Serious SBO gearheads only! (LONG)
February 13th, 2010, 08:14 AM
#1
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Serious SBO gearheads only! (LONG)
We are in the research and notebook phase of building a pretty hot SBO 350. What this will be going in is undetermined as of yet. Most likely a '73-'77 Cutlass, but I'm always looking for a decent '67 Cutlass "for the wife." 
Either way, I don't have a car for it to go in at this time but I'm sure something will turn up. This will be my first Olds engine build of any kind so I'm in unknown territory. While having been a SBC/BBC gear head and built and wrenched on those most of my teen and adult life, I want a challenge. Anybody can schmooze HP out of a Chebby. It's not that easy to get it out of a BOP engine. So I mentioned I was in the research and notebook phase. Well I chose to start my research on this forum because there are alot of you guys (and I won't exclude the ladies, cutlassgal) on here that have already been where I am going or just plain have the knowledge from years of experience. I will just use joe_padavano as an example. I can read a thread where someone is asking a general question or a very, very specific and odd ball out of the way question and 3 or 4 posts down the page there is joe_p (or some others on here) with the correct answer or advice. And when I read that I'm always thinking "How the heck does he know all this stuff?"
Alright, down to the dirty business. Every performance engine build starts with a good base. Let's start with the block. Is there a specific year SBO 350 block that was made better in general? Stronger webbing, metalergy (SP?) etc? I'm already anticipating having to bore it, but .10 over standard is all I'm willing to go on this build.
Heads? As I see it, this is where BOP failed miserably! BOP heads don't flow worth a darn! What is the best head? How do I ID it? I'm willing to stick with cast heads, but If I can't get the flow I want out of them on the bench I'm more than willing to go aluminum aftermarket. But before I do that I want to give the cast heads a try. I'm talking SBO heads. I considered the whole BBO head swap, but the gain in flow with the larger valves of the BBO is not worth the loss of compression and what I'd have to do to make that compression up. I'm not worried about detonation or piston knock. That can simply be solved with 2 things, 1 of which alot of people overlook. The simple one is timing. The other is quench. Getting the quench right is the key.
Let's start with that. Block and heads. The base. Strength and flow. I still need to outline alot. This will be going into a heavy car (all Olds are heavy!). Targeted compression is somewhere around 10.5:1, even more if I can get away with it. I'm going with a 350 trans. The 400 is stronger I know, but it takes more power to work the 400. And since this will be a street/strip car and my transmission guy builds bullet proof 350's, I'm not worried at all about the tranny.
Nitrous is a must! So now we are into a whole 'nother mess. Let'a talk valve train geometry and how I can be strong there. Is spinning 6 to 7K out of the question? Can I do more than that?
So chime in here my Olds experts. I wanna pick your collective brains. I want the MOTHER of all SBO's.
Either way, I don't have a car for it to go in at this time but I'm sure something will turn up. This will be my first Olds engine build of any kind so I'm in unknown territory. While having been a SBC/BBC gear head and built and wrenched on those most of my teen and adult life, I want a challenge. Anybody can schmooze HP out of a Chebby. It's not that easy to get it out of a BOP engine. So I mentioned I was in the research and notebook phase. Well I chose to start my research on this forum because there are alot of you guys (and I won't exclude the ladies, cutlassgal) on here that have already been where I am going or just plain have the knowledge from years of experience. I will just use joe_padavano as an example. I can read a thread where someone is asking a general question or a very, very specific and odd ball out of the way question and 3 or 4 posts down the page there is joe_p (or some others on here) with the correct answer or advice. And when I read that I'm always thinking "How the heck does he know all this stuff?" Alright, down to the dirty business. Every performance engine build starts with a good base. Let's start with the block. Is there a specific year SBO 350 block that was made better in general? Stronger webbing, metalergy (SP?) etc? I'm already anticipating having to bore it, but .10 over standard is all I'm willing to go on this build.
Heads? As I see it, this is where BOP failed miserably! BOP heads don't flow worth a darn! What is the best head? How do I ID it? I'm willing to stick with cast heads, but If I can't get the flow I want out of them on the bench I'm more than willing to go aluminum aftermarket. But before I do that I want to give the cast heads a try. I'm talking SBO heads. I considered the whole BBO head swap, but the gain in flow with the larger valves of the BBO is not worth the loss of compression and what I'd have to do to make that compression up. I'm not worried about detonation or piston knock. That can simply be solved with 2 things, 1 of which alot of people overlook. The simple one is timing. The other is quench. Getting the quench right is the key.
Let's start with that. Block and heads. The base. Strength and flow. I still need to outline alot. This will be going into a heavy car (all Olds are heavy!). Targeted compression is somewhere around 10.5:1, even more if I can get away with it. I'm going with a 350 trans. The 400 is stronger I know, but it takes more power to work the 400. And since this will be a street/strip car and my transmission guy builds bullet proof 350's, I'm not worried at all about the tranny.
Nitrous is a must! So now we are into a whole 'nother mess. Let'a talk valve train geometry and how I can be strong there. Is spinning 6 to 7K out of the question? Can I do more than that?
So chime in here my Olds experts. I wanna pick your collective brains. I want the MOTHER of all SBO's.
February 13th, 2010, 08:27 AM
#2
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I'm not going to copy over the whole thing.
Block...diesel block. No-brainer.
Best "factory production" heads to go with are #5's (just look for this # by the #1 plug) in my opinion, even with the shallow spring seat. You can get these to flow 270 on the intake side, with big valves. 7K rpm, no problem with modifications.
You need to do a sit down with Smitty.
BTW-Starfire body (78 vintage or so) will be the lightest, did not come with a SBO from the factory.
It can still fit in there.
Do a search on BTR, even check out Nick's car.
http://btrperformance.com/phpbb/index.php
Both are SB based.
JMO
Jim
Block...diesel block. No-brainer.
Best "factory production" heads to go with are #5's (just look for this # by the #1 plug) in my opinion, even with the shallow spring seat. You can get these to flow 270 on the intake side, with big valves. 7K rpm, no problem with modifications.
You need to do a sit down with Smitty.
BTW-Starfire body (78 vintage or so) will be the lightest, did not come with a SBO from the factory.
It can still fit in there.
Do a search on BTR, even check out Nick's car.
http://btrperformance.com/phpbb/index.php
Both are SB based.
JMO
Jim
Last edited by Warhead; February 13th, 2010 at 08:35 AM.
February 13th, 2010, 08:39 AM
#3
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,298
Alright, down to the dirty business. Every performance engine build starts with a good base. Let's start with the block. Is there a specific year SBO 350 block that was made better in general? Stronger webbing, metalergy (SP?) etc?
Diesel blocks. DX is preferred, but D blocks are still miles better than gas blocks. Requires either main bearing spacers or a 425 crank due to BBO-sized main bearings.
NASCAR block. Very limited production of special blocks for Oldsmobile's NASCAR engines from the late 1970s. I rank these behind the DX in strength only because they were lighter. That may or may not be a fair comparison. In any case, expect to pay VERY dearly if you can even find one for sale.
68-76 gas block. Easy to find, easy to buy, probably good enough for any street engine.
77-up gas block. Windowed mains, avoid.
I'm already anticipating having to bore it, but .10 over standard is all I'm willing to go on this build.
Heads? As I see it, this is where BOP failed miserably! BOP heads don't flow worth a darn! What is the best head? How do I ID it? I'm willing to stick with cast heads, but If I can't get the flow I want out of them on the bench I'm more than willing to go aluminum aftermarket. But before I do that I want to give the cast heads a try. I'm talking SBO heads. I considered the whole BBO head swap, but the gain in flow with the larger valves of the BBO is not worth the loss of compression and what I'd have to do to make that compression up. I'm not worried about detonation or piston knock. That can simply be solved with 2 things, 1 of which alot of people overlook. The simple one is timing. The other is quench. Getting the quench right is the key.
Let's start with that. Block and heads. The base. Strength and flow.
Let'a talk valve train geometry and how I can be strong there. Is spinning 6 to 7K out of the question? Can I do more than that?
February 13th, 2010, 08:48 AM
#4
Seasoned beater pilot.
Join Date: Jan 2007
Location: Chicago
Posts: 5,468
Here's a build that Nick on here did.
https://classicoldsmobile.com/forums...all-block.html
February 13th, 2010, 09:33 AM
#5
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joe_P "Well, the other thing is the crank. You want a forged 330 crank, which bolts into any SBO gas block. 403 rods are a little beefier than other SBO rods, but aftermarket may be even better depending on budget and ultimate package."
Is the 330 crank the same throw as the 350? If so, what years for the forged 330 crank?
I've not done research on con rods yet. Are the 403 rods the same journal size as the 330 crank?
Good Lord, I've opened up a can of worms.
Is the 330 crank the same throw as the 350? If so, what years for the forged 330 crank?
I've not done research on con rods yet. Are the 403 rods the same journal size as the 330 crank?
Good Lord, I've opened up a can of worms.
February 13th, 2010, 09:46 AM
#6
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[quote=J-(Chicago);148890]The mother of all SBO motors will more than likely not be a street car.
Most likely not, but if I see you at a stop light, then watch out......!
Most likely not, but if I see you at a stop light, then watch out......!
February 13th, 2010, 09:49 AM
#7
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joe_P "Well, the other thing is the crank. You want a forged 330 crank, which bolts into any SBO gas block. 403 rods are a little beefier than other SBO rods, but aftermarket may be even better depending on budget and ultimate package."
Is the 330 crank the same throw as the 350? If so, what years for the forged 330 crank? 64-67 330's. You'll need a 330 flexplate.
I've not done research on con rods yet. Are the 403 rods the same journal size as the 330 crank? Yes.
Good Lord, I've opened up a can of worms.
Is the 330 crank the same throw as the 350? If so, what years for the forged 330 crank? 64-67 330's. You'll need a 330 flexplate.
I've not done research on con rods yet. Are the 403 rods the same journal size as the 330 crank? Yes.
Good Lord, I've opened up a can of worms.
February 13th, 2010, 11:08 AM
#9
car guy
Join Date: Apr 2008
Location: Dallas TX
Posts: 5,656
Instead of a generic statment like the mother of all SBO lets talk about what your goals really are. Things like that are very subjective I have built a 11 and high 10 sec street cars were borderline boring to me but there were people I would take for rides that thought they were in a rocket ship
What kind of ET are you after? Do you have a realistic HP goal? Are you going to build the car around the power you plan to make or are you just going to toss it in a hope for the best.
What kind of ET are you after? Do you have a realistic HP goal? Are you going to build the car around the power you plan to make or are you just going to toss it in a hope for the best.
February 13th, 2010, 11:18 AM
#10
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Yes. All SBO (except the diesel and NASCAR blocks) use the same main and rod journals.
EDIT: With the 330 you will also need a different flexplate because they use a different bolt pattern.
Last edited by svnt442; February 13th, 2010 at 11:24 AM.
February 13th, 2010, 12:45 PM
#11
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The Big Block Olds head will achive a desired CFM level with less grinding than a Small Block head.
I have done the swap before, and I loved it.
Check prices from head porting experts...Smitty for example.
Other than the lifter size, the D, and the DX block are virtually identical from what I can see. Joe may have more information than I do, but a score on either of these blocks will be a worthwhile investment. I have 1 of each, and am unable to detect ANY difference, other than the lifter size (.921 for the DX-.842 for the D).
Either block will be light years ahead for metalurgy, and for thickness where it counts. They were, and are the BEST blocks Oldsmobile ever cast for a production vehicle. If you can find one-buy it.
The crank is pretty stout for a cast iron unit.
I am forced to agree with Mark (eficutlass) with his suggestion on rods, and pistons. Light wieght, better price, great rods for less cost in this application. Plus you can gain a few inexpensive cubes while you have the crank ground. You can't beat it.
Goal, and budget?
Jim
I have done the swap before, and I loved it.
Check prices from head porting experts...Smitty for example.
Diesel blocks. DX is preferred, but D blocks are still miles better than gas blocks. Requires either main bearing spacers or a 425 crank due to BBO-sized main bearings.
Either block will be light years ahead for metalurgy, and for thickness where it counts. They were, and are the BEST blocks Oldsmobile ever cast for a production vehicle. If you can find one-buy it.
The crank is pretty stout for a cast iron unit.
I am forced to agree with Mark (eficutlass) with his suggestion on rods, and pistons. Light wieght, better price, great rods for less cost in this application. Plus you can gain a few inexpensive cubes while you have the crank ground. You can't beat it.
Goal, and budget?
Jim
Last edited by Warhead; February 13th, 2010 at 12:47 PM.
February 13th, 2010, 01:26 PM
#12
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"I want the MOTHER of all SBO's."
I think you should lower your sights a tad bit unless you have a very deep pocket book. Here is what was in my 380.......made good power.
http://www.realoldspower.com/phpBB2/viewtopic.php?t=830
Or follow those 3 tech articles on Drag Racing Online. It lays alot out there about my current build which is 425 cubes. PM me if you like or email is snjeff@mchsi.com. I'll answer any questions I can.
Nick
I think you should lower your sights a tad bit unless you have a very deep pocket book. Here is what was in my 380.......made good power.
http://www.realoldspower.com/phpBB2/viewtopic.php?t=830
Or follow those 3 tech articles on Drag Racing Online. It lays alot out there about my current build which is 425 cubes. PM me if you like or email is snjeff@mchsi.com. I'll answer any questions I can.
Nick
Last edited by 380 Racer; February 13th, 2010 at 01:28 PM.
February 13th, 2010, 05:43 PM
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February 13th, 2010, 09:29 PM
#14
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You can use the bottle with any compression you just have to tune it right. My Malibu I sold to help finish the Olds was 13.9 to 1. the new owner finished it and is running high 5sec 1/8 mile with it.
February 14th, 2010, 02:13 PM
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February 14th, 2010, 04:11 PM
#16
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You have to remember that the engine is only part of the build when building a drag car. Before I would even start with the engine I would start planing. Car, ET, 1/8 or 1/4 track car, weight of the car. How do you want the car to launch "maybe front end in the air". Transmission, rear end, and suspension have be factored in too. All of this needs to be decided before the engine build is started, because this info is key into picking cam, stall, and gears. So it is rocket science.
Then heads, intake, carb, ignition, crank "stroke", rods, cylinder bore, pistons, and the list goes on. Looks like your going have to open up your pocket book. Good luck with your build.
Then heads, intake, carb, ignition, crank "stroke", rods, cylinder bore, pistons, and the list goes on. Looks like your going have to open up your pocket book. Good luck with your build.
Last edited by 70 cutlass s; February 14th, 2010 at 04:18 PM.
February 14th, 2010, 06:50 PM
#17
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WOW! Well, I asked for a challenge and I guess it slapped me in the face. Looks like I've got ALOT of research, PM'ing, and questions. Right now I'm just about recovered from last nights Puddle of Mudd / Shinedown show in Peoria. I'm only 39, but this morning I realized that I'm getting to old to go to that crap!
February 15th, 2010, 08:04 AM
#18
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Ok, back on the horse this morning. I have been copiously taking notes and doing research. And it looks like the options are plentiful here, maybe a little too much so! But that is why I chose to start here....endless knowledge from members that you can't find in a book. Cutlassefi, those options blew my mind. And I spent alot of time just looking at journal sizes, rod length, etc, etc.....Wow! That would certainly be a frankenstein!
Alot of you have mentioned goal and budget. Seriously, I haven't thought about any of that and maybe that is where I should have started. I'm not looking to put this thing together overnight. It's going to be a long term project that will morph several times I'm sure. Can I get you guys a little more pinpointed by generalizing that my goal and budget for the engine would be to utilize as many reconditioned parts as I can and still have a reliable engine. And make as much HP as I can and stay around +/- $7K.
As far as ET's, an 1/8 or 1/4 mile car....This is where I'm torn. And still need to look at what's out there as far as tracks. Charleston, Il has a popular 1/8 mile, but then there's Chicagoland to the north of me. I don't know of anything else around me. Guess I need to decide. Last night I was thinking about how cool it would be to build a nostalgia dragster. Something Olds and straight axle? Cool, but....eh? You know. Anyway, hope this pinpoints it a little more. If it doesn't, then let me know. Smack me in the head with the voice of reason.
Alot of you have mentioned goal and budget. Seriously, I haven't thought about any of that and maybe that is where I should have started. I'm not looking to put this thing together overnight. It's going to be a long term project that will morph several times I'm sure. Can I get you guys a little more pinpointed by generalizing that my goal and budget for the engine would be to utilize as many reconditioned parts as I can and still have a reliable engine. And make as much HP as I can and stay around +/- $7K.
As far as ET's, an 1/8 or 1/4 mile car....This is where I'm torn. And still need to look at what's out there as far as tracks. Charleston, Il has a popular 1/8 mile, but then there's Chicagoland to the north of me. I don't know of anything else around me. Guess I need to decide. Last night I was thinking about how cool it would be to build a nostalgia dragster. Something Olds and straight axle? Cool, but....eh? You know. Anyway, hope this pinpoints it a little more. If it doesn't, then let me know. Smack me in the head with the voice of reason.
February 15th, 2010, 10:03 AM
#19
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Ok, back on the horse this morning. I have been copiously taking notes and doing research. And it looks like the options are plentiful here, maybe a little too much so! But that is why I chose to start here....endless knowledge from members that you can't find in a book. Cutlassefi, those options blew my mind. And I spent alot of time just looking at journal sizes, rod length, etc, etc.....Wow! That would certainly be a frankenstein!
Alot of you have mentioned goal and budget. Seriously, I haven't thought about any of that and maybe that is where I should have started. I'm not looking to put this thing together overnight. It's going to be a long term project that will morph several times I'm sure. Can I get you guys a little more pinpointed by generalizing that my goal and budget for the engine would be to utilize as many reconditioned parts as I can and still have a reliable engine. And make as much HP as I can and stay around +/- $7K.
As far as ET's, an 1/8 or 1/4 mile car....This is where I'm torn. And still need to look at what's out there as far as tracks. Charleston, Il has a popular 1/8 mile, but then there's Chicagoland to the north of me. I don't know of anything else around me. Guess I need to decide. Last night I was thinking about how cool it would be to build a nostalgia dragster. Something Olds and straight axle? Cool, but....eh? You know. Anyway, hope this pinpoints it a little more. If it doesn't, then let me know. Smack me in the head with the voice of reason.
Alot of you have mentioned goal and budget. Seriously, I haven't thought about any of that and maybe that is where I should have started. I'm not looking to put this thing together overnight. It's going to be a long term project that will morph several times I'm sure. Can I get you guys a little more pinpointed by generalizing that my goal and budget for the engine would be to utilize as many reconditioned parts as I can and still have a reliable engine. And make as much HP as I can and stay around +/- $7K.
As far as ET's, an 1/8 or 1/4 mile car....This is where I'm torn. And still need to look at what's out there as far as tracks. Charleston, Il has a popular 1/8 mile, but then there's Chicagoland to the north of me. I don't know of anything else around me. Guess I need to decide. Last night I was thinking about how cool it would be to build a nostalgia dragster. Something Olds and straight axle? Cool, but....eh? You know. Anyway, hope this pinpoints it a little more. If it doesn't, then let me know. Smack me in the head with the voice of reason.
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