Ryan 1969 Chevelle SS396

Hello ClassicOldsmobile.com Engine gurus.

I am completing a chassis restoration on my 1969 Oldsmobile Cutlass 'S' Sports Coupe W-31, 4 speed M20, 3.42 Antispin rear.

I have documented every step in a build thread on yenko.net (Sorry I used to be a Chevelle guy:-) if you wish to catch up on my thread please do.

http://www.yenko.net/ubbthreads/ubbt...opics/650037/1

I am fast approaching the point in my Chassis restoration at which point my chassis will require motivation:-)

I have read LOTS of online Oldsmobile "SBO" engine information, some old, some new, some accurate some I am sure 100% inaccurate. I always feel this is step one towards a successful outcome of a project to understand the basics.

I am an amateur, this is my first time doing most things car related, so I welcome support as I work through item after item, detail after detail.

All good projects start with clear goals:

This portion of the build (intake to oil pan, flywheel to Harmonic Balancer/timing chain cover) needs to be "cost effective" ........ I know for a fact I just lost half my audience:-(

W-31 Original parts that must be used:

OAI breather, etc. (could use a performance element)
Carburetor
Intake
Distributor (changed to solid state upgrade) Pertronix etc.
Water pump, and KA/KB pulleys, etc. (no power steering, YUK)
Harmonic balancer
Fly wheel
Nodular Cast Iron Crank
Warranty SR block (missing one piston and rod, sat partially disassembled for years)
Original W-31 heads (they are in terrible shape, rusted combustion chambers)
Oil Pan, timing chain cover, valve covers, etc.
Cast Exhaust manifolds, with block off plate for cross over.
M-20 Muncie 4 speed, completely rebuilt:-)
Luk Diaphram clutch/pressure plate new :-)
TM code 3.42 anti spin rear end, (I have all the parts to rebuild)
H shifter handle, and ball, and boot:-)

W-31 Not Original:

Hurst Competition Plus Shifter (original didn't have adjustable stops)
2.5 inch Stainless Magnaflow exhaust with X pipe, turn downs, no trumpets this aint no 442:-)
CPR driveshaft loop

Intended use:

Drive it 2000 miles per year, including a few 4-5 hour trips (Lansing MI Homecoming for example)
Wicked idle :-)
Smoke the tires when ever I want.
15-18 MPG (when not smoking the tires)
PSMCDR legal
Pick up Al Stager the original owner and go for ice cream:-)
Pump gas 91-93 Octane (110 Octane for PSMCDR)
RPM range idle to 6.5K RPM, with power from 2-6.5K


FUTURE: I have an extra 1969 Olds 350 engine (4 speed crank with pilot bearing) to use/build for serious PSMCDR mayhem, as well as an M22, and someday I will buy/build a 4.33 rear.

SIDE NOTE: I have specific instructions not to use the warranty short block and keep it off to the side. I can and still may do that but my gut says I should put the heart and soul of the car back as it was and use the extra drive train in future for real rod bending action.

After all that preamble......... what am I asking?

I would like to garner as much great information as possible from the great, respected, Oldsmobile engine builders on here to guide me through the build, especially to steer clear of known issues.

Thanks in advance for thinking about my project and sharing information:-)

Ryan

coppercutlass

You should contact member Joesw31 He has built a few w31 sbo engines and is a great guy. I have bought a few items from . Nice guy to talk to.

Im all for budgets. The biggest single most important thing is a good machine shop and even then check their work. The rest comes down to careful assembly and attention to detail. Good parts help too although i have made it a habit to build my engines with hand me downs and left overs and swap meet parts.

10 to 1 compression on iron heads is pretty good for 93 octane. I have ran 91 octane in a pinch but i wouldnt make a habit of it lol. In reality your biggest restrictions will be the manifolds and intake. My 355 is a very bare bones build nothing special pretty much a w31 style build with a good cam intake and headers. I have flat tops , #6 heads with bigger valves 2.07 1.63 no porting , ran 12.60's last summer many long drives , it was also drive to the track and back many times. 120 mile round trip.

Ryan 1969 Chevelle SS396

Thanks

Appreciate the advice!!

Ryan

Ryan 1969 Chevelle SS396

I would like to plan the oiling system first, it is the most important and by what I have read and heard can be an issue in a SBO.

Does anyone have schematics, or drawings, or calculations? I would like to see the path of flow, the size of the passages, cc/rev or the pump, etc, etc.

Ryan

Rick Finsta

Don't worry too much about the oiling system, it'll work fine. Number one priority for good oiling (and parts not touching) is proper clearances. Pick up a copy of Trovato's book, there is good information there for your machinist. Spend money on excellent machine work and check everything on assembly.

83hurstguy

A lot of your options and budget are going to be limited by what condition your block and heads are in. How much bore does it need? Will the heads need the seats replaced to be usable without sinking the heck out of the valve? Do they pass a pressure test? You can rack up a pretty hefty head bill if they need seats, guides, valves. You want a very competent machinist doing this, as you'll need all the valves heights set properly for the awesome Olds non-adjustable stock rockers. If you plan to turn 6500 rpm, you'll want to make sure geometry is perfect and probably also cryo the rockers... any valve float and you'll likely start breaking rocker arms.

10:1 compression with wicked idle, 16-18 mpg, PSMCDR legal, and 3.42 gears aren't exactly compatible. The legal 308* cam will be a turd without gearing, Dave H had a lot of experience with racing his ram rod. Probably should look at a more modern, faster ramped, shorter duration cam with something on a 108 LSA if you want the idle sound, just know with manifolds you won't be helping power, as it won't scavenge (it's not PSMCDR legal, but keep the lift around .475" and nobody will know/care). If you really want efficiency, running a quadrajet with no power piston/primary rods isn't the way to go (and it's not compatible with low vacuum cams).

There used to be some neat oil flow diagrams on ROP before it crashed, can't find them anymore. Wouldn't waste the time on calculations, as the numbers won't tell you anything. You'll also get 18 different answers on what to do regarding mods and restrictors. The simple answer is don't do anything, ensure clearances are right, parts are straight, block is good. We put a stepped oiling system in mine, but there's only one shop currently doing that. I'd stay away from restrictors.

Precision oil pumps modifies the melling HV pump and tests them, they are nice pieces. They also have a nice oil pump drive rod.

Ryan 1969 Chevelle SS396

I like to understand the systems before deciding if they are acceptable as is, or if upgrades are required/beneficial.


A couple basic oil system plans I have are to use a WIX 51258 filter, and Brad Penn Grade 1, Mineral, Break-in Oil, 30W, ZDDP Enhanced, and then Brad Penn Grade 1, Mineral, 30W, ZDDP Enhanced, oil:-)


SBC info is everywhere, I would like to see SBO oil system information:-) I can disassemble and trace out the passages etc, but this must be know information. priority oiling?


Ryan

Ryan 1969 Chevelle SS396

Now we are getting somewhere, let me process this info....


Ryan

oldsmobiledave

Ryan


Get rid of the 3.42 gears & build your engine around the 3.91 gears & a 26" tire or 4.33 gears & a taller tire.

83hurstguy

Just a few other comments... with stock rockers, you especially won't want to be restricting oil to the top end. With a hydraulic cam, you have a metering plate in the lifters that will restrict oil anyways.

Maybe consider putting on a 7 qt deep pan for some additional oil capacity. Paint it to match the engine, and other than the square sump, it's not a horrible modification. That may help if you are driving it a lot, though it's not required. The bottom of the stock pan typically sits about 1" higher than the engine crossmember, so a 1" deeper pan will sit about flush with it, won't hang down a ton.

Ryan 1969 Chevelle SS396

Now we are on a roll!!!!!


Keep the ideas flowing guys!!!


Ryan

Ryan 1969 Chevelle SS396

I visited an engine builder in Guelph (Close to me) his suggestions were to do a complete rebuild as stock as possible with a few modifications. We were on the same page budget wise which was promising/makes me want to know more about his process. (can be good or not good, eyes wide open)

His suggestion on oiling was the same as Luke, new stock pump and he may add a little to the spring but doesn't see value in driving all the oil into a hot, foamy dither for no reason with a HP/HV pump.

Try to share more later:-)

Ryan

cutlassefi

Find another machinist, that's really not what causes the oil to foam.

Ryan 1969 Chevelle SS396

I can't remember if he said foam or If I added that myself:-) he deffinetly said it is wasted energy and excessive heat in the oil.

Thanks for chiming in Cutlassefi, I like what I have read in your previous posts:-) what would you do, if you were me? What oil pump?

Ryan

Fun71

I have used the 51049 filter since the '80s as it is a larger (taller) filter with the same diameter. I like more filter area than the short 51258 filter.

coppercutlass

Fwiw . Im running a stock replacement oil pump , and the big block oil pan. takes 6 qts. I turn my 355 north of 6000 rpm hitting the shifter at 6300 so it shifts around 6500. I was worried about sucking the pan dry but i was told by a very well respected olds guru that its no really an issue. The biggest advantage to a deep sump oil pan is keeping the crank out of the oil and the engine having less drag while maintaining adequate oiling.

Im also lucky if i see north of 10 mpg with my combo.

Ryan 1969 Chevelle SS396

Great info:

Longer filter, rev the heck out of it, and use a stock pump....... but what brand oil pump..... Sealed Power $39.99?
Sealed Power Stock Replacement Oil Pumps 224-41203

coppercutlass

Im using the melling stock replacement pump.

Are you planning on going to adjustable rockers ?? like a full roller ??

Ryan 1969 Chevelle SS396

Engine Pictures.

Poor heads:-(

Ryan

coppercutlass

Fwiw . I destroyed a good set of factory flat tops lol. Got a good deal on them and ran them a season and a half with .0055 piston to wall clearance. Broke skirts on 4 pistons. they didnt completely break off but made some serious noise on the big end. i took it apart ., i avoided catastrophic failure the skirts where dangling on surprisingly the bores where in great shape still . I hope you plan on buying new forged units.

Ryan 1969 Chevelle SS396

Yes new pistons are in the budget.......

several options.....

Ryan

Ryan 1969 Chevelle SS396

more engine pictures

Ryan

Ryan 1969 Chevelle SS396

Speed-Pro Forged Pistons L2320F30

Seem like the most cost effective option.....


Is the general consensus that stock rods are "ok" for my application?



Ryan

oldsmobiledave

That depends....how fast do you want to go & how long do you want this NEXT engine to stay together. Now is not the time to pinch pennies. Build it right the 1st time.

Ryan 1969 Chevelle SS396

The only alternative I have seen is the SBC Scat rod and IDCON piston combo....... please share options!!!

I used to be a Chevy guy and options fall out of trees for Us/Those guys:-)

Ryan

PS: I have taken you gear suggestion under review, and the biggest tire PSMCDR allows is one size larger than stock, my car came with F78 X 14 so I am allowed a G70 X 14 no larger..... I fear 3.91's would a bear on the street, especially on longer trips...... I want the diggers for future. Opinions welcome;-)

oldsmobiledave

Put 3.91s in it and run the tire you are allowed. For street driving put 28" tall 275 60 15 drag radials on 15" rims to help tame the rpm a little. You won't be happy with the 3.42 gear.

coppercutlass

I just went to a 3.90 on the street its not that bad at all. I had a 3.73 and with a short tire 26 in. roughly a 3.90 i would haul on my way home from the track usually 60 65 mph.

coppercutlass

Fwiw with a 3.90 and a 28 in tall tire you are spinning 3100 rpm @ 65 mph. In reality thats not that bad. Its the loud exhaust that will drive you nuts. I have an x pipe and the mufflers dump at the rear axle and a 2hr drive is about all i can do before i need a long brake lol.

Ryan 1969 Chevelle SS396

Thanks guys:-)

I know the W-31 will like to rev!!

Ryan

Ryan 1969 Chevelle SS396

Al ordered the car with an M-20 and 3.91 gears and thought it had come with 3.91 gears but it came with 3.42's......

Ryan

83hurstguy

Holy crap... that head is a disaster. I'd find another set of #5's, they aren't that expensive, have them cut for the bigger valves (and you have the advantage of being able to do a great competition valve job because there's actually material there to cut). If the outside looks like that, there are water jackets on the other side of the seats that can also look similar that you won't be able to see. Now you'll be pressing in new seats into badly corroded heads and hoping it all stays together. You'll be money ahead starting with a nice set... just my .02...

You can possibly investigate NHRA legal pistons or custom pistons from someone to work with the SBO rods. I wouldn't want to consistently spin heavy speed pro slugs with stock rods and a stick shift, but I'm sure others will disagree. The rods won't break, but they'll tend to flex at the parting line and you risk trashing bearings.

Inline

About gearing. Think first where are you going to drive it. When i was seriously considering BBO, i didnt care, there for sure would have been enough torque to pull it despite of gearing.

But now when good SBO fall next to free to my hands, ive taken gearing into consideration too. Since i cant just hang with my cubes.
This is just one example, and my suggestion:

Wait until you have dynosheet of your motor. Then think where are you going to really drive it? Really drive, not where you fantasy to drive it all the time ( strip etc).
Take local speed-limits into consideration.
Im going to play my gearing so i have max acceleration when passing cars from local speed limits. For traffic-lights..? Dump the clutch with higher revs if you feel so. There are plenty of calculators on internet where you input your tire size etc, and can see your rpms with different speeds.

Ryan 1969 Chevelle SS396

Agree, the original heads are hurting badly, I plan to bead blast them assembled as most of the valves are seized in the guides or worse. I have the extra 69 310hp 350 if these are as bad as they look on the surface. If someone has an extra set of non W-31 #5 heads I would consider. (I have seen reasonable prices....... 1-2 hundred?

Are there no reasonably priced rods for SBO? I am already missing one and won't steal one from my extra engine:-) so I would also like to buy one or two SBO rods:-)

Ryan

Ryan 1969 Chevelle SS396

Dyno tune is really part of my plan as I have limited knowledge I really want the break in completed, and tune set before putting the engine in the frame. I also want to see it dynoed' as it will then sit a while as the rest of the car goes together.

I will check out the rpm calculators.

Ryan

1BOSS83

Ryan, I want to chime in but I'm having an issue with entry point in regards to price. You are a self proclaimed Chevy guy and this is a first build and I will tell you that everything about building an Olds motor is more expensive. When you start talking w-31 equipment those numbers can really balloon. The reason I want to make that point is when you inquired about 100-200 dollar heads I almost fell over- 100-200 $ CHEVY heads will probably be decent cores but I wouldn't build a birdbath with $200.00 Oldsmobile heads. What is most important the stock appearance/equipment? The performance/longevity of the engine? Or the driving experience you described? Sans the mpg..that ain't happening :-)

Ryan 1969 Chevelle SS396

I Must have missed a zero on the #5 core heads:-)


I have every single W-31 specific item:-) (everything needs rebuild of course)


MPG, is low on the list but it has to be there, I plan to drive my car:-)


All three priorities in my build are equally important, stock appearance/equipment, performance/longevity, and driving experience, I don't see a reason why I can't attain all, even if my MPG goal needs tweaked into a more reasonable range.


I am learning!!!


Ryan

83hurstguy

If #5 core heads have suddenly become worth significantly more than $150, I'll happily sell mine. I wouldn't be motivated to go through all the hassle of shipping them for that... they were a two year head, so they aren't hard to find. A true unmolested set may be a bit more challenging, but they are out there and available for very reasonable money.

Rick Finsta

Priority Main. The idea behind restricting the top end is to "keep oil down where it's needed!" but it turns out the real answer is just using proper clearances. If you've got a machinist that doesn't want the rods, bearings, crank, and block in hand prior to machining anything, RUN. Lots of shops just use numbers out of a book and think clearances are what you get when the machine work is done. NO. Clearances are PLANNED from the start and you get what you wanted or you get your money back. I wasted a lot of money once paying attention to oil restriction to the top end, only to spin a bearing because of too-small rod side clearance. Maybe I should have bought a micrometer or dial bore gauge instead of sooper-speshul coated bearings (and I'm not saying don't use coatings, I'm saying it is a lower priority than proper clearances).

The book I recommended is excellent reading and contains the information you seek. I'm not endorsing all Bill's thoughts, but if you want everything in one place that book is an economical choice. I think most people who have built a few Olds engines would agree that you're better off spending $25 on that book than $40 on cam oil restrictors. If nothing else it will give you a better frame of reference to come back and ask more questions.

Rods - stock rods can be fine. Or not. "The mission drives the gear train." - Pat Rogers.

1BOSS83

x2, Read it, great book.

If you like video and want some commentary from the author, this is part 1 of a cool series on a very high performance stroker build but good olds information is covered.

Octania

I believe your Chassis Service Manual shows the layout of the oil passages. Not much to it. oil pump to filter. Bypass in filter adapter in case filter will not pass oil. Back into block to RH gallery. Front of RH gallery has plug with hole to oil timing chain. crossover to LH gallery is at the #1 main bearing- always thought a little smoothing here would help the R to L flow. It's 3 holes intersecting just above the #1 bearing top half. Be sure the plug at aft end of LH gallery has a hole to lube the distributor gear. Many a builder puts in "the new plug" instead of "the correct" plug.

Each main bearing also feeds up to the cam bearing. Each fore-aft gallery feeds up to the lifters. Lifters pump to the rockers and valves of course. Heads' oil goes back thru horizontal-ish passages at each end- anything you can do to help that return is a good idea. smooth the sharp edges. Can't really drill larger w/o getting into water or whatnot.