Engine 305, Adjust help

[ylmalaver]

This was my first time swaping a cam. I left the heads stock on my 305, but i installed the following:
-Pistons Std. Bore Size 3.766 Comp.. Height 1.54 Pin Diameter 0.9273 offset
-Comp Cams Magnum Camshaft, Hydraulic Roller Tappet, Advertised Duration 280/280, Lift .525/.525.
-Rocker Arms, Stud Mount, Self-Aligning, Roller Tip, Steel, 1.52 , 3/8 in. Stud
-Valve Springs, Dual, 1.430 in. Outside Diameter, 322 lbs./in. Rate, 1.150 in. Coil Bind Height.
-COMP Cams Pro Magnum Hydraulic Roller Lifters.
-Carburetor, Quadrajet Stage 2, 750 cfm, 4-Barrel, Spread Bore, Single Inlet.
-TH 350 Shift Kit, Transpak, GM, TH350C
this is my first time working with this kind of modification and I spent a several days looking for answers about the adjustments or settings for this configuration,the engine is running, it feel great but not perfect,adjusted initial advance time to 10 degrees, the mixture air/fuel is too rich, you can smell gas, the intention of a big carburetor and a big cam is to place turbo, What would be my best choice for a turbo? I would like to know if the combination mentioned is correct? If you have any comments or some knowledge about this, for example advance time adjust, I would appreciate your opinion. Thanks in advance.
P.D.I would like install a Ignition Box, MSD 6AL-2, Digital CD, with Rev Limiter

[HOSS429]

you should have started with anything but a 305 ..

[glennsexton]

Welcome to CHR!

We’ll need a bit more information to adequately address your situation –
What heads are you using? What head modifications did you have done? Use of a cam of the size you described (Comp Cams 12-430-8?) with the stock heads will be a major disappointment on several fronts – First, the 322 pounds springs (Comp Cams 986-16?) you selected will address the pressure issues associated with this cam but unless you’ve had the proper machining performed, the retainers typically will hit the guides/seals around .470. Second, if you have the early cast iron 305 heads have 1.84 intake 1.50 exhaust valves – real small.

This cam requires the use of a thrust button & wear plate.

What stall speed is your converter?

What’s your rear end ratio?

What’s his engine in?

What brand “single inlet” intake manifold?

Headers?

My insides tell me that you’re over cammed and a bit over carbureted. As to the turbo – with almost absolute certainty I can tell you that the only thing a turbo would do for you is grenade this engine.

Give us some more info and we might be able to help you achieve what you’re after – bear in mind that you’ve maybe started this project backwards..

[techinspector1]

I left the heads stock on my 305

Not enough head. Even with a turbo, I think you'll be disappointed.

Pistons Height 1.54

Compression height too short. Should be 1.560" If you plan to install a turbo, you will need a very thin squish (0.035"-0.040") to help prevent detonation and you will not get there by starting with a fosdick rebuilder piston that has a 1.540" compression height. Install 1.560" forged pistons, 10105117 GM head gaskets and cut the block decks to 9.010". This will give you a squish of 0.038".

TH 350 Shift Kit

This will be fun for about 10 minutes. After that, it will be just a pain in the @@@, jerking your head back on every shift. You'll learn very quickly to hate it, but you won't admit it to yourself or anybody else because you don't want to be perceived as foolish.

adjusted initial advance to 10 degrees

Not nearly enough for that cam. Dial in another 10 degrees at the crank and dial in 16 on the weights, for total of 36 naturally aspirated. With a turbo in place, cut back on the advance at the weights or use an electronic advance limiting system and leave the 20 degrees at the crank.

the mixture air/fuel is too rich, you can smell gas

I suspect the fuel pressure going into the bowl is excessive. Quadrajets don't like more than about 5 psi at the inlet. More than that will simply overpower the needle and seat and blow raw fuel into the intake manifold. Tee off at the inlet and run a nylon or copper line back to the firewall, then up past the hood lip and up to the cowl. Temporarily mount a mechanical fuel pressure gauge (0-15 psi) on the cowl with tie wraps, racer's tape or whatever, so you can observe the fuel pressure as you drive. Regulate down to 5 psi, remove gauge and line.

[techinspector1]

you should have started with anything but a 305 ..

You know, I see this all the time and just can't make any sense of it. 350 blocks and decent heads are laying around for the taking and I still see fellows starting with a fosdick 305 or 307 or some other abomination.

[1gary]

Richard-there is a whole movement that involves 305's.Not sure why either.Might be because of some of the Carmero's and that whole 5.0 thinkie.But it is a learning curve....................that is something we all have gone threw.

[glennsexton]

I've rebuilt a few 305s in near stock configuration and they're not bad for a dependable daily driver if that's what ya have and can get by with rings, bearings, and valve job (and have no "need for speed").. Did one in an early 70's Camaro 4 speed. Stripped off the emission control, had a used HEI w/Accel ignition from a previous project, swap meet Weiand with a Q-jet and headers and 40 series Flowmasters. All for well under $1,000. It was a nice starter car for a 17 year old young lady - 20-22 mpg and fun to drive. She put a bit more into some nice paint and had a great ride.

Just saying the 305 has it's place..

[gassersrule_196]

so instead of everybody telling him how wrong he is, why dont we try TO HELP him?!?!?!


i have seen some 305's and 307's that were surprising. around here 305's are free 350's are not parts depends on where you buy them, i can get a 283 kit same price as a 350 kit so really no difference there.

[glennsexton]

Right on - let's see what he comes back with..

[1gary]

X3 from here.

[1gary]

This forum never ref's builds or how to's.Well that isn't completely true.My point is the knowledge is here by members of the forum.One of my pet peeves is the articles that are suppose to represent auto enthuses like Hot Rod,Popular Hot Rodding and alike.It's that advise that gets some people in trouble with them not considering the articles are there to sell the products of companies that bought ad space in their magazine.Not like here,the advise is not with clean hands and it would be here from the forum members.What is here is what people did or could expect as results day to day from a build.I think it was coined as a "real street".Here is a example of one of those articles:

http://www.popularhotrodding.com/eng...cks/index.html


What some guys don't know,is how to read between the lines on things like I posted in the link above.The article specks about how the bore/stroke ratio being better than a stock 454 and even better than a 4.30 x 4.00 engine and ignores one basic rule of there is no replacement for displacement.Notice how they managed to fit in the use of roller rockers.Cute huh.But not a roller cam conversion because that would cost toooooo much.

So why am I preaching here about all this.Well I do think I am answering the question of where do these guys come up with all this stuff.It is because some rag mag published a article,it must be true and work like it said it does.

[tango]

Them 305's work well with mild mods done to them This Engine is in My 1989 Chevy Pick up . And it runs Much Stronger then the Stock 5.7 350 TBI that was in it .


http://www.youtube.com/watch?v=cN-ADdVSTB0