Ok, so I've asked this in the past and just wanted to ask one more time because I'm about to start buying the parts for my engine to rebuilt in December. I'd like to know what combination of parts I should go with to get me a decent 350 horsepower with a quick response when I hit the gas. I was told earlier to go with the Comp Camshaft XE262H model, a 650 edlebrock carb, performer rpm intake, and 3:23 gears. Sound about right? I'm searching for parts as we speak...

 

There are a million similar builds on here, just access one of those.

You didn't give your budget, heads, headers, etc., just your desired hp. You want to run premium, or not, smooth idle or you want to hear it. Too many variables yet.

 

my build got me 242 HP at the wheels on the chasis dyno - Max HP at about 5500 RPM, but not exactly sure as I do not have the sheet with me. Figured I lost 105 - 110 to wheels

355
10.3:1 forged pistons - adverstised compression, not sure of actual
Nodular crank
Performer RPM cam, lifters and intake
#5 heads with SS valves and HP springs, standard size valves and roller tip rockers
Malloy unilite ignition, MSD wires and autolite 85s
Flowtech ceramic coated headers
Edelbrock 650 AVS
TH350 with 2500 stall
3.42 gears

Great sound and responsiveness - pretty happy, but wish I would have spent the $$ on porting and bigger valves.

 

my build got me 242 HP at the wheels on the chasis dyno - Max HP at about 5500 RPM, but not exactly sure as I do not have the sheet with me. Figured I lost 105 - 110 to wheels

355
10.3:1 forged pistons - adverstised compression, not sure of actual
Nodular crank
Performer RPM cam, lifters and intake
#5 heads with SS valves and HP springs, standard size valves and roller tip rockers
Malloy unilite ignition, MSD wires and autolite 85s
Flowtech ceramic coated headers
Edelbrock 650 AVS
TH350 with 2500 stall
3.42 gears

Great sound and responsiveness - pretty happy, but wish I would have spent the $$ on porting and bigger valves.




Here's one of my old combos.



I took the #5 heads off and put big valve's in.

New hydraulic cam from Ultradyne 270/274 219/226 .491/.499 108/104

Short block had a 170,000 miles on it very tired.
Measured 9.14cr,about 175-180psi cyl pressure Cometic head gasket RPM intake and 1 3/4 headers,750dp.
2800 11'inch PTC converter flash was about 2400rpm.
3.90 gears th350 27" 10.5 tire ET street.
The motor put 266hp to the wheel @5200rpm.
I figured about 330 crank hp

Track times were with full exhaust race pro mufflers x pipe.

60..... 2.007
330.... 5.668
1/8.... 8.746
miles per hour... 79.24
1000.. 11.447
1/4.... 13.747
miles per hour... 97.84

In crap 4500ft air.

 

Here's my build;

350, .030 over, 9.7:1 measured, #7 heads
Hyd Roller 222/230 on a 112, .544 lift
2.00/1.62 Valves, center divider welded, crossover filled.
Performer RPM modified for Multiport EFI, 1000cfm throttle body, 30# injectors
1 3/4 Dynomax Headers
Balanced
3.73 posi
200-4R w/lockup

You can see it on www.accel-dfi.com then to "featured video"

According to the fuel map on the EFI I'm putting out about 375hp. You can do the same build minus the roller if you want, and scrap the XE 262 cam, wrong cam for older stock or nearly stock heads imo. You need more off the seat time.

 

Thanks guys...I've actually started accumilating parts over the months and what I have right now is:

600 cfm edelbrock carb, lunati 60802 cam, performer rpm intake, and hooker 3901 full length coated headers. The ration I'm looking at is 9.5:1. and 3:42 gears. I still have to buy the lifters for the cam and I'm wondering if I should go with a stall and if so what size? Still looking for the same results...a quick take off and a dependable weekend cruiser. If there's anything else you would suggest, let me know.... thanks!!!!!

 

I think I need a bigger cam (one step up), but at any rate,
here's my 350 build specs:

Edelbrock Performer RPM intake manifold
Edelbrock Performer Carburetor (600CFM 4 barrel).
Edelbrock carburetor insulator gasket (0.320")
Edelbrock True Roller timing chain
Comp Cams Camshaft XE262H(Duration @.050 218/224 Lift 475"/.480" LSA110)
Forged flat top pistons/rings (by Diamond) from Dick Miller Racing
W-31 stainless steel valves (2" intake, 1.625" exhaust)
Head porting (pocket) 3 angle valve job, tear drop valve guides
Sanderson Headers (Part # 0351—shorty type)
3.42 Posi track (originally 2.56 open)
TCI Torque converter 2400 stall (Breakaway # 241100)
Transgo shift kit #2
MSD Pro-Billet Distributor and MSD Blaster 2 Ignition Coil
MSD Super Conductor spark plug wires (8.5mm)
Walker Dynomax turbo mufflers/dual exhaust (originally single)
Spectre Performance Air Filter w/ K&N X-Stream Air Filter lid
Bored 60 over, 10.5:1 compression ratio

 

It would help if people knew what year engine you have, and what model # heads.
It's not going to be the same for any Oldsmobile 350 out there.
BTW torque is what moves you off the line.

70's had some horrific emissions heads.....
http://www.442.com/oldsfaq/ofhed.htm

 

BigTrav
You seem on the right track with that setup.

I would suggest a Converter of 11"2400-2800RPM If you like to drive the car alot.

Peak power should be in the 5100-5300 range
Good work.

 

71 Cutlass
I like that duration for that gear and converter but I think you will have to mix race gas.

Maybe look for a cam with lazy ramps advertised or seat timing and keep @.050 under 220.
cutlassefi will have a good recommendation for you.

 

Thank you.

Let me explain why I don't like the generic stuff or the Lunati VooDoos for relatively unported stock headed OLDSMOBILES.

First off the heads don't flow that well, just like a camel hump Chevy. Above that the exhaust side is even worse, even after you make the mods (welded center divider etc). Therefore you need more off the seat time to make comparable hp/tq. The Lunati stuff is real quick and doesn't have enough off the seat time. Plus like the generic stuff they use the same lobe proflies for both the intake and exhaust. Example, a Generic at .050 204/214 then 214/224 and so on. A typical VooDoo at .050 207/213, then 213/219 and so on. Just as important the advertised durations follow the same pattern, wrong. And how do you know that spread of exhaust/intake duration is necessarily right for your application?

To make good torque and retain throttle response you typically want a smaller faster lobe on the intake than on the exhaust, plain and simple. Quite frankly Comp does this better than Lunati VooDoo's and the generics. In a typical Comp, let's say an XE262, the advertised duration is 262/274 with it being 218/224 at .050. Notice only a 6 degree spread in the duration at .050 but a 12 degree spread in the advertised duration? That means the exhaust lobe is slower than the intake, that's more in the direction of what you want. However both lobes on these cams are somewhat quick, not what you typically want in a stock headed 60's-70's engine. These are better suited to a good flowing aluminum headed application. Remember Comp is as good of a marketing company as they are a cam company. They got the Chevy guys to buy another cam from them by hyping that waste of time 4/7 swap bullshyt.

If you're going to go with that cam and intake you need more carb. But with that gear and compression, I'd go with both more/different cam and more carb. Your call.

Jmo
Mark

 

Mark, isn't it true too big of exhaust duration lowers cylinder pressure? Must be my generic, big 204/214 cam stealing compression on my 8.5 to 1 403. Not my cheap *** build. Supposedly kills torque too. Man my car has a lot of that, good thing I didn't put in a proper cam. Seriously though Bill said the same as you in his book about cam choices. Just shows why a custom grind from a builder is better. Nearly all the off the shelf grinds ARE generic, not motor specific.

 

That's true most of the time, some will work well in more than one application, others won't.

Your "big" 204/214 cam would be better ground on a 108 instead of the 112 it's on. That would give you more power sooner, especially with 8.5:1

 

Mark you save me a ton of time typing LOL.

 

Ok, so in this case, if I kept the equipment as it is...maybe upgrade the carb like suggested, what would be the best compression ratio and gears for me to go with to ideally match the setup? The engine hasn't been rebuilt yet and won't be until right after Christmas...

 

Originally Posted by rkk69olds
my build got me 242 HP at the wheels on the chasis dyno - Max HP at about 5500 RPM, but not exactly sure as I do not have the sheet with me. Figured I lost 105 - 110 to wheels
110 hp is pretty close to a 50% drivetrain loss there buddy.
I don't think you lost 110hp to the wheels.

Aceshigh, that statement is incorrect, your math is off. If he had 242 RWHP and lost 105 HP to the driveline, that means he started with 350 HP +/- which puts loss roughly at 30%. IMO, 30% is closer to the real-world loss on a/t equipped drivers with accessories than the much advertised 18%-20%.

Mark, the only argument I will make regarding cams is that Harold has a pretty good rep in the Olds community, and he designed those Voodoo cams.

 

I like the cam Harold provided for me. I heard about him from ROP and communicated with him when I built the 455 in my '46 which has C heads, a Torker intake, hydraulic lifters, Qjet, TH400, TRW L2323f pistons at about 9.75:1 cr with the heads. He provided this cam grind for that engine:

272/276 H12
Intake Exhaust
Duration at .050 217 221
Lobe lift .3027 .3027
separation 112

seat duration @ .0045 272 276
Gross valve lift 484 484

degreed intake to 106 ATDC

I know some people don't think a symmetrical lift works with a BBO and some don't think 112* separation is correct but all I can say is that I like the way the engine runs. I don't understand camshaft grind theory well but do think that this cam is good in my engine. If there is a better grind then great, I would just be even more pleased. I got my cam from Harold when he had Ultradyne but understand he is grinding for Lunati now. Anyway, just wanted to pitch my two cents in and give my testimonial. I think Harold makes a good cam and he is real decent guy too.

 

http://72.22.90.30/phpBB2/viewtopic.php?t=28012
^^^ Here is a link to my 9 to 1 355 which ran 13.9 in a 3920 lb car with 3.42 gears shifting at 4600.

You could bump up the Cr a tad, and do a little more cam, but as always, I recommend being conservative on the cam with a 350 in a heavy car.

 

I don't believe I said the VooDoo was junk and I think they're o.k., just not the best for stock headed Olds. I'm sure your stuff runs fine, doesn't mean it couldn't run better with something else though. Actually I'd like to try a VooDoo intake lobe with something a bit slower on the exhaust side, hmmmmmm.

I get the same thing with EFI, there's a good and better there too.

Jmo.

 

You're right, I did it backwards.

I've seen modern automatic vehicles with GM quoted HP specs throw down a 20% loss and they all have accessories.
In fact I've also seen them throw down less then 20% in an automatic. (1998-2002 LS1 Camaro's)
Could be GM under rating them though too.

So to say a classic is losing 30% because of accessories sounds a bit high. Just my .02

 

You may be correct, 30% is high. But, IMO you can't use the "percentage" theory anyway and here is why. The following is just my personal opinion.
An accessory takes "x" amount of power to drive. Say a w/p takes 15 hp, a p/s pulley 20 hp, etc. This does not change with the output of the engine. So, say the entire drive line loss is 100 hp. On a 400 hp engine, that is 25%. On a 200 hp engine it is 50%. See where I am going? Same loss, different percentage. The 20% works, sort of, on a roughly 350 hp engine.
One last thing, we built a road race engine that had a max 400 hp limit. We engine dyno'd it then chassis dynod it. On a full out race car with a manual trans, loss was 18%. What do you think that would be on a street car.

 

Accessory losses are calculated at FULL loads. aka Frictional Losses.
When doing a dyno run, they are at the very low loads, or in the A/C case, a free spinning clutched pulley.

Power steering = ~1hp-3hp - (electric = maybe ~10-15hp) On a dyno pull, hardly used.
Alternator = ~1hp - on a dyno pull, all accessories are off, which = minimal load. See link below.
Air Conditioning A6 = >1hp without a load it's a free spinning clutch pulley.

http://www.fuel-saver.org/Thread-ALT...-MUCH-HP-DRAIN
Not much more. See above.

Manual loss is ~15% they say, but depends on everything being tight.
Same goes with Automatics and TC's, how loose or worn down it all is.

Either way, I stand by my opinion that 30% is way too high.
I'd say 25% tops if it's all loose which is what most of the dyno techs have told me as well.
Outside of that, people are trying to bench guess HP to feel better.