Streetmaster 318 vs. Performer for street use

[DQ81]

Hi

I´ve got a 318 with:

Edelbrock Perfromer Plus cam and a Holley 4160 600 CFM carb. Hooker headers.

At the moment it has a Streetmaster 318 on it which looks very new even though I know these haven't been produced for a while. Perhaps it was old stock. It's a single plane so I wonder...

My 1st question:

For street use and off the line performance is it worth switching the Streetmaster 318 (single plane) out for an Edelbrock Performer (dual plane)?

If so by what kind of margin? I realize a dual plane results in more low end torque but how much more with these specific two. The Streetmaster has narrower runners to maintain velocity but it's single plane....

2nd question:

a:

The Holley stumbles off the line at WOT, just a 1/4th second or so then takes off. Only happens if I plant the pedal. Bad power valve?

b:

Also in Reverse, if I give a litte punch of gas and let go and engine stalls. Could the two be related? Verry irritating when parking!

I run 95 octane pump gas, stock electonic dizzy with vac. advance (ported vac.) set at 10* BTDC with hose disconnected at idle.

Holley Idle Screws set at 3 turns out (Holley's advised starting point) and idles very well.

Thirdly:

This is kind of a rhetorical question but:

Is it 'normal' that when not fully warm/cold I punch the throttle by hand at the carb for a short burst (as short as possible, like a jab) that it bogs? Could this also be related to the Holley having vac. secondaries that only open under load?

Thanks!

David

 

[tobysoldblue]

I ran a streetmaster for about 4 years.Mine was gasket matched to 340 size,because my 302 casting heads were gasket matched.I noticed that the streetmaster was good from idle to about 4500 rpms,were it fell on its face.The cam i was running was good up to 5500,and had matching valve springs.As far as your carb goes,it sounds like the secondary spring is too weak.I would buy a secondary spring kit,and start with the strongest spring first.After you get the carb tuned to your engines liking,start tuning the distributor.Your vaccum and mechanical advance need to be adjusted to get the most out of what you have.You may try to adjust the vaccum advance first to see if it helps with your bogging problem.All it takes is a allen wrench(7/32 i think).Turning counter clockwise quickens vaccum advance,clockwise slows it.

 

[fishy68]

I think Toby nailed it on tuning the secondaries but I'll add a little for other questions. First I've never heard of having to turn out the mixture screws 3 turns. If Holley has that on their website it is probably a misprint. With them out that far it's probably too rich and that's why it stalls when you stab it quickly. It may appear to idle well but will do better if adjusted. Warm the engine up completely and set the parking brake and block the wheels and put it in gear. Double check that it won't roll on you. Better yet get somebody to sit inside to hold the brake on if you can. Go out to the carb and start turning in the mixture screws 1/4 turn at a time alternating from side to side each 1/4 turn. When the engine begins to slow down back them back out 1/4~1/2 turn. in other words you don't want those mixture screws out any further than they have to be to provide a clean idle in gear. You may have to reset the idle speed if the mixture screws were way off. Generally mixture screws on a Holley run only about 1~1-3/4 turns out max. Also do this adjustment on a cool day. That way it won't be too lean when it cools off.

I don't think you'll gain enough performance switching to a Performer to warrant the work involved. It is a dual plane but the streetmaster is a very small plenum narrow runner intake so it builds good torque and generally pulls to 5k or a little more on a 318. My cousin ran one on a bone stock 318 and it pulled to 5k no problem. You might be running lean is why your not pulling good on top. Have you looked at the plugs to see what they look like?

Why are you running 95 octane fuel? If it's a stock low compression engine it'll actually run better on 89 octane because the higher octane the slower it burns. 89 will burn faster and produce more power on a low compression engine. If it's real low compression (like in the 8's) 87 octane should be enough to produce max power.

 

[340 8BBL]

i ran a street master on a 9to1 motor with an isky 256 super cam with very good results.3 turns is way to much on the idle screws imo.the others pretty much covered everything so i dont have much to add other than to check the accerator pump adjustment.if it adjusted incorrectly it will make it hesitate.

 

[grumpuscreature]

318s like single plane intakes. They also like initial timing set at 7 degrees BTDC. Don't understand the fascination with Edelbrock carbs. They are a rehash of the Carter AFB and I can remember when the hot tip was to replace your AFB with a Holley.

 

[DQ81]

thanks guys,

the idle screws out '3 turns' , I meant 1.5. That's what I have them set at now, time to bust out the vac gauge and set this thing properly and double check the power valve too.

See here at 1:14 or so...

Good advice to fine tune those, will do.

Also checking the accel pump is on the list.

Fishy68:

The lowest octane fuel here in the Netherlands is 95. That's why I run 95, it's all there is.

I can run up to about 6k at the moment without issue with this setup. So that's more than enough.

My compression is @ 9.5 to 1

tobysoldblue:

I'm gonna take your advice on the timing as I'm not sure my secondaries are even opening properly or fully. I've got to do the 'paperclip test' to check if and how far the secondaries open.

My 'fascination' with Edelbrock's is that they are simple, don't have power valves that blow and are generally easier to dial in on a street motor. On the other hand, if you take the time, a Holley is a very flexible carb that you can dial in specifically. Hence the poll.

I suppose one is a sledgehammer, the other a set of hammers w/ specific applications.

I was actually thinking of putting a weaker spring on my secondaries, this is also something Holley advises on light cars meant for performance...

I'll order a spring kit, mess with the accel pump cams and definately follow the advice given with regards to the Idle mixture, pump clearance and vac advance.

Questions leave me with questions:

1. If I dial in more advance on the pod I need to dial back my initial advance correct?

2. Why would a rich idle cause the stumble?

 

[fishy68]

thanks guys,

the idle screws out '3 turns' , I meant 1.5. That's what I have them set at now, time to bust out the vac gauge and set this thing properly and double check the power valve too.

Good advice to fine tune those, will do.

Also checking the accel pump is on the list.

Fishy68:

The lowest octane fuel here in the Netherlands is 95. That's why I run 95, it's all there is.

Wow I wish we even had 95 octane. But I wonder if they rate it the same? I know Canada's rating system is a little different than our so yours might be too. Your 95 octane might possibly be equal to our 87 or 89 octane.

I can run up to about 6k at the moment without issue with this setup. So that's more than enough.

My compression is @ 9.5 to 1

tobysoldblue:

I'm gonna take your advice on the timing as I'm not sure my secondaries are even opening properly or fully. I've got to do the 'paperclip test' to check if and how far the secondaries open.

My 'fascination' with Edelbrock's is that they are simple, don't have power valves that blow and are generally easier to dial in on a street motor. On the other hand, if you take the time, a Holley is a very flexible carb that you can dial in specifically. Hence the poll.

I suppose one is a sledgehammer, the other a set of hammers w/ specific applications.

I was actually thinking of putting a weaker spring on my secondaries, this is also something Holley advises on light cars meant for performance...

Holley does mention this but it's just a general rule of thumb. Since you said you already have a stumble when you floor it I bet it'll get worse with a lighter spring. I have to put in a stiffer spring to keep it from stumbling ocasionally. You might also try a bigger pump shooter and maybe a different pump cam to give it more pump shot to alleviate the WOT stumble. That may allow you to run the spring in it now. /quote]

I'll order a spring kit, mess with the accel pump cams and definately follow the advice given with regards to the Idle mixture, pump clearance and vac advance.

Questions leave me with questions:

1. If I dial in more advance on the pod I need to dial back my initial advance correct?

No

2. Why would a rich idle cause the stumble?

I don't usually but it can cause a stall condition when you stab the throttle because when you do that the throttle blades snap back fast and cause your overly rich condition to be even more rich.

 

[DQ81]

Thanks Fishy68, I'll try flipping the current cam on the pump and see what that does. You've also made me curious about the octane rating systems, gonna look into that, let you know what I find

David

 

[fishy68]

Your welcome David. Good luck.

 

[furz4]

I run a 600 holley list 6009 on a streetmaster intake on my 318. Am running manifolds and stock 340 cam. Pulls realy hard to about 5600 but will go to 6000 no problem. I suspect you may be running a bit lean, I had to jet up a couple of numbers from 60-62 to get rid of part throtle surging as the 6009 is an old emissions carb. With headers and a cam I think I would start around 64 on jetting and read the plugs and see what they look like. Holleys are realy simple carbs and very easy to tune.

 

[DQ81]

I run a 600 holley list 6009 on a streetmaster intake on my 318. Am running manifolds and stock 340 cam. Pulls realy hard to about 5600 but will go to 6000 no problem. I suspect you may be running a bit lean, I had to jet up a couple of numbers from 60-62 to get rid of part throtle surging as the 6009 is an old emissions carb. With headers and a cam I think I would start around 64 on jetting and read the plugs and see what they look like. Holleys are realy simple carbs and very easy to tune.

So bigger jets then eh...how can I know for sure if it's running lean under load while driving for certain?

Or is it just trial and error with bigger jets etc.

TIA

David

 

[dodgetkboy78]

I voted Holley because you already have it..........in case someone here points out that the guy that hates holley recommended one.
The small port heads like single plane intakes, going to the dual plane will be going backwards, IMO.
I have had streetmasters, while not as good as a street dominator, (IMO) they are better than the Performer.
The performer manifolds always left something to be desired, I like the cast iron manifold better for performance.

 

[DQ81]

I voted Holley because you already have it..........in case someone here points out that the guy that hates holley recommended one.
The small port heads like single plane intakes, going to the dual plane will be going backwards, IMO.
I have had streetmasters, while not as good as a street dominator, (IMO) they are better than the Performer.
The performer manifolds always left something to be desired, I like the cast iron manifold better for performance.

Hmmmm...I have a cast Iron 360 dual plane intake with Thermoquad on it lying around.

I don't like Holley's either but I'm kind of determined to get this one running well to at least understand them.

I flipped the accel pump cam today. It seems to be better. I also adjusted the idle screws and that might have helped as well.

I have an orange cam now on setting 2, it seems like the lobe is smaller but that it pushes the pump in more. This make any sense?

David

 

[340 8BBL]

yes,it increases the pump shot.if that helped it you may want to try a different squirter(discharge nozzle)or try switching to the blue pump cam if you have one.also,what is your initial timing set at?on the 318 i mentioned in my earlier post i had it set at 10*

 

[dodgetkboy78]

With your cam, I would set my timing 12before at idle, and 36 full. You want full timing by 55MPH in high gear, whatever RPM that is. (Use your vac advance)

 

[twofosho]

I ran a non EGR E-brock Performer for years on a bone stock '67 318 automatic in a Coronet 2dr post with various Carter and Holley carburetors. Ran good, vast improvement over the stock two barrel, and not really a wits difference in performance in any of the carburetors once they were dialed in.

 

[DQ81]

I'm running 10* now at idle in gear at aprox. 650RPM.

Where's the allen nut to dial the timing in faster?

A higher octane fuel should allow me to run more initial timing correct?

Also, I'm at sea level.

I have a Thermoquad and I'm thinking I'll throw it on at some point just to see how different it feels.

It's got such tiny primary's and huge secondaries, makes me curious what would 'feel' more powerfull even though the net result will be aprox. the same.

I don't have any other cams, but I've just orderd the cam and spring set.

dodgetkboy78:

Why 36* at 55mph?

 

[DQ81]

Thanks Fishy68, I'll try flipping the current cam on the pump and see what that does. You've also made me curious about the octane rating systems, gonna look into that, let you know what I find

David

Fishy68:

Here we go:

http://hondaswap.com/reference-materials/us-octane-vs-other-countries-octane-ratings-59435/

Long story short, multiply the European Octane rating by 0.95 and you get the US equivelant.

Therefore I am running a 90.25 Octane gas. Close to your basic US "Premium"

That being said we can obviously reverse the process to get the European equivelant of US rated fuels by dividing the US Octane rating by 0.95.

You guys running 89 Octane US, are running a 93.7 Octane by European standards.

Even longer story short, we're all running the same stuff. I seriously doubt international oil companies are refining US specific batches and Eurasia specific batches that only differ by 1 octane point roughly.

David

 

[fishy68]

Fishy68:

Here we go:

http://hondaswap.com/reference-materials/us-octane-vs-other-countries-octane-ratings-59435/

Long story short, multiply the European Octane rating by 0.95 and you get the US equivelant.

Therefore I am running a 90.25 Octane gas. Close to your basic US "Premium"

That being said we can obviously reverse the process to get the European equivelant of US rated fuels by dividing the US Octane rating by 0.95.

You guys running 89 Octane US, are running a 93.7 Octane by European standards.

Even longer story short, we're all running the same stuff. I seriously doubt international oil companies are refining US specific batches and Eurasia specific batches that only differ by 1 octane point roughly.

David

Thanks David. That clears up things. Tracy

 

[dodgetkboy78]

dodgetkboy78:

Why 36* at 55mph?

What RPM is it at 55?

 

[DQ81]

What RPM is it at 55?

I don´t know about 55, but it´s at 2100 RPM at 62 MPH,

Right around 1900 at 55ish

 

[dodgetkboy78]

Hoofta.

So full on by 2200 to start, and you need your vac advance!

Wow, is that like 2.70 gears? LOL

 

[DQ81]

Hoofta.

So full on by 2200 to start, and you need your vac advance!

Wow, is that like 2.70 gears? LOL

Actually I looked manually and it appears they are 3.21's

But I just went for a drive and kept it at 62.5 exactly (100kph) and that was steady at 2100 RPM which would correspond w/ 2.74's...

I don't friggin know with this car. The speedometer could be off so I'll have to check it witha GPS or somethin...

Gotta get 2 new spark plug wires on monday (melted to header, any tips?) go out and do the manual test again when it's not raining and with an assistant...

 

[doktor_x]

Actually I looked manually and it appears they are 3.21's

But I just went for a drive and kept it at 62.5 exactly (100kph) and that was steady at 2100 RPM which would correspond w/ 2.74's...

I don't friggin know with this car. The speedometer could be off so I'll have to check it witha GPS or somethin...

This makes me wonder about speedometer accuracy in general with these cars. Mine is weird in the other direction. Rear is tagged as 3.21, tires are 195 75R 14 and GPS shows 72 MPH on the speedo to be 65 MPH actual speed. My intended fix is to stuff a 235 60R 15 under it (two birds w/ one stone).

The allen screw previously mentioned is inside the vacuum canister. You'll be able to feel it by sticking the correct-sized allen wrench in through the nipple.

 

[DQ81]

This makes me wonder about speedometer accuracy in general with these cars. Mine is weird in the other direction. Rear is tagged as 3.21, tires are 195 75R 14 and GPS shows 72 MPH on the speedo to be 65 MPH actual speed. My intended fix is to stuff a 235 60R 15 under it (two birds w/ one stone).

The allen screw previously mentioned is inside the vacuum canister. You'll be able to feel it by sticking the correct-sized allen wrench in through the nipple.

Thanks, I was just thinking the same thing about the speedometer accuracy on these things...

I just went out for another run in the Dart (found some wires for 5 and 7) and used a program I have on my Iphone called Dynolicious, using the gyroscope in the phone it acts as a virtual Dyno and is supposed to be quiter accurate. One thing it does accuratly is 0-60 time.
Mine was 9.2 on average. I'm not very impressed with that at all. I'm thinking with my setup I should be pushing close to 250 horse if not more? The car weighs aprox 3k lbs, surely that should be more like 7 second 0-60?

What is the exact weight of a '73 2 door Dart with a 318 with all the seats etc. still in place?

Also with reference to speedo's, the Dynolicious app had me at 90 kph when my speedo said 105 kph.

What is the correct tire size to use as a reference to calculate speedo accuracy?