It’s time we tear down this 403 Oldsmobile v8 and see what exactly the issue is, along the way we will be upgrading a few parts, should help us get a little more power out of this old rig, should be sweet!
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P.S., I have built a lot of cars in a barn, machine shed or on the gravel driveway. I would rather see you keep the car inside than outside. Have a great morning and enjoy your day today! Monday or not, I hope it goes flawless today.
find a set of #5a or 7a 350 heads and change valves to 2.07 1.622 455 valves 455 camshaft will fit. to that point though you would like a main gridle cause the 403 is an open main web block and thats the weak point also oil restrictors under the mains that feed the cam to keep oil flow consistent. that alone will take a smog 403 to decent power not saying push it to hard.
A lot off effort just to do things shoddy, same goes for spraying with regular paint, straight over grommets and gaskets that should have been replaced. Back yard hack.
Would the bearing damage have caused rod knock when it was running? Im a total n00b…..
i would like to see part 2! is it posted yet?
The stock cam should be 187/200 duration at .050. and .400 lift intake and exhaust. You generally need adjustable rocker arms or pushrods with a lift over .500 with an Olds.
403’s are decent. They aren’t a big block Chevy or a 426 Hemi or whatever and you can’t zing them to the moon, but they can make good power for the street. The best thing you can do with any Olds is get rid of their horrible exhaust manifolds, probably the worst of all the BOP’s and Chebbies. Looking forward to part 2!
looks like a non windowed main web block ! rare block usually come in wagons best 403 to have yey as the cat says 350s are better for your money BUT big bore .short stroke will make a street engine
Get rid of ACCEL wires and coil. THERE are better coils out there, you want a coil that makes 60k volts, and plug wires that are 50 ohm per foot, so you can at least gapp the plugs up to .060s, or get better custom S plugs from Torquemaster
Nice. I have a 79 trans am myself with a 403 that i custom built. Number 5a heads. 2.25 vaslves installed, scorpion alminum shaft roller rockers. custom pushrods. iskedarien cam. 268 duration with lobe separation. nice idle. arp studded throughout. even intake and oil pan. custom quadrapower q jet. i would like to find an aluminum intake, for heat. i do havea. 4 core huge rad. flowcooler ewater pump and milodon high flow t stat. she stays between 165 and 185. 19 inch fan on heabvy duty clutch. even with the 2.41 diff. smokes the tire off the line and rockets to speed. pulled a 13.9 with the 2.41 axle and just recently found a ws6 disc break 3.23 axle to redo and swap inb. these are fun motors.
People who say a 403 is of little point are not engine builders ! The 403 has something almost every engine builder wants ! A massive bore and a short stroke ! Big valve heads as well , 6 deg valve angles ( Honda uses 6 deg valve angles on CRF 450 motorcross bikes , and all high performance engines like Lamborghini,s ) The 403 is light and responds to smsll changes very well , if it was designed with a fordged steel crank, fordged rods, fordged pistons this would have been an unbeatable motor , the things it has from an engine builders perspective is outstanding , the chev guys would love 6 deg valve angles , shit they get a hard on going from standard 23 deg to 15 deg let alone 6deg , chev guys love the " big" 400 chev bore of 4.125 let alone the Olds 403,s 4.351 inch bore , the Chev guys love the destroked 350 to 302 chev because it revs well but the 403 olds has the perfect stroke 86 mm , why do you think this majic 86 turns up sooo much in modern motors ? The Toyota 86, Subaru Impreza WRX 86 mm , Toyota 4 litre 86 x 86 mm bore stroke , and so on all the major performance motors around the world 86 mm stroke same as 403 olds . Even intake port spacing that gives equal shot to all cylinders , chevy guys had to move ports on the Nascar SB2 heads and Ford did the same and what set up was found to be the best ??? The Olds standard port arangement ! And i didnt even mention the standard olds combustion chamber the twin squish design same as the new Ford Godzilla , wich just took the tital away from the Olds 403 as the biggest small block motor at 445 ci . So the Olds 403 probably the best design you could want bar the crap cam and low compression but all the is fixed these days very cheaply , and with those magic new low temp cast iron welding rods we all see on tv being so good and cheap , dont worry about those windowed main webs , sit down one week end and weld them up , ive seen it done and it works very well , bingo a solid main web 403 ! As far as cooling with Siamese bores , those alloy heads from china cost $975 a pair complete , they are an exact copy of Edelbrock ones , alloy conducts a lot of heat and solves any cooling problem on a 403 .
Yeah, siamese bore 403 runs hot. Actually there was a 4" billet 5140 and 4340 stroker crank. A guy did a 478 ci 403 stroker with one. Mark Remmel is looking at doing a cheaper cast steel crank possibly in a 3.875" stroke.
Find yourself a 350 diesel block install a 425 Forged crank A nice hydraulic roller lifter street cam and roller rockers and you will have a bulletproof 420 inch oldsmobile engine making high horsepower for that trans am ..
Good luck with that engine
The 403 motor in my own personal opinion is a big waste of money and time,go ahead and find a 350 Oldsmobile motor block and your gonna be a much more happier person believe me
A 403 small block olds motor is really a waste of junk, your better off with building a small block olds 350 gas block olds motor or the 350 Olds diesel blocks at least with the diesel blocks you can make it in to a different combination with the right parts
Use a lapping compound with fine grit and you can get a mirror finish ☑with id micrometers and you CAN get all marks off even if u have to start with a heavy grilk lapping compound.
The biggest problem with the 403 was SMALL BLOCK PUNCHED OUT TO 403 LEFT LITTLE WALL OVERHEATING was the result and the reason it was discontinued BAD ENGINEERING IDEA!!
I have a 79 with the olds too, still deciding weather to send it to be rebuilt by an olds specialist or drop an LS in it (sac religious) I know
Definitely wanna see part 2 cant wait
Also like the blue color makes it look like a dodge
Also video i totally forgot how to get the 45 cross hatch an didn't no that about cam bearings thanks great videos awesome channel