I want to add a couple more random thoughts. One big difference between us and the Bow-tie and Blue oval boys is that the difference between their small and big blocks is significant, both in weight and dimension. The SBC is a light, compact little engine, and if you can squeeze out some extra cubes, great. In our case (and Buicks and Pontiacs as well) this is not true. As Joe alluded to (or outright stated) why stroke a small block when you can have the massive cubes in a BBO platform for a few extra inches and pounds? Also, there already is a big inch SBO, the 403, which they made a bunch of.
At our shop, our business is primarily hard core racers, resto guys, and retail work for shops. Most casual hot-rodders just don't want the hassle of building an engine when for a modest sum they can get one in a box, ready to run. We seldom build $3500 engines, most are exotic stuff (right now we have a Porshe, a Daimler, an Oliver tracktor, an old VW, a 313 Ford, and a $15,000 BBF going. No street 383s, we can't compete with those guys, price-wise.
So, the big question, if Eagle makes a bolt in stroker kit good to 400 HP for a grand, will it sell? I think so, but am not smart enough to make that call. Again, we are a small market. If you look at this,
http://72.22.90.30/phpBB2/viewtopic.php?t=64191
the guys are split 50/50 on whether a cast or forged unit is the way to go. A lot of them say they are willing to pay the extra $500-$600 for a forged crank. Of course, that would be prohibitive for the casual guy. Again, identify the market and cater to it, you can't be all things to all people. I do think the worst thing would be if they made one and it did not hold up to a fair amount of abuse.

 

I agree 100% with this theory.
The bigger the rod journal, the further distance around the bearings the oil must travel.
I also have gathered from my experiences with 455s that the rod bearings are the first to go, due to losing their "crush" in the rod and spinning.

 

As far as the new crank..... I like the idea of having a newer prettier option on the table. However, for lack of a better analogy I'm going to stick with my old faithful wife the stock 350 junk. Let me know how the new girlfriend works out, she sounds like a knockout!!

 

This was my statement earlier. Milan assured me he had to shim the pump more with a BB than a SB to maintain 60 psi with higher rpms (cruising) and 30 psi at idle.

 

Milan is a sharp fella, and I'd trust his judgement on that.
I have personally never shimmed a pump in either of my motors.
The BBO had 40 hot at idle and 65 cold idle right out of the melling box with 10-30 synthetic. W.o.t. is above 65.

I'm not sure if I'm just lucky, or have overly friendly gauges. It'd be nice to check it with a 6" some time instead of A 2.5"

 

I am one of the few people that opted to build a 350 olds vs 455. I have one of each sitting on a stand. a 1970 olds 455 out of a olds 98 and the engine I built for my 85 olds 442 a 1968 olds 350 out of a 68 cutlass. Mine has the #6 heads with a Big hydralic Isky cam and 11/1 compression. Car is light 2800lbs. I run at 5400 altitude here in Pueblo Colorado, and have beaten Many big block cars and small block cars. Their expression when they got beat by a small block olds is Priceless!!!! I even beat a corvette Z-06. That was really cool!!! The guy in the vette said" my tires on my car cost more that your engine" He ran 12.70 @ 112mph to my 12.53 @ 106. he was comming but couldn't catch a $3500.00 small block olds. Great post. I want to build a 496 stroker olds and I'm still doing research. Any help would be greatly appreaciated. Olds power Forever!!!!!!!

 

So I realize that this thread is pretty much dead, but wondering if there is still even a small chance these cranks are gonna be built? Just wondering 'cause I'd buy at least a couple of 'em. I'm one of those that all I have are 307s and I want to build at least a slightly non-turd 307 based block for my '85 Delta 88. Call me weird or dumb or whatever you want, but it's still the original block in the car, and it was given to me for my 19th birthday by my grandma, who bought the car new in April of '85. So I'd like to keep it almost 100% stock looking under the hood, but it really needs more torque. And I don't want to put in a different motor if I can help it.

 

This would be a nice option for the full weight olds street cars that want to run less gear and converter.

 

You know with one of these 3.75 cranks and a 4.125 bore you could have a 400 cu in small block for a 442 clone build.

 

Still a lot of good forged 330 cranks out there and they sell for peanuts. If few are willing to pay more than $150 for a forged factory crank, how many will shell out $400 for an aftermarket casting? Still millions of 350 N cranks available, too.

I've always believed the 330 cranks are undervalued, so I resisted selling the one I have stashed. Who knows, maybe someday I'll do another SBO build, if both my BBO's grenade

 

I feel this would be a nice option for a small block. The main reason I went for a custom billet crank was due to the fact that the good cranks are 40 years old. The 330s have had how many heat cycles and how many are left? If I would have had a tamer new crank option, I would have went for it instead. More of the fun factor around 11.00 seconds.

 

I think you're missing the point. You can't stroke any sbo crank to 3.75, much less 4.00. That opens up a whole bunch of opportunities as the earlier sbo blocks are plenty sturdy enough to handle 500hp and beyond.
I'd buy a stroker sbo crank in a minute.

 

Not to mention it is a great way to add more torque for people like me who have a big full size sedan that lives on the street below 3000 rpm, but don't really want to put in a bigger motor that is still a short stroke. Or people who have small block cars and want to keep them completely original looking under the hood, but want more power to play with. Guilty as charged!

 

I have my doubts how well even a complete stoker kit would sell. It seems to me the majority of small block Olds street engines are pretty mild bolt-on types (read: not expensive).
Guys looking for more in older cars usually swap in a BBO. As for G-bodies, many came with Chevy mills stock, so the stroker SBC is an easy alternative and the more ambitious types can still do the BBO or D/DX swap. IMO, SBO guys are split mainly into 2 subsets: the mild street set and the serious racers (who know it's advantages over the BBO), neither of whom are gonna be inclined to buy an aftermarket cast stroker crank in large numbers. Again, that's just my opinion and I'm NOT trying to discourage new product development. Just stating my observations after being involved with Oldsmobiles for 30+ years.

 

Copper128, not arguing with you one bit, I'm one of those rare people that would buy the drop in cast stroker kit. I'd actually buy multiple kits. But then again I'm an absolute Oldsmobile addict. And all of my builds are gonna be SBOs for the foreseeable future (excluding a couple of restorations I've got planned soon. My grandad's old '72 Ford F-100 & my mom's '87 GMC pickup). But I like low speed torque, and the best way to get that is more stroke. Just not that many options for us SBO guys & gals. So I'd jump on this kit.

 

I think that with a stroked crank and the new cheaper Pro Comp heads that you could build a very nice street big-inch SBO. The problem is, for the most part, the Olds guys are cheap and won't spend the money. Every thread that I post in where I suggest spending the money to do it right I get massacred.

Back when I worked at the machine shop I looked into mild stroker kits using 400 SBC pistons and 350 cranks. Price was VERY reasonable and reception lukewarm at best, so I did not move forward with it. Bottom line, it is a niche market with not a lot of demand. I was sure that with all the 307 powered G-bodies out there that these engines would be more popular, but they aren't. And now that those are old, it ain't going to happen

 

I think that sums it up nicely.

 

You know I wonder if Edelbrock had these same discussions when they were thinking about the Olds BB aluminum heads ?How many have they sold since they introduced them to the buying public ?and how many ppl have built an BBO instead of dropping in a Chevy motor in their cars ? I would think that if someone did offer a nice stroker kit for the SBO at this point at a reasonable cost (1k?) guys would jump all over it to keep the SBO in their cars. BUT it would have to be a drop in kit with rods and pistons also so no mixing and matchin parts from all over the place.I would definitely be interested in making a 400cu in out of my 350 block and keeping it in the car instead of dropping in a 455.Just my .02 .

 

The problem I ran into was everybody wanted something different. Think about this; every 350 and 403 used the same connecting rod dimentions. 6" rod, .980 pin and 2.25" big end. Yet not a single company makes a direct replacement rod for a street engine. Why? No market.

 

Doesn't a stroker kit require longer rods anyways ? so you wouldn't need to worry about obtaining the stock rods,I would think that Eagle (or whoever)
would engineer a correct length rod and piston to match for the stroke of the crank in the dimensions needed .If it can be done for a 455 why not a 350.

 

My point was that one part number would fit EVERY 350 or 403, yet none was made. It CAN be done, but it won't, IMO. As to the 455, as I stated earlier in the thread, a SBO and BBO costs almost the same to build, very close in dimention and weight, so in most cases, guys will choose the 455. Similar situation with Buicks and Pontiacs. That is why there are a LOT more parts for all three big blocks, IMHO.

 

You don't need a longer rod for a stroker....

 

Krooser, anytime you stroke an engine you need to change either the piston (shorter pin hieght) or shorter con rods. If you don't the piston will go up to high & hit the cylinder head.
Anyways, I've beed reading about stroking the sbo engines, I wonder if anyone has taken a look at the Ford 390 crankshaft. The mains are alittle larger then the sbo, the bore center of the blocks are very close, the 390s have a 3.78'' stroke. The ford does have a different firing order, so a different cam would be required. I'd bet that the olds engineers took a long look at the FE engines when they were designing the second gen olds v8s.
There was a similar crank swap that they took a bbc crank, machined it, & fitted it into a 409 chevy. Two totally different engine families.

 

Actually the 409 and regular bbc are almost exactly the same engine family, just newer vs older.
I'd like to see you put a ford fe crank in any olds. Just because they're close in one way or another doesn't mean much.
And krooser was correct. He said you don't NEED a longer rod in order to stroke an engine. He's correct.

 

But should you not use a longer rod and a shorter piston ?
Doesn't that make more sense than a regular rod and a taller piston ? Or am I missing a detail ?

 

I would've gone for the new crank... But I do still have an extra block kicking around....

 

If a SBO crank is made with a stroke between 3.75"-4.00",I would be interested. If a new one was made with 3.500",I would not bother.I would just offset grind a 330 or 350 stock crank.

 

I think the 350 olds engine is under valued,I know of a few friends that would be interested in a stroker small block crank. I would not look at building a 455 if there was a big inch 350 gas block option. The 350 dx and nascar blocks are great race base blocks but are also big $$$$ .This is not a back yard engine build option. The 455 and G block 400 have a real problem not spinning rod bearings,I know this first hand as far back as 1980.The 403 is week and you have to think hard before you dump money into one. It would be great if you could buy off the self rods,crank and pistons in a stroker kit.What would you guess the hp/tq with a 9.5/10 to 1 comp and out of the box ebrock heads.?

So what are the negative points to a 4.00 stroke V 3.75 stroke?

I'm with others that there is a lot of 455 engine failures. I have seen vary few 350 posts were a 350 failed just after a rebuild unlike the 455 weekly horror stories. Not just on forums but local racers as well, herd of two in the last month that failed over the summer with not that many runs on them. Both had good machine work and parts, both cars were in the high 10's

I think for the Back Yard engine builder a 350 gas block engine is a safer build / less problems /local machine shop can get the job done you don't have to use XYZ machine shop only.

 

The DX builds aren't that much more than a gas build,but the NASCAR block builds are since the blocks are scarce and costly when found.The 403 blocks could have been a great thing IF they would not have bored the cylinders into the main webs,thus makings windows.They could have stopped where piston travel stopped,and left all the needed strength down there.Most of the typical 455 build failures occur due to improper bearing clearances.You can't put Chevy clearances on Olds journals and expect it to live.This will often weed-out the elite engine builders from the rest.
You should expect a new 350 Olds crank to have SBC rod journals.It's the 21st century,and we need to practice what we've learned through time.If you expect to use your 40+ yr old rods,you are not taking advantage of modern knowledge and technology,and degrading the job to be done half-right.

 

just my $.02, the 3.75 offst / 3.50 offset = 1.07 My engine was just dynoed (9:1 compression) torque is 398 lbs-ft So mine would have been around 425 lbs-feet...
Mild build 320 Hp... Higher compression will up it somewhat!

 

The two local engine failures were a block and a crank. One was turned into a open main web block the other was a crank that broke and took out the bottom end .Both were using quality after market rods/pistons and balancer. Heavy cars running in the tens.I think the two local 455 engines that failed were the result of blocks with out a bottom end support system. I will not build my engine with stock rods to many horror stories.I know you have had good results with your big block from your posts.Maybe all these engine failures are improper bearing clearances and stock rod stretch?

 

Do you think a quality sbo strocker crank that is in the $400 to $500 range will be coming to the market any time soon,if ever?

 

What quality parts were in those engines in the cars running tens?

 

When my 425 was built, I spent about $1500 extra on the DX over a gas block. Since it is a DX not a D, I sent it out to BTR for lifter bushings, rear main seal. 4.190x3.85 and I wouldn't want to go much further overbore. I really don't remember why I decided on a 3.85 stroke but I'm sure the 6.200 rods had something to do with it. I am very satisfied with this combo but would have went to a less expensive option/cubes and run mid/low 10s instead of 9s. Would have been more in my budget.


PS- My 380 with 4.155 bore and 3.50 stroke 13.5 to 1 compression, somewhat ported heads, RPM intake and a 950HP Holley produced 518 HP. Much easier with an off the shelf crank, if one was available.

 

A 455 olds at 9.7 comp with a 238 @ .050 hyd roller will go well past 500 hp with ported production heads, I dont know what happened on Joes build.

 

Joe theres no secrets to making bearings live in a 455, it been done in stock and super stock since release of these engines, just look at the thread Oldsmobile race cars. It comes down to a few oil system mods and good machine work and being able to set bearing clearences, its that simple, Ive never had a bearing problem on an Olds 455. 7000 rpm applictions would require a different approach, Ive never turned a 455 this hard before.

 

How far past it? Why don't you build one then dyno it on another dyno besides yours and show us?

For the record, BTR made 545 with a 10.7:1 Edelbrock headed 496 with the exact same size cam. So you can do better/same as that with 40 less c.i. and 1 full point less compression? On ported irons? On pump gas?

http://highperformanceolds.com/phpbb...=3806&start=30


I'm all ears. Talk is cheap. If you give us a build and valid dyno sheet, you'll get my immediate congratulations, I promise.

 

Here is the message my hood scoop sends people

 

Rods were Crower
Balancer was ATI
Pistons were CP and Ross
One had a N stock crank
One had a factory steel crank
One of these engines was a class car/its not for me to say more.
The class car had good parts but had to run the NHRA heavy piston and rod weight

 

Stock and supper stock engines are on the edge and are not for the street
They run from $10,000 and up and a lot are from well known engine shops /builders.
A lot of these engines spend a lot of time with the pan off for inspection.