69350rocket

I have been wanting to build my 350 for a while now, but the car keeps having issues that are forcing me to keep pushing it back. I am in college, so budget is limited, as I only work in the summer. But, I work full time in the summer, so I should have a couple thousand to throw into the car. I am starting to plan the engine build, and am going to do it over time. This summer I am just hoping to get the bottom end done. My eventual goal for the car is 400-450 hp. I know what most of you are saying, drop in a 455. I would, but my car has the original 350, so I want to keep that in. Compression will be in the 9.75-10.25 range, and the I will have Cutlassefi grind me a cam. I know this goal will be hardish to reach with the 350, and I want to increase the stroke a bit to make it easier. Whats the most size I can get out of a non diesel block 350? I believe 380racer had a gas block build before his diesel one right? How was this accomplished, just offset grinding the crank? My goal is to get the car into the mid to low 12's.

captjim

Nobody loves 350 Olds engines more than I do, but a streetable pump-gas low 12 second full weight driver is going to be tough. Piece of cake with a 455/468. However, you can have a fun car to drive, but IMO 350 HP and mid-high 13s is more reasonable goal. A short block bored to 4.125 and stroked to 3.510 will cost you around $2500 for parts and machine work if you assemble it.

69350rocket

I know it will be hard, but I dont think its impossible, especially with my gears. Reading through the builds section on ROP I see someone has a dyno proven 430 hp 362. Its nothing extreme, 10.5:1, ported #7s, 224/234 cam. I see a few more on there also making over 400 hp, on pump gas. I will have to have the crank ground to accept SBC or Honda rod journal sizes correct? Then custom pistons?

captjim

No, that is the best part, if you bore to 4.125" you can use 400 SBC pistons. Here are some combos I put together on ROP,
http://www.realoldspower.com/phpBB2/...hlight=stroker
CI Bore stroke piston CH/weight rod length/weight pin
364 4.060 3.510 1.560 474g 6.00 535g 118g

364 4.060 3.510 1.425 540g 6.125 540g 118g

375 4.125 3.510 1.560 485g 6.00 535g 118g

375 4.125 3.510 1.425 466g 6.125 540g 118g

375 4.060 3.620 1.260 440g 6.250 545g 118g

387 4.125 3.620 1.260 451g 6.250 545g 118g

There are multiple variations of P/h and rod lengths that will work. Mahle sells a NICE piston set with a quality ring pack for around $600 with different p/h and dishes. Nick was running mid 11s with his, but that was a race car.

The 387 is a nice combo, but decent rods are expensive for the Honda journal size and you will need a perfect 330 crank.

The cheapest way to run fast with a SBO is to build it stout and spray it, mild manners, flip a switch, run high 11s. I just think mid 12s on pump gas will be tough in a full weight driver.

yankees

Look at the ET's that Sam Murray is running with his 350 Olds. Mind you his engine spares no expense and I'm sure he (Boucher) squeezes every last HP out of it with minimal (8.8:1, I know there are other factors to include) compression. He was the J/S record holder in NHRA at one time.

11.37/114.57 mph using (stock) 7A heads and a (stock) 410446 intake on his 72 350 Cutlass (3700 Lbs). Low compression motor and could run on pump gas if needed (NHRA makes you run an approved fuel).

It's not about the power the motor is making, but the rear gearing, suspension, transmission and weight distribution/transfer.

I would bet you could take a bone stock 72 olds 350 and put it into Sam's car and it would run low 13's. The whole setup is very important.

Spend your money on getting the car setup and worry about the motor last.

69350rocket

Well after reading the builds on ROP I think that I can achieve my power goals without messing with the stroke, then use the rest of the money elsewhere. I think I will just purchase a rebuild kit with flat top pistons, and compression should be around where it needs to be. I plan to install OPP main caps, ARP main studs, ARP rod bolts, and a two piece timing cover so I can swap cams without pulling the engine in the future.

As for building the rest of the car first, I would, but luckily this car was used for racing sometime in the late 80's/early 90's. It already has a stall converter, 4.11 rear, and a rear sway bar. I raced it in the spring and had no issues with traction. However, I had huge issues with what seems to be really bad valve float. Also did a compression test in the winter, and all cylinders were 120-135. Pretty weak. I have thousands to spend in bodywork still, but I would like to get a solid, reliable drivetrain first. And as for the weight of the car, yes its still going to be heavy, but I'm trying to do whatever I can to reduce weight. A/C system is completely gone, fiberglass hood and decklid in the future, lightweight seats, aluminum radiator. So hopefully all of that will help some.

captjim

The 2 piece cover has nothing to do with pulling the engine, just makes cam swaps a tad easier. I have changed many cams in the vehicle. I think you are underestimating the $ you will have oin head work, plus the effects of the extra weight and accessories. A race car and a street car are different animals, but good luck!

captjim

[QUOTE=yankees;340704]Look at the ET's that Sam Murray is running with his 350 Olds. Mind you his engine spares no expense and I'm sure he (Boucher) squeezes every last HP out of it with minimal (8.8:1, I know there are other factors to include) compression. He was the J/S record holder in NHRA at one time.

11.37/114.57 mph using (stock) 7A heads and a (stock) 410446 intake on his 72 350 Cutlass (3700 Lbs). Low compression motor and could run on pump gas if needed (NHRA makes you run an approved fuel).QUOTE]

I think using SS guys to give examples of performance results is absurd.

IMO, a better example is the Ram-Rod, which ran mid-low 13s with stock manifolds. High compression, big cam, etc. Add headers and intake, high 12s.

380 Racer

Yes my 380 was in a gas block at first. It was a 70 block bored to 4.155, definitly sonic checked. It had JE 14:1 pistons, Manley rods, 330 crank.

Here are some of the prices:
Pistos-$800
Rods (half price)-$600
Had $800 in the crank
Total in the motor (already had the heads) was $8000

Jim is right.......big difference between street and race

yankees

You're right it's not realistic for most, but it shows one that it's very achievable with the right setup on pump gas if wanted for a 350 SBO. Don't forget the long duration Bullet Cam and plenty of valvesprings to go with it.

coppercutlass

i think mid 12's is abit hard to get with just a few grand im gonna agree with captjim here. My car has fiberglass fenders,hood gutted interior with light weight racing buckets and a 4 point rollbar and it wheighs in at 3400 lbs with me in it .i have 2800 into my whole engine but i did alot of stuff some guys wouldn't recommend but im a gambling man and so far my engine has exceeded my expectations. So far im runnning 13.34 with a small carb and stock suspension. I know it's capable of 12's but money is an issue. I spent 1400 alone in the heads and valve train after milling the intake it came to 1545. it's not impossible to get into the mid 12's with a 350 but on a budget its gonna be hard. I might also add my car is still streetable and has a 3.73 gear

69350rocket

Yes, money is going to be the issue here. That is why earlier I said I'm going to have to do it in stages. This summer I can put my money towards building the bottom end right, and then have some left over to get a little bodywork done. Then, the next summer I could do cam, valve springs, pushrods, and roller rockers. And the following summer, spend my money on having the heads ported, 3 angle valve job, and bigger valves. So, by the time I graduate college, I'll have a pretty mean engine, and still have saved up some money each summer.

So yes, I agree with you guys, I'm not going to be able to reach that power level and run 12's with a few thousand. But by slowly adding power and parts over the next few summers as I get more money, I think that I can run 12's, on pump gas, and still have a fairly streetable car.

And another question, would a SBO aimed at that power level be able to utilize those new Pro-Comp aluminum heads without killing the low end? Because I could afford those, where as the with the Edelbrocks I probably could not...

Jharken

Here is a link.https://classicoldsmobile.com/forums...29634-355.html

bccan

If you are willing to consider PC heads, why hung up on orig block? Why not use a 425-455 BB, painted gold? You could squeeze more power, especially torque at a much more streetable rpm range w/ better manners & less octane req.

Not trying to be a dick, just devil's advocate. I am a sbo lover but for the same appx amount of $$ spent you can more easily attain your goal of mid 12's & have a more pleasant driver - if that is a consideration.

350 is important / great for resto or slightly hotter performance but there are not a lot of guys pulling the performance out of them like you seek. I think your goal will be somewhat elusive with good streetability or without N2O. Most somewhat "snotty" 350's I've had or seen will get you to low 13's but after that the street manners tend to quickly disappear.

coppercutlass

I beg to differ im running low 13's and it should see high 12's next year and my set up is fully streetable . It does not drive like a stock 350 but that comes with the territory. I wouldn't get hung up on numbers. My first engine i built when i restored my cutlass I just picked good parts that would work with my combo. My first time out i said maybe mid 14's would be good. on my first pass i ran a 13.99 . That was back when it was all steel . I added an x pipe it ran 13.86 . I then crashed it and put a fiberglass front end it went 13.71. Build a good engine first then see what it does and then make it faster by shedding wheight adding x pipe etc. When you set out to reach a certain e.t. i found u get disappointed. That also makes it more fun because you see the progress and improvement.

69350rocket

I have been thinking a high compression E85 350 might be kinda fun..?