Not sure if this belongs in "advanced" but since I had gotten a lot of useful info on my stroker build-up here I decided to put it here.
Building a 408 (iron block) for 99% street use that might see the track 1-2 times a year. Compression will be 11-1 and it will see anywhere from a 100-250 shot of nitrous. The entire rotating assembly is Lunati and the rest of the supporting parts will all be upgraded as well.
To my cause of concern,
My engine builder (who is very knowledgable) contacted his good buddy at Comp to order a custom grind cam. He informed the person at Comp what we were building and this is the cam he sent: 232/238 .575/.584 112lsa. To me that sounds a bit tame but remember I do want a car that I can take out on a sunny day and just drive for a couple of hours with no issues whatsoever. Am I leaving a ton pf power on the table by not choosing a cam such as a 236/240 .585/.594 112lsa or bigger?
Sorry this is so long but this car is my baby and I freak out about stuff like this. You guys seem to be the most helpful compared to other boards so any opinions would be greatly appreciated!

Thanks,
Mark

 

What cylinder heads, transmission, rear gears and torque converter are you running?

 

Currently I have stg II 5.7 heads that flow ~ 300cfm at .600 lift. The tranny is a M6, 3.73 gears.

Thanks,
Mark

 

I think you need to trust your engine builder.

While I haven't simulated you engine, those extra 4 degrees/2 degrees and .010 lift probably won't get you much, if anything you can feel. If the cam takes into account your driving (99% street with no issues whatsoever), gears, tires, etc. my thought is that you'll be happy. If they fibbed to you and said it was a 250/260 would you feel better about it? If the 232/238 goes like stink, which I think it will, you can always fib to your buddies about how much cam you have. Don't we always lie about "size"?

FWIW, I'd want the complete flow curves rather than just the .600 flow, but your builder probably gave those numbers to CC anyway.



"Better to undercam a street car than overcam it." ---NOT said by Stroker McGurk

 

First nice name, but I swear I know the real DrunkMark!

I'm guessing you are talking about a SR cam here.

Depending on cylinder head volume (crosssectional area) and RPM range that cam is not going to be the most aggressive thing in the world for a street 408. Normally I don't post about specific cam specs but a 23deg headed 409 SBC is something I've been doing some digging on for the 2004 Engine Masters contest.

For N2O the LSA is ok, but you should put at it in at least 3-4degs advanced. I would also look at more exhaust duration on that thing too.

I'm guessing you could have more cam on that thing and still make it a street car, but those choices are going to work really well and be tame.

If you have small heads then you can handle more camshaft, and by small I'm talking relative to the cubes. You could realistically have up to a 240cc port volume and still make it driveable with that many cubes.

Who is his guy at Comp anyways. Interesting cam choices.

Bret

 

I would go with something upwards of 240* @.050 if this isnt a daily driver. Anything smaller would be absolutely TAME in a 400+ CI motor.

Something like:

245/258@.050 and .650 lift on a 112 LSA if its a solid roller.

 

My bad that it's a HR LS1. So a 6.0L block with a 4" crank.

Something like the G5X2 cam from LG that's 232/240 112LSA would drive like a kitten, you could even add more if you wanted.

Actually that cam would work very well and be very passive, it's already on a 108ICL too!

Bret

 

Talk to Gordon Holloway at comp cams he helped me pic the cam for my 434. the specs were 254 duration intake and exhaust .575 lift and 110 lsa. Also, this cam is in my suburban and i drive on 500 mile trips with it.

 

Thanks for the help guys! I guess one good thing with the cam choice is that it's not really a huge ordeal to swap it out if I'm not happy with the results. I think at this point I'll just try this one out and see how it goes. The one thing I don't want to do is go too big, that's obviously something I won't be doing with this cam! Hopefully this thing will be ready to fire up in 1-2 weeks and after some break-in miles I'll post up the dyno results.

Thanks again,
Mark