I'm sure there quite a few you out there who are saddled with the same problem I am. Trying to go as fast as possible while staying emissions legal. I have had my ARE heads/cam setup for around 4 years and have been trying to run 11s since then. The heads flowed 270/197 @ .600 and the cam specs were 222/230 .533/.544 on a 112 lsa. The best I could run was 12.01 with a 1.67 60'. Unfortunately my motor came apart on what would've been possibly my first 11 second run. I say this because the 60' was a 1.64. Everything was destroyed including 1 of the heads, which had to be rebuilt. I ended up getting a gm846 cam to replace my original. Duration was the same but the lift was greater. (.543/.563) I could tell the difference immediately. It felt alot stronger down low. This was confirmed when I pulled off a 1.58 60' time and a new best of 11.94. There is definitely more to be had because the car hasn't been tuned for this cam. I'm still running a stock bottom end. There are a lot faster combos out there but here is 1 that will pass emissions and still run a decent number. Sorry for being so long.

 

congrats on the 11 second run. Thats is very impressive. I sure wish i had an auto. You should of gone with a 224/230 i don't care to do the math right now but since it is an XE design it gives you more duration at high lifts but less overlap = less emissions.

 

aren't the xe grinds harder on valvesprings?

 

I'm in shock you can pass emissions!

 

They might not be harder on springs but they are more aggresive which can give you issues with the springs.

Bret

 

Not trying to be a smartass or anything, but you can't trust any spec's ARE gives. A long story I won't go into, but two sets of heads did not flow even close to what the flow sheets said and the parts in one ARE engine were not the same as the build sheet. That included the cam spec's.

Good luck, but next time have your heads reflowed as you may be leaving something on the table there.

 

Sorry, but the diehards on this board know that ARE is full of bullsh*t. They ruined many people's stuff, etc, but I'm not going to get into it here, because every time someone says anything about them, a war erupts. Usually Canadians vs. Americans.

ROFL

Mike

 

By the way:
Your heads don't flow 270 cfm. If they did, your MPH would be more like 116-118 as a rough guess. 112 mph sounds more like around....... 240ish cfm.

Mike

 

My bolt ons/HOTcam/homeported heads combo passed emmissions no problem. It was good for about a 12.5 I estimated, maybe more with a dyno tune. I actually passed emmissions with only about half the limit of hydrocarbons being put out, so I know there was a lot more room to play. I'd like to get a bigger cam in there when the motor goes back together along with some more portwork on the heads. I wonder if 400+ rwhp and passing emmissions is possible?

 

I'de probably have to agree. I trapped 111 with a slipping transmission and a tiney crane 210/224 cam and ported heads (don't know the flow #'s though). With a 6-speed (conversion kit is ordered) I think I could hit 114-115 no problem, but I'm not going to launch it that hard since I still have the stock 10 bolt.

 

FWIW, I ran almost 114 with a slightly smaller cam. My new dyno numbers show that I picked up almost 20 rwhp with only a slight increase in lift while still running the same duration. I do appear to be having some serious issues above 5k. As far as the heads not flowing what was claimed, well that's you opinion. I did have the heads reflowed after I got them and the numbers were very close to what my flow sheet showed when I got the heads...+/- 2 or 3 cfm here and there. I think my numbers are right in line with where it should be. My friends 396 ran 116 mph with a larger cam and better flowing heads.

 

That 396 should be at 120+

Mike

 

There is a local guy with LT-1 castings and 383CID running 127MPH.

 

what size cam? Notice I did say emissions legal. You guys are quick to point out the extreme but not the norm. I've seen numerous heads/cam cars run low 11s and trap 117-120 but with monster cams. I'm sure I can run those numbers with these same heads and a much larger cam. Anyways, I'm happy with what I'm running. I'm not out to impress anyone. Once I get my bugs worked out, hopefully much faster times will be right around the corner. Thanks for the replies regardless. I have no problem taking advice...or criticism. There will always be someone else faster.

 

I'd say could be, not should be