I am having a local machine shop put me together an iron eagle block 427. Callies crank, Oliver billet rods, coated BME pistons, and Brodix 18x heads. It will be run with 2 gt40-67 turbos in search of 1200 rwhp.

I am going with the big cubes and better flowing heads because I want to have the motor as docile as possible. My thinking is that with the head flow (340ish/240ish, along with awesome midlift numbers), I can go with as small a cam as possible for idle/drive quality, and still be able to move the air necessary to reach my goals.

With this setup, do you think I can get away with a 224/224 cam on say a 113-114lsa with 4* advance ground in? I think that small of a cam will idle very well in a 427, and should still be able to make the power at 25psi.

Any advice on this motor would be appreciated, as we are currently waiting for parts, so I still have some flexibility if something isn't matched well.

 

My concern with only 224 duration and 18 deg heads is that you're missing out on the huge high-lift flow numbers they offer. I suspect that 340 cfm will come at .700+ lift. I would recommend stepping up to 230/230 and grind it on a 116 to get your idle quality. If you use the Comp Extreme 3194 lobes, you can get .661 lift with 1.7 rockers.

Mike

 

Thanks for the input Mike. That is one of my main concerns. The reason for the smallish twins, and the small cam are to have excellent spoolup and for my torque to be as instantaneous as possible with turbos.

As cast, the heads have excellent flow (as good as full cnc afr 227s). The whole reason I am going with this head is so that the motor can be undercammed and still move the required air. If I went with a big duration turbo cam, I would probably step down to like an afr 210 or something. I just wouldn't have the idle quality i want. If the heads dont have the ability to reach my current goal, I will have them worked over for even better flow, but only if I NEED to.

I forgot to mention, for street manners sake, I do want to keep this a hydraulic roller motor. IIRC, the lobe you mentioneed is for a hydraulic roller, correct?

I want to keep the LSA as narrow as possible without having overlap, in hopes of keeping it from running out of steam up top. I also want to get the advance that is ground in close, but I am not incredibly worried about that because the motor is getting a belt drive that can easily be adjusted on the dyno incase the motor could use a slightly different advance to reach my goals.

 

If you were to go with 230/230-116, it would have the same overlap and idle quality as the 224/224-113. Besides, wide LSA's, not narrow, will increase top end power so it won't run out of steam. In fact, 230/230-116 will make significantly more top end than the 224/224-113 because the IVC is 6 degrees later.

The 3194 lobe is hydraulic roller.

 

i also think you should go with something a little bigger than the 224. a 224 in a stock LT1 is still docile enough to live with on the street and your talking about another 77ci. That 224 will be very docile in the 427. Its almost like your building a "old" LS7. The LS7 cam has close to .600 lift somewhere in the 22X range on a 116 or higher LSA and it sounds like a stock car.

 

Thanks for the input. I actually want this car to drive as close to 'stock' as possible, with good vacuum. I can always crank up the boost more if needed to get the airflow I need.


So, Does everyone agree the 230/230 on a 116 lsa would fit my bill? The rpm range I am really interested in is 3500 to approx 6500. I dont want to have to rev this motor to the moon to make it work.


Thanks for the input, I really appreciate it.

 

I never cease to be amazed at guys who build monster size 400+ small blocks with forced induction and yet find themself worrying about low end torque.



Seriously...?

If I were in your shoes I would be taking Mike's advice, but not only for the reason that HE mentioned.

You're expressing the desire to have the engine be docile, but I think you're forgetting to take into account how the power itself will affect it's driveability.

If you build too much power too quickly you'll have the sensation of driving on ice.

You actually WANT to reduce your power on the lower end to avoid sending your tires up in smoke every time you so much as look at the pedal.

I think about a friend of mine who has an "old-school" Satellite with a single barrel 440 that's probably only making around 600hp or so. It's a car that he drives on the street, he runs a 325 width tire and at anything more than 1/4 pedal he gets sideways.


Just food for thought.