Another 403

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
I'm not crazy about the solid hub-type harmonic balancer that came with the engine. I went over my buildings today and pulled a factory type with the rubber between the rings off one of my builder 403s. I came home and weighed them both. Solid hub type weighed 2,608 grams vs Factory rubber sandwiched type @ 3,804. I'm going with the solid balancer.
 

Olds 307 and 403

Active member
Oct 4, 2018
582
200
43
Melville, Saskatchewan
Yeah, I don't get how GM thought a tiny, solid balancer was a good idea on a flimsy block and big heavy pistons. Supposedly my 403 was from 78 Delta 88, old man owned. Pulled it down, found red Detroit head gaskets and .010" rod bearings. And this was with a proper balancer. 1200 grams is a big difference.
 

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
A have a couple of sets of NGK B8S that I got off of Andy @ Olds Performance. I think I've got a couple of old (but new) AC's. Just a putt-putt engine.
 

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
I would say, a "quesstamation" of 8.5 : 1 :•)
Because the dish in the pistons looked less than the factory soup bowls and the heads were decked but I used Fel-Pro gaskets so I may be back to 8.0:1. My purpose for this engine is just a reliable driver but I did put a "baby" camshaft in just because I'd had a new Sealed Power stick (over 20 years)that I'd looked for the right engine.
H 280/290. 204/214 .448. .472. 112
The "new" stock 307 camshaft,that came with the engine, I felt was to "anemic."
If stock was 185 hp/ 320 fts lbs, I'm shooting for 186hp/ 321 Fts lbs. :)
Seriously though I feel the camshaft should add 20 hp/30 ft lbs.

I have a couple sets AC 443S, I'm not sure if they make them anymore. My new kick I'm on is to use parts I've accumulated over 30 years of Oldsmobiles, I was a Chevy guy before.
 

Olds 307 and 403

Active member
Oct 4, 2018
582
200
43
Melville, Saskatchewan
Pretty sure all those plugs are too cold. Use either NGK XR45 or AC Delco 46SZ plugs.
 

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
Even though I'm retired, it seems I don't accomplish much. First, Christmas keep me busy, all four Grandkids and one in the oven. I made two trips to N.J. and back. I have a 1975 Olds 350 on the startup stand. I primed the 350, all fresh oil & filter. Fired it up, all good. Then I started "thinking" hmmm, it had a new water pump but no timing set change. Pulled the new fuel pump. Chain was a little sloppy. Should have buttoned it back up but M.A.W. might as well, put a new timing set in it. I have a few Coyles sets plus plenty of gaskets, so it's just time. Unfortunately I couldn't get the oil pan clearance to get the timing cover on without the possibility of leaking.
So now the easiest way is to put it on an engine stand. If it's not one thing it's two.
Anyhow I started to button up the romper-stomper 403. :)•》I went with the generic Sealed Power Camshaft. It's a never used 24 Y/O camshaft that I got in one of many Oldsmobile deals. I'm shooting for "186" hp. I'll take heat on this next comment! I put a "used" stock oil pump on it. I have 3 high volume pumps but I didn't want to use them on a next to stock build, putt-putt engine. I cleaned the pump, check the gears plus gear to end plate clearance. I used a Toronado pump end plate because it was thicker than regular Olds oil pumps plate, new gasket between plate and pump. After I set the pickup to pan clearance, I tack welded the pickup to the oil pump body. I used the same "blowoff" spring but I drilled the cotter pin hole 1/8" closer, kind of like shimming but different. "WHAT POSSIBLY COULD GO WRONG"
I put a new oil pump shaft, even though I have some "almost new shafts" and I put the big block baffled oil pan. I was going to use the lifters that came with the engine. The were "gummed" up, so I pulled each one apart. They had a thin round "baffle" and putting them back together, yes, I dropped one and couldn't find it. I dug out a new set of Comps Cams lifters. I'm changing my mind on the balancer. Instead of using the "new" Korea made NAPA "hub" type balancer, I "borrowed" a normal type balancer from another 403. (Great to have spare engines, I have 6 403s) Some of the 403s I have got the #16 intake, I'm not to sure about that intake. I dug out a A4 and cleaned it up. I borrowed a set of 403 five hole valve covers, boy, how much weight did that save? I'm thinking of using this engine for another purpose depending on how the startup/cam break-in go. I spayed some paint on it. 20200122_140657.jpg 20200122_140610.jpg
 

TURNA

Active member
Oct 5, 2018
189
95
28
NY
With the 403 covers you actually put on weight since those 5 holes arent drilled out!!

🤪🤪🤪🤪🤪🤪
 

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
The "Engineer" who thought up the "windowed mains" weight savings, probably got a $25 Saving Bond. I'd like to have given him a knuckle sandwich. :)•》If only they'd built a 403 Diesel. My Grand Daughter is sick to so I'm babysitting. Then this evening I'm taking my Grandson to Boston Mills, for his sking lesson from 7:30 to 9 pm. So busy, so little time! Thank God, I'm retired. I'm wanting to seal down the A4 intake. I have a new turkey tray but now I'm thinking of blocking off the exhaust crossovers. Even though I'm not going to race this engine, I hate to leave free hp blow out the exhaust. I'd have to get the composite gaskets. I was thinking using a sheet metal plate that fits in the crossover port and one a little larger than the outside port. Line them up, drill some holes then plug weld them. Put some sealer to hold in place, trim gasket as needed. Doubled up sheet metal should hold up. Might get 2 more ponies. I'm going to Summit Racing after a "Racing parts" swap meet at Medina fairgrounds, indoor meet. Sunday till 2pm. Lady Friend's birthday is Sunday, spoiling her. :)•》
 
  • Like
Reactions: Olds 307 and 403

TURNA

Active member
Oct 5, 2018
189
95
28
NY
If they would have made the 403 a solid normal main

It would have been one of the best engines built Huge bore short stroke a real screamer
 
  • Like
Reactions: Olds 307 and 403

Kennybill

Active member
Oct 3, 2018
203
127
43
Braceville Ohio
I love the bores of the 403 and love the main webs of the 350 Diesel. I always thought the diesel with the 425 crankshaft was the engine to build. I still have a couple diesels and around ten 425 crankshafts. You can get around 440 cu in. That way. Cutlassefi has a stroker small block aftermarket crankshaft that can be used with the spacers. I have one 330 crankshaft left. There was a young Olds racer I sold a perfect uncut 330 crankshaft/balancer/flexplate. He seemed like he was really into Olds racing. I gave him a good deal to help him out. Right after he just disappeared. I understand "stuff" happens in life plus racing is an expensive sport. This is the guy.
 

Vikingblu442

New member
Jan 26, 2020
4
2
3
19061
Kind of wondering if someone here can answer a question?
I have a 1985 delta 88 with a 307. Do you think my stock carb and computer will run this 403?
Thanks guys new here kind of not up on how forums really work..

#6 heads, 2.000" and 1.625" valves. Filled exhaust crossover and center divide
Milled, 67cc’s 9.5to1 compression ratio
Stock .030 over bottom end, but balanced
Howard’s roller cam, 219/229 @ .050”
 

rfpowerdude

New member
Dec 19, 2018
25
6
3
Palm Bay, FL
Kind of wondering if someone here can answer a question?
I have a 1985 delta 88 with a 307. Do you think my stock carb and computer will run this 403?
Thanks guys new here kind of not up on how forums really work..

#6 heads, 2.000" and 1.625" valves. Filled exhaust crossover and center divide
Milled, 67cc’s 9.5to1 compression ratio
Stock .030 over bottom end, but balanced
Howard’s roller cam, 219/229 @ .050”
I put this in your other thread, but here it is again in case you miss it.

It will run it, but the timing table in the firmware may not be ideal. Mostly, the computer affects ignition timing. Under closed loop steady state conditions, the fueling will be determined by O2 sensor feedback crosscounts and is not as much affected by engine size. With that said, you may need to use different primary rods to deliver enough fuel for a given duty cycle of the MCS (mixture control solenoid) in the carb. The timing table, however, is a fixed table that may be too little or too much under certain load/rpm conditions. Give it a try. That cam and compression may be just right for the timing already programmed in the ECM. You always have the option of getting a non-computer Q-Jet and standard HEI distributor if there are issues..
 

Olds 307 and 403

Active member
Oct 4, 2018
582
200
43
Melville, Saskatchewan
Big problem is the swirl port timing tables, super aggressive. Plus the carb is very lean on the primary side and secondary side. The secondary can easily be fixed, primary not so easy.
 

Olds 307 and 403

Active member
Oct 4, 2018
582
200
43
Melville, Saskatchewan
Yeah, the water pumps, spacers and corresponding pulleys make Olds V8's fun. I currently have 3 of the long water pumps, 2 cast iron, one open and one closed impeller. I also have an older Flowkooler with the riveted plate on an open impeller in 6". I have been using with non A/C brackets and spacing out the alternator.
 
  • Like
Reactions: Kennybill

Olds 307 and 403

Active member
Oct 4, 2018
582
200
43
Melville, Saskatchewan
I like the simplicity of a serpentine setup. Larry's billet conversion brackets allow this along with the still available V6 RWD diesel water pump, makes it possible. The biggest issue was grinding down the sbc truck bracket and needing reduced head 3/8" bolt, the Olds SB RPM reduced head bolt intake bolt is the perfect length. Along with a 1/4" drive 12 point socket on the inside adapter bracket, no other wrench or socket will work to run a mechanical fuel pump. A block off and electric pump makes it a much easier conversion, then just a stepped drill bit, right length belt and basic tool set and easy peasy.