I need recommendations on building a smog legal 350. I have to keep the computer, egr, etc. I'll be tearing down the block in a couple of weeks and will be building it over about 6 or 8 months. This is my first build from scratch project so please....be gentle!

 

Anyone? I really need advice on cams rebuild kits and such. Due to finances I need to use stock heads...I think...

 

Try the web sites of various manufacturers. Crane, for example, tells which cams are smog legal. A Summit or Jegs catalog will do the same, or at least give you some companies to look up on the web.

 

What engine are you going to build L98? I would reccomend better heads to start with. Some aftermarket aluminium or vortec heads will get you claen horsepower without sacrificing emissions.

You can get a custom grind cam at comp cams. The trick is to get moderate duration, high lift and LSA no less that 114. Go for a high flow cat like the Random 3" with fat pipes.

You are off to a good start by keeping your fuel injection in tact, however, you will probably have to get bigger injectors depending on the horsepower you want to make.

 

Here's the scoop on what I currently have. After running the numbers on the block, it's from a 72 (or so) truck. The heads are pretty much useless 'cus there's no accsessory holes in them.

Currently I have an LG4 and need to keep the carb set up. I'll be getting headers (I don't know what I should get) and a cat back, etc. Like I said, this is my first attempt from scratch. I'm not even going to pretend I know enough about cam's to get a custom grind. I was in the right ball part about the LSA though! That makes me feel a little better!

The biggest questions I have are as follows:
Is getting stock heads from the yard and doing a porting job on them myself a good, economical idea? Who makes a good but economical exhaust system? What headers and intake should I get? Any part #'s on a recommended cam is definatly welcomed!

 

I have a 305 short block, with a set of old double-hump heads (I had them laying around, already ported and otherwise worked up); Edelbrock TES; and a Comp XR264HR-12 cam. It has the stock air cleaner, stock carb, stock intake, stock exhaust behind the headers except a replacement cat and a Dynomax muffler, stock cooling system except for a Stewart water pump. It passed California emissions inspection easily. It does 214 RW HP and 282 RW ft-lbs, which is more than some modded TPI 350s, and drills 4.6 Mustangs like it does Civics.

I would think that you could use the same recipe on a 350 and get correspondingly better results, and still pass emissions.

 

How big of a diff would a 3" cat back and corresponding cat make? Are you saying, using a similar setup should yeald about 240 hp with a 350? Can I use the same cam? Wish I had a chance to buy you that beer while you were in Carlsbad RB!

 

The cat and exhaust will make a big difference. There is about 20-30 hp lurking in exhaust improvements.

If you are staying with the LG4 carb setup I would also consider going to a roller cam. I would go 214 -216 on the duration and .479 - .499 lift. You will need springs and hardend pushrods.

The casting numbers are important on the heads. There is another post today that mentions the castiong numbers to search for. Otherwise, you can go aftermarket.

Numbers can add up. What's your budget?

 

I'm trying to stay under $500 for engine parts. I can go over if I stretch the build out. I want to do it right so if I have to streach it out the so be it.

 

That might be tough. What are your horespower requirements?

 

I'm hoping for at least 300 - 350. Like I said, if I need to stretch out the time to build it for fiscal reasons then I will.

 

Possible. I would plan on stretching the project out. T get those numbers you will need porting, polishing a hot intake, and all I mentioned above. I would save up for some aluminuim heads. Holley makes a smog legal carb that has the ecm connectors.

 

RB, on your Comp XR264HR-12 cam, will that go into a 72 block? Summit shows it for 87 and up.

 

High compression.... the higher the compression, the more of the fuel you will burn, making for a cleaner running car AND more power. This is were some self-restraint can come in handy.

Thats how i was told it works anyway.

hehe... get flamethrowers.... that will burn ALL the fuel the engine doesnt

 

If its for '87+ then its for the roller cam blocks. You may be able to get a roller conversion for the block you have and use that cam, but i'm not 100% sure.

 

I have the OE 83 block.

I used the version of roller stuff that we've all been using so successfully for all those years that all the rest of us had been building roller motors, before the factory "invented" their stupid crap that sodomized the idea of roller cams.... no special blocks, no special timing chains, no nothing, just bolt it in and go.

 

OK, it sounds like I can use RB's cam with no problem. Now I need suggestions on lifters, pistons, rockers, etc. What's the best way to increase compression? I'm guessing pistons but, like I said, I'm a rookie to be sure on what's proper...

 

He's talking about retrofit roller hydraulic lifters, which are a bit pricey. A flat-tappet version of that cam, with new lifters (typically they are available as a set), would cost less than the roller cam, or lifters, alone. The performance difference in a street engine is about nil.

Comp Magnum roller-tip 1.5:1 rockers are good street performance choices (have them in the 396), or most any roller-tip stamped rockers (have Elgin in the 305, hear Crane's are made by them).

Flat-top pistons (typically 4-valve relief) and 64-67cc chamber heads will give you streetable compression. Rather than risk junkyard heads, World S/R Torquers or Pro Lighting heads are good, solid, relatively budget-friendly choices. I don't know about the Lightings, but the Worlds benefit from some basic port/bowl cleanup. Valve springs should be chosen to match the cam.

 

Chevy High Performance just built a smog legal 355 that made like 385 HP, and they built it for a thirdgen camaro from california. I will try to scan that article in for you as soon as I can.

 

Alert! Caution! Beware!

They "cheated" to get that dyno sheet. They used non-CC q-jet and distributor, a big ol' dyno airhorn instead of a "real" smog-legal air cleaner, and no cat after the y-pipe (and different shorties, to boot).

Their results when they put it back in the car with "legal" parts were a lot less impressive.

 

[QUOTE]Originally posted by five7kid
[B]He's talking about retrofit roller hydraulic lifters, which are a bit pricey. A flat-tappet version of that cam, with new lifters (typically they are available as a set), would cost less than the roller cam, or lifters, alone. The performance difference in a street engine is about nil.

QUOTE]

Got any model #'s or summit/jegs part #'s for the kit? I'm working up a budget right now so that would help.

 

The Crane I've got is their computer-compatible, emissions-legal version. Summit p/n CRN-114142. $154.95 includes lifters, assembly lube, cam gear lock. You'll need springs to match and a higher-stall torque converter. Idles at 500 RPM in gear, spins to 6000 with ease.

Factory roller block type is CRN-104224. Reuse factory lifters for that. $269.95. Won't work in a non-roller block (no cam retaining plate - haven't heard that a cam button will work on factory roller style cams).

Comp flat tappet would be same number w/o the "R" at the end. Go to their website for more details (www.compcams.com).

 

So, in a nutshell, what stall TC should I get and what cam? I'm a bit confused. It looks like RB is saying his cam suggestion will work in my 72 block and, after running the cam on digital dyno, I can get 30 hp more out of it than the comp CC compatable cam. What do I do???