does anybody have a combo close to mine?? if so, can you tell me your carb setup and what kind of timing your at, im having trouble dialing mine in. could you tell me the jets i need, vaccum secondary spring color, stuff like that. another problem i have is i try to break the tires loose but it just wont happen. sometimes ill do a brake torque, the tires will spin, but not above like 3000rpms, it just stays there, could i get some help with that pproblem too. i have a rigged exhaust, that would hurt me alot wouldnt it, i was thinkin a hooker cat-back, would that make a big difference? thanks a lot

 

Your setup is very similar to one I set up for a guy a while back. Should be a good street engine except for the camshaft.....Now I know there are a thousand guys out there that will disagree with me but I have done this several times with success. I personally never use a cam with more than like 218 duration and .470 lift on a street motor, much bigger than that and the bottom end of your power curve really suffers. Yes, there are remedies to that, but wouldnt it be easier just to go with the smaller cam than change everything else? .......... As for the timing, every setup needs something a little different, you'll have to play around alittle bit. But a good starting piont would be to disconnect your vacuum advance, and hold the idle around 2500 rpm, set the timing at approx. 36degrees. Then reconnect the vacuum advance, set the idle to something your comfortable with and take the car for a run...if its pinging, turn the timing down until it stops.........The 600 holley usually comes with 66 primaries and is pretty close for your setup, I used 64 , but thats just my preference.

 

That's an awfully small carb you've got. 600 cfm would choke a stock 350, much less one with aftermarket heads and a large cam. Those 3.08 gears don't help either. Why not try something closer to 750 cfm and see how that helps out? Also, how large is the exhaust from the headers back?

 

I agree, you need a bigger carb. My friend has a the exact same carb you have, on a dead stock 305 running 64 jets. Your engine needs alot more fuel and air then his, so I'd go with a 750.
Don't know how this applies, but I have a 377 with Victor Jr. heads, Victor Jr. intake, and a Comp Cams Magnum cam 230/230 duration and .560/.560 lift. I have a Speed Demon 750 and have 85 jets all the way around. I know the fuel mixture is right, it was tuned on a dyno and made 440 HP and 450 Ft.Lbs. of tq. on 93 octane in 90 degree weather with 37 degrees of timing and no spark knock.

BTW this is a street motor.

Joe

 

You have a basic mismatch which is why you can't spin the tires
easily. the cam you choose is real short on torque below 3000 rpm. it likes to be matched to a 3500stall converter and high rear gearing (3.73/ 4.10)

You have a choice either swap in a smaller cam (more bottom torque sooner) or swap in a high stall converter and higher gear.

If you want to go the smaller cam route I would consider
a Comp Xe262 or crane powermax 272. Both these work fine with the stock 2200 stall and 3.08's

If you want to go with the converter and gear change and keep the bigger cam,
I'd go with a 10" 3500 stall converter and 4.10's
Your car should scream.

The carb is not too small ( a 750 would have been better) but does need some tuning.

Primary jetting should be 64 to 67. the secondary metering plate can be changed to a #21 plate ( out of a 750VS 3310)
You may have to experiment with different acelerator pump shooters than the stock one. Try a .031" one.
Change the power valve to a 4.5" rated pv.
Swap the sec vac spring for a purple or yellow one.

Timing should be checked at high rpm (4000+) and be 32 to 36
total with vac adv disconected.
Your compression ratio may not be high enough either.
If you have a non blueprinted ( not "0 decked) flat top motor or a dished piston motor and felpro .039" gaskets you could get it closer to optiminum with thinner gaskets an or head milling.
You could port the heads while your at it.

Exhaust system is important. Just like cylinder heads,
if it can't breath it won't go.

Should be a whole different beast once you do these tweeks.
Good luck.

 

would a 2800 stall and a 3.42 with 15" tires or 3.73 with 16" tires work too? 3500 is a lot of converter for the street isnt it. i still drive it.

 

Hee HHee Hhee ... GO BIG or GO HOME!!!

No it's not too much... Why go half way there to
matching up your combination.

If you're going to go to the expense of changing the converter and gear, why not get the right ones for the rest of the car.
In city driving the 3500 converter and 4.10's will not be any worse than a 2800 and 3.42's.

If you do a lot of hyway driving and mileage is that important then you'd be better off changing the camshaft to one that
suites the 2200 stall and 3.08's that you have.

You'll have to decide which way you want to go. It's your car.
But you can't have it all. If you go half way you'll end up with a
car that doesn't go like it could and will not be any good on gas anyways.

Simply put, the cam is too big, If you want to make the camshaft
work as it's supposed to then get the right converter and gear for it. It will go like stink and won't be that hard on gas.
If what you really want is a car that goes pretty good but has reasonable mileage on the hyway than change the cam.

By the way I have a 3600 stall and 4.10's and drive it back and forth to the track (1 hr each way). It is only a little worse on gas
than the stock 2200 stall and th700 I had in before.

The amount of runs I make that day has much more effect on fuel consumption than the change in converter and gear.

You can juggle the actual gear ratio required based on the actual height of your tires. I am using a 26" tall tire for reference.
If your tires are shorter than use 3.73's.
With that cam you want the car to cruise @ 60mph at right around 3000 to 3200 rpm.

 

i didnt have time to read the whole post, so if i mention something someone else has, i apologize. my setup is in my sig.
for that size of cam, thats wayyy small of a convertor. i have a 268 xtreme cam and off the @050 stats, everyone recomended at 2500-2600stall. I personally thought that was alot, but i am no convertor expert. Now that its in the car and running i am happy with it, you cant even really tell its there. Call TCI, art carr or B&M and they can recomend a good one. Actually pass all those guys up and call Dana at probuilt. He super nice and knowledgable. We talked for 45 minutes one day on his dime about convertors and pontiacs.

the carb is again wayy to small. For all the mods you have you need alot more air flow than 600. I have a 650DP because I had it laying around, but pretty much everyone recomended a 750DP.

thats all i remember now from your sig. lol

 

<b>You have a choice either swap in a smaller cam (more bottom torque sooner) or swap in a high stall converter and higher gear.
</b>

Or you can keep your converter, gear, AND CAM and just add a Blower to get back lost low end like i did
I light em up on the converter for about 60 feet and still cruise @ 2800 on the highway (no overdrive) I get 13-15 MPG on a good day. and this is with a 303/313 duration cam. I have 2.77 gears! without the blower of course, the thing is crazy slow