Just to compare a 242/252 on a 108LSA to something I would think is acceptable, not to mention that the stock ports aren't going to like RPM anyways and really need a good match of a cam.

You are talking about a loss of around 20rwTQ at 4000rpm and maybe a pickup of 5-8rwhp at the top end....

Not to mention the average power thru the RPM range that you are going to use the thing on the track is going to be way down so the ET would then be less.

Going back to LS1 style cams..... The TRex is not the fastest thing down the track, when something like a F13 cam which is about 10 degs smaller makes more average power and is a really fast cam in a LS1.

Bret

 

A GM847 is a good cheap choice..... I don't really get into what I think is bad and good about it. It wouldn't be a bad N2O cam by anymeans, maybe more duration on the exhaust would make the cam a better N2O cam amoung other things.

Bret

 

Steves car was a stock bottom end car. It did have worked heads and was running around somewhere arount 12:1 CR. this cam on a stock cubes stock head motor would be a pig. YOu need heads/ stall/ gear to make it work. steve ended up with a 4800 stall(flashed to 5000ish) non lock up converter and only had 3.73s in it..it needed more. He was going to run a 4.10 or 4.30 to get everything out of it but a spark plug put a stop to all that. But..the car was a stock lt1 bottome end meaning pistons/rods/crank/ etc. etc. etc. it was just like it cam from the factory. He raced it to 6800 but it pulled to over 7000..he did take it to 7 grand one time ont he dyno but we all agreed that it wasn't a good idea with his stock internals. It would have been a 10 sec stock bottem end car if we hadn't have had problems. Plus..there was a lot more to the way the car ran besides the cam.

http://www.thunderracing.com/project...n=read&pgid=82

 

Still post that sound clip, if you could..Im interested fo sho'...

 

i dont understand this...u say this would be a bad cam for me and that it would be a pig yet Steve ran it in his stock bottom end with other various bolt-ons and had good results???

 

It's not just the cam it's the combination of the whole system. You notice how he had a Static Compression Ratio(SCR) of 12:1 there? That puts the Dynamic Compression Ratio (DCR) 8.3:1 or more. There was a lot more work than just a cam.....

Motors that work are about the combination of parts.... 300cfm heads, 396 cubes, huge solid roller cams, trick bottom ends really don't mean much if the parts don't work together as a system. It's like Mindgames LT1, that thing works very well as a system, so do both of steves combos. Cams aren't magic.... I know it sounds like most people who understand them make them out to be that way. I just tend not to get into the details for business reasons and because of the lack of people who really understand what I'm talking about. Cams in essence are there to bring the combination together and make it work, sometimes they do and sometimes they don't.

Bret

 

Like bret said..steves combo was more than a cam on stock heads/bottome end..it was a high compression (needed race gas to be safe if your running it) motor that needed a big stall and alot of gear. Like I said..those 3.73s he had in the car weren't enough even for a 5000 stall. Even with that converter it was still alittle lazy out of the hole..it needed gear to really wake the car up and use the power/torque curve. I saw that power/torque curve of this cam...it really turned on up top but was sluggish down low. My HP/TQ curve had about 50 rwtq and about 30 rwhp or more over it in the lower/mid range. You will need alot of gear with this cam and I just think it will be a pig with stock heads..steve had some good heads and alot of CR. But hey..run what you want. If your going for a wild lope then this is a killer cam for ya..but I think there are better cams for stock heads out there. This cam is way out of the stock heads flow range. Hey..I could be wrong...its never been tried with stock heads so you may find something no one else has tried yet. Good luck with your decisions.

 

For everyone on this board that thinks bigger is better.....Steve's heads flowed a peake of 250.....but as you all know there is much more to heads than flow numbers......

 

It's always been about the combination.

 

I totally agree. I am just pointing this out to people who come on this board thinking that the biggest of everything will make the most power which is not the case at all.

The 847 is a good place to start. Later down the road you could always get a custom grind to match your combination and needs.

Brandon

 

I think you would do good calling Futral motorsports and talking to allan about Tellys cam.

 

I know bigger isnt better and that the whole setup has to work to benefit every other part of the system. Also how was he running a 12:1 CR on the stock bottom end? Did he mill his heads and then have the stock heads ported?

 

Patrick I got the PM, but just now have time to get on the net since I just moved.
Ok... yet another big cam thread, LOL...
The big cam route all depends on what you truly want and how much $$$ you have. If all you want to do is sound meaner than everyone else in town at the red light... please don't do the big cam... you'll hate your car inside of a month, I guarantee it.
Now if you truly want to haul a$$ and want to keep a stock bottomend be ready for a few things. First off the car better not be a daily driver as you will be the owner of a time bomb. Remember big cam + small cubes = high RPM. As mentioned before I spun the hell out of my set up. We pulled to 7,000 on the dyno and the power was still going. At the track my shift points were set inthe 6,800+ area. For this kind of RPM you are starting to get into the range where valve trains eat $$$. I had the best of everything in my set up and still managed to flex all 16 of the 7/16" ARP rocker studs since I didn't have stud girdles. Pretty sure it was one of the 7,200 rpm burnouts, LOL.
The lobes on my cam are that aggresive that's why I have ONLY recommended it to 1 or 2 people. Those folks were all out racers who know the deal. Weekend only or strip only car, then by all means my cam is the way to go... as long as you're ready to spend the time & money getting the rest of the combination right as well. Get ready for 4.10 gears as a minimum with an auto, honestly might need more than that. Gas mileage had better not be a concern... 13 mph highway with 3.73's for me WITH cruise control. Emissions.... HAHAHAHAHA!!!! Driveability... actually pretty good with tuning, though a vacuum cannister is a must for brakes.
Back to the stock bottomend. A few of us have pulled off some nice power & runs on them, BUT they are a wildcard. Longevity can be an issue of luck of the draw. The factory had no intention of 7,000 rpm runs on these engines, in all honestly we've just been pushing our luck. It's not out of the question for some of these setup to live a good while AND it's not out of the question for set ups like this to blow up on the 2nd trip down the strip... luck is a big part, don't forget that.
If you decide you can afford the risk involved, either shoot me another PM and I'll steer you to a nasty cam or give Alen @ FMS a call and he'll hook you up just as well.
That's my $.02
Steve...

P.S. my compression was 11.8:1, milled the heads & ran .028 head gaskets.

 

I have a custom cam, 236/246@5 and 600 lift,112 LS with a A4 3k stall, 4.10 gears. This cam is perfect for my car with a 355 CI 9.5:1 and a 45 HP shot of spray. At 6k altitude it runs 11.9X as listed. I have good power from 3-7k. This motor wants to spin well past 7k!!! As for driveability, not much surge, good vacuum and was a little tough to tune with LT1 edit at first, but when I got my baseline setup, this thing screams. I also have 2.08/1.65 fully race ported and polished heads w/AFR Hydra Rev, so that makes a big diff too at high rpm's.

 

Steve, you have a PM waitin for ya..