burn around the block. can't wait to be able to drive it out of 1st gear and open it up. Here is a couple hyper links to youtube on idle and go carting.Enjoy!! Bermblaster http://www.youtube.com/watch?v=xGppRZyQQCE http://www.youtube.com/watch?v=YXJGU4GETE8

[carmine]

boy that sounds good! what duration at 50 and lift is that cam

[bermblaster41]

Duration intake 252 exhaust 255 .600 lift lobe sepperation 104. Bermblaster