I just got my 350 running in my 83 TA. First ill tell you about the motor. Its a 350 block, 9.8:1, "993" heads w/ 1.94 valves, Crane 2040 cam and valve springs, windage tray, 305 HO intake, CC carb, CC dist, Edlebrock headers and 3" y-pipe, and 3" Flowmaster catback, Centerforce dual friction clutch, BW 9-bolt, w/ 3.45 posi. Now the problem....ITS UNBELIEVABLY SLOW!!! My stock LG4 and XE 256 with the same trans and rear end ran 14.94@91mph at sea level here in Phoenix. This thing would be lucky to run high 15's. The carb has a "G" hander and "DR" rods. I readjusted the rockers yesterday just to be sure and they were right on the money. Also, Im running about 10-12 degrees of initial timing. Shouldnt this be pinging with this compression on 87 octane? The carb is so unbelievebly loud, it drowns out my exhaust completely. Throttle response is also very poor. I know its not a fuel delivery problem because I have an in-tank pump out of a Cross-Fire car regulated down to 8psi. The loud carb and poor throttle response leads me to believe the timing chain was installed maybe a tooth off. The motor is pulling a decent 19in. of vacuum and is very steady. This seems a little low for a fresh motor that has just been broken in. Oh yeah, its getting horrible gas mileage. And I mean HORRIBLE. Is there a way to tell if the chain could have been installed a tooth off or something? This thing is a complete dog from 1000-5500rpms. I also just realized the distributor looks to be turned a little funky compared to the way it was with the 305. Everyone told me that this car should have no trouble running 13's. Can someone PLEASE help me here. I need to get this fixed. Thanks to all that reply.

 

well before ya start with all the complicated stuff why not pull a plug and see what color it comes out just to completely rule out a fuel delivery problem.. carb may not be jetted properly for the new engine..

 

Well, I just pulled 3 plugs out and they were all very clean with a "tannish" tint to them. They were gapped a little close though. The gaps on the 3 I pulled were .028-.030....instead of the .045 like they should be. A friend gapped the plugs when he was helping me. I dont thing that could be doing it though, at least not enough to be slowing me around 2 seconds in the quarter. Ill regap the plugs and put them back in. Any ideas on the timing chain though?

 

993 heads are "Hecho en Mexico" smogger 75cc units. 1.94" is the stock valve size for them.

Unless you have domed pistons, your CR is about 9.0:1, or less; by my calculations, using .025" deck clearance and a .039" (stock composition) head gasket, and 4 cc valve reliefs in flat top pistons, it's about 8.8:1. So there's part of your problem right there.

Loud carb usually means the secondary air valve is opening too fast. Set it to around 5/8 turn of tension and see if it's any better.

Your actual problem sounds to me like the EST connector is unplugged from the dist, which will keep the timing at base 100% of the time. Make sure it's plugged in.

I don't want to seem mean, but I'd be very surprised if that combo could run in the 13s with a full-bodied car. I'd guess that you should see around 14.6 when you get it tuned right. Those heads will protect the rest of the motor from producing any more power.

As far as the timing chain, the easiest way to tell where the cam is, is to get a degree wheel and a dial indicator, and find the intake's peak open point. It should be at about 106° (crank) ATDC.

 

RB83L69: My pistons do have quite a dome on them. The heads are off a 1971 350. Were they making heads in Mexico back then? These arent the "lightweight" castings used in later years. So worst case scenario, im running around 9.5:1. I talked to the manufacturer of the pistons before I bought them. My 8.5:1 LG4 was running consistent 14.90's with 120,000 miles on it at seal level with a 2.20 60ft time. I find it hard to believe that this car wouldnt run at least a low 14 with the 350. I did however notice something when I just drove it again....it has a steady miss at idle, and is even worse as RPM increases. Not so much on heavy acceleration, but mild acceleration from a steady cruise. Im wondering about the ignition system. It has the original Packard wires on it date coded 10-82, and a set of plugs that were never gapped, (friend didnt do it like he said). Im gonna replace the wires and plugs and see if that does anything. It seems like its not even hitting on all 8. BTW, those times were here in Phoenix at sea level....give or take a couple hundred feet. Believe me, im taking all this input seriously, but I think before I go any further I have to eliminate the basic stuff first. But I do appreciate everybody voicing their opinions and to what could be wrong. When it comes to computer controlled cars...im lost. But thanks again. Ill take all the ideas I can get.

 

They started using that casting # back then, it came on the 350 2-barrels. They continue to use it to this day on the "Goodwrench 350" that people buy and then are disappointed with.

But however all that may be... if it has an ignition miss, then it surely won't run to its full potential. Definitely fix that. Check the other things and make sure they're OK while you're at it.

There's really nothing different about computer-controlled carbs, except that there's no mechanical timing advance, and the idle and cruise mixture is largely outside of your control. But with the combo you have, the values the computer will try to use are at least in the ballpark of what the engine will need, so check all the simple obvious stuff first.

 

RB83L69: Sorry...I hope I didnt come off like a wise-***. Im sure you know much more about these cars than me. Deep down, Im a MOPAR guy. I just love the thirdgens. Anyway, I got to looking at my wires. Get this, the wire to the number 6 cylinder is burned almost all the way through on the header! Im gonna go now and get another set of wires, since th miss is getting worse. Thanks for the advise though.

 

ditch the CC Qjet and distributor... and get rid of those smogger heads

 

I have those same heads on my 350, only from 1973. They suck.
As soon as I get them replaced I will turn them upside down and plant flowers in those huge cumbustion chambers. They will work better for that then they will for making horsepower.

BTW, With those heads and flat top pistons I have never heard this engine ping on 87 octane. RB83L69 is right on about the compression.

 

what is your total timming? 10to 12 inital is ok but what is it at 3000 rpm .

mike

 

Are you running the stock balancer and timing chain cover? If not, did you set the engine to TDC with a degree wheel (piston stop or dial indicator) THEN set the timing tab to the balancer? If not, then there is no telling where your timing actually is. I use to see it all the time, people would bring their cars to me set at 10 degrees running like crap,,, I’d zing the timing up where the engine wanted it,, just to “see” 18 degrees at the tab. Sometimes they would come in a tooth off. Most every time I would find they used degree bushings in the cam sprocket w/o actually degreeing the cam. As RB said, use a degree wheel and piston stop to find TDC (adjust your timing tab if needed), then check the intake’s lobe centerline. Most of the time I would find timing, plugs/wires (old or off), “simple” carb adjustment(s) - most people don't know how to do this with the CCC, and vacuum leaks, (in that order) causing the problem. As said, rule the simple stuff out first.

 

Like RB eluded too, I was very dissappointed in the the "Goodwrench 350", quality wise it was great, but at the time I needed a motor, little did I know the stock heads were pretty bad. I think I'm more mad at the pistons in the motor though

 

This man speaks the truth, I got that engine, and about a month later I decided it was a horrible choice, worst thing I ever did to my car.

I just want to back this up. I have the goodwrench 350. with those heads, they are total crap.

I put this cam in
Comp Cam Kit 238 Grind: 262 Lift: .462"/.469" RPM: 1300-5600

and right about where the cam starts making real good power the heads stop flowing. At least thats what it feels like to me I get a nice pull from 2000-3000 in 1st and 2nd gear and then its done. horrible engine horrible heads.

 

Yes, but as horrible as the heads may be by todays standards or compared to our current selection of aftermarket heads....im sure they arent the greatest. But you cant tell me that this 9.5:1 or so 350 with the cam and the way its built wouldnt beat my tired old LG4? I dont get it. There has to be something holding this motor back. I went from an 8.5:1 305, to a 9.5-9.7:1 350, better cam, 45 extra cubes, and better heads than were on the 305. And this motor is slower. Also, my pistons do have a dome. They are not flat tops. The piston manufacturer said that when I bought them, with my 75cc heads, and a .041" head gasket the compression would be in the 9.6-9.8:1 area. Now unless they lied to me....I dont know. But anyway, Im gonna go put my new plugs and wires on and see if that cures my miss. Thanks again everybody.

 

I am definatly not an expert but recently I was considering an engine upgrade (heads, cam, pistons, rockers, pushrods etc)

I did a good amount of research (and asked some questions here)and I played with Dyno2000 quite a bit.

I can definatly say that Compression isnt everything. Heads and cam make most of the the engines power. If you are running 8.5:1 and you put heads and a cam in, and make sure they match up nice, you are still gonna make really good power.

If you have 10:1 compression and u have a cam that is good at high rpms but heads that dont flow for ****, then u might get some good launches but the engine is gonna be weak

 

I'm certainly no expert either, just an amateur with a little experience... but I've seen quite a few instances of what you are describing happening to people in my day.

What pistons are these exactly? mfr & part #

Also, what is your distributor curve? That's what the one post was getting at... if your timing isn't advancing as RPMs increase like it's supposed to, you'll end up with a very lazy-running engine. Ideally you'd want a curve that, with the vacuum advance disconnected, gave about 10-12° at idle (500 RPM), and started to advance at around 1000-1200 RPM, and reached a maximum of 36° or so at around 2500 RPM; and then, if you hold it at 3000 RPM and plug the vac advance back in, it should add another 10-12°. In most cars you'd want the vac adv to drop back out when the vac goes below about 3-4 in. less than whatever the cruise vacuum is (which will depend on alot of things, including gears).

 

HOLY CHRIST!!!!! I just put new plugs and wires in it. 4 of the plugs were backed out about 2 turns, 2 plug wires were burned all the way through on the header, and the gaps were average .028"-.032". Lets just say I took it or a test drive after I put the plugs and wires in, and I happened upon a new Ford Lightning that wanted to play a little. I had him off the light up until about 65 when we let off and I was about a car length ahead and pulling a little on him. Keep in mind this was also on street tires too. Unbelieveable!! I know what youre gonna say about racing on the street...but I was in a sort of desolite area and I was so full of adrenaline from my car being fixed that I just had to do it. Anyway, thanks for all the help. Now its time to do some metering rods swapping and adjust the timing. Thanks again all. :hail: Thirdgen.org

 

I still say those heads are crap
im getting rid of mine asap

oops forgot, glad to see u fixed it

 

LOL, yeah Im sure theyre not the best. But theyll do for now. Maybe sometime down the road ill upgrade to a better set. But for right now, Im just glad it runs good. Anyway, thanks to all who offered advise.