Stroker Olds or Cadi Swap?

[fleming442]

Olds. Get the best heads you can: https://www.dragzine.com/tech-stori...erings-new-oldsmobile-aluminum-cylinder-head/

Ahhhhhh, the mythical Wise heads..... They don't actually exist, and that dude has robbed the few that tried to acquire them.

As far as rods, get Chevy rods and custom pistons. I'm no engine builder, but I can tell you that the 425 crank has a shorter stroke and is steel as opposed to the nodular 455 (there are rare 455 steel cranks out there, too). The counterweights have to be turned down on a 425 crank to fit between the pan rails. My 425 crank in my 468 was offset ground to Chevy rod journals with 4.24 stroke. I don't know if it can go more or not. It would be best to talk to a known Olds builder like Bernard Mondello, Bill Travato, Mark Remmel, or John Stolpa (each of the 4 corners of the country, sort of). If you're in Canuckistan, there are a few known buildes up there, too: Dale Robinson and Joss(?) Racing.
The Mondello book describes the removal of the injector pump; I'll see what it says later.

 

[Streetbu]

Personally I like the Caddy engine BUT..... I say do whichever one has a better chance of actually getting done and you being able to drive the car again. Way too many cars languish in a garage because of "I'll get back on it someday". Life happens, things happen, kids, houses, sudden unknown expenses etc. Have a plan, stick to it. Don't say well I'll just take it apart while I'm saving the money up and buy all the parts I need in a couple months. Odds are it won't happen and you'll be stuck with a car that's torn apart and worth almost nothing. JMO

 

[L92 OLDS]

Cool build. I see a lot of $$ and hassle acquiring the right parts with either. Working with 50 year old technology makes it tough! When your done please post back with $$ spent and dyno results / qtr. mile times.

 

[fleming442]

Oooops, f-ed that up; I'll get another tomorrow.

 

[Kennybill]

What's your purpose for your car? Mostly street, occasional dragstrip? I'd only go the diesel route if you are going full dragstrip. There's a lot of machine work involved in making a 440 stroker engine. Your whole drivetrain will need to be upgraded. Your right on the edge of the rabbit hole. You need to figure out your goals for your car then stick to it. Jmo.

 

[fleming442]

What's your purpose for your car? Mostly street, occasional dragstrip? I'd only go the diesel route if you are going full dragstrip. There's a lot of machine work involved in making a 440 stroker engine. Your whole drivetrain will need to be upgraded. Your right on the edge of the rabbit hole. You need to figure out your goals for your car then stick to it. Jmo.

Shhhhhh! I want to see another badass DX!!!

 

[Kennybill]

Well, if he goes that route I know "someone" that has "uncut" 425 crankshafts. About two years ago I sold a std/std 425 crank to a guy having a diesel built by Bill Travado. He said Bill will only stroke an "uncut" 425 crank for the diesel builds. Around the same time I sold a 330 std/std crankshaft, harmonic balancer and flex to a guy on this site. His build is in the racing section but his build stalled out. Actually both guys builds stalled out. The 425 crank guy was on Classic Oldsmobile site. Just saying.

 

[fleming442]

Well, if he goes that route I know "someone" that has "uncut" 425 crankshafts. About two years ago I sold a std/std 425 crank to a guy having a diesel built by Bill Travado. He said Bill will only stroke an "uncut" 425 crank for the diesel builds. Around the same time I sold a 330 std/std crankshaft, harmonic balancer and flex to a guy on this site. His build is in the racing section but his build stalled out. Actually both guys builds stalled out. The 425 crank guy was on Classic Oldsmobile site. Just saying.

How many of these 425 cranks are we talking? I'd be in for 1 or 2.

I can see where Bill wouldn't touch a turned piece; too many variables.

 

[pontiac guy]

I have a 425 Caddy I'd gladly part with. Complete carb to oil pan with all the brackets if you want to go big caddy. It's not a 500 but the same engine family so parts are available.

 

[kornball426]

What rods and pistons would I use with a 425 crank? and whats the difference between the 425 crank and the 455? If I did stroke the block I have, I'd want at least 400 cubes. what crank would get me closer to that ball park? Also, what to do about the gap left by the injector pump on the DX block? On the other hand I could pick a Cadi motor up for $300 bucks, then all the new parts, but I don't know how to get any more performance out of a 500. And then all the extra weight...

A caddy big block is relatively light for how many cubic inches they are. Lighter than a big block Olds for sure, honestly probably lighter than an older 350 diesel. As I recall an all stock 500 with iron heads, intake, and exhaust manifold weighs about 75 lbs more than an all iron 350 chevy. Shorty headers, aluminum intake, and if you have the money heads, and it weighs about the same as an all iron SBC.

They have a lot of potential, the three things that hold it back in stock form are the oil system, rockers, and connecting rods. Aftermarket rockers are more expensive than typical engines because only a few specialist places make them, everyone pretty much agrees they MUST be upgraded for any kind of performance work, the stock rocker setup is fragile.

Big block Chrysler 440 rods can be modified to work with the Caddy block and crank which opens up pretty big number of options for rods. Or alternatively you can get nice forged i beam or H beam rods for Cadillac now, they're a bit more expensive than Chevy rods but in line with other BOP and Caddy performance parts, but cheaper in the long run than using Mopar rods because there shouldn't be any special machine work needed. Cool thing about using Chrysler rods is since they're smaller big end diameter, the crank needs to be turned down to use them, but that means you can have the shop offset grind the journals and make your 500 caddy a stroker, think it makes for like a 535 but I can't remember the exact details.

That said, if it were me, and this is just my opinion... If you are not going to run a Chevy engine, and you want to keep it Olds, I'd find a 400, 425, or 455 and rebuild it and plop it in there. Should fit perfectly where the 350 diesel was, and won't be as expensive a headache as converting the 350 diesel into a gas powered 400+ ci stroker. It'll still be an expensive headache but not nearly as bad.

400 or 425 would be my first choice.