cutlassefi

1 jet change and a squirter change. The vacuum secondary has an adjusting screw, not multiple springs. Great setup, changed the screw about 1/4 turn.

coppercutlass

That sounds great. Thank you.

380 Racer

Nice for a street motor. I thought the 380 cube is a nice combo. Always liked the RPM intake too. Good job Mark!

kitfoxdave

Chomping at the bit! I can almost smell those 2 black stripes in the road.....

61reoldsman

Mark , If I read the dyno sheet correctly is the peak HP
around 320 ? Isn't that a bit low for a 380 cu in Stroker
or am I missing a detail or reading the sheet wrong ?
Thnx

captjim

It IS a 9 to 1 mild street engine. Personally, I'll take the 400 ft/lbs at 3500 over 360 HP at 6 grand any day.

kitfoxdave

Mark and I discussed this engine at length prior to the build. The goal is low end torque, about 315 HP, and the ability to use 89 octane fuel. The car is a cruiser to go on LONG trips with. The Rocky mountain grades will be easier with the higher torque. Premium fuel can be hard to come by in some areas, therfore the lower compression. Yes it could have had more compression, and a whole pile of other options and cranked out a huge amount of Horsepower, but that was NOT the goal... (I do plan on leaving some black parallel stripes here and there!)

olds 307 and 403

I bet 87 will be useable. With right gears and converter, high 13's should be easy. Nice street build. Upgrades can always be done, if not enough. Nice solid foundation. My 403 was slower than what it should have been. I would have been lucky to hit 275 hp when it was running right. It was fun for one reason, torque! I sure miss that torque driving the v6 Dakota and Challenger. Of our streets of ice here right now, the traction control and 4x4 make up for it. Come spring, different story.

DoubleV

I would think high 13's even with sub-optimal converter and gears ( unless the car's a tank ). Either way it should be a fun cruiser with enough power to be fun.

61reoldsman

So in essence the goals out of this engine build have been met and that's awesome ,I hope it serves you well ,kudos to Mark for delivering the right combo .Have fun and let us all know when you drop it in the car and go for the first real CRUZE.(BTW what's it going in ?,PICS eh!)

kitfoxdave

Going into the 72 cutlass convertible in my avatar... more pics in major build forum. or at www.sport-pilot.us click on oldsmobile link

Inquisitive Old Guy

Mr. Cutlassefi,

Do you dyno test over at Robert's ?

Just inquisitive as I saw him at the recent PRI show (late November) for the first time in years.

Thanks in advance,
IOG

cutlassefi

No, I do all my dyno stuff at Automotive Performance Engines in Auburndale Florida.

Inquisitive Old Guy

Thanks for the heads-up.

Fulco's place is over near Tampa.

When I looked at the dyno sheet, I couldn't feature why it might have been run without recording the airflow into the engine as that loses VE%, A/F, BSAC and an easy way to evaluate the engine as a self-driven air pump.

IOG

61reoldsman

Just for interest sake what would a motor built like this 380 cost the average joe?

61reoldsman

I guess if ya have ta ask ya cant afford it !!!

kitfoxdave

Best to figure what you really want. Make a list of goals and then pm an Olds engine builder. As everyone else has said Olds's are more expensive than chevy's so keep tbat in mind! Also keep in mind the good builders are always busy... It will take time to do it right so be patient!

61reoldsman

So Mark how are ya coming along with the 434 stroker motor?,any updates?

J-(Chicago)

I'd guess More than 6k, less than 10.

cutlassefi

Correct, depending on the pieces used.

I had to wait for the new style .921 lifters to become available. Got em now, should be next week.

61reoldsman

Cool,should be interesting to see the results.

f85 rocket

What is the proscribed procedure for running a sbo crank in a diesel block ?
I know in the 400 sbc a 327 crank can be used with saddled bearings. Is there something like this for the olds ? I was thinking a 330 crank in the diesel would be extra stout.

cutlassefi

There are some spacers out there, but using a sbo crank severely limits the available stroke.
IMO it's best just to turn the counterweights down on a 425 crank and grind the rod journals to a bbc size.
From there you can use a bunch of different off the shelf rod and piston combos to get the most cubic inches possible.

380 Racer

Personally, I liked using a 330 crank in my 380. Yes cubes were limited, got the spacers from BTR, but the crank weighed less, less Mallory, less labor to get it to fit, 2" crank pins (also less bearing speed). All made it a little monster..........I would build another one too.

61reoldsman

So what is the most stroke that can be safely ground into a stock 350 crank ?without welding ?

380 Racer

Going 2.0" pin gives you a 3.50" stroke. Going with a 1.88 Honda bearing will result in a 3.60" stroke. I'm not sure how strong that would wind up.

61reoldsman

So with that 2.0" pin you'd be using a SB chevy rod with a 2.100 hole?and the rest would be the bearing ,is that correct?and then to get to the 380 you'd use a chevy 400 piston @4.155 size.What length rod did you use ?6.125 ?6.2?

cutlassefi

You're going to use a small journal rod, the housing bore is 2.125.
As far as length goes, you can use a 6.125 rod with a 1.425 cd piston or 6.00 rod with a 1.550 cd piston.
You normally have more choices with the 1.425 cd piston.

61reoldsman

Hey Mark ,thanks for responding I've been doing a lot of researching online with rod and piston combinations,(even made an Excel spreadsheet!) and it seems like its endless.So many choices for SBC stuff,that can be used in a 350 Olds motor.I really don't see why anybody wouldn't want to use SBO parts stuff when there is so much available at reasonable prices.

cutlassefi

I agree.

61reoldsman

I'm coming to Florida in April any chance your shop is around the Orlando area ?

380 Racer

I used a 6.300" Manly rod with a custom JE piston to come up with just under 14:1 compression. The rod/stroke ratio caused very minor wear patterns. Ran like a raped ape.......the left shot in my sig line had the 380.

61reoldsman

That piston must have had a really short compression height !?

380 Racer

Yes the pin heigth was very short along with the skirt. The official piston build sheets went with the rods and pistons to their new home.

cutlassefi

Piston would be about 1.250 cd. That's not overly short by today's standards.
The DX build is using a piston with a 1.165cd but the pin still isn't up in the oil ring because of the narrow ring pack, 1.5/1.5/3.0mm.

61reoldsman

Ive seen some pictures of pistons that have a pin button that gets installed before the rings do ,thats seems pretty extreme.