I have an 83 T/A with the LG4/auto. It has 69,000 ORIGINAL miles on it. I need to know what you guys think of the Comp XE262 cam. Would it help me out enough to be worth putting it in? My goal right now, as pitiful as it is, is to run at least high 15's with the car. If it needs more gear, Ill do it. It has a 3.08 posi right now. What what would it take to go 15's? Will the cam and gear do it of I run it without an air cleaner? Im thinking 3.73's. I need all the replies I can get as I am ready to but the stuff. Thanks guys (and gals)

 

GTA,

Not to discourage you, but the bigger problem with your engine is the fact that your dished pistons are limiting your static compression to about 8.6:1. Granted, the head flows are not all that great either, and the cam profile isn't helping that a bit. I'm thinking that your '83 may also have "swirlee" heads - swirl ramps cast into the intake valve bolws that were supposed to help scavenge exhaust gasses out of the cylinders by directing the intake flow in a circular pattern. It looked great on paper at the GM Powertrain design center. Couple that with the possibility of smaller valves on an '83 (I'm not sure when they went to 1.84/1.50 valves) and you'll find that the cam may not be the answer to all your woes. It certainly can't hurt, but it might not provide all the advantages you are expecting.

However, all is not lost. The beauty of the LG4 is that the compression ratio is about ideal for a charger. If you want to drop a lot of cash on an axial compressor, you can overcome a lot of the flow problems without worrying about blowing the bottom end out onto the pavement.

A cam replacement is not a bad idea, but probably should be done in conjunction with head replacement or porting/valve work. Since the components are all part of a system, you need to consider the entire system when devising a plan.

Even if you don't plan to replace the heads, a cam that will lift the valves enough to allow respectable flow will require larger valve springs, so the heads will need to be machined for the large springs at least. What better time is there to enlarge the valves and ports?

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Having dealt with numerous of that motor for other people over the years, I'll take a certain amount of exception to Vader on this one.

The heads (if original) are 416 casting, with 1.84/1.5 valves. They're probably the best of the pre-87 305 heads which isn't saying a whole lot. They do respond quite well to a bowl port job, as their casting is very small there, and the seat machining process leaves a huge blob of metal hanging out into the port. That's something you can do yourself. Get the Standard Abrasives kit and follow the instructions.

The single biggest limitation in that motor is the exhaust. Every piece of it, from the heads to the street, is way too small. Get a good set of chassis-specific headers like Edelbrock TES or SLP; a cat; and a cat-back. DO NOT get the ones for the LG4, as these will be the same weenie size as the stock pipes (since they are designed to bolt right up) and will therefore preserve the inferiority you now have. Get the stuff for something like a single-cat 88 350 TPI, as a set, and stick it all on at once. By itself it won't make a whole lot of difference, but without it, absolutely nothing else you do will be of any value.

Next, do the cam. That particular engine has what everyone affectionately refers to as the "peanut" cam. It's even worse than the one they used in mid 70s 350s that made them put out 165 HP. The XE262 is one that alot of people have used and gotten very good results with.

After those 2 things, and a pocket port job on the heads, you should have picked up at least 65 HP, maybe a good bit more. The next bottleneck is the compression, which is caused by the dished pistons. At that point you're looking at a complete engine rebuild to upgrade it, so the economics might not make good sense.

A better intake would help but isn't a huge thing as long as it's a 305 running less than 5500 RPM. A better air cleaner such as one from a L69 (NOT an open element) is worth several more HP and is something you can do at any time. The L69 one in particular has 2 large snorkels instead of one small one, and they pick up cold outside air instead of hot under-hood air.

3 major things — exhaust, cam, head porting — are where you should start on that motor, plus the air cleaner. Another small but noticeable improvement is to get an electric fan setup, there's about 5 or 6 HP lost in the clutch fan.

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"So many Mustangs, so little time..."
ICON Motorsports