gscott819

I have a 1980 olds cutlass,I have recently purchased a 350 rocket and 350 tranny.I am asking you all for all of your great suggestions on headers,stall,cam etc......

citcapp

Hang in there a 350 guy will read your post and offer some suggestions. Just remember it all depends on what you what to end up with and the money you are willing to spend. You might discribe what your intent is.

Good street performer, Drag racing, Etc.

gscott819

Just trying to have a good reliable street performer.

citcapp

I moved your thread to the small block forum. I think you will get better answers there. good luck

Aceshigh

I have a 1970 350 rocket and I'm looking for the same tips for a good powerful street cruiser that gets somewhat DECENT MPG.
I don't want to sacrifice streetability for power. But I don't want just a 260hp V8 when there's 304hp V6's on the street now.
I've been looking at LS2 / T-56 combo's because I've already retrofitted an LS1 / 4L60e into my 78 Camaro.....
So I'm hoping I can do something worthwhile with this 350 Rocket.....without spending a huge fortune.

I'd LIKE to keep it all Olds......but modern Gen III drivetrains are the **** these days for not much.
So looking for some proof that it's worthwhile to make me want to keep it all Olds inside.
Also trying to find out if there's any way to determine what cam I have in my engine without ripping it apart.

Aceshigh

I guess what I want to see is HP #'s and MPG ratings.

Who has gotten the best combination out there with an OD trans
and a fairly good amount of HP to justify putting the money into this engine.

LS2 / T-56 and some tall gears I can get 14-16mpg city and in the mid 20's on the hwy.
So I'm hoping I can build a Rocket 350 to at LEAST get 11-14mpg city with some decent power.
Right now I'm averaging 14mpg a tank, but I have no clue what HP this engine is pushing.
Gotta do a dyno.

HARDLUCK88

here is some food for thought, i am running a rebuilt pre '77 350 rocket, 4bbl q-jet, with a th350 trans in a 4 door cadillac that is prolly about 1500 lbs over its gross weight, and im getting like an average of 15/17 mpg i do both highway and around town on 14'' wheels. its by no means fast, and a 4 spd would get better gas mileage on the highway, but i reckon considering the car can still pass emissions, its okay with me

captjim

http://72.22.90.30/phpBB2/viewtopic.php?t=28012

Here is my 350 build. Very mild, 9 to 1 Cr, 3.42 gears in a 3800 lb car. Drive it anyplace, 16-18 mpg without OD. Probably makes 300 HP, but don't get caught up in numbers, HP is really not as important as torque and throttle response in a driver.

That said, it is going to be tough to compete with a modern computer controlled fuel injection system and a modern OD transmission.

Aceshigh

TH350 final gear is 1:1
4 Speed 4th gear is 1:1

So I don't quite know how you figure the 4 speed would get better mpg on the highway.

cutlassefi

Easy, a 4-Speed won't have the converter slippage of the TH-350. That's worth a few hundred rpm. Less RPM, Better MPG.

Gscott/Aceshigh- The first build on my car I did, headers, duals, Performer RPM, Edelbrock 750, and a Crane Powermax Cam. Ran good but there are a few things I''d recommend differently;

Cam wasn't the best, something smaller, a little more aggressive on a tighter lobe sep would do well for you.
If you go with a 200-4R, which I highly recommend, a regular Performer with a 625 Barry Grant or 670 Holley SA should work well.

Currently mine is fuel injected with a full Hyd roller valvetrain, new age technology with the nostalgic look. I get mid teens in the city and around 20 on the highway, without the converter locked. That's worth another 1-2 mpg. The single biggest drawback of a stock block Olds vs. an LS are the heads. The Olds heads just aren't nearly as efficient as the new stuff. Still and all you can build a pretty nice ride with what you have.

Don't get caught up in being able to match new car mpg. Not only is engine management and developement worlds apart, but let's face it, a 68-72 A-body has the aerodynamics of a brick. That doesn't help either.

Aceshigh

Cutlassefi,

I'm VERY interested in finding out how your motor is built and what EFI you have.
Can you give us your engine specs and part #'s by chance ???
You basically have what I want and I don't know what part #'s and costs are associated with all that.

So maybe ballpark it for us ??
What valvetrain, cam, etc all that jive did you get ??
Also do you know what HP/Tq #'s you're pushing with that motor ??

Thanks bud.

cutlassefi

I don't want to steal Gscott post, so this is just what I have. Consider it in that way,

.030 over 350 Speed Pro pistons
Stock Rods and crank, Balanced,
Erson hyd Roller, 222/230 @ .050, on a 112, .550 lift with 1.72 Scorpion roller rockers
Basically Stock #7 heads with 2.00/1.62 valves, Combustion Chambers and valve pockets smoothed
Performer RPM modified for EFI, Had a Holley Street Dominator first, this is head and shoulders above that
1000 CFM 4-hole throttle Body
30# Injectors
Headers, Dynomax Long Case Turbo Muffs
Accel Gen 7 DFI EFI, Controls Fuel (Sequentially), Spark (thru an Accel Dual Sync Distributor), 2 Cooling Fans, A/C clutch interuption (shuts the A/C clutch off when I put my foot in it), and locks up the converter on my 200-4R. I'm now an Accel Dealer and tech and the "How-to" DVD that now comes with every kit was done by me, my 72 Supreme Convertible is in it.

It runs better now on 89 octane than it ever did on 93 with the carb, ever. Night and day.

EFI would run about $4000.00 with a big part of that being the mods to the manifold. Professional Products makes an EFI manifold for BBO for under $400.00 with rails and regulator, nothing yet for the SBO.

I wouldn't trade the driveability and modern day features for anything. There are alot guys on here that boast the driveability of a Q-Jet or Holley or whatever. But just when you get it dialed in the weather or local fuel composition changes and you're back to square one. Not for me.

ent72olds

Exactly what I was thinking....not exactly an apples to apples!

agtw31

if the motor isnt worn out,put a fresh cam,lifters,timing chain and oil pump in it,and see how you like it the way it is.

you dont need to open a jegs catalog and go nuts to have a good running small block.

Aceshigh

Here's a simple question.....but I don't know where to find the info.

Stock 1970 350 Rocket heads flow #'s ???
Stock 2004 LS1 heads flow #'s??
Stock 2005 LS2 heads flow #'s ?? (L92 heads IIRC)

Reason I'm asking......is because spending $4,000 on a SBO for EFI just
doesn't make enough sense to me to do when I can get a low mile LS2 / T56
for under $6500. That precludes me from purchase hydraulic roller everything,
EFI, a 200-4R etc etc etc......I already did this retrofit in my 1978 Camaro
with a 4L60e.....and the more I look at costs of keeping the SBO's to get
what I want......the more I'm realizing it will cost an arm and a leg to get it
even remotely competitive with todays engines.

I think those guys that DO this upgrade to their existing Olds motors have
awesome setups, no doubt, it's just the cost......the cost to get there is
where it scares me away.

I'm all about Pro-Touring too......not numbers matching....it's cool for those
that are....but it's just not my thing. This entire drivetrain with only 26K on it
I got from a 2004 GTO for just $4500.....Engine, trans, harness, and ECM.

Warhead

Miles on the engine???
Condition of engine???
What gears are in the car???
Before you even start working on the engine, I would put a set of 3.23 gears in the 7.5 axle, with a posi unit.
Then get a dual exhaust, with dual cats.

It will NEVER be a fun car with the 2.29 gears that are known to come in these things.

JMO
Jim

cutlassefi

It's what ever you decide you want to do. If you think you want to put an LS motor in it then do it.

I went a different route because anyone can go to the junkyard and get an LS and stick it in just about anything. I wanted to keep the stock, numbers matching motor in it. I chose a different course, but that's the point, there are a whole bunch of options out there. IMO that's a good thing.

The Stickman

I am doing the PT thing as well and I believe doing an EFI SBO's is a great bet. Sure the engine itself is old school tech but with EFI all that changes. The SBO's are a different mind set and have great torque numbers which is what you want for a PT car. Wether it's AutoX or a raod course torque is what's going to pull you off the corners. And EFI can be done cheaper if you want no disrespect to Cutlassefi. Wether it can be done as nice with all those bells and whistles probably not. Either way I am going to try. Besides if I have my way I will need it for the twin turbos I want.

Joeypete

"This entire drivetrain with only 26K on it
I got from a 2004 GTO for just $4500.....Engine, trans, harness, and ECM."

That is seriously cool...I'd love to buy a newer engine like that and drop it in my custom cruiser....it would kick butt!

cutlassefi

Stickman- no disrespect taken. However if you're going twin turbo, you'll need the "bells and whistles" if you want it to have good street manners. I guarantee it.

The Stickman

Yea I kinda know but right now it's baby steps. I need to get the intake done. Think I am going to have to have the EGR and heat riser cut down for the fuel rails to fit right. It's either the Holley or the Edelbrock High rise I have. The Turbo's will take alot of time to design exhaust manifolds that work the way I want. But hey I dream big.

captjim

"Sure the engine itself is old school tech but with EFI all that changes."

IMO, no. As Mark mentioned in another post in this thread, cylinder head technology has come a loooooong way. You can't compare the big chambered slow burning Olds heads to a modern head. Besides the chamber there are and less-than-optimum valve angles, along the crappy turns. The intake has long runners, too.

Again, IMO, build the Olds to suit it's design. It is basically a very durable, relatively low rpm engine that makes a fair amount of torque with very good throttle response. As always, just my humble opinion.

Aceshigh

Hard to argue with that ^ ^ ^

I do agree, it was a great motor for it's time.
Upgrading it does cost some serious coin tho.....

Joeypete

Definitely...the 307 in my 86 Custom Cruiser was pretty neglected when I bought it a couple months ago. I've done lots of work to it (just maintenance, not mods) and it drives a ton better. I noticed the most when I adjusted the TV cable a few days ago. I live on a hill and it just took off right up...no hesitation whatsoever. It's really a workhorse!

The Stickman

Well let's look at things. While what you are saying makes sense it's not all that straight forward. My wagon get's 20mpg. Now compare that to say Honda's SUV which get's 23mpg. My car is large to say the least and is using a poorly tuned(by me) carb. With EFI I could get more. I won't try and say I have goobs of HP but it has get up and go but does it with with 2.73 rear gear. Not saying the newer engines aren't great. Just that simply updating our engine to the same management technologies will greatly close the gap.

agtw31

the guy has a Olds 350,not a Vette motor.

captjim

I respectfully disagree, to a point. While a computerized FI system will be an improvement, it will not make up for the deficiencies in the cylinder head design. And, factor the cost of the FI system to pick up a couple of mpg. Do an honest cost comparison and weigh the gains vs the costs. Your call. Modern aluminum heads with fast burn chambers will out perform our old stuff, it's just the way it is. Pistons are pistons, cams are cams, but not all heads are created equal. As always, IMHO.