Engine specs:
377 ci – old style block
-16cc SRP dished pistons
6” H-beam rods
4340 crank
Weiand 250 blower
(2) 750 CFM throttle bodies – electronic fuel injected
Trick flow 23 degree heads (72cc combustion, 215 cc runner volume, .700 max lift)

Car specs.
Manual trans (TKO-600)
Approx. car weight – 3400lbs. (1966 Chevelle)
Gear ratio 3.50

I am looking for a fairly rough idle that is aggressive. I am planning to spin the motor to 6,000 rpm with the majority of the power down low. I am planning to drive the car on the street with an occasional trip to the track. I have contacted a couple of cam manufactures and have gotten varying feedback (especially on lobe separation – 110 vs. 112-114). Any suggestions?

Anybody???

We just put a nx288hr in my friends new 377" motor with 177 blower. It seems to idle with a little lope at 850 rpm in gear but not too extreme. Don't really have any serious time on the motor yet so cannot say how it runs at WOT.

The cam that Eric mentioned was exactly the one I was about to recommend. 236/ 242 duration at .050, .520/.540 lift. I originally wanted that same cam but ended up using a slightly smaller version as that would my peak rpm a few hundred rpm higher than I wanted.

I am a bit confused about your objectives. You built a 377 destroked 400, then put on big runner 215cc heads and then you say you only want to turn 6000rpm?? That motor is screaming (pun intended) for a cam that will have a peak hp of 6500 rpm plus..maybe 6500-6800.

If you wanted low end torque, then a 383 stroker might have been better with 190-200 cc runner heads max. The NX276HR cam in my sig will give you more low end torque than the NX288HR, but be forewarned, a roots blown motor does NOT need low end torque. You will have too much. I like those 250 blowers.. good size for a street SBC.

Tokyo touched on my first question. Is this a destroked 400 or a standard bore 350 stroked (3.75") to 377? You can get to 377 two different ways.

Personally I think a solid cam would be the way to go (solid flat tappet).

As far as lope or aggressive idle that is not always easy to achieve with a blower. Blowers tend to smooth out the idle in many cases. You didn't mention your compression ratio and that would have a large factor on which cam grind to choose (LSA). If your compression is on the high side a tighter LSA 110 might be the ticket, if not I would stick with something in the 112-114 range (assuming your compression is 8.5:1 or lower). You also didn't mention how much boost you have planned.

You might want to give Mark a call at Engle Racing Cams (310) 450-0806, tell him exactly what you have planned and what you except and he will nail it. He is also very honest and won't try to sell you something that won't work or that you don't need. I bought a custom grind (solid flat) for my blown engine and the cam does EXACTLY what I asked for, I could not be more happy. The phone call is a lot cheaper than guessing wrong and having to buy a different cam when you are disappointed. I would be interested to hear what he suggests to you. By the way Engle was recommended to me by Don Hampton of Hampton Blowers.

This is actually a motor for my best friends car. It is a standard bore 350 with 3.75" stroke. I kniow he was told that with a blower he needed big runner heads so that motor can breathe. He is going to have about 8.6 to 1 compression.

Thanks, Erik

It is very common to get different recommendations on cams. Even more so than just about any part in a engine. This is because there are so many ways to grind a cam. First of all the owner needs to decide what person/company he trusts to make this critical decision. If he wants you to make it thats fine but remember you will be the one standing there when he cranks it and he will look at you if it doesn't idle or perform to his standards. It is very hard sometimes to understand exactly what someone wants their idle to sound like. What is choppy to one is erratic to another this is sometimes why people are dissatisfied with their engine. So be careful when your friends ask you to spend their money.
Cam companies usually have slightly different theories as to what is the best method to get you what you want. For example Isky usually recommends on the aggressive side using high lifts and pretty healthy duration #s from my experience. Where Erson usually uses a more moderate lift from my past experience. Elgin on the total other side uses considerable less lift. These are just really basic ways to describe the different theory's used to get you the cam you want.
Once he decides who he wants to go with just stick with what they recommend. The key here is to be very specific on what you want and what it is going in and how you want it to perform. It is best not to tell the cam company I want a XXX lift or duration or that is what you will get a cam you designed not a professionals cam. Remember you went to this guy because of his knowledge and experience and thats what you are paying for so use it.
Again this is just my opinion based on my experience. Good luck. :thumbsup:

Steve