My goal is to build a strong 455 for minimal cash, that'll take 91 octane. I currently have a '73 455 in the car now. My dads guess was that this engine has stock replacement cast pistons, and compression is probably around 8:1. This engine also has a .500"L hydraulic crane cam. Other wise it is totally stock. What do these engines respond best to as far as bolt ons? I have never even had a timing light on this engine, so there is some easy HP to be had with a simple tune up. I'll set a budget at $700-1000. Thanks for the help, Kevin
With a budget of $1000 max, you aren't going to do any bottom end work. You "probably" won't do any cylinder head work, either. This is going to be a "performance tune up",to assure you're getting all the horsies that Buick intended, and perhaps some bolt-ons. 1. Verify distributor has working mechanical and vacuum advance. Fix as needed. Check the points, set dwell and initial timing. 2. Verify usable spark plugs (Pull 'em all out and check them ) and plug wires, cap, rotor. I ALWAYS use a touch of anti-sieze on spark plug threads. When you put it back together, start the engine, SHOVE YOUR FOOT ON THE BRAKES, drop it into reverse and goose the throttle. Do the same in "Drive". Have someone watch the engine to see if the motor mounts are broken. 3. Verify secondaries open on stock quadrajet. Often throttle blades stick, and car is only running on primaries. Verify car runs without bogs, sags, or hesitation. Adjust idle mix, idle speed and fast idle to specs. (depending on cam. Rough cam may need some compensation here!) Overhaul stock carb as required. It should be an 800 CFM QJ, so don't be in any hurry to get rid of it. EGR valves began in '73 or '74, if you have one, be sure it works properly, and the EGR passage is clear. The idle should get really rough if you apply vacuum to the valve at idle, then smooth out when you release vacuum. EGR is FANTASTIC for getting rid of part throttle pinging. 4. Verify car doesn't overheat. (while you're running it hard for #3) Verify no oil smoke, or other symptoms of impending doom. Check the fan clutch for play when you shut off the engine to do the next step. 5. Verify compression in all 8 cylinders. Do this test warm, which it will be after you perform #3 above. You've already pulled the plugs out for #2, so you shouldn't have any problem getting 'em out now. Since you'll be cranking the engine to do the compression test, you'll also be listening for how fast it cranks for all the cylinders. If the engine cranks slower as you go through the cylinders, the battery may be weak. 6. If you have access to a tester, do a leakdown test while the plugs are out for the compression test. If either of these tests reveal problems, start saving money for "big" repairs. 7. ASSUMING THAT EVERYTHING ABOVE COMES OUT "GOOD", change ALL the fluids. Coolant, oil, trans, power steering, brake fluid, rear axle grease, pack the front wheel bearings, etc. 8. Buy and install a QUALITY oil pressure gauge. 9. With whatever money is left, buy a set of (coated, if you can afford them) headers and a proper dual exhaust with an "X" pipe system. Rejet the carb if needed. Edelbrock makes a tuning kit for Q-J, it's about $110, or you can buy individual parts. If you still have money left over, dump the points distributor for an electronic ignition. (GM HEI, Dave's small body HEI, MSD electronic, etc. ( My advice: MAGNETIC PICKUP, NOT infra-red light, "laser"or hall effect.) Once you decide on a distributor, whether it be stock or electronic, curve it. Resist the urge to chuck the QJ and stock intake manifold, you won't gain any real performance until you get more compression, and that's way beyond your current budget. Have fun. This should all be enjoyable.
If you have a little more money, start checking out ebay. You can pick up a done set of 67'-71' heads redone for cheap some times. They would bring the compression up a little and flow better.(If you get lucky you might find 67'-69' big ports or 70'-71' Stage 1's) Here are all the 400,430,455 Casting numbers.(all 400,430,455 heads are swapable.) Casting Numbers Kevin
THATS SOME GOOD ADVISE maybe a rear end swap? in one of my cars i went from 270 gears to 308's, the moter was a stock 70 455 with a stage one cam, stock dual exhaust,100,000 miles, it still ran very good, but the gear change really made it feel like it had a lot more power, and i think i got that rear end for $100 it wasnt a posi but the car was still fun to drive
Second the motion I think Schurkey is right. Check the motor out and make sure it's solid. I have nothing against the stock points ignition for a street car though. Invest in the exhaust system - headers and duals. 2 1/2" with an x-pipe would be ideal. 3" is not needed unless you get into a pretty high performance motor. Is this motor going into the A-body in your handle? The easiest and cheapest suspension mod possible is to put an air bag in the rear on the passenger's side. Cost for a pair is about $60 and you can really help your launch/60' time. Save your money for a rebuild with forged pistons, new cam+lifters, reconditioned rods/ARP bolts, aluminum Stage 1 heads, and an SP-1 manifold. That will cost 5 times your present budget, but you can get by just fine in the meantime by maximizing the performance of what you have.
Thanks for the info Kelly. I ran a HOT comp. test and compression is a good 130-140 on all 8. When I pulled the plugs, and they were all dark, but they have not been replaced in 10+ years. The back barrels open, it's an 800 QJ and I plan to keep it. Motor mounts are good. There is no exhaust smoke. I found a sheet in the glove box made by the previous owner that states all of the engine mods it had done to it. The sheet says that the heads were bowl ported. The heads on it are '73 castings. Do you recommend an aftermarket intake? I can't afford coated headers, but I can swing a pair of painted ones. this engine will be mated to a 3000 converter, and a 3.73 posi. Would you use the crane cam, or would you put a stock cam back in it? I have been told that putting a big cam in an engine that has no compression, actually takes away HP. Thanks, Kevin
thats correct, long duration cam have more overlap, thats the time that both valves are open, called scavaging, you need higher commpresion because this causes bleed off, great for high rpm but kills low end, and a low commpression moter will feel like it has no power.
Compression and cam Kevin - Keep what you have for a while. You have a chance to modify the car over time. This is the best way - to learn as you go rather than try for the "ultimate" right out of the box. The 3.73's and 3000 stall will make your car scoot with a fairly mild low rpm motor. Besides, at your age you need some seat time to learn the basics of safe driving. Be cool with that bad motorscooter - it'll be plenty fast enough to get you into all kinds of trouble.:laugh:
I would NOT buy heads off ebay! Without expecting to have them professionally rebuilt. NO MATTER WHAT THEY CLAIM! :Smarty: Exception, a seller with a reputation, Jim Weise, Jim Burek, Greg Gessler, etc. (but you won't find those heads within your budget).
leave the intake. I'd through a 1in. spacer in thow, it really does make a difference. Get the spacer, set your timming to 32-35 total@2500, some exhaust upgrades(even 21/4 with good mufflers will help), and let it rip. It's a buick, it will supprise people.
