hey guys, i am currently building my engine which should be done in about a month. its a stock bottom end lt1 with cc306 cam, trickflow 185 heads, hooker supercomps, 1.6 rr, elecric water pump, slp intake and all the main things to support the cam and stuff. I was wondering if anyone did a setup like mine and also what kind of power they made out of it. its stock compression and 350 c.i.

Thanks in advance

Jim

 

Should make just about 400 maybe more or less depending on the tune. If its a4 or t56, stock 10 bolt or not?

 

Ive seen the new Trickflow 23 degree heads with milder cams than the 306 with big stalls put down 405+. Ive seen 455 rwhp out at our shop with a mild lloyd elliot cam on a m6 with the trickflow heads.

 

the heads i have are the 21 degree heads. im going to have it dyno tuned and its a 6 speed

 

Are you auto or m6?

 

Really? Are those as cast 21 degree heads?

 

yepp, got um from summit

 

Why not put a bigger cam in and then use the stock heads too? That way you'll save a couple G's!

 

Sorry but that is some of the worst advice I have seen on here.

TFS heads and a cc306 will demand some good rpm which will be pushing it for a stock bottom end. Sticking in a cam that is already larger than a large cc306 is just a terrible idea with a stock bottom end unless the person was willing to undershift the hell out of it like your setup. That is what gives us LT1's a bad name, when someone over cams their car and revs it to where they would with the stock cam or baby Crane 227 aka it runs like **** when it sounds like a racecar. Just sad how some people on here think more cam is better and makes a car faster, truly sad.

The 306 and those heads should make for some decent power, haven't seen any results but I would imagine around 400+rwhp in a manual.

 

More of a question of affordability. That's all. And there is nothing wrong with keeping an engine stock.

 

I would like to see proof that these heads can pull off 400+ RWHP! Out of the box.

 

Id think with that setup you would hit over 400 rather easily. You have to spin it clsoe to 6800-7000 to see the max gains from the CC306's duration but its worth it. Id throw in some better bearing and possibly rod bolts to be safe, therefore you can spin the snot out of it and not hurt the motor. Dont let the guys on this board scare you away from making power.

 

The CC306 stops making power well before 7k.

 

So your claiming that a bigger cam than the cc306 as in a GM847 or XFI292 with untouched stock heads would make equal or similar power to a car with 21 degree TFS heads and a cc306 would? I sure hope not...

21 degree TFS heads and a cc306 will easily make 400+rwhp in an M6 with full bolt-ons. A full bolt-on GM847 or XFI292 car with stock heads is going to make 360-370rwhp in an M6 on average.

 

what if the stock heads were ported pretty good w bigger valves?

 

well if you have someone like AI or LE port the stock castings it would be close to where the TFS heads flow. But still your talking about aftermarket castings vs. stock. The stock castings are really going to need good portwork to compete. Otherwise TFS all day.

 

you should be right around 400 with those heads and that cam

 

thats the number i was looking for. this car isnt a race car, but its not a DD. my plan was to have a car that i can cruise around with and take to the track when i want to. had i been racing this thing every weekend i would have built the bottom end up. if i do spin a bearing then its time to pull it back out and build the bottom end up

 

I think I'm gonna get a pair of those bare Tfs 195 heads instead of buying a set of stockers and having them ported.

 

My experience with heads and cam decisions:

I spent close to $1800.00 building up my stock heads including all the hardware (putting on fire-retardant underwear now). The flow numbers are great, but I might have done better starting from some well-built aftermarket heads with the valve size I wanted, and added springs, 7/16" studs, 1.6RRs, etc. after a good hand porting. I really learned my lesson building these stock heads up. They go really well with my cc503, a small step up, but very close to the 306's numbers. I'm hitting 377RWHP just shy of 6,000 with a nice plateau out to 6,500. Steve Ashworth in Fuquay, NC did the porting and did a hell of a good job with what I gave him. You can't make chicken salad out of chicken sh*t. HOWEVER, I think I might have done better if I'd planned better with the heads as the starting point for my power plans and measure that against my driveability goals. Absolutely agree 100% with StealthFormula about bigger cams not equaling better performance...

My bottom end is stock, but I did go through it completely and found some unpleasant things with the crank bearings (65k orig. miles on '94 motor), so I had new bearings put in / line honed, etc. for tight tolerances and to avoid oiling problems. I'm not gonna take this car to the track; that was never my plan. Hypereutectic pistons are brittle and don't tolerate a lot of time above 6,800 or detonation before they come apart.

I could have made a little more power if I had planned better with the heads and been willing to spend more, but I still have a hell of a fast ride that's very streetable. Next build, I'll plan starting with the heads and have a custom grind cam. My .02...